Effect of draining temperature on the biochemical characteristics of Feta cheese

Two different draining temperatures, 15 and 21°C were applied to five Feta cheese curds made with different starters, containing mesophilic or thermophilic strains or mixtures of them. After 20 h of draining, the pH of curds made with thermophilic starters ranged from 5.28 to 5.49. The draining temperature significantly affected (P<0.05) the pH and the total solids of the cheeses. The inclusion of whey proteins in the cheese curd due to the insufficient draining of cheeses at 15°C, resulted in higher water-soluble nitrogen (WSN), as % of total nitrogen content. Free amino acid contents were significantly affected (P<0.05) by the draining temperature and by the presence of thermophilic lactobacilli in the starter mixture. Draining temperature also significantly affected (P<0.05) residual αs- and β-casein and the RP-HPLC profiles of the WSN. The C2:0 to C8:0 free fatty acids, hardness (kg) and fracturability (kg), as well as the total organoleptic scores, were significantly (P<0.05) higher in feta drained at 21°C.