Effects of genetic variants of κ-casein and β-lactoglobulin and heat treatment of milk on cheese and whey compositions

Abstract

Milk samples with different phenotype combination of κ-casein and β-lactoglobulin and different preheating temperatures of 30, 70, 75 and 80°C were used for cheesemaking under laboratory conditions. For the 853 batches of cheese, mean composition was 59.64% total solids, 30.24% fat and 23.66% protein, and the whey contained 6.93% total solids, 0.30% fat and 0.87% protein. Least squares analysis of the data indicated that heating temperature of the milk and κ-CN/β-LG phenotypes had significant effects on cheese and whey compositions. The total solids, fat and protein contents of cheese were negatively correlated with preheating temperatures of milk. Cheese from BB/BB phenotype milk had the highest and those from AA/AA phenotype milk had the lowest concentrations of total solids, fat and protein. Mean recoveries of milk components in the cheese were 53.71% of total solids, 87.15% of fat, and 80.32% of protein. For the 10 different types of milk, maximum recoveries of milk components in cheese occurred with preheating temperature of 70°C or 75°C and lowest recoveries occurred at 80°C. The whey averaged 6.94% total solids, 0.30% fat and 0.87% protein. Losses of milk components in the whey were lowest for milk preheated at 80°C and for milk containing the BB/BB phenotype.