Powders obtained from three grape pomaces (Barbera, Chardonnay before distillation, Chardonnay after distillation) were added at two concentration levels (0.8 and 1.6 % w/w) into semi-hard and hard cheeses (Italian Toma-like and Cheddar, respectively) to increase their polyphenol content. Effects on physicochemical characteristics, total phenolic content (TPC), radical scavenging activity (RSA), proteolysis, organic acids content, starter and non-starter bacteria were evaluated during ripening. The amount and the type of powder used did not significantly affect the physicochemical parameters of cheese with the exception of pH their values. Italian Toma-like and Cheddar cheeses fortified with Chardonnay after distillation powder showed at the end of ripening (30 days and 120 days respectively) the highest TPC and RSA values. Proteolysis and microbial counts did not show statistically significant differences between fortified and control cheeses. This study demonstrated that grape pomace powder can be a functional ingredient to increase TPC and RSA in consumers' diets and the addition of this by-product to cheese is an environmentally friendly way to manage winemaking wastes.
Keywords: Antioxidant activity; Cheese; Grape pomace; Polyphenols; Proteolysis.