In: Handbook on Cheese ISBN: 978-1-62618-966-9 Editors: Henrique Castelli and Luiz du Vale © 2013 Nova Science Publishers, Inc.

No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services.

Chapter 9

CHEESE AS A SOURCE OF NUTRIENTS AND CONTAMINANTS: DIETARY AND TOXICOLOGICAL ASPECTS

Fernando Cámara-Martos*, Rafael Moreno-Rojas and Fernando Pérez-Rodríguez Dpto. Bromatología y Tecnología de los Alimentos. Universidad de Córdoba, Córdoba, Argentina

ABSTRACT

Cheese is an important food in the diet of many countries as this preserves the majority of nutrients present in raw milk, considered the most wholesome food. It is a food rich in good quality proteins, with a varied content in vitamins such as riboflavin and minerals such as calcium and phosphorus, which are very important in growth age. On the contrary, in certain cases, cheeses can be a food with high content in cholesterol and therefore its consumption should be moderate. However, the nutritional value of cheeses depends on numerous factors such as the type of milk used for its elaboration (cow, sheep and goat, mainly), the manufacturing conditions (rennet, draining, salting), and finally the fermentation process. In addition, the capacity of human body to absorb and retain all these nutrients present in cheese depends on other components in food, giving rise to the concept of bioavailability. On the other hand, cheeses can be a source of contaminants and toxic substances. Toxicological contamination (from microorganisms and other sources) is a serious concern for the cheese industry since products can be contaminated in origin or become contaminated throughout the Food Chain, reaching to consumers. Therefore there is a need to develop precise tools to assess food risk derived from consumption of cheese. Given above, the present chapter aims at carrying out an in-depth review of nutritional, toxicological and microbiological aspects derived from consumption of cheeses.

* Corresponding author: Prof. Fernando Cámara-Martos, PhD, Dpto. Bromatología y Tecnología de los Alimentos. Universidad de Córdoba. Campus de Rabanales s/n. Edificio Darwin C1. 14014 Córdoba. E-mail: [email protected] 342 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez

INTRODUCTION

Cheese is one of the most appreciate foods in the occidental civilization. In addition to the wide variety of cheeses, with very different sensory characteristics satisfying any consumer preference, cheese is a wholesome food due to the high content of macro and micronutrients in relation to its energy level. The domestic species producing more milk are cows and buffalo followed by sheep and goat [Mercasa, 2012] hence most part of cheeses are made of milk of these species or mixture of them [Ash  Wilbey, 2010]. Likewise, cheese elaboration processes are so different among the different cheese typologies that it would be difficult to detail each one of them. Nevertheless, it should be taken into account that handcraft cheeses should be elaborated with refrigerated milk with a shelf-life lower than 48 hours and the cheeses intended to be consumed due by 60 days after elaboration should be made of pasteurized milk.

Figure 1. Generic diagram of the Process of Cheese Manufacturing. Cheese as a Source of Nutrients and Contaminants 343

However, cheese manufacturing comprises a series of common steps among which we could highlight coagulation, draining, salting and ripening (Figure 1). Thus, cheese coagulation can be carried out by means of use of rennet (animal or vegetal), called enzymatic coagulation which lasts around half an hour, or my means of milk acidification with lactic acid, known as acid or lactic coagulation, which occurs in one day, approximately. The former coagulates rapidly yielding a solid thing absorbing whey while the latter gets a firmer curd and it is more specific to cheeses manufactured with raw milk in which there is a great activity of bacteria or ferments. There also exists a mixed coagulation combining both techniques, very often in soft paste cheeses in which molds are applied for the final ripening. The molding of cheese, process whereby cheese is shaped, can be carried out with perforated molds for soft paste cheeses to lose whey without pressing after the lactic coagulation by means of draining, while enzymatic pastes are introduced in molds with taps and are pressed strongly in order to remove whey rests and join the grainy. In the case of mixed coagulation, a very slight pressing is applied. The addition of salt can be performed by hand in the case of soft pastes and small size cheeses. In contrast, hard paste cheeses are maintained in brine during a specific period of time. Salting by hand can be applied in different manners among which we highlight salting by rubbing the cheese surface with dry salt or salting by sprinkling. Finally, one of the most important steps in cheese elaboration is the ripening process. During this step, the initial product called fresh cheese is going to undergo a series of physical, chemical, microbiological and enzymatic changes providing the final product the desired organoleptic characteristics. Depending on ripening time, cheeses can be classified into soft, semi-hard and hard cheeses. In the European Union (EU), there is a serious concern on producing cheese of quality from both nutritional and organoleptic and food safety point of view. From that, the cheese productions like other type of foodstuffs are grouped in geographical indications, which endorse and protect names of quality agricultural products. At the same time, these can be classified as Protected Designation of Origin (PDO), Protected Geographical Indication (PGI) and Traditional Specialty of Guaranteed (TSG). A PDO cheese is defined according to its geographical area of production, the description of the raw materials and of the technology used for its elaboration [Karoui et al. 2005]. In the EU, the main countries (Table 1) with a greater number of PDO of cheese are France, Greece, Italy and Spain [Moreno-Rojas et al. 2010a]. As consequence of this wide range of products, nutritional composition of cheese and the possible presence of contaminants will vary from one to another. Therefore, the present chapter aims at assessing cheeses from a nutritional point of view as source of macro and micronutrients, with special attention to the influence of the different cheese making steps and the type of milk used for its elaboration. Also, the main chemical and microbiological contaminants that can be present in cheese will be discussed.

Table 1. Some of the main Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI) of cheeses in Europe

Name Type of milk Origen Name Type of milk Origen Savoie PD Abondance PDO Cow Majorero Goat Canarias (Spain) (France) O Afuega Asturias PD Castilla-La Mancha PDO Cow Manchego Sheep L´Pitu (Spain) O (Spain) Arzua - Galicia Mahon - PD PDO Cow Cow Islas Baleares (Spain) Ulloa (Spain) Menorca O Setúbal PD Campania and Lazio Azeitão PDO Sheep Mozarella Buffalo (Portugal) O (Italy) Savoie PD Beaufort PDO Cow Murcia Goat Murcia (Spain) (France) O Lombardia PD Bitto PDO Cow - Goat Murcia al vino Goat Murcia (Spain) (Italy) O Brie de Nata de PD PDO Cow Ile-de-France Cow Cantabria Meaux Cantabria O Cow Ŕ Goat Ŕ Asturias PD Cabrales PDO Palmero Goat Canarias (Spain) Sheep (Spain) O Normandy Parmigiano- PD Emilia-Romagna Camembert PDO Cow Cow (France) Reggiano O (Italy) Canestrato PD PDO Sheep Puglia (Italy) Pecorino Sardo Sheep Sardinia (Italy) Pugliese O

Name Type of milk Origen Name Type of milk Origen Asturias Picon-Bejes- Cow-Goat- Casín PDO Cow PDO Cantabria (Spain) (Spain) Tresviso Sheep Galicia Quesuco de Cebreiro PDO Cow PDO Cow - Sheep Cantabria (Spain) (Spain) Liébana Savoie Emmental PDO Cow Provolone PDO Cow Campania (Italy) (France) Sardinia Fiore Sardo PDO Sheep Roncal PDO Sheep Navarra (Spain) (Italy) Flor de Cow Ŕ Goat - Canarias Midi-Pyrénées PDO Roquefort PDO Sheep Guía Sheep (Spain) (France) Aosta Valley San Simon Da Fontina PDO Cow PDO Cow Galicia (Spain) (Italy) Costa Cow Ŕ Goat - Asturias Gamonedo PDO Tetilla PDO Cow Galicia (Spain) Shepp (Spain) Piemonte and Tomme de Midi-Pyrénées Gorgonzola PDO Cow Lombardia PGI Cow Pyrénées (France) (Italy) Extremadura Torta del Ibores PDO Goat PDO Sheep Extremadura (Spain) (Spain) Casar

Table 1. (Continued)

Name Type of milk Origen Name Type of milk Origen País Vasco Idiazabal PDO Sheep and Navarra Salers PDO Cow Auvergne (France) (Spain) L´alt Urgell Cataluña Cow-Goat- Castilla Ŕ León y la PDO Cow Valdeón PGI (Spain) Sheep (Spain) Cerdanya Extremadura Castilla Ŕ León La Serena PDO Sheep Zamorano PDO Sheep (Spain) (Spain)

Cheese as a Source of Nutrients and Contaminants 347

PROTEINS

Cheese has high content of proteins with high biological value, ranging between 10 and 30% according to the type of cheese (Table 2). Within milk proteins, two main groups can be made, which correspond to whey proteins such as albumin, -lactoalbumin, and - lactoglobulin [de Frutos, 1992] and caseins. Principal caseins in goat, sheep and cow milk are

S1-, S2-, - and -caseins [Farrel et al. 2004; Park et al. 2007]. During cheese making process, the most part of whey proteins is lost hence this protein fraction only represents for 2-3% total protein in cheese. On the contrary, caseins undergo a transformation process, which starts in most cases with the cleaves the Phe105 Ŕ Met106 linkage of -casein through the addition of chymosin giving rise the destabilization of all casein micelles, which join to form cheese curd [St-Gelais  Haché, 2005]. In the subsequent cheese ripening process, caseins undergo a proteolysis process resulting in smaller size peptides and free aminoacids. Many of these peptides can exert hormone-like regulatory effects in the human body [Fitzgerald  Meisel, 2003]. These compounds, known as bioactive peptides, have been defined as specific protein fragments that have a positive impact on body functions or conditions and may ultimately influence health [Kitts  Weiler, 2003]. Thus, peptides derived from sequences 60 Ŕ 70 of the  - casein have demonstrated an inmunostimulatory, opiod and Angiotensin Converting Enzyme (ACE) Ŕ inhibitory activity [Haque  Chand, 2008]. According to Ryhanen et al. [2001] in ripened cheese types this inhibitory activity of the angiotensin increased during cheese ripening but started decreasing when proteolysis exceeded a certain level. Furthermore, an antihypertensive effect has been observed in peptides derived from S1-caseins of Parmesan cheese (Italy) with 6-month maturation but not in the same cheese with 15-month maturation [Meisel et al. 1997]. However, in other cases, this relation between ACE Ŕ inhibitory activity and ageing is not clear as shown in the study by Gómez Ŕ Ruíz et al. [2004] for cheese type ŖManchegoŗ (Spain) in which this inhibitory effect was higher in cheeses with 2- and 8-month as compared to cheeses with 4 and 12 months. A recent study [Gómez Ŕ Ruiz et al. 2006] has identified and characterized the ACE Ŕ inhibitory activity of some peptides found in Spanish cheeses belonging to different PDOs (Cabrales, Idiazábal, Roncal, Manchego and Mahón). In general, this study concluded that most part of these peptides derives - and S1- casein. In addition, the presence of a proline residue in the C- terminal end contributes to the correct location of the peptide in the active site of the enzyme probably due to the rigid structure of this residue, which may lock the carboxyl group into a conformation favorable for interacting with the positively charged residue at the active site of the enzyme [Cushman et al. 1977]. Aside from this antihypertensive effect, other properties attributed to this type of bioactive peptides are stimulation and suppressing effect on lymphocyte proliferation and a stimulatory activity on immunoglobulin production [Möller et al. 2008]. Other types of bioactive peptides have attracted the interest of researchers over the last few years are caseinophosphopeptides. They are fragments of highly phosphorylated caseins with high capacity to uptake bivalent and trivalent cations. This fact results in the increase of the bioavailability of minerals such as calcium, zinc and iron in the distal small intestine since they remain in soluble state before being absorbed by means of formation caseinophosphopeptide Ŕ metal ion complexes also reducing interactions between these 348 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez elementsthat would ocurr if they were as free ions [Park  Allen, 1998a; Park et al. 1998b, Peres et al. 1999a, Peres et al. 1999b]. The capacity of uptaking minerals by caseinephosphopeptides seems to be related to the presence of a phosphoserine cluster Ser(P) Ŕ Ser(P) Ŕ Ser(P) Ŕ Glu Ŕ Glu coming from a native protein. Some studies have suggested that indigenous phosphatases in milk play a role in breakdown of caseinephosphopetides; hence the level of phosphorylation of caseins and the products of their hidrolysis would depend on acid and alkaline phophatase activity during cheese processing [Hynek et al. 2002; Ur- Rehman et al. 2006]. These caseinephosphopetides that are accumulated in cheese during ripening process are ingested as other nutrient and the only inconvenience would be that these caseinophosphopetides are not affected during the digestive process and the successive action of the human pepsin and pancreatin and are not broken down in inactive fragments. However, a recent study carried out by Adt et al. [2011] has identified 79 caseinephosphopetidos in Beaufort cheese (France) after a digestive process in vitro con pepsin and pancreatin from which 17 still contained the characteristic cluster sequence Ser(P) Ŕ Ser(P) Ŕ Ser(P) Ŕ Glu Ŕ Glu which evidences the resistance of these protein fragments to the digestive process. Finally, it should be also taken into account that not only milk caseins are the unique sources of these bioactive peptides. As mentioned above, the presence of whey proteins in cheese only accounts for 2 Ŕ 3%, however some of these proteins such as -lactoglobulin or -lactotensin have shown antihypertensive, hypocholesterolaemic, antioxidant and antimicrobial activities [Hernández Ŕ Ledesma et al. 2008]. Furthermore, lactoserum could not be considered a residue with high Biological Oxygen Demand any longer and could start to be considered as food by-product with remarkable nutritional value, worthy of being incorporated to other foods.

FAT

Fat is the most important component in milk in terms of cost, nutrition and physical and sensory properties that are provided to the resultant dairy products [Park et al. 2007]. The fat content in cheese (Table 2) is often inversely correlated to protein content and it depends on the type of milk used for its elaboration. In general, cheeses made of sheep milk show a major fat content than those made with cow or goat milk [Moreno Ŕ Rojas et al., 2010a] due to a high fat content present in sheep milk [Park et al. 2007]. Also, ripening influences on fat content in cheese positively since it reduces the moisture content. From a nutritional standpoint, digestibility of the fat of cheese is 88 Ŕ 94% [Renner, 1987]. This digestibility is related to the fat globule size. Some studies [Mehaia, 1995; Mens 1985] found that the fat globule average size is smaller in sheep and goat milk as compared to cow milk which means an advantageous for digestibility and a more efficient lipid metabolism compared with cow milk fat. Most lipids are found in form of tryacilglycerides (98%) and a minority fraction is found as cholesterol, phospholipids and other types of liposoluble compounds.

Table 2. Proximate composition of Spanish cheese belonging to PDOs, per 100 g

Name Water (g) Fat (g) Protein (g) Carbohydrate (g) Energy (Kcal) Afuega L´Pitu 27.8 40.6 26.8 1.6 478.2 Arzua - Ulloa 39.4 34.5 22.2 0.6 401.8 Cabrales 36.5 34.6 23.5 0.2 406.8 Casín 40.3 30.8 23.1 1.5 375.0 Cebreiro 59.4 22.2 14.9 1.8 266.4 Flor de Guía 35.3 31.1 27.2 1.5 394.0 Gamonedo 30.5 35.1 27.2 2.5 434.0 Ibores 35.5 34.3 23.9 1.5 410.3 Idiazabal 30.9 38.8 25.7 0.6 454.5 La Serena 42.2 26.3 24.3 2.0 341.6 Majorero 38.4 28.7 25.7 2.2 369.8 Manchego 31.6 38.0 24.7 1.3 445.6 Mahon - Menorca 35.3 34.3 24.9 1.2 413.1 Murcia 59.3 24.9 13.8 0.2 280.4 Murcia al vino 32.6 38.9 23.2 1.1 446.8 Nata de Cantabria 42.8 30.2 21.5 1.6 363.7 Palmero 48.0 27.8 19.5 1.1 332.4 Picon-Bejes- 39.3 33.0 22.7 0.1 388.3 Tresviso Quesuco de 46.8 29.1 19.8 1.0 344.8 Liébana

Table 2. (Continued)

Name Water (g) Fat (g) Protein (g) Carbohydrate (g) Energy (Kcal) Roncal 30.0 38.3 26.2 1.3 454.4 San Simon Da 30.1 37.9 26.1 1.2 450.0 Costa Tetilla 41.5 32.2 21.6 0.8 379.0 Torta del Casar 46.6 32.4 18.2 0.1 364.8 Zamorano 24.8 42.2 26.8 1.4 492.0

Cheese as a Source of Nutrients and Contaminants 351

In milk just obtained, the most part of fatty acids are found esterified with glicerol, in form of tryacilglycerides in the fat globules, however during cheese manufacturing and ripening, many of these tryacilglycerides undergo a breakingdown process due to the action of lipases, releasing many of these fatty acids. These lypolitic agents present in cheese can come from milk, coagulant or cheese microflora (starter, nonstarter and adjunct microorganisms). Many molds of type Penicillium spp., which grow in some types of cheese during the ripening process such as Cabrales, Roquefort and Gorgonzola are also lypolitic microorganisms [McSweeney, 2004]. Moreover, it has been shown that this type of cheeses categorized as blue cheeses has the highest free fatty acid contents followed by hard cheeses whereas soft cheeses show a relatively low free fatty acid contents [Contarini  Toppino 1995; McSweeney, 2004]. The most part of fatty acids corresponds to saturated fatty acids from which lauric, myristic and palmitic have a high atherogenic potential. Likewise, cheese made of cow milk have a high content in long chain fatty acids (LCFA) much higher than those cheeses made with sheep or goat cheese, while cheesemaking processes also increases the content in LCFA being much higher in semi hard such as Gorgonzola in contrast to cow fresh cheeses [Prandini et al. 2011]. From this, fat in milk have been associated with a high incidence of cardiovascular diseases over many years. However, recent studies have evidenced the presence of healthy components in this type of fat, including conjugated linoleic acids (CLA) [Parodi, 1999]. This type of CLA isomers such as rumenic acid (cis- 9, trans-11 CLA) or trans- 10, cis-12 CLA have demonstrated a series of beneficial effects in animals such as anticarcinogenesis, immunomodulation, antiatherosclerosis or body mass Ŕ enhancing properties [Kelley et al. 2007; Collomb et al. 2006; Pariza, 2004; Martin  Vallei, 2002]. This fact has led to some researchers suggest that cheese is different, even from butter, in its influence on the serum cholesterol in humans, having minimal effects on plasma lipidic profiles [Biong et al., 2004]. In keeping with this, a recent study [Roupas et al., 2006] has shown how high levels of total cholesterol and non-HDL cholesterol in plasma were significantly lower in rats fed with Cheddar cheese as compared to rats fed with diet based on beef meat. In addition, the concentration of these CLAs originally present in milk fat seems not to be affected by the different cheese manufacturing steps such as heat treatment of milk and/or curd, ripening or addition of starter cultures (lactic bacteria, yeast and moulds) [Prandini et al. 2011; Bisig et al. 2007; Gnädig et al. 2004], cheese maintaining all health beneficial micronutrients. Again, cheese elaborated with sheep milk showed higher CLA contents than those elaborated with cow or goat milk. Likewise, sheep and goat cheese showed a better profile of polyunsatured and monounsaturated fatty acids in contrast to cheese made with cow milk [Prandini et al. 2011]. Also, over the last few years, several investigations are being carried out [Alonso et al. 2003; Ogawa et al. 2005; Song et al. 2005] intended to increase the content of these CLAs in cheese by means of addition of specific bacterial cultures belonging to the groups of Bifidobacteria, propionic bacteria and lactic acid bacteria which show capacity to product these kind of compounds. However, in this moment, results have been optimum only at laboratory scale and under certain controlled conditions. Other type of strategies are being also carried out in order to diminish the fat content during cheese manufacturing Ŗlower Ŕ fat cheesesŗ. This term is used in a general manner to describe a reduction of cheese fat content without designating a specific fat level in the cheeses [Johnson et al. 2009]. However, this 352 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez reduction is not always easy since sensory attributes can be affected such as noncharacteristic taste and higher elastic and gummy texture among other changes, which entail a less acceptance by consumers [Childs  Drake, 2009].

CARBOHYDRATES

Lactose is the main sugar in milk, however this disaccharide formed by glucose and galactose joined by  - 1,4 bond is hardly digested by a considerable percentage of population. In order to absorb it in the intestinal lumen, it needs to be hydrolyzed into monosaccharides by means of enzyme lactase. Mammal animals are born with a remarkable capacity to synthesize lactase, taking into account the high exposures to milk at which they are going to be submitted during the early life stages. However, from weaning, nonhuman mammals are genetically programmed to reduce lactase synthesis. In the case of humans, the pattern is similar [Gilat et al. 1972], however some population groups allows the infantile level of lactase to persist throughout adulthood, known lactase persistent individuals, while others lose this capacity to produce lactase and they are known as lactase non-persistent individuals. Malabsorption of lactose leads to this disaccharide uptakes water in the intestinal lumen due to the elevated osmotic capacity (osmotic activity) and when it gets the colon, it is fermented by the present bacterial microflora giving rise to diarrheas, abdominal discomfort and flatulence, characteristic symptoms of lactose intolerance. This pathology gains more repercussion if it is considered that milk and dairy products are the main dietary source of calcium and that it is important to carry out appropriate contributions of this mineral during infancy in order to achieve a correct bone mineralization and to avoid osteoporosis problems during adult age. However, during the cheese manufacturing, in the step of renneting the milk, around 90% of water is removed into whey along with 90% of the lactose [Harju et al. 2012]. In addition, residual lactose originally present in the cheese is fermented to lactic acid during the ripening process; hence the content of this disaccharide is practically residual and it makes this food an excellent source of calcium for individuals with problems of lactose intolerance.

VITAMINS

The milk fat is an excellent source of liposoluble vitamins such as retinol,  - carotene, vitamin D and tocopherols, which remain in cheese after the manufacturing process [Herrero Ŕ Barbudo et al., 2005; Panfili et al. 1994] exerting an antioxidant activity on both biological tissues and the food itself. In concrete,  - carotene and retinol scavenge both singlet oxygen and lipoperoxides, thus preventing or limiting the oxidation of fatty acid [Donelly  Robinson, 1995]. On the other hand, although hidrosoluble vitamins (water Ŕ soluble vitamins) are lost during the draining process (in the removed whey), cheeses have also shown to be a good sources of riboflavin, niacin, pyridoxine, biotin, folic acid and cobalamin [Altangerel et al. 2011] since these losses can be compensated through the microbial synthesis during the ripening process. Cheese as a Source of Nutrients and Contaminants 353

Some studies have demonstrated that fatŔ soluble vitamin contents depends on the milk production conditions while variability in water Ŕ soluble vitamin contents is almost exclusively influenced by the cheesemaking process [Lucas et al. 2006a; Lucas et al. 2006b]. In consonance with this, a study found a major content of tocopherols and a lower retinol concentration in mozzarella cheese obtained from organic buffalo milk in comparison to the same type of cheese obtained from conventional buffalo milk.[Bergamo et al. 2003].

Table 3. Levels of minerals and trace elements of Spanish cheese belonging to PDOs, mg/Kg edible portion

Name Ca Mg P Na K Zn Fe Afuega L´Pitu 1312 123 3002 5883 1410 4.91 1.50 Arzua - Ulloa 7639 274 4777 4202 925 33.5 2.68 Cabrales 7846 284 5429 18871 1113 34.0 3.84 Casín 6916 291 4996 7590 1759 33.9 9.86 Cebreiro 971 102 2026 4223 1135 4.73 1.05 Flor de Guía 8019 449 6009 6132 1182 38.4 3.3 Gamonedo 8717 344 5893 4907 1198 43.1 3.64 Ibores 8974 464 5808 7515 1103 9.5 1.6 Idiazabal 9846 476 6259 5530 1099 30.8 6.25 La Serena 8571 467 5806 4449 1199 31.5 20.4 Majorero 7795 442 5745 8002 1142 30.4 3.5 Manchego 9277 440 5925 6554 1039 31.2 4.3 Mahon - Menorca 7148 304 5035 8760 1254 30.9 4.2 Murcia 5612 292 3470 1002 920 17.1 2.2 Murcia al vino 8139 385 5277 5374 1064 26.5 3.6 Nata de Cantabria 7804 289 4930 5551 978 30.6 3.42 Palmero 6724 439 4563 4619 1069 24.8 2.9 Picon-Bejes- 4729 5.94 219 4854 13511 1336 34.1 Tresviso Quesuco de 6998 2.93 280 4447 2862 1167 25.3 Liébana Roncal 8235 360 5827 6006 1038 30.0 3.48 San Simon Da 9547 356 5943 5520 1233 33.4 2.98 Costa Tetilla 8090 315 5127 5400 1020 33.0 2.82 Torta del Casar 5256 331 3886 5382 1122 19.7 5.3 Zamorano 9995 492 6404 8684 1158 33.9 10.6 Moreno Ŕ Rojas et al. 2012 and 2010a.

MINERALS

The mineral compounds participate in the coagulation, influence the draining of the whey and the texture of the curd and on their properties such as stability to heat and the capacity of coagulation depend [Patiño et al. 2005]. From a nutritional point of view, cheese together 354 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez with milk and other dairy products are the most important dietary sources of calcium for the most part of population in the western world and one the most important sources of other elements such as phosphorous and magnesium (Table 3). Moreover, they are the foods in which ratio Ca:P provides the best possible value, 1.5:1 [Moreno-Rojas et al. 2010a] and in other studies is even higher reaching the ratio 2.15 [González Ŕ Martín et al. 2009]. On the contrary, other fundamental elements such as iron are at low levels in cheese, with the exception of the possible contaminations derived from the utensils and recipients used in the manufacture [Cichovski et al. 2002]. As in the rest of nutritional components, mineral composition of cheese is influenced by very diverse aspects like type of used milk (cow, sheep or goat], animal breeding, seasonality, manufacturing conditions, month and ripening time among others [Moreno Ŕ Rojas et al. 2012, 2010a; González Ŕ Martín et al. 2009]. In general, cheeses with sheep milk show a higher content in mineral elements such as Ca, Mg, P y Fe as compared to those made with goat and cow milk. Cheeses elaborated with cow milk often show the lowest minerals and trace elements concentration [Moreno Ŕ Rojas et al. 2012] due to cow milk usually contains lower concentration of mineral elements while sheep milk has the highest levels [Raynal Ŕ Ljutovac et al. 2008; Moreno Ŕ Rojas et al. 1993]. Seasonality also affects the composition of mineral elements due to changes in the bio-availability and quality of the pastures throughout the year and to an increase in the proteolytic activity associated to the age of lactation of the animal [González Ŕ Martín et al. 2009]. The step of curdling also affects the mineral content of cheeses. Cheeses elaborated with rennet, mainly of vegetable nature, show higher mineral concentrations than those in which curdling is obtained by acidification of milk by lactic ferments [Moreno-Rojas et al. 2010a]. It seems that lactic ferments produce a substantial reduction of pH, what means that mineral losses during cheese processing increase [Bueyuekkilic et al. 1994; Patel et al. 1991]. Also, ripening process, in addition to the reduction of water activity, is going to lead to modifications of the mineral concentration and trace element levels originally present. In general, the ripening process entails an increase in the concentration of element such as Ca, P, Mg, Zn, Fe, Cu y Na as compared to fresh cheese [Moreno Ŕ Rojas et al. 2012] due to an effect of concentration when the moisture in food is eliminated. However, other elements such as K can decrease during the ripening process due to the process of draining of the whey [González Ŕ Martín et al. 2009]. The elevated concentration of Na throughout the ripening process is also caused by the addition of salt during the process and throughout ripening. The addition of salt has three functions, acts as preservative, contributes directly to flavor and provides a source of sodium, which is important for the regulation of blood pressure, water transport into and out of cells, tissue osmolarity and transmission of nerve cell impulses. Along with these functions, salt exerts a number of considerable important effects in cheese. It is a main determinant of water activity, and therefore, it exerts a control on microbial growth, enzymatic activity, and the biochemical changes during cheese ripening and the simultaneous development of the desired flavor and aroma [Guinee, 2004]. However, due to the close relationship existing between salt consumption and the high prevalence of certain pathologies such as hypertension and coronary diseases, several international organization are proposing a reduction of Na levels in foods as consequence of processing [Champagne and Lastor, 2009; Dötsch et al., 2009]. In this sense, replacing Sodium Chloride added to cheese by other salts providing salty taste can be eventually satisfactory specially in cheeses with slight taste. However, in the long-term, Cheese as a Source of Nutrients and Contaminants 355 this can lead to the multiplication of microorganisms, producing undesirable tastes. Therefore, for dairy technologists, the challenge will be to develop and use ingredients, microorganism and enzymes that can result in the desired cheese [Johnson et al. 2009].

CHEMICAL CONTAMINANTS

Cheese, in addition to including components with nutritional value, both macro and micronutrients, often present in any type of food, can also be a vehicle of contamination and toxicological substances, both of chemical and microbiological nature, some from which will be treated in this section. Within the contaminants of chemical type present in foods, we highlight, in the first instance, heavy metals such as lead, cadmium, arsenic, and mercury. These elements can cause adverse effect against health, such as damage in the central and peripheral nervous system, kidney damage, growth inhibition and interferences in the use of other trace elements such as Fe and Zn [Rubio et al. 2005; Aschner, 2002; Frery et al. 1993]. Except for rare cases of contamination, cheeses are not usually a frequent source of heavy metals. A study performed on 57 varieties of Spanish cheese with different geographical origin [Moreno Ŕ Rojas et al. 2010b] showed that levels of Pb, Cd and Hg were quite below the Provisional Tolerable Weekly Intake (PTWI), except for a specific type, suggesting that that cheeses are generally a safe food in relation to levels of these contaminants. The influence of processing also shows how cheeses elaborated with cow milk have the lowest heavy metals levels while the use of lactic coagulation produces a decrease in pH, leading to increased mineral loss during cheese processing and a lower concentration of heavy metals. On the other hand, due to a misuse of pharmacological products in the treatment of mastitis and other diseases, in many cases without veterinarian prescription, milk can be contaminated with drug residues, which can interference with cheese manufacturing, even more if this milk is used raw, as well as having serious consequences on health [Molina et al. 2003]. Although the presence of specified veterinary residues in milk is regulated by European Union (UE), residual concentrations of this type of products have been found many times in cheese [Imperiale et al. 2011] with the subsequent negative consequences on public health.

MICROORGANISMS IN CHEESE

The ripening process in cheese manufacture reduces water activity and increases lactic acid levels among others physic and chemical changes thus generating a stringent environment for pathogenic bacteria growth. Nevertheless, some pathogens are still able to survive on such harsh conditions reaching final consumers and resulting in foodborne diseases if infective doses are ingested. The most relevant pathogens associated with cheese are Listeria monocytogenes, Salmonella spp., Escherichia coli and Staphylococcus aureus. Most changes produced during ripening are derived from the metabolic activity of specific bacterial groups, which can be present in raw milk naturally or can be added as starter cultures to favor the ripening process. The acid-lactic bacteria are the most often bacteria used as starter in cheese. They are able to produce organic acids during fermentation, 356 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez particularly lactic acid, which favors the formation of casein curd and syneresis (i.e. expelling water) as consequence of the lower pH produced because of lactic acid. However, certain bacteria can survive these acidic conditions, and due to their metabolic activity, can produce important changes in the typical organoleptic characteristics of cheese. These bacteria group are considered as spoilage microorganisms and should be taken into account given the important economic loss associated with their appearance. Most starter cultures correspond to lactobacilli (e.g., Swiss cheese), though in some cases, this genera can comprise undesirable microorganisms as they can recontaminate cheese after pasteurization, and as consequence of their growth, they can modify sensory attributes generating unpleasant off-odors and tastes (e.g., Cheddar cheese). As starter cultures, cell- wall-bound, intracellular, and extracellular proteinases occur in lactobacilli; those from some species of Lactobacillus preferentially hydrolyze αs1-casein, whereas those from others prefer β-casein. Peptides released from casein by proteinases are subsequently hydrolyzed by peptidases inside cells of lactobacilli. The intracellular peptidases are a vital part of the mechanism by which lactobacilli make free amino acids that are precursors of some cheese flavor compounds. Aminopeptidase, dipeptidase, carboxypeptidase, and endopeptidase activities have been associated with lactobacilli. Although largely intracellular, membrane- associated peptidases have been noted. Intracellular lipases and esterases also occur in lactobacilli, but activity of these enzymes has been designated as Ŗweakŗ. Despite this, they probably contribute to flavor development in some varieties of cheese. Certain lactobacilli can cause defects such as formation of white crystals of calcium lactate on the surface of cheese or of biologically active amines that sometimes can cause illness in consumers.

PATHOGENIC MICROORGANISMS

As in many processed foods, the presence of pathogens greatly depends on the characteristics of the food and attendant process parameters. In the case of cheese, the great variety of cheeses and the different cheesemaking processes unavoidably determine the types of pathogen being more probable to contaminate the product. This can depend on factors such as processing, temperature, acidity, salt content, starter culture, moisture content and ripening. On the basis of epidemiological data in the European Union (EU), the pathogens most frequently linked to foodborne illnesses by consumption of cheese are Salmonella spp., L. monocytogenes and E. coli O1527:H7. In the case of L. monocytogenes, the recent EFSA report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2010 [EFSA/ECDP, 2012] showed that 0.2 % analyzed cheese samples contained levels above the microbiological criterion established in Regulation (EC) 2073/2005, that is, 100 cfu/g, with the highest prevalence in semi-soft and soft cheeses. Almost 10 % listoriosis cases out of the total cases in which transmission route was stated, were linked to cheese consumption. These figures highlight the importance of this pathogen in dairy product and specially in cheese products. For Salmonella spp., 0.1 % analyzed cheese samples were positive for this pathogen. Concerning Salmonelosis cases, the European report showed that 2.1 % cases derived from Salmonella Typhimurium were related to cheese consumption while for Salmonella Enteritidis, no cheeses were involved in outbreaks in 2010 even though other dairy products were involved. Finally, in the case of Verotoxigenic E. coli strains (VTEC), in Cheese as a Source of Nutrients and Contaminants 357 the surveys carried out in 2010 by EU member states, positive samples were found in Germany only, corresponding to cheeses made of cow´s milk [EFSA/ECDP, 2012].

Listeria Monocytogenes

The maintenance of the cold-chain has been considered an effective limiting factor preventing growth of microorganisms in foods. However, over the last few years, psychotrophic pathogens such as L. monocytogenes have demonstrated to be able to grow at refrigeration conditions, reaching infective doses at consumption, hence it is a food-borne pathogen that has had an increasing interest in the last decades. This microorganism is characterized by its ubiquity since it is present in a wide variety of ecosystems including animals, plants, water, food industries or domestic environments. Besides, L. monocytogenes has an ability to target particular subsets of the population presenting a high death rate (20-30 %). As above-mentioned, L. monocytogenes is a serious concern for dairy industry due to its high prevalence and the incidence of food-borne outbreaks during the last few years [EFSA/ECDP, 2012]. In cheese, L. monocytogenes may be present in the raw milk [Thévenot et al. 2005], either from unclean equipment during milking. Also, environment in the cheese companies is an relevant contamination source of L. monocytogenes and the microorganism is often isolated from the environment (e.g. floors, drains) even when good sanitation and hygiene protocols are in place [Kornacki and Gurtler, 2007]. If the microorganism is present in the milk or reaches the food through cross contamination, it could survive during the cheesemaking and ripening processes if conditions are suitable. These conditions are mainly related to pH, salt content and temperature. This pathogen, in addition to growing at 4 ºC, has the ability to grow over a wide range of pH values (4.3Ŕ9.6) [Lou & Yousef, 1999], and survive under salt concentrations as high as 10% NaCl [McClure et al. 1989]. Studies have reported that the pathogen can grow during the cheesemaking and ripening processs in soft cheeses even though these studies also found that the use of pasteurized or raw milk determined the inactivation or growth of the pathogen. This different behavior can be due to the interaction between starter cultures and the presence and absence of competitive microflora in pasteurized and raw milk, respectively [Schvartzman et al. 2011]. In contrast, other studies have reported no growth or survival during cheesemaking, ripening and distribution/storage in processed cheeses and soft cheese [Morgan et al. 2001; Angelidis et al. 2010]. New strategies have been proposed to reduce the risk by L. monocytogenes in cheese, many of them are related to the use of natural antimicrobial substances and bioprotective cultures [Malheiros et al. 2012; Soni et al. 2012; von Staszewski & Jagus 2008; Vera Pingitore et al. 2012]. For example, a recent study showed the efficacy of adding malic acid, nisin and natamycin to whey protein films, used to coat cheeses, against certain pathogens and spoilage microorganisms, including L. monocytogenes and molds [Pintado et al. 2010]. Similarly, new physical inactivation treatments have been applied to milk intended for cheesemaking with good results, such as High Hydrostatic Pressure (HHP) [Linton et al. 2008]. The application of HHP was effective in reducing Listeria in milk to undetectable levels and preventing the subsequent growth during cheesemaking and ripening processes in contrast to untreated milk, which allowed Listeria growth from 2 to 5 log cfu/g during 358 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez cheesemaking process and remained at the same level during ripening. Besides, the combination of different preservative technologies, based on the hurdle technology concept, has been also studied by researchers as effective approach to reducing L. monocytogenes contamination in cheeses since different action mechanisms (harsh environment, bacteriostatic substances, injured cells, etc.) are combined to inhibit or reduce microorganism at the different stages in the food chain. For example, the study by Al-Holy et al. [2012] found that the combination of nisin (bacteriocin) and heat treatment had a synergic effect on L. innocua (used as surrogate microorganisms) reducing growth potential in brined white cheese even at abuse temperatures. Nevertheless, the use of appropriate hygienic procedures, e.g., Hazard Analysis Critical Control Point system, during processing should reduce the likelihood of listeriosis outbreaks associated with dairy foods and specially cheese products.

Salmonella spp.

Salmonella spp. are generally not heat resistant and normally grow at 35 to 37°C, but they can grow at much lower temperatures, provided that the incubation time is suitably extended [ICMSF 1998]. Although surveys rarely find Salmonella spp in cheese, data suggest that this microorganisms can survive and/or grow if conditions are adequate [Erkmen & Bozogluce, 1995; ICMSF, 1998]. This seems to be confirmed through numerous outbreaks occurred in the past and more recently [Haeghebaert et al. 2003]. Moreover, the microorganism has been isolated from various dairy products in the market place hence it is also considered a serious concern for the dairy industry. Salmonella spp. have been mainly isolated from raw milk, this being a prime contamination source in cheese: salmonellosis cases are more likely to occur in cheeses made from raw milk or when pasteurization fails and storage temperatures allow pathogen growth or survival during the different steps along the cheesemaking process and distribution chain [Donnelly 2004]. To minimize these problems, cheeses should be held at or below 2 to 5°C at all times. As noted above for L. monocytogenes, Salmonella spp. behave differently in different kinds of cheese: they survived in ripening Cheddar cheese for up to 7 month at 13°C and for 10 months at 7°C [Park et al.. 1970] ; in cold-pack cheese food for several weeks, depending on the pH and preservative used [Norholt, 1984] ; and in Crotin goat´s soft cheese it can survive up to 40 days at static and dynamic temperature conditions, and even it can grow, if an abuse temperature is applied [Tamagnini et al. 2008; Tamagnini et al. 2005]. In Mozzarella cheese, temperatures of stretching and molding (60°C) eliminated all salmonellae present, but, in cottage cheese, survival of the pathogen depended on the cooking temperature of curd [Bishop & Smukowski, 2006]. In general, as pointed out by Bishop & Smukowski [2006] in hard cheeses, Salmonella spp together with other pathogens are not able to grow and in most cases they show a inactivation pattern during ripening and subsequent steps. Similar to above-commented L. monocytogenes, different methods to reduce Salmonella spp. growth in cheese have been suggested. Again, HHP has been effectively applied in eliminating Salmonella spp. in milk while maintaining original sensory characteristic in cheese [Voigt et al. 2012; Yang et al. 2012]. On the other hand, it is also proved the inhibitory effect of starter cultures and bacterocins on this pathogen along the different steps from cheesemaking to consumer [Bleicher et al. 2010; Topisirovic et al. 2006]. In this sense, it has been previously reported that the use of Lactobacillus plantarum as starter culture markedly Cheese as a Source of Nutrients and Contaminants 359 reduced the survival of Salmonella Typhimurium in Montasino cheese (Italy). However, although several bacterocin types have been identified as effective antimicrobial against Salmonella spp., so far few investigations have been carried out in cheese with regard to this pathogen while most studies are focused on L. monocytogenes [Settanni et al. 2011].

Enteropathogenic Escherichia coli

This microorganism is an important causative agent of gastrointestinal diseases in human and animals and its presence and illnesses are often linked to meat products as its origin and reservoir [ICMSF, 1998]. This microorganism is quite sensitive to heat treatments, and pasteurization is supposed to eliminate potential contamination by this pathogen in milk. In addition, cheesemaking and ripening conditions, specially pH, do not support growth of this pathogen however, in spite of these limiting conditions, some outbreaks by this pathogen have been linked to cheeses [Kousta et al. 2010]. Among the pathogenic types of E. coli of greatest relevance to milk (the dairy industry), and therefore to cheese, we highlight Verotoxigenic E. coli (VTEC) strains, where the main representative is E. coli O157.H7, because of its high virulence and relatively high prevalence as compared to other VTEC strains [Farrokh et al. 2013]. Results from several studies indicate that VTEC E. coli strains are able to survive to stringent conditions in hard cheese [Caro & García-Armesto 2007]. According to the review by Farrokh et al. [2013], the compliance with good hygienic practices at the farm level and the exhaustive control along the subsequent steps in the food chain is probably the reason for the quite low number of outbreaks linked to milk and dairy products. Therefore, these factors should be also considered as a critical element to maintain food safety in cheeses in relation to VTEC strains.

Staphylococcus Aureus

This microorganism is also a common cause of gastrointestinal diseases all over the world, and related to multiple food commodities (milk, meat, egg, etc.). However, due to the relatively low severity of the attendant foodborne illness is not considered as relevant as the previous pathogens [ICMSF, 1998]. Nevertheless, this microorganism is often found in milk at low levels, probably derived from animals with mastitis, which is considered as an important source of this pathogen. S. aureus is sensitive to the typical pasteurization process applied to milk intended to the cheese manufacturing, therefore, in cheeses made from pasteurized milk the presence of S. aureus is less probable unless the pasteurization process control fails or cross contamination (from environment or handlers) takes place in subsequent steps during manufacturing [Kousta et al. 2010]. In this respect, studies have confirmed the presence of this pathogen in raw milk and the processed cheeses in different farm-dairies [Rosengren et al. 2010]. Acidification by starter cultures usually inhibits the multiplication of the pathogen and only when this process is slow (pH decrease), the pathogen is able to grow and produce enteroxin at sufficient levels to produce illness (at > 6 log cfu/g or ml). However, there are also studies evidencing the capacity of S. aureus to grow in the ripening process, even though temperature can affect the survival capacity of the pathogen. Similar to the previous cases, the use of starter cultures could inhibit the potential growth of this pathogen 360 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez due to the acidification and other antimicrobial substances [Gaya et al. 1988]. Also the use of bacterocin/bacterocin-producing bacteria or bacteriophages have been assessed with positive results against the pathogen, even though they are still preliminary results [Bueno et al. 2012; Hamama et al. 2002]. Therefore, adequate control measures focused on assuring adequate hygienic practices and effective process controls should be applied along the food chain from farm to consumers in order to minimize the risk by VTEC strains.

SPOILAGE MICROORGANISMS

Cheese spoilage can be caused by bacteria or molds able to survive to the different steps along the cheesemaking process [ICMSF, 1998]. The type of microorganisms causing spoilage depends on the cheese characteristics and cheesemaking process. However, in some cases, molds are necessary to confer the organoleptic characteristics specifics to each type of cheese. Molds require oxygen to be able to grow and low pH values can be a limiting factor for them. However, certain mold species such as Penicillium, Mucor, Monilia, Aspergillus, Cladosporium, etc. can overcome such limitations and grow, inducing undesirable changes in the organoleptic properties of cheeses [Ledenbach & Marshall 2010]. Penicillium is the genera of molds most frequently isolated from naturally contaminated cheese rind samples and include mycotoxigenic strains as mentioned later. All these microorganisms include strains with psychrotrophic characteristics that could increase in number during cold storage [Sorhaug & Stepaniak, 1997]. Low pH and compositional profiles of cheeses are also compatible with yeast growth, which could cause some specific alterations in the cheese surface. Many types of yeast can produce alcohol and CO2, providing cheese yeasty taste [Horwood et al. 1987]. Some yeast genera show lypolisis activity, which results in short-chain fatty acids that form fruity esters when combined with ethanol. Besides that, some proteolytic yeast strains are responsible for the production of sulfides producing an egg odor. Common contaminating yeasts of cheeses include Candida spp., Kluyveromyces marxianus, Geotrichum candidum, Debaryomyces hansenii, and Pichia spp. [Johnson, 2001]. Bacteria can cause two types of spoilage, according to scientific literature: Ŗearly blowingŗ and Ŗlate blowingŗ. The former can be often observed in fresh cheeses or after maturation few days; the responsible microorganisms can be Bacillus subtilus and coliform bacteria. The slow lactic acid production by starter cultures at those early stages favors the growth and production of gas by coliform bacteria, which are able to grow rapidly when conditions of pH and temperature are favorable. In soft mold-ripened cheeses, the pH increases during ripening. This enhances the growth potential of coliform bacteria. The proliferation of coliform bacteria can give rise to different types of metabolites depending on species and strains: lactic acid, acetic acid, formic acid, ethanol, etc [Fox et al. 2004]. Also, when concentration levels of coliforms are high, cheeses can show "early blowing" due to the production of CO2 and mainly H2 which is little soluble in cheese. Although this bacterial group is quite sensitive to heat treatment, and therefore cheese made from pasteurized milk should not show this kind of spoilage, recontamination during the cheesemaking process is likely to occur if non-appropriate hygienic conditions are applied during handling and processing, resulting in a coliform contaminations which is not necessarily related to fecal Cheese as a Source of Nutrients and Contaminants 361 microorganisms since coliforms like Enterobacter aerogenes from environment can be also responsible for this kind of spoilage mechanism. Accordingly, other control measures should be adopted to reduce the likelihood of multiplication of coliform bacteria. Theses consist of a rapid acidification of the curd, which leads to decrease of pH, and the same time to a reduction of lactose content, which is used as source of carbon by coliforms. The Ŗlate blowingŗ takes place during ripening and storage in hard cheeses and can be observed after 10 days in Gouda or Edam cheese and up to 5 months in Emmental. This alteration is due to spore-forming microorganisms able to survive to heat treatments [Montville & Matthews, 2008]. The clostridiums, mainly Clostridum tyrobutyricum and Clostridium butyricum are the responsible for this type of alteration. C. tyrobutyricum is more often in winter and its presence in milk comes from ensilaged foods. In turn, C. butyricum is rather found in summer. Essentially, this alteration is associated with the production of butyric acid resulting in gas formation and unpleasant odor-off. The butyric fermentation is produced by the breakdown of lactic acid to butyric acid, CO2 and H2, mainly.

2CH3CHOHCOOHCH3CH2CH2COOH +2CO2+2H2

The butyric fermentation by Clostridium spp. is a serious concern for dairy sector since the defect produced is associated with important loss of commercial value of cheese. Different methods have been trialed against the proliferation of these microorganisms such as: lysozymes, addition of nisin-producing starters, hydrogen peroxide, other oxidizing substance, the addition of nitrate to the milk, salt content and pH of the cheese. Heterofermentative lactic acid bacteria such as Lactobacilli and Leuconostoc can develop off-flavors and gas in ripened cheeses. These microbes metabolize lactose, subsequently producing lactate, acetate, ethanol, and CO2 in approximately equimolar concentrations [Hutkins, 2001]. Cracks in cheeses can occur when gas is produced in excess by certain strains of

Streptococcus thermophilus and Lactobacillus helveticus that form CO2 and 4-aminobutyric acid by decarboxylation of glutamic acid [Zoon & Allersma, 1996]. In the case of superficial spoilage, we highlight aerobic bacteria, particularly, the Gram- negative bacteria Pseudomonas spp. which are the most important ones of the psychrotrophics that dominate the microflora of raw milk [Sorhaug &Stepaniak, 1997]. Strains of Pseudomonas aeruginosa have been associated with undesirable browning reactions on cheese rind [Ogunnariwo & Hamilton-Miller, 1975], and some are also pathogenic.

BIOGENIC AMINES

Biogenic amines are non-volatile, low molecular mass aliphatic, alicyclic or heterocyclic organic bases, which cause physiological effects in sensitive individuals with deficient in mono and diamino oxidase [O' Brien et al. 2000]. Tyramine and histamine are often found in cheese. Both amines are formed during the ripening step by enzymatic descarboxilation of the aminoacids tyrosine and histidine. The responsible microorganisms are usually mesophylic lactobacilli and some members of the family Enterobacteriaceae. Amine levels in cheese are limited since the precursor aminoacids are present at low levels in maturated cheeses, and 362 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez only high levels can be observed in raw milk and some cheeses matured with molds [ICMSF, 1998].

MYCOTOXINS

Mycotoxins are a group of secondary metabolites produced by various filamentous fungi, which can cause a toxic response when ingested at low levels by animals [O' Brien et al. 2000]. Mycotoxins in cheese can proceed from two basic mechanisms: they are already present in the milk used for the cheese manufacturing or they are formed by molds during ripening. In the former cases, mycotoxins are produced by mold grown on the feedstuff that is consumed by animals. It is well-established that if aflatoxin B1 (AFB1) or aflatoxin B2 (AFB2,) produced by Aspergillus spp. are ingested by animals, monohydroxylated AFM1 and AFM2 can be excreted a few hours after ingestion [O' Brien et al. 2000]. In addition, it is known that aflatoxins can resist the typical heat treatment, so their elimination is not easy once they reach the food. In such cases, specific treatment on feedstuff should be applied to reduce mold growth and eliminate contamination (e.g. ammoniac). In other cases, contamination can come from maturation rooms, hence that adequate cleaning and disinfection procedures and air filters should be applied to reduce the risk by mycotoxin- producing molds. Also, mycotoxins can proceed from some starter cultures including molds with capacity to produce toxic compounds such as Penicillium camemberti or Penicillum roqueforti. However their presence in cheese does not mean necessarily that mycotoxins are produced and rarely mycotoxins have been isolated from cheese in such cases [ICMSF, 1998].

REFERENCES

Adt, I. Coralie, D. Boutrou, R. Oulahal, N. Noel, C. Mollé, D. Jouvet, T.  Degraeve, P. (2011). Identification of caseinophosphopetides generated through in vitro gastrointestinal digestion of Beaufort cheese. International Dairy Journal, 21, 129 Ŕ 134. Al-Holy M., Al-Nabulsi A., Osaili T.M., et al. (2012). Inactivation of Listeria innocua in brined white cheese by a combination of nisin and heat. Food Control, 23, 48Ŕ53. Alonso, L. Cuesta, E.P.  Gilliland, S.E. (2003). Production of free conjugated linoleic acid by Lactobacillus acidophilus and Lactobacillus casei of human intestinal origin. Journal of Dairy Science, 86, 1941 Ŕ 1946. Altangerel, B. Sengee, Z. Kramarova, D Rop, O. & Hoza, I. (2011). The determination of water-soluble vitamins and in vitro digestibility of selected Czech cheeses. International Journal of Food Science and Technology, 46, 1225 Ŕ 1230. Angelidis, A.S. Boutsiouki, P. & Papageorgiou, D.K. (2010). Loss of viability of Listeria monocytogenes in contaminated processed cheese during storage at 4, 12 and 22 degrees C. Food Microbiology, 27, 809Ŕ18. Aschner, M. (2002). Neurotoxic mechanism of fish-borne methylmercury. Environmental Toxicology Pharmacology, 12, 101 Ŕ 104. Cheese as a Source of Nutrients and Contaminants 363

Ash, A.  Wilbey, A. (2010). The nutritional significance of cheese in the UK diet. International Journal of Dairy Technology, 63(3), 305 Ŕ 319. Bergamo, P. Fedele, E. Iannibelli, L. & Marzillo, G. (2003). Fat-soluble vitamin contents and fatty acid composition in organic and conventional Italian dairy products. Food Chemistry, 82, 625 Ŕ 631. Biong, A.S. Muller, H. Seljeflot, I. Veierod, M.B.  Pederson, J.I. (2004). A comparison of the effects of cheese and butter on serum lipids, haemostatic variables and homocysteine. British Journal of Nutrition, 92, 791 Ŕ 797. Bishop, J.A.Y.R. & Smukowski M. (2006). Necessary to Maintain Cheese Safety. Trends in Food Protection, 26, 714Ŕ724. Bisig, W. Eberhard, P. Collomb, M. & Rehberger, B. (2007). Influence of processing on the fatty acid composition and the content of conjugated linoleic acid in organic and conventional dairy products Ŕ a review. Lait, 87, 1 Ŕ 19. Bleicher, A. Stark,T. Hofmann, T. et al. (2010) Potent antilisterial cell-free supernatants produced by complex red-smear cheese microbial consortia. Journal of Dairy Science, 93, 4497Ŕ4505. Bueno, E. García, P. Martínez, B. & Rodríguez A. (2012). Phage inactivation of Staphylococcus aureus in fresh and hard-type cheeses. International Journal of Food Microbiology, 158, 23Ŕ7. Bueyuekkilic, N. Erdinc, B. Yalcin, B. & Uenver, G. (1994). Effects of acidity of cheese milk on properties of white cheese. II Kontrol Laboratuvar Muederluegue, Ankara. Caro, I. & García-Armesto, M.R. (2007) Occurrence of Shiga toxin-producing Escherichia coli in a Spanish raw eweřs milk cheese. International Journal of Food Microbiology, 116, 410Ŕ3. Champagne, C.M.  Lastor, K.C. (2009). Sodium intake channels for researchers attempting to asses consumption relative to health risk. Journal of Food Composition and Analysis, 22S, S19 Ŕ S22. Child, J.L. Drake, M. (2009). Consumer perception of fat reduction in cheese. Journal of Sensory Studies, 24(6), 902 Ŕ 921. Cichoscki, A. Valduga, E. Valduga, A. Tornadijo, M.  Fresno, J. (2002). Characterization of Prato cheese, a Brazilian semi Ŕ hard cow variety: evolution of physico Ŕ chemical parameters and mineral composition during ripening. Food Control, 13, 329 Ŕ 336. Collomb, M.A. Schmid, A. Sieber, R. Wechsler, D. & Ryhänen, E.L. (2006). Conjugated linoleic acids in milk fat: variation and physiological effects. International Dairy Journal, 16, 1347 Ŕ 1361. Contarini, G.  Toppino, P.M. (1995). Lypolisis in Gorgonzola cheese during ripening. International Dairy Journal, 5, 141 Ŕ 155. Cushman, D.W. Cheung, H.S. Dabo, E.F. & Ondetti, M.A. (1977). Design of potent competitive inhibitors of angiotensin Ŕ converting enzyme. Carboxyalkanoyl and mercaptoalkanoyl amino acids. Biochemistry, 16(25), 5484 Ŕ 5491. de Frutos, M. Cifuentes, A. Amigo, L. Ramos, M.  Diez-Masa, J.C (1992). Rapid analysis of whey proteins from different animal species by reversed-phase high-performance liquid chromatography. Zeitschrift Lebensmittel Untersuchung und Forschung, 195, 326 Ŕ 331. 364 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez

Donelly, J.K. Robinson, D.S. (1995). Invited review free radicals in food. Free Radical Research, 22, 147 Ŕ 176. Donnelly, C.W. (2004). Growth and Survival of Microbial Pathogens in Cheese. In P.F. Fox, P.L.H. McSweeney, T.M. Cogan and T.P. Guinee (eds.), Cheese: Chemistry, Physics and Microbiology, 3rded. Volume 1. Elsevier: New York, pp. 541-559. Dötsch, N. Busch, J. Batenbrug, M. Liem, G. Tareilus, E. Mueller, R.  Meijer, G. (2009). Strategies to reduce sodium consumption: a food industry perspective. Critical Reviews in Food Science and Nutrition, 49(10), 841 Ŕ 851. Erkmen, O. & Faruk Bozogluce, T. (1995). Behaviour of Salmonella typhimurium in feta cheese during its manufacture and ripening. LWT - Food Science and Technology, 28, 259Ŕ263. European Food Safety Authority/European Center for Disease Prevention (EFSA/ECDP) (2012). Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2010. 10:1Ŕ442. doi: 10.2903/j.efsa.2012.2597. Farrell, H.M. Jiménez Ŕ Flores, R. Bleck, G.T. Brown, E.M. Butler, J.E.  Creamer, L.K., et al., (2004). Nomenclature of the proteins of cow´s milk Ŕ Sixth revision. Journal of Dairy Science, 87(6), 1641 Ŕ 1674. Farrokh, C. Jordan, K. Auvray, F. et al. (2013). Review of Shiga-toxin-producing Escherichia coli (STEC) and their significance in dairy production. International Journal of Food Microbiology, 162, 190Ŕ212. Fitzgerald, R.J.  Meisel, H. (2003). Milk protein hydrolysates and bioactive peptides. In: Advanced Dairy Chemistry, Vol 1, Proteins, Fox, P.F.  McSweeney, P.L.H.(eds). Kluwer Academic/Plenum Publishers, New York, pp. 675 Ŕ 697. Fox, P.F. McSweeney, P. Cogan, M.T. & Guinee, T. (2004). Cheese: Chemistry, Physics and Microbiology: Major Cheese Groups. 3rded. Volume 1. Elsevier: New York. Frery, N. Nessmann, C. Girard, F. Lafond, J. Moreau, T. Blot, P, & Huel, G. (1993). Environmental exposition to cadmium and human birthweight. Toxicology, 79, 109 Ŕ 118. Gaya, P. Medina, M. Bautista, L. & Nuñez, M. (1988). Influence of lactic starter inoculation, curd heating and ripening temperature on Staphylococcus aureus behaviour in Manchego cheese. International Journal of Food Microbiology, 6, 249Ŕ257. Gilat, T. Russo, S. Gelman Ŕ Malachi, E. & Aldor, TAM (1972). Lactase in man: a non Ŕ inducible enzyme in man. Gastroenterology, 62, 1125 Ŕ 1127 Gnädig, S. Chamba, J.F. Perreard, E. Chappaz, S. Chardigny, J.M. Rickert, R. Steinhart, H. & Sebédio, J.L. (2004). Influence of manufacturing conditions on the conjugated linoleic acid content and the isomer composition in ripened French Emmental chese. Journal of Dairy Research, 71, 367 Ŕ 371. Gómez Ŕ Ruíz, J.A. Taborda, G. Amigo, L. Recio, I.  Ramos, M. (2006). Identification of ACE Ŕ inhibitory peptides in different Spanish cheeses by tandem mass spectrometry. European Food Research and Technology, 223, 595 - 601 Gómez Ŕ Ruíz, J.A., Ramos, M.,  Recio, I. (2004). Identification and formation of angiotensin Ŕ converting enzyme Ŕ inhibitory peptides in Manchego cheese by high Ŕ performance liquid chromatography Ŕ tandem mass spectrometry. Journal of Chromatography A, 1054, 269 Ŕ 277. Cheese as a Source of Nutrients and Contaminants 365

González Ŕ Martín, I. Hernández Ŕ Hierro, J.M. Revilla, I. Vivar Ŕ Quintana, A. Lobos Ŕ Ortega, I.  González Ŕ Pérez, C. (2009). Changes in the mineral content in cheeses of different compositions during 6 months of ripening. Czech Journal of Food Science, 27, S114 Ŕ S118. Guinee, T.P. (2004). Salting and the role of salt in cheese. International Journal of Dairy Technology, 57(2/3), 99 Ŕ 109. Haeghebaert, S. Sulem, P. Deroudille, L. Vanneroy-Adenot, E. Bagnis, O. Bouvet, P. et al. (2003) Two outbreaks of Salmonella enteriditis phage type 8 linked to the consumption of Cantal cheese made with raw milk, France 2001 Eurosurveillance, 8, 151Ŕ156. Hamama, A. El Hankouri, N. & El Ayadi, M. (2002). Fate of enterotoxigenic Staphylococcus aureus in the presence of nisin-producing Lactococcus lactis strain during manufacture of Jben, a Moroccan traditional fresh cheese. International Dairy Journal, 12, 933Ŕ938. Haque, E.  Chand, R. (2008). Antihypertensive and antimicrobial bioactive peptides from milk proteins. European Food Research and Technology, 227, 7 Ŕ 15. Harju, M. Kallioinen, H. & Tossavainen, O. (2012). Lactose hydrolysis and other conversions in dairy products: technological aspects. International Dairy Journal, 22, 104 Ŕ 109. Hernández Ŕ Ledesma, B. Recio, I.  Amigo, L. (2008). -lactoglobulin as source of bioactive peptides. Amino Acids, 35, 257 Ŕ 265. Herrero Ŕ Barbudo, M.C. Granado Ŕ Lorencio, F. Blanco Ŕ Navarro, I. & Olmedilla Ŕ Alonso, B. (2005). Retinol, - and -tocopherol and carotenoids in natural and vitamin A and E fortified dariry products commercialized in Spain. International Dairy Journal, 15, 521 Ŕ 526. Horwood, J.F. Stark, W. & Hull, H.H. (1987). A fermented, yeasty flavour defect in Cheddar cheese. Australian Journal of Dairy Technology, 42, 25Ŕ26. Hutkins, R.W. (2001). Metabolism of starter cultures. In E.H. Marth & J.L. Steele (Eds.), Applied dairy microbiology. New York: Marcel Dekker, pp. 207Ŕ241. Hynek, R. Zuzalkova, L. Sikac, Z.  Kas, J. (2002). Influence of phosphorylation on proteolytic cleavage. Journal of Liquid Chromatography and Related Technologies, 25, 2307 Ŕ 2314. ICMSF (International Commission on Microbiological Specifications for Foods) (1998) Milk and dairy product. Microorganisms in Foods 6. Microbial Ecology of Food Commodities. Maryland: Aspen Publishers, Inc.: Gaithersburg, pp. 521Ŕ529 Imperiale, F. Ortiz, P. Cabrera, M. Farias, C. Sallovitz, J.M. Iezzi, S. Pérez, J. Álvarez, L.  Lanusse, C. (2011). Residual concentrations of the flukicidal compound triclabendazole in dairy cows´milk and cheese. Food Additives and Contaminants, Part A, 28(4), 438 Ŕ 445. Johnson, M.E. (2001). Cheese products. In E. H. Marth &. J. L. Steele (Eds.), Applied dairy microbiology. Marcel Dekker: New York, pp. 345Ŕ384. Johnson, M.E. Kapoor, R. McMahon, D.J. McCoy, D.R. & Narasimmon, R.G. (2009). Reduction of sodium and fat levels in natural and processed cheeses: scientific and technological aspects. Comprehensive Reviews in Food Science and Food Safety, 8, 252 Ŕ 268. Karoui, R. Bosset, J.O. Mazerolles, G. Kulmyzaev, A. & Dufour, E. (2005). Monitoring the geographic origin of both experimental French Jura hard cheeses and Swiss Gruyere and 366 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez

l´Etivaz PDO cheeses using mid-infrared and fluorescence spectoscopies. International Dairy Journal, 15, 275 Ŕ 286. Kelley, N.S. Hubbard, N.E. & Erickson, K. (2007). Conjugated linoleic acid isomers and cancer. The Journal of Nutrition, 137(12), 2599 Ŕ 2607. Kitts, D.D.  Weiler, K. (2003). Bioactive proteins and peptides from food sources. Aplication of bioprocesses used in isolation and recovery. Current Pharmaceutical Design, 9, 1309 Ŕ 1323. Kornacki, J.L., & Gurtler, J.B. (2007). Incidence and Control of Listeria in Food Processing Facilities, In, E. T. Ryser and E. H. Marth (eds.), Listeria, Listeriosis and Food Safety, CRC Press, Taylor and Francis Group: Boca Raton, FL, pp. 132-196. Kousta, M. Mataragas, M. Skandamis, P. & Drosinos, E.H.(2010).Prevalence and sources of cheese contamination with pathogens at farm and processing levels. Food Control, 21, 805Ŕ815. Ledenbach, L.H. & Marshall, R.T. (2010) Microbiological Spoilage of Dairy Products. In W.H. Sperber, M.P. Doyle (eds.), Compendium of the Microbiological Spoilage of Foods and Beverages, Food Microbiology and Food Safety, Springer: New York, pp. 41-67. Linton, M. Mackle, A.B. Upadhyay, V.K. et al. (2008) The fate of Listeria monocytogenes during the manufacture of Camembert-type cheese: A comparison between raw milk and milk treated with high hydrostatic pressure. Innovative Food Science & Emerging Technologies, 9, 423Ŕ428. Lou, Y. & Yousef, A.E. (1999). Characteristics of Listeria monocytogenes important to food processors. In, E.T. Ryser, E.H. Marth (Eds.), Listeria, listeriosis and food safety, New York: Marcel Dekker, pp. 131Ŕ224 Lucas, A. Agabriel, C. Martin, B. Ferlay, A. Verdier Ŕ Metz, I. Coulon, J.B. & Rock E. (2006a). Relationships between the conditions of cow´s milk production and the contents in components of nutritional interest in raw milk farmhouse cheese. Lait, 86, 177 Ŕ 202 Lucas, A. Rock, E. Chamba, J.F. Verdier Ŕ Metz, I. Brachet, P. & Coulon, J.B. (2006b). Respective effects of milk composition and cheese Ŕ making process on the cheese composition variability in components of nutritional interest. Lait, 86, 21 Ŕ 41. Malheiros, P.D.S. SantřAnna, V. Barbosa, M.D.S. et al. (2012) Effect of liposome- encapsulated nisin and bacteriocin-like substance P34 on Listeria monocytogenes growth in Minas frescal cheese. International Journal of Food Microbiology, 156, 272Ŕ7. Martin, J.C. Valeille, K. (2002). Conjugated linoleic acids: all the same or to everyone its own function?. Reproduction Nutrition Development, 42, 525 Ŕ 536. McClure, P.J. Roberts, T.A. & Oguru, P.O. (1989). Comparison of the effects of sodium chloride, pH, and temperature on the growth of Listeria monocytogenes on gradient plates and liquid medium. Letters in Applied Microbiology, 9, 95Ŕ99. McSweeney, P.L.H. (2004). Biochemistry of cheese ripening. International Journal of Dairy Technology, 57(2/3), 127 Ŕ 144. Mehaia, M.A. (1995). The fat globule size distribution in camel, goat, ewe and cow milk. Milchwissensch, 50, 260 Ŕ 263. Meisel, H. Goepfert, A.  Gunther, S. (1997). ACE inhibitory activities in milk products. Milchwissenschaft, 52, 307 Ŕ 311. Mens, P.L. (1985). Proprietés physico-chimiques nutritionalles et chimiques (physico Ŕ chemical nutritional and chemical properties). In, Laits et Produits Laitiers (vol 1). F.M. Cheese as a Source of Nutrients and Contaminants 367

Luquet (ed) Milk and Milk Products from Cows, Sheep and Goats. Apria (Paris), pp 349 Ŕ 367. Mercasa (2012). Alimentación en España 2012 http://www.munimerca.es/mercasa/ alimentacion_2012/3_info_sectores.html. Molina, A. Molina, M.P. Althaus, R.L.  Gallego, L. (2003). Residue persistente in sheep milk following antibiotic therapy. The Veterinary Journal, 165, 84- 89. Möller, N.P. Scholz Ŕ Ahrens, K.E. Ross, N.  Schrezenmeir, J. (2008). Bioactive peptides and proteins from foods: indication for health effects. European Journal of Nutrition, 47, 171 Ŕ 182. Montville, T.J. & Matthews, K.R. (2008). Spoilage organisms. In: Montville TJ, Matthews KR (eds) Food Microbiology: An Introduction. ASM Press, Washington, DC., pp 271Ŕ 292. Moreno Ŕ Rojas, R. Amaro Ŕ López, M.A.  Zurera Ŕ Cosano, G. (1993). Micronutrients in natural cow, ewe and goat milk. International Journal of Food Science and Nutrition, 44, 37 Ŕ 46. Moreno Ŕ Rojas, R. Cámara Ŕ Martos, F. Sánchez Ŕ Segarra, P.J.  Amaro Ŕ López, M.A. (2012). Influence of the manufacturing conditions and discrimination of Nothern Spanish cheese using multi elemental analysis. Interantional Journal Dairy Technology, 65(4), 594 Ŕ 602. Moreno Ŕ Rojas, R. Sánchez Ŕ Segarra, P.J. Cámara Ŕ Martos, F.  Amaro Ŕ López, M.A. (2010a). Multivariate analysis techniques as tools for categorization of Southern Spanish cheeses: nutritional composition and mineral content. European Food Research and Technology, 231, 841 Ŕ 851. Moreno Ŕ Rojas, R. Sánchez Ŕ Segarra, P.J. Cámara Ŕ Martos, F.  Amaro Ŕ López, M.A. (2010b). Heavy metal levels in Spanish cheeses: influence of manufacturing conditions. Food Additives and Contaminants. part B, 3(2), 90 - 100. Morgan, F. Bonnin, V. Mallereau, M-P & Perrin, G. (2001). Survival of Listeria monocytogenes during manufacture, ripening and storage of soft lactic cheese made from raw goat milk. International Journal of Food Microbiology, 64, 217Ŕ221. Norholt, M.D. (1984). Growth and inactivation of pathogenic microorganisms during manufacture and storage of fermented dairy products: A review. Netherland Milk Dairy Journal, 38, 135Ŕ150. O' Brien, N.M. O' Connor, T.P. O'Callaghan, S.J. & Dobson, A.D.W. (2000). Toxins in Cheese. In P.F. Fox, P.L.H. McSweeney, T.M. Cogan and T.P. Guinee (eds.), Chemistry, Physics and Microbiology, Third edition - Volume 1: Elsevier, New York, pp. 561-571. Ogawa, J. Kishino, S. Ando, A. Sugimoto, S. Mihara, K. & Shimizu, S. (2005). Production of conjugated fatty acids by lactic acid bacteria. Journal of Bioscience and Bioengineering, 100(4), 355 Ŕ 364. Ogunnariwo, J. & Hamilton-Miller, J.M. (1975). Brown- and red-pigmented Pseudomonas aeruginosa: differentiation between melanin and pyorubrin. Journal of Medical Microbiology, 8, 199-203. Panfili, G. Manzi, P. & Pizzoferrato, L. (1994). High Ŕ performance liquid chromatography method for the simultaneous determination of tocopherols, carotens, and retinol and its geometric isomers in Italian cheese. Analyst, 119, 1161 Ŕ 1165. 368 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez

Pariza, M.W. (2004). Perspective on the safety and effectiveness of conjugated linoleic acid. American Journal of Clinical Nutrition, 79(Suppl.), 1132S Ŕ 1336S. Park, H.S. Marth, E.H. Goepfert, J.M. & Olson, N.F. (1970). The fate of Salmonella Typhimurium in the manufacture and ripening of low acid Cheddar cheese. Journal of Milk Food Technology, 33, 280Ŕ284. Park, O.  Allen, J.C. (1998a). Preparation of phosphopeptides derived from alpha(s) Ŕ casein and beta Ŕ casein using immobilized glutamic acid Ŕ specific endopeptidase and characterization of their calcium binding. Journal of Dairy Science, 81, 2858 Ŕ 2865. Park, O. Swaisgood, H.E. & Allen, J.C. (1998b). Calcium binding of phosphopetides derived

from hydrolisis of s-casein or -casein using immobilized trypsin. Journal of Dairy Science, 81, 2850 Ŕ 2857. Park, Y.W. Juárez, M. Ramos, M.  Haenlein, G.F.W. (2007). Physico-chemical characteristics of goat and sheep milk. Small Ruminant Research, 68, 88 Ŕ 113. Parodi, P.W. (1999). Conjugated octadecadienoic acids of milk fat. Journal of Dairy Science, 60, 1550 Ŕ 1553. Patel, H.G. Upadhyay, K.G.  Pandya, A.J. (1991). Effects of milk acidity at renneting and acidity of whey at draining on partitioning of minerals during manufacture of buffalo milk Cheddar cheese. Asian Journal Dairy Research, 10, 217 Ŕ 222. Patiño, E. Faisai, E. Cedres, J. Mendez, F.  Guanziroli Ŕ Stefani, C. (2005). Contenido mineral de leche de búfalas (Bubalus bubalis) en Corrientes, Argentina. Revista Veterinaria, 16, 40 Ŕ 42 Peres, J.M. Bouhallab, S. Bureau, F. Neuville, D. Maubois, J.L. Devroede, G. et al. (1999a). Mechanism of absorption of caseinophosphopetide bound iron. Journal of Nutritional Biochemistry, 10, 215 - 222 Peres, J.M. Bouhallab, S. Bureau, F.Maubois, J.L. Arhan, P  Bouglé, D. (1999b). Reduction of iron/zinc interactions using metal bound to the caseinphosphopeptide 1 Ŕ 25 of  - casein. Nutrition Research, 19, 1655 Ŕ 1663. Pintado, C.M.B.S. Ferreira, M.S.S. & Sousa, I. (2010).Control of pathogenic and spoilage microorganisms from cheese surface by whey protein films containing malic acid, nisin and natamycin. Food Control, 21, 240Ŕ246. Prandini, A. Sigolo, S. & Piva, G. (2011). A comparative study of fatty acid composition and CLA concentration in commercial cheeses. Journal of Food Composition and Analysis, 24, 55 Ŕ 61. Raynal Ŕ Ljutovac K. Lagriffoul, G. Paccard, P. Guillet, I.  Chilliard, Y. (2008). Composition of goat and sheep milk products: an update. Small Ruminant Research, 79, 57 Ŕ 72. Renner, E. (1987). Nutritional aspects of cheese. In, Cheese: Chemistry, Physics and Microbiology (Vol. 1). General Aspects. P.F. Fox (ed). Elsevier Applied Science. London (pp 345 Ŕ 363). Rosengren, A. Fabricius, A. Guss, B. et al. (2010) Occurrence of foodborne pathogens and characterization of Staphylococcus aureus in cheese produced on farm-dairies. International Journal of Food Microbiology, 144, 263Ŕ9. Roupas, P. Royle, P. Descamps, R. Scherer, B. & McIntosh G. (2006). The impact of cheese consumption on markers of cardiovascular risks in rats. International Dairy Journal, 16, 243 Ŕ 251. Cheese as a Source of Nutrients and Contaminants 369

Rubio, C. González-Iglesias, T. Revert, C. Reguera, J.I. Gutiérrez, A.J. & Hardisson, A. (2005). Lead dietary intake in a Spanish population (Canary Islands). Journal of Agriculture and Food Chemistry, 53, 6543-6549. Ryhanen, E.L. Pihlanto Ŕ Leppäla, A.  Pahkala, E. (2001). A new type of rypened; low Ŕ fat cheese with bioactive properties. International Dairy Journal, 11, 441 Ŕ 447. Schvartzman, M.S. Maffre, A. Tenenhaus-Aziza, F. et al. (2011) Modelling the fate of Listeria monocytogenes during manufacture and ripening of smeared cheese made with pasteurised or raw milk. International Journal of Food Microbiology, 145, S31Ŕ8. Settanni, L. Franciosi, E. Cavazza, A. et al. (2011) Extension of Tosèla cheese shelf-life using non-starter lactic acid bacteria. Food microbiology, 28, 883Ŕ90. d. Song, Y.S. Kang, S.W. Oh, D.K. Rho, Y.T. Hong, S.I., & Kim, S.W. (2005). Bioconversion of linoleic acid to conjugated linoleic acid by Bifidobacterium breve. Biotechnology and Bioprocess Engineering, 10, 357 Ŕ 361. Soni, K.A. Desai, M. Oladunjoye, A. et al. (2012). Reduction of Listeria monocytogenes in queso fresco cheese by a combination of listericidal and listeriostatic GRAS antimicrobials. International Journal of Food Microbiology, 155, 82Ŕ8. Sorhaug, T. & Stepaniak, L. (1997). Psychrotrophs and their enzymes in milk and dairy products: Quality aspects. Trends in Food Science & Technology, 8, 35Ŕ41. St-Gelais, D.  Haché, S. (2005). Effect of -casein concentration in cheese milk on rennet coagulation properties, cheese composition and cheese ripening. Food Research International, 38, 523 Ŕ 531. Tamagnini, L.M. De Sousa, G.B. González, R.D. & Budde, C.E. (2008). Behavior of Enterobacter amnigenus and Salmonella typhimurium in Crottin goatřs cheese: Influence of fluctuating storage temperature. Small Ruminant Research, 76, 177Ŕ182. Tamagnini, L.M. De Sousa, G.B. González, R.D. et al. (2005). Behavior of Yersinia enterocolitica and Salmonella typhimurium in Crottin goatřs cheese. International Journal of Food Microbiology, 99, 129Ŕ34. Thévenot, D. Delignette-Muller, M.L. Christieans, S. & Vernozy-Rozand, C. (2005). Prevalence of Listeria monocytogenes in 13 dried sausage processing plants and their products. International Journal of Food Microbiology, 102, 85. Topisirovic, L. Kojic, M. Fira, D. et al. (2006) Potential of lactic acid bacteria isolated from specific natural niches in food production and preservation. International Journal of Food Microbiology, 112, 230Ŕ235. Ur Ŕ Rehman, S. Farkye, N.Y.  Yim, B. (2006). A preliminary study on the role of alkaline phosphatase in cheese ripening. International Dairy Journal, 16, 697 Ŕ 700. Vera P.E., Todorov S.D., Sesma F., de Melo Franco B.D.G. (2012) Application of bacteriocinogenic Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch in the control of Listeria monocytogenes in fresh Minas cheese. Food microbiology, 32, 38Ŕ 47. Voigt, D.D. Chevalier, F. Donaghy, J.A. et al. (2012). Effect of high-pressure treatment of milk for cheese manufacture on proteolysis, lipolysis, texture and functionality of Cheddar cheese during ripening. Innovative Food Science & Emerging Technologies, 13, 23Ŕ30. 370 F. Cámara-Martos, R. Moreno-Rojas and F. Pérez-Rodríguez von Staszewski, M. & Jagus, R.J. (2008). Natural antimicrobials: Effect of MicrogardTM and nisin against Listeria innocua in liquid cheese whey. International Dairy Journal, 18, 255Ŕ259. Yang, B. Shi, Y. Xia, X. et al. (2012) Inactivation of foodborne pathogens in raw milk using high hydrostatic pressure. Food Control, 28, 273Ŕ278. Zoon, P. & Allersma, D. (1996). Eye and crack formation in cheese by carbon dioxide from decar- boxylation of glutamic acid. Netherlands Milk and Dairy Journal, 50, 309Ŕ318.