The objective of this study was to improve the physicochemical properties and functional qualities of soy based mozzarella cheeses by ultrafiltration (UF) of soy milk blends, adding skim milk instead of cow's milk or increasing the soy milk proportions in cheese milk. Eight types of mozzarella cheeses made using soy milk and analyzed for nutritional, structural, and functional characteristics for 4 weeks at 4 °C. Cheeses made with cow milk, 10, 20, and 30 % soy milk in cow milk, skim milk, 10 % soy milk in skim milk, and ultrafiltrated 10 % soy milk in cow milk for first and second volume concentrations. Refrigerated storage of the soy-mozzarella led to a decrease in total solid, mineral, protein, fat, and lactose contents and rheological characteristics after 2 weeks. The nutritive quality of the mozzarella tended to increase proportionally to soy milk content, but the physical and functional qualities decreased. The UF-fortified soy-mozzarella showed more improved qualities among the other soy cheeses like long shelf life, improved nutritional, structural and functional qualities. Blends of 10-20 % soy milk and UF soy milk blends can be used to achieve good quality, nutritive mozzarella cheese, even with skim milk instead of cow milk in a milk shortage.

This study investigated the ACE-inhibitory effect of yogurt beverage fortified with hydrolysates as well as the suitability of hydrolysates as a nutraceutical additive to yogurt beverage. Three whey protein hydrolysates hydrolyzed by alcalase, protamex, and trypsin were each added to yogurt beverage at concentrations of 1.25, 2.5, and 5 mg/mL. Yogurt beverage fortified with 2.5 mg/mL of hydrolysates had 61-69% ACE-inhibitory activity, whereas yogurt beverage fortified with 5 mg/ mL of hydrolysates showed 74% ACE-inhibitory activity. There were no significant differences in ACE-inhibitory activity between the alcalase or protamex hydrolysates during storage; however, trypsin hydrolysate exhibited significant differences. On the other hand, physicochemical characteristics such as pH (3.47-3.77), titratable acidity (0.81-0.84%), colority, viable cell count, and sensory qualities were not significantly different among the tested yogurt beverage samples during storage. These results showed that yogurt beverage fortified with whey protein hydrolysates maintained antihypertensive activity and underwent no unfavorable changes in physicochemical characteristics regardless of enzyme type.

This investigation was undertaken in order to elicit the relationship between the extent of ultrafiltration processing of whey and its effect on composition and yield of resultant whey protein concentrate (WPC). Cheddar cheese whey was fractionated through ultrafiltration to an extent of 70, 80, 90, 95, 97.5% and 97.5% volume reduction followed by I stage and II stage diafiltration. After each level of ultrafiltration, the composition of WPC was monitored. Similarly, the initial whey was adjusted to 3.0, 6.2 and 7.0 pH levels and ultrafiltration was carried out to elicit the effect of pH of ultrafiltration on the composition. Further, initial whey was adjusted to different levels of whey protein content ranging from 0.5 to 1.0 per cent and subjected to ultrafiltration to different levels. The various range of retentate obtained were further condensed and spray dried in order to assess the yield of WPC per unit volume of whey used and the quantity of whey required to produce unit weight of product. With the progress of ultrafiltration, there was a progressive increase in protein content and decrease in lactose and ash content. The regression study led to good relationships with R 2 values of more than 0.95 between the extents of permeate removed and the resultant changes in composition of each of the constituents. Whey processed at pH 3.0 had significantly a very low ash content and high protein content as compared to processing at 6.2 and 7.0. The yield of WPC per unit volume of whey varied significantly with the initial protein content. Higher initial protein content led to higher yield of all ranges of WPC and the quantity of whey required per unit weight of spray dried WPC significantly reduced. Regression equations establishing the relationship between initial protein content of whey and the yield of various types of WPC have been derived with very high R 2 values of 0.99. This study revealed that, the yield and composition of whey can be monitored strictly by controlling the processing parameters and WPC can be produced depending on the food formulation requirement.

Whey protein concentrates containing 50 and 60% protein were manufactured and were hydrolyzed for 0.5, 1, 2, 3, 4, and 5 h with 5 commercial enzymes (flavourzyme, protease A, protease M, protease S, and trypsin). Functional properties such as degree of hydrolysis (DH), non-protein-nitrogen (NPN), 5-hydroxymethyl-2-furfural (HMF), solubility, and free-sulfhydryl (FSH) levels were measured. In food applications functional efficiency of whey protein hydrolysates (WPHs) depended on hydrolysis time, protein composition and enzymatic specificity. WPHs treated with protease A were found to be suitable for applications that require extensively hydrolyzed (>2 h) WPHs, because they had high solubility, DH, HMF, and FSH contents. Proteases S and M hydrolysates delayed the Maillard reaction and had high DH in mild hydrolysates (≤2 h) of WPHs. Aggressive hydrolyzed WPHs of protease A, and mild hydrolysates of proteases S and M are preferred in beverage fortification for maximum functional efficiency.

The objective of this study was to develop yogurt-cheese using cow’s milk, ultrafiltrated cow’s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow’s milk, and stored at 4℃ during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow’s milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow’s milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α2-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food.