The Influence of Milk Fat and Starter Cultures on Cholesterol Content and Nutrient Characteristics of Quarg Cheese
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FOOD TECHNOLOGIES MIRELA ILIČIĆ1*, SPASENIJA MILANOVIĆ1, MARIJANA CARIĆ1, ANAMARIJA MANDIĆ2, RADE POPOVIĆ3 *Corresponding author 1. University of Novi Sad, Faculty of Technology, Bulevar Cara Lazara 1, Novi Sad. Serbia 2. University of Novi Sad, Institute of Food Technology, Novi Sad, Serbia 3. University of Novi Sad, Faculty of Economics of Subotica, Subotica, Serbia Mirela Iličić The influence of milk fat and starter cultures on cholesterol content and nutrient characteristics of Quarg cheese KEYWORDS: Quarg, cheese, starter culture, milkfat, cholesterol. The effect of milk fat content and different starter cultures on cholesterol content and other nutrients Abstract characteristics of Quarg cheese was investigated in this study. Quarg samples were produced from milk of 1.6%(w/w), 2.2%(w/w) and 3.2%(w/w) fat content by using traditional culture or traditional culture in combination with probiotic starter culture in ratio 1:1. The sample produced from milk with 1.6%(w/w) fat with traditional culture contained 26.18mg/100g of cholesterol, while the cholesterol content of the same sample produced from 3.2%(w/w) fat content was 57.46mg/100g. The cholesterol/fat ratio is maximum in low fat Quarg (5.65) in contrast to Quarg from full fat milk (3.38), in which the fat/protein ratio is approx. two-fold higher, while the isocaloric value cholesterol/energy ranged from 249mg/1000 kcal to 274mg/1000 kcal. INTRODUCTION Microorganisms play essential roles in the manufacture of Fresh cheeses are unripened cheeses, manufactured by the cheese, largerly contributing to the development of coagulation of milk, cream or whey using acid, a organoleptic properties by their metabolism and to combination of acid and rennet or a combination of acid microbiological safety through barrier, effects of complex and heat. Many processing factors (milk pre-heat treatment, microflora and production of several low molecular weight rate and temperature of acidification, level of gel-forming antimicrobial compound (6). Probiotics application, protein, pH, etc.) influence the coagulum structure and specifically Bifidobacteria and Lactobacilli, in Quarg hence the rheological and physico-chemical stability and manufacture is becoming more and more interesting nutritive value of the Quarg (1, 2, 3). because of their beneficial effect on human health by The cheese is the main source of animal fat and dietary improving the balance of intestinal microflora and improving cholesterol. Cholesterol is essential for membrane structure, mucosal defenses against pathogens (2, 7, 8, 9). and biosynthesis of hormones and steroids. It has been recognized that its elevated levels in plasma are directly The aim of this study was to investigate the effect of fat correlated to increased cardiovascular heart diseases (4). content and starter cultures on cholesterol level and nutrients Cholesterol content in Quarg varieties produced in Europe characteristics of Quarg cheese obtained by traditional and ranged from 9.5mg/100g for Cottage to 30.5mg/100g for low probiotic starter cultures. fat cream cheese and 35mg/100g for Ricotta (5). Some authors found that the values of cholesterol/fat ratio and their ranges are different according to cheese type, the Anthotyros MATERIALS AND METHODS and Manouri varieties exhibiting the highest and lowest values, respectively. They also concluded that although Milk Greek cheeses have on average a high fat content, they do Pasteurized (72°C, 40 sec) cow’s milk from local dairy in not overload the consumers with dietary cholesterol, with a Novi Sad, was used for the production of fermented milk possible exception being the whey-soft cheese types. The products. The fat content of the used milk samples was as cholesterol intake by consuming cheese is not directly follows: 1.6%(w/w) (M1), 2.2%(w/w) fat (M2) and proportional to the fat content of the cheese (5). 3.2%(w/w) (M3). 56 Agro FOOD Industry Hi Tech - vol 26(4) - July/August 2015 Starter cultures “Statistica 9.1” (StatSoft Inc. 2009). The results were expressed Two different starter cultures were used: traditional culture T as average, standard deviation of values obtained at three (CH-N22-Flora Danica: Lc. lactis subsp. lactis, Lc. lactis subsp. independent experiments. T-test for comparisons of several cremoris; Chr.Hansen, Denmark), in concentration 0.01%(w/w) averages was applied for determining differences between and probiotic starter culture P (ABT-1: Lactobacillus the chemical parameters. acidophilus-5, Bifidobacterium-12, S. thermophilus; Chr. Hansen, Denmark) in concentration 0.01%(w/w). RESULTS AND DISCUSSION Enzyme Microbiological enzyme Hannilase L 2235 isolated from Nutritive characteristics of samples Rhizomucor miehei (Chr.Hansen, Denmark) was applied in The analysis of Quarg samples for nutrient parameters and concentration 0.005%(w/w) for milk coagulation. energy value of samples are presented in Table 2. Low fat samples (TP1.6) had the highest level of water (80.54g/100g), Quarg manufacture while sample produced from full fat milk (TP3.2) contained for Quarg samples were produced in laboratory conditions from 8.5% lower water content (67.72g/100g). Fat content in milk of 1.6g/100g (M1), 2.2g/100g fat (M2) and 3.2g/100g samples ranged from 5g/100g (sample TP1.6) to 17g/100g (M3) fat content. Traditional culture or traditional culture in (T3.2), while fat content in total solid varied from 24.89g/100g combination with probiotic starter culture in ratio 1:1, and (T1.6) to 53.21 g/100g (TP3.2). Significant differences were 0.005% enzyme were added into milk at 28°C. After observed in water content of all Quarg samples (p<0.05). On coagulation (pH=4.6), the coagulum was cut, pasteurized by the basis of water and fat content on total solids, all samples gently stirring at 60°C for 5 minutes, quickly cooled and fulfilled the criteria to be classified as soft Quarg cheese. The drained. Cheese samples were homogenized by mixing, chemical composition of full fat Quarg is in accordance with packed in cups (1.8 dL) and stored in the refrigerator at 4°C. the results of authors Andricopulous et al. (5) and Abou The trials were repeated three times. Sample identification is Jaoude et al. (16). Andricopulous et al. (5) found that presented in Table 1. Anthotyros (Greek fresh cheese) samples contained on average: 66-70.1% (w/w) water, 14.4-18.4% (w/w) total proteins, ash 0.8-1.6% (w/w), while the energy value of the samples was in the range 185-222 kcal. Results of Abou Jaoude et al. (16) showed that moisture of full fat Double Crème was 60.3g/100g, while moisture of fat free cheese was 69g/100g . The cholesterol content of cheese is a function of its fat content and varied from 35.9mg/100g (fat free cheese) to 81.5mg /100g (full fat cheese) (5,16-17,18-19). By definition, the fat /protein ratio higher than 1.25 to 1.50 corresponds to Table 1. Symbol of samples. fat and extra fat cheese, respectively (5). The fat /protein ratio in all of Quarg samples was lower than 1.5. Total proteins ranged from 8.78% (w/w) (TP41.6) to 12.38% Analyses (w/w) (T3.2) and directly affect the minerals content and their The following physicochemical analyses were determined in all ratio (phosphorus and calcium). samples: pH value of milk and cheese was measured by The phosphor content varies between Quarg samples ranging pH-meter Iskra, MA 5713, (Kranj, Slovenia), total solids (TS) of milk from 131.5mg/100g (TP2.2) to 170.4mg/100g (T3.2). and cheese (10), total protein (TP) by Kjeldahl method (11), fat It is evident from Table 2 that the calcium content varies from by Gerber method (12). The content of calcium in milk as well 55.6mg/100g (T1.6) to 120.9mg/100g (T3.2). The calcium as in cheese was analyzed by atomic absorbtion content in cheese produced from full-fat milk was by 48% spectrophotometry (Varian SpectrAA-10). The samples were higher, on average, compared to samples produced from prepared by dilution (1:1 v/v) with 0.5% w/w of cesium chloride (13). skim-milk. Phosphor content in all samples was determined according to the referent method (14). Differences in minerals content are significant between low The cholesterol content in milk and all Quarg samples was and full fat Quarg samples produced with traditional and determined using Liquid Chromatograph HP 1090 with DAD probiotic culture (p<0.05).The values of P/Ca ratio were detector (Hewlet Packard, USA). The components were calculated for all cheese samples and presented in the table 2. separated on Hypersil ODS (C18) 5µm, length 125 mm, internal diameter 4mm using methanol as a mobile phase at the fow rate of 0.2 mL/min at ambient temperature. Injection was performed manually, injection volume was 2 µL. The cholesterol in samples was detected at 212/4 nm using DAD (15). Statistical analysis Table 2. Chemical composition and energy value of Quarg samples. Statistical analysis was carried out abcdeDifferent letters for the same column indicate significant differences (P<0.05) with the computer software program Agro FOOD Industry Hi Tech - vol 26(4) - July/August 2015 57 It is obvious that the increase of protein content is followed by and their ranges are different between Quarg samples, phosphorus content increase. The phosphorus:calcium ratio is varying from 2.90 (T2.2) to 5.65 (TP1.6). The cholesterol content decreasing with increase of the milk fat content in samples. in fat varied from 4.6mg/g fat to 3.5mg/g fat in samples with There is no significant difference in phosphorus/calcium ratio traditional culture, while cholesterol in fat in sample with between Quarg samples produced from milk with the same traditional and probiotic ranged from 6 to 3mg/g fat .