Milk pre-treatment by high pressure homogenization in the manufacturing of "queso fresco" fortified with omega-3 fatty acids

The aim of this study was to evaluate the feasibility of high pressure homogenization (HPH) as milk pre-treatment in the process of manufacturing cheese fortified with omega-3 fatty acids. Raw milk was fortified with animal and vegetable sources of omega-3 fatty acids and homogenized at increasing pressure from 20 to 100 MPa. Treated milk was then used to prepare queso fresco, a soft and fresh Hispanic cheese. Cheese yield, moisture, fat content, and texture were evaluated after processing. The development of oxidation was also monitored during cheese storage at 4 degrees C for up to 21 days. Pressure higher than 50 MPa was necessary to effectively incorporate omega-3 fatty acids in cheese and at the same time to reduce the quantity of oil lost in the whey. Homogenization treatments caused cheese quality attribute changes due to modifications induced by HPH process on native structures of milk. Cheeses obtained with homogenization showed higher moisture and yield and lower fat content than untreated cheeses. A decrease of texture parameters was also observed for homogenized samples. The source of omega-3 did not affect the cheese quality attributes.