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Home , Calcium lactate, Magnesium carbonate, Magnesium citrate, Magnesium sulfate, Zinc gluconate, Zinc sulfate

Wellness Foods Europe THE MAGAZINE FOR NUTRITIONAL AND FUNCTIONAL FOODS & BEVERAGES

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Mineral fortification in dairy

Reprint from Wellness Foods Europe issue 1/2013 Wellness Foods Europe

Mineral fortification in dairy

Markus Gerhart and Martin Schottenheimer

Introduction > The global functional foods be healthy and fortification makes them even market is dominated by dairy products, with healthier. They are a popular part of the diet sales valued at 9.23 bn USD in 2010 [1]. De- and their consumption is a daily routine. This spite already being a well-developed market favours their usage as a carrier for functio­ in many countries, manufacturers are con- nal foods that should be consumed regular- tinuing to innovate, driven by the consumers ly. Milk products are already a good source demand for products that fit into their diet of and fortification leads to products and nutritional needs. In consequence, the that can contribute more than 50 % of the scope for the growth of new, innovative, and daily requirements to the diet. healthier products is steadily increasing [2, Functional dairy products have been 3]. This success is based on various pillars. impac­ted in the EU by the recent health In general, dairy products are perceived to claims regulation, as the usage of claims on Minerals Wellness Foods Europe

popular functional ingredients like pro- or tions are dissolved in the aqueous phase [6]. prebiotics is restricted. However, there is still Mineral supplementation of milk is challeng- room in the market for new products [3]. Es- ing, because the soluble phase is considered pecially minerals like calcium, or to be saturated at its normal pH, making fur- can offer a wide range of claim options ther addition difficult [7]. that address the top health topics like bone Therefore, selection of the appropriate health, immunity, energy or cognitive func- mineral source for a specific application is tions. These health benefits can be clearly de- extremely important. Commonly used calci- fined and are easy for the consumer to under- um, magnesium and zinc in dairy appli- stand. Recent examples like “Yoplait Calin+” cations are shown in table 1. or “Danone Densia” underline what is still Properties of the respective mineral com- possible in the market. Containing 50 % pounds such as mineral content¸ RDA of calcium per serving plus ­ D and taste are essential parameters for pro­ and referring to bone health, these products duct development while bioavailability and set a new benchmark for calcium fortified economic considerations are also of high im- yoghurts. portance. However, feasibility of mineral addition Suitable mineral salts can roughly be sub- has to be considered, as milk products are a divided into soluble or insoluble minerals. complex food matrix and high fortification When using soluble salts, sedimentation and levels are challenging. With the right selec- influence on mouth feeling are negligible tion of the appropriate mineral compound at first sight, while impact on taste and pH and the proper application success is possible. value is increasing with rising fortification Based on our history and expertise on levels. However, pH changes and the addi- mine­ral fortification, Jungbunzlauer has re- tional free can destabilise the system cently started a cooperation with the Univer- especially du­ring heat treatment. This may sity of Hohenheim in Germany to fully un- lead to coagu­lation, syneresis and reactions derstand the applicability of mineral salts in with further ingredients of the milk product dairy products [4]. like phosphate and proteins [8]. Addition of This article discusses important nutritional chela­ting agents such as citrate and technological aspects of mineral fortifica- has been shown to enable higher fortification tion of dairy products. It provides the major levels by adjusting the pH level, chelating free findings of our internal lab work and our co- cations as well as competing with calcium to operation with the University of Hohen­heim reduce cross-linking [7]. with specific focus on calcium, magnesium In contrast to soluble minerals, low or and zinc fortification in milk, yoghurt as well insoluble minerals remain mainly dispersed as drinking yoghurt. within the product, thereby having much lower impact here on the dairy matrix. In Challenges > Milk is an important source of addition, their influence on taste is less pro- minerals in our diet and about 40% to 74% of nounced, as bitter and astringent off-tastes daily calcium is provided by dairy foods [5]. are related to free ions of dissociated minerals. Together with magnesium, potassium and so- While being mainly suspended, insoluble dium, calcium plays an important role in the minerals can affect mouth feeling in terms structure and stability of casein micelles. In of grittiness and chalkiness, and can lead to whole milk, about two thirds of its calcium sedimentation in low viscous products. Mi- and one third of its magnesium is bound in cronised mineral salts are a good option to the micelle and the remaining mineral­ frac- address these undesired effects. Speed of sed- Wellness Foods Europe Minerals

Table 1. Overview of calcium, magnesium and zinc salts approved for fortification in Europe acc. to Regu­lation (EC) No. 1825/2006

Compound Mineral Content Solubility Taste Calcium 40 % Insoluble Soapy, lemony

Calcium Chloride · 2 H2O 27 % 745 g/l Salty, bitter

Calcium Lactate · 5 H2O 14 % 90 g/l Bitter at high concentrations Gluconate 13 % 400 g/l Slightly bitter at high conc. Ca (as Calcium Lactate & )

Tricalcium Citrate · 4 H2O 21 % 1 g/l Tart, clean Tricalcium Phosphate 40 % Insoluble Sandy, bland

Magnesium Carbonate basic · 5 H2O 24 % 4 g/l Earthy

Magnesium Lactate · 2 H2O 10 % 70 g/l Neutral

Magnesium · 7 H2O 10 % 710 g/l Saline, bitter Mg Trimagnesium Citrate · 9 H2O 12 % 16 g/l Neutral Trimagnesium Citrate 16 % 200 g/l Neutral Trimagnesium Phosphate · 5 H2O 21 % Insoluble Neutral Zinc Citrate · 3 H2O 31 % 3 g/l Slightly bitter

Zn · x H2O 13 % 100 g/l Bitter, astringent 80 % Insoluble Bitter · 7 H2O 23 % 960 g/l Astringent, bitter, metallic

Source: Internal evaluation and [7]; Jungbunzlauer products are marked in bold

imentation is reduced by decreasing particle Fortification of milk > When fortifying milk, size and ultrafine particles are no longer per- solubility, dissolution characteristics, sedi­ ceived. Particles significantly smaller than mentation behaviours and stability of the final 20 µm allow fortification levels far above the formulation are major challenges. Organic ones achievable with dissolved minerals. calcium salts like calcium gluconate, calcium lactate, or calcium lactate gluconate and in- Bioavailability > Any nutrient’s effectiveness organic are highly soluble, depends on its bioavailability, meaning how but their use is limited due to off tastes at well the human body absorbs and utilises it. higher concentrations. Having the lowest Mineral bioavailability from food sources taste impact within the range of soluble cal- can vary from e. g. 10–30% for calcium, 40– cium salts, calcium lactate gluconate can be 60 % for magnesium or 5–50 % for Zinc [7]. added to achieve 200 mg of total calcium Several scientific studies indicate that organic to 100 ml milk without a significant influ- mineral salts like citrates, lactates or gluco- ence on its taste. Due to their influence on nates outperform inorganic mineral sources pH value and the contribution of free calci- such as oxides, and phosphate um ions, products tend to be unstable during with regard to their relative bioavailability heat treatment. However, with the addition [9, 10]. of tripotassium citrate the system can be sta- Minerals Wellness Foods Europe

bilised, but the effect is limited to lower for- Sedimentation behaviour can be further im- tification levels. As a new route, addition of proved, by increasing the viscosity of the sterilised or ultrafiltrated mineral­ solutions milk. In our trials, the addition of kappa car- after the heat treatment step is a recommen­ rageenan has shown the most promising re- ded alternative and results in stable fortified sults. At above mentioned fortification levels UHT milk (Figure 1). sedimentation can still appear, but ultra- Inorganic and calcium fine tricalcium citrate typically shows good phosphate are insoluble. The organic tricalci- re-dispersability compared to other calcium um citrate in the commonly used tetra­ forms. form shows a slight solubility of 1 g/l while In contrast to calcium, magnesium for- having low effect on product pH value and tified milk products are less common and thus minor effect on product stability, even available literature is limited. Being also a when applied at higher concentrations. Tri- bivalent cation, the addition of magnesi- shows an “inverse solubility”,­ um salts has shown similar behaviour as in i. e. it is more soluble at lower and less soluble case of calcium according to our experience. at higher temperatures. The latter is beneficial Vari­ous liquid milk products contain readily during heat treatment, as the risk of coagula- soluble magnesium salts like organic trimag- tion can be further reduced (Figure 1). nesium citrate anhydrous or magnesium lac- tate and inorganic . They also destabilise the milk matrix during heat treatment. In this respect, tripotassium cit- rate improves heat stability and enables a for- tification to 210 mg magnesium per 250 ml serving (55 % EU RDA). Addition of trimag- nesium citrate anhydrous after heat treat- ment allows similar or even higher magnesi- um contents, without need for stabilising via tripotassium citrate. Surprisingly, the forti- fication showed positive effects on the taste profile of milk. In contrast, addition of mag- nesium sulfate had a negative taste impact. Insoluble magnesium salts like inorga­ nic and magnesium Fig. 1: Process flow chart for fortified UHT milk phosphate or low soluble organic trimagne- sium citrate nonahydrate show sedimenta- However minerals with low solubility tend tion during storage. As with tricalcium ci- to sediment during storage. Usage of micro- trate, addition of kappa carrageenan can nised forms improves dispersion during ad- reduce sedi­mentation. However, as fortifi- dition, helps to keep particles in suspen- cation is feasible in homogeneous phase at sion longer and results in better mouth feel. reasonable levels with trimagnesium citrate Jungbunzlauer’s M1098 (98 % < 10 μm), the anhydrous, whilst even improving the taste finest available micronised grade of trical- profile, insoluble salts are considered asse­ cium citrate, allows to increase the calcium condary choice. content of plain milk up to 200 mg/100 ml Due to the low RDA and thus the low (25 % EU RDA) without negative taste ef- usage levels of zinc salts, solubility is not a fects. major issue in fortified milk products. The Wellness Foods Europe Minerals

range of zinc salts for milk fortification com- ness, destabilises the fruit preparation and prise high soluble inorganic zinc sulfate or impacts the mouth feel and shelf life of the organic zinc gluconate and zinc lactate, as fortified yoghurt. In our trials, yoghurts for- well as low soluble zinc citrate (2.6 g/l) and tified with mineral citrates do not show such insoluble zinc oxide. While the soluble zinc a phenomenon. salts are fully dissolved, the presence of or- With increasing fortification, micronisa- ganic anions like gluconate, lactate or citrate tion of minerals is indispensable. Ultrafine help to reduce negative taste effects like bit- particles ease dispersion and reduce sedi- terness and astringency associated with free mentation within the fruit preparation and zinc ions. improve texture and mouth feel of the final product. Jungbunzlauer's tricalcium citrate Fortification of yoghurt > When fortify- can even be suspended in yoghurts at con- ing high viscous dairy products such as centrations of more than 500 mg calcium per yoghurts, Greek yoghurt or curd cheese 125 mg serving (62.5 % EU RDA). In case of (petit Swiss) organoleptic properties like magnesium and zinc similar or even higher taste or mouth feel are major issues. Soluble RDA can be achieved with trimagnesium minerals are of minor importance as disso- citrate and zinc citrate. lution is not required and negative effects In plain yoghurts, a liquid mineral suspen- on taste dominate at higher concentrations. sion can be applied and the addition of starch Minerals are generally applied via the fruit has shown to stabilize these suspensions by preparation (Figure 2). Their low pH value reducing sedimentation. and high citric /fruit acid concentration increase mineral solubility. On one hand this Fortification of drinking yoghurt > Drinking can help to facilitate a proper distribution. yoghurt holds an intermediate position be- On the other hand when inorganic minerals tween milk and yoghurt products. Produced like carbonates or phosphates are used, a from yoghurt, it has a pH similar to yoghurt neutralisation reaction between free calci- (~pH4) while the viscosity tends to be much um ions and abundant may take lower. Like yoghurts, these products are best place over time. This may result in an un- fortified via fruit preparations. As the addi- controlled de-novo growth of especially cal- tion of low or insoluble minerals is preferred, cium citrate , which leads to gritti- sedimentation may become a challenge. Be- sides the usage of micronised minerals also viscosity adjustment is of high importance. Options comprise:

– Usage of exopolysaccharide cultures for the – Higher usage levels of pectin in fruit pre­ parations – Reduction of added – Reduction of the homogenisation pressure (e. g. 75/15 bar)

A viscosity above 225 mPa*s enables forti- fication levels similar to the ones achievable Fig. 2: Process flow chart for fortified yoghurt in yoghurt. Minerals Wellness Foods Europe

Table 2: Recommended mineral salts and maximum fortification levels in milk, yoghurt and drinking yoghurt

Application Recommended mineral Max. fortification level Recommendations (EU RDA) Milk Calcium Lactate Gluconate 500 mg/250 ml Ca (63 %) Addition of mineral salt after heat treatment. Tricalcium Citrate M1098 500 mg/250 ml Ca (63 %) Addition of kappa carra- geenan (0.025 %). Trimagnesium Citrate 200 mg/250 ml Mg (53 %) Addition of mineral salt Anhydrous after heat treatment or addition together with Tripotassium Citrate (0.3 %) before heat treat- ment. Zinc Citrate 7.5 mg/250 ml Zn (75 %)

Yoghurt Tricalcium Citrate M1098 500 mg/125g Ca (63 %) Plain yoghurt: Addition Trimagnesium Citrate 200 mg/125g Mg (53 %) of minerals together with Nonahydrate starch (Ultra Sperse 5; 0.08 %). Zinc Citrate 7.5 mg/125g Zn (75 %) Fruit yoghurt: Addition of mineral to fruit prepa- ration.

Drinking Tricalcium Citrate M1098 500 mg/100 ml Ca (63 %) Yoghurt Trimagnesium Citrate 120 mg/100 ml Mg (30 %) Addition of pectin (H&F Nonahydrate CM 201; 0.35 %) Zinc Citrate 7.5 mg/100 ml Zn (75 %)

Summary of results > Table 2 provides the key as calcium lactate in dairy applications and findings of our trials in various dairy matrix- enabled manu­factures to fortify products to es. This toolbox serves as a guidance to deve­ more than 50 % RDA of calcium per serving. lop new product concepts with magnesium, The combination of outstanding technologi­ calcium, zinc or blends thereof with fortifi- cal properties and high nutritional value cation levels up to 75 % EU RDA. Our trials (bio­availability) makes micronised tricalci- show that high fortification of milk, yoghurt um citrate the number one option for calci- as well as drinking yoghurt is feasible, with- um fortified milk products [11]. In contrast out compromising taste or product stability. to calcium, fortification with magnesium and zinc is not as established in the market. Es- Outlook > The challenge for dairy pro­ pecially in Europe, where health claims on duct manufacturers is to provide products products are regulated by the new EFSA with highest mineral content and appeal- health claim regulation, magnesium and zinc ing sensory properties. Since micronised tri- offer various options for new product con- calcium citrate has been available, it has re- cepts. With the raising awareness for these placed inorganic as well as organic salts such two minerals and their various beneficial ef- Wellness Foods Europe Minerals

fects on human health they should gain im- portance in dairy products soon as such or together with calcium and other nutritional ingredients. As technological hurdles will in- crease with higher fortification levels, trimag- nesium citrate and zinc citrate will be able to prove their superior performance in dairy ap- plications.

References > [1] Leatherhead Food Research; Future Directions for the Global Functional Foods Market; 2011 [2] Global Industry Analysts: Dairy Products: A Global Strategic Business Report; 2012 [3] Weston, S.; The 2013 yogurt innovation phenomenon; www.foodbev.com; 2013 [4] Hinrichs, J.; University of Hohenheim, Stuttgart, Germany; Dairy Science and Tech- nology (150e); personal communication 2013 [5] Wark, J. & Nowson, C.; Calcium supple- mentation: the bare bones; Australian pre- scriber; 2003 [6] Gaucheron, F.; The minerals of milk; Re- production Development; 2005 [7] Hurrel, R. (ed.); The mineral fortification of foods; Leatherhead Food Research; 1999 [8] Omoarukhe et al.; Effects of different cal- cium salts on properties of milk related to heat stability; International Journal of Dairy Technology; 2010 [9] Gerstner, G; How can we get more cal- cium? International Food Ingredients; 2003 The Authors: [10] Lindberg et al.; Magnesium bioavaila- Markus Gerhart is Product Manager Special Salts for Jungbunzlauer in Ladenburg, Germany bility from and magnesi- Martin Schottenheimer is Project Manager Food at um oxide; Journal of the American College the Application Technology Center of Jungbunzlauer of Nutrition; 1990 in Ladenburg. [11] Mintel GNPD; Number of launches Jungbunzlauer Ladenburg GmbH, Germany Telephone: +49 6203 104-0 “white milk, liquid”, “Drinking Yogurts & Fax: +49 6203 104210 Liquid Cultured Milk, liquid”, “Spoonable [email protected] Yogurt”. www.jungbunzlauer.com