Fortification of queso fresco, cheddar and mozzarella cheese using selected sources of omega-3 and some nonthermal approaches

Queso fresco (QF), cheddar (C) and mozzarella (M) were fortified with omega-3. Three stages of cheese-making were evaluated for fortification: after milk pasteurisation, during curdling and salting. Better retention was observed with microencapsulated oil, after milk pasteurisation (8.49 mg/g) in (QF), during salting (8.69 mg/g) in (C), and during curdling (2.69 mg/g) in (M). Nonthermal approaches such as high hydrostatic pressure (HHP), pulsed electric fields (PEF) and ultrasound (US) were used to increase the retention of omega-3. In (QF), PEF and US achieved the highest retention (5.20-5.12 mg/g); whereas in (C) and (M), HHP was the best method (5.49 mg/g and 6.64 mg/g). Some characteristics of (QF) using sonication changed after processing; higher weight (up to 19% more), increased moisture (5%), and increased pH (6.35). During storage (QF) and (M) demonstrated faster spoilage (4 degrees C), even though PEF was able to delay microbial growth in (QF) and HHP in (M). (C) 2012 Elsevier Ltd. All rights reserved.