The use of ultrafiltrated goat milk in soft cheese making

摘要

White soft cheese was manufactured using whole goat milk concentrated by ultrafiltration process to 26, 29, 32% total solids. Calcium chloride and rennet were added to each concentration in ratios of 0.002, 0.004 and 0.005, 0.01% respectively. Cow UF cheese manufactured with CaCl2 and rennet was used for comparison. Cheese samples were examined for total solids, fat, ash, lactose, total nitrogen, salt, and pH value. Whey syneresis, penetration value and sensory quality attributes of cheese were carried out on fresh samples and weekly during the storage period. The milk components except salt were increased in the cheese with increasing the retentate concentration of milk. The UF cheese of cows milk showed higher TN and salt content while, the pH value was lower than that of goat milk. The deference between components in both cheeses depended on the concentration value. Curd syneresis decreased with increasing the retentate concentration, the amount of rennet and CaCl2 used in cheese manufacture.During storage of goat cheeses, the whey syneresis increased in all treatments in different UF concentrations, with different CaCl2 and coagulant ratios, even in UF-cow cheese (control). Penetration of curd increased during storage until the 4th week andthen decreased. The penetration value also decreased at same milk concentration with increasing CaCl2 and rennet ratios. Storage of cheese up to 4 weeks resulted in higher penetration values in all treatments including the control of UF cows. The totalquality of goat cheeses indicated that the preference for UF goat cheese increased and the quality improved with increasing UF concentration from 26 to 29% and then decreased with increasing the concentration to 32%. Among all goat cheeses, the cheese of26% UF concentration with 0.01% rennet and 0.004% CaCl2 or 29% UF concentration with 0.005% rennet and 0.002% CaCl2 scored highest and produced the best cheese quality.