Obtaining a hydrolyzed milk fat fraction enriched in conjugated linoleic acid and trans-vaccenic acid

Anhydrous milk fat (AMF) rich in conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA) was enzymatically hydrolyzed and dry fractionated. Oxidation kinetic parameters of hydrolyzed AMF was determined by differential scanning calorimetry. Hydrolysis yielded 90.4% free fatty acids (FFAs) after 24 h at 50 °C, using a ratio of 70 for water to fat (w/w) and a ratio of 40 for enzyme to fat (w/w). The oxidation of hydrolyzed AMF started at a lower temperature (108.3 ± 4.1 °C) compared with non-hydrolyzed AMF (155.7 ± 3.4 °C). Upon fractionation of hydrolyzed AMF, three fractions were obtained (high-, middle- and low-melting point FFA fractions). The middle fraction contained the highest concentration of CLA and TVA (64.8 and 249.3 mg g−1 fat, respectively). The middle fraction shows great potential for fortification of dairy products but further optimization is needed to maximize the CLA and TVA contents, while minimizing the presence of the other fatty acids.