Lepesioti Sofia, Zoidou Evangelia, Lioliou Dionysia, Moschopoulou Ekaterini, Moatsou Golfo
Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece.
Foods. 2021 Jan 18;10(1):184. doi: 10.3390/foods10010184.
The effect of homogenization and fat reduction in combination with variable heating conditions of cow milk on the characteristics of Quark-type cheese were investigated. The mean composition of full-fat cheeses was 71.96% moisture, 13.95% fat, and 10.31% protein, and that of its reduced-fat counterparts was 73.08%, 10.39%, and 12.84%, respectively. The increase of heat treatment intensity increased moisture retention and improved the mean cheese protein-to-fat ratio from 0.92 to 1. Homogenization increased the moisture and protein retention in cheese, but the effect was less intense for milk treated at 90 °C for 5 min. The extended denaturation of whey proteins resulted in harder, springier, and less cohesive cheese ( < 0.05). Treatment of milk at 90 °C for 5 min resulted in higher residual lactose and citric acid and lower water-soluble nitrogen contents of cheese ( < 0.05); the latter was also true for homogenization ( < 0.05). Storage did not affect the composition and texture but decreased galactose and increased citric acid and soluble nitrogen fractions ( < 0.05). In conclusion, heat treatment conditions of milk that induced a considerable denaturation of β-lactoglobulin and left a considerable amount of native α-lactalbumin was adequate for the manufacture of a "clean-label" Quark-type cheese, whereas homogenization was more effective for full-fat cheese.
研究了均质化和减脂处理与牛奶不同加热条件相结合对夸克型奶酪特性的影响。全脂奶酪的平均组成为水分71.96%、脂肪13.95%、蛋白质10.31%,其减脂对应产品的平均组成分别为73.08%、10.39%和12.84%。热处理强度的增加提高了水分保留率,并使奶酪的平均蛋白质与脂肪比从0.92提高到1。均质化增加了奶酪中的水分和蛋白质保留率,但对于在90℃下处理5分钟的牛奶,其效果较弱。乳清蛋白的长时间变性导致奶酪更硬、更有弹性且粘性更小(P<0.05)。将牛奶在90℃下处理5分钟会导致奶酪中残留乳糖和柠檬酸含量更高,水溶性氮含量更低(P<0.05);均质化处理也有同样的情况(P<0.05)。储存对奶酪的组成和质地没有影响,但会降低半乳糖含量,增加柠檬酸和可溶性氮组分(P<0.05)。总之,能使β-乳球蛋白发生显著变性并保留大量天然α-乳白蛋白的牛奶热处理条件适合用于生产“无添加标签”的夸克型奶酪,而均质化对全脂奶酪更有效。