Effects of feeding system, heat treatment and season on phenolic compounds and antioxidant capacity in goat milk, whey and cheese

Phenolic compounds are present in goat milk and cheese. The composition of goat milk and its products may vary depending on factors such as season, feeding system and heat treatment. The aim of this work is to quantify total phenolic compounds (TPC) and antioxidant capacity in pasteurized and unpasteurized samples of milk, milk whey, and cheese from goats fed in two different systems (free-range grazing and permanent confinement), during dry and rainy seasons. TPC concentrations were highest in unpasteurized samples from dry season compared to pasteurized and rainy season: 132.4 ± 27.3, 76.5 ± 5.77 mg of gallic acid equivalent (GAE)/L for unpasteurized milk and milk whey, respectively, and 363.21 ± 52.97 mg GAE/Kg for cheese. Antioxidant capacity for dry season produce was significantly higher (P < 0.05) than rainy season produce. Free-range grazing was found to be a good option for producing a higher concentration of phenolic compounds and a higher antioxidant capacity.