The Effect of Raw Milk Quality and Starter Cultures on the Yield and Nutritional Value of Polish Acid Curd Cheese (Tvarog)

The aim of the study was to characterize variants of traditional acid curd cheese obtained in Poland in artisanal conditions in terms of their yield and nutritional value. The curd cheeses were made from raw milk obtained in various conditions: with and without the use of pasture forage (i.e. in traditional and intensive systems), in two seasons of production (spring/summer and autumn/winter), from two breeds raised in Poland (Polish Holstein-Friesian and Simmental), and on the basis of two types of starter culture (i.e. freeze-dried and traditional cultures). The basic chemical composition and content of selected fat-soluble vitamins, i.e. A, D₃ and E, were determined in samples of bulk milk and cheese. The cheese yield was calculated as the number of litres of milk used to produce 1 kg of curd cheese. The nutritional value of the experimental curd cheeses was determined by calculating the calorific value and the Index of Nutritional Quality (INQ). All analysed factors except for the bacterial cultures significantly affected the chemical composition of the cheese. Curd cheese made from the milk of Simmental cows had higher content of protein and fat-soluble vitamins (A, D₃ and E) than cheese from the milk of Holstein-Friesian cows. However, curd cheeses produced in a traditional system and/or in the spring and summer were a richer source of vitamins, mostly vitamin E. The high INQ values obtained indicate that curd cheese is a rich source of protein and vitamin A.