Gross chemical composition and texture profile analysis of full-fat, reduced-fat and low-fat goat cheese elaborated with raw milk using traditional procedures in Canary Islands (Spain)

Abstract

Three different milk fat contents were used to elaborate 72 goat¡¯s raw milk cheeses according to traditional hand-made cheese practices in Canary Islands: full-fat cheese (FFC), reduced-fat cheese (RFC) and low-fat cheese (LFC) with 5, 1.5 and 0.4% fat in milk, respectively. At 1, 7, 14 and 28 days of ripening, cheese samples were taken to analyze chemical composition, pH and texture profile. The cheese fat content, as expected, was higher in FFC (18.5%) than in RFC and LFC (9.4 and 1.2%, respectively), at day 1. At the end of this study, fat in dry matter values were 48%, 26% and 18%, FFC, RFC and LFC, respectively. At day 1, protein content was higher in LFC (22.8%) than in RFC (21%) and FFC (19%). Throughout maturation, protein percentages were increasing over time, showing values of 33%, 25% and 20%, LFC, RFC and FFC, respectively at day 28. Moisture was 47% in FFC, 52% in RFC and 56% in LFC at 1 d of maturation, dropping until 40%, 50% and 51%, respectively at 28 days. The average of external and internal pH value at 1 day was similar in all groups (¡Ö6.6). During the first two weeks of ripening, external and internal pH values decreased, but at day 28, the external and internal pH increased slightly. pH values were significantly higher in LFC than in RFC and FFC in all ripening times. Values of fracturability and hardness of LFC and RFC were significantly higher than FFC throughout the 28 days of ripening. At day 28 both parameters increased significantly for all cheeses, 190, 83 and 38 N for fracturability, and 193, 106 and 51 N for hardness, in LFC, RFC and FFC, respectively. The cohesiveness was higher in LFC than in the other groups. Adhesiveness increased in all cheeses until day 14, dropping significantly at 28 days of maturation in RFC and LFC. Elasticity dropped slightly over the 28 days on the FFC, but in the RFC and LFC decreased significantly, and presented differences between the 3 types of cheese in all times of the ripening. Gumminess was constant over the 28 days of ripening in FFC. But for de RFC and LFC, gumminess increased during the experiment, and also remained significant differences among the 3 types of cheese in the four times when the measures were made, with higher values in the LFC. In conclusion: fat reduction resulted in lower fat and fat/dry matter content, and higher protein and moisture content. Fracturability, cohesiveness, masticability and hardness increased as fat decreased in cheese, while elasticity and adhesiveness decreased.