Effect of Thermal Processing and Pressure Assisted Thermal Processing (PATP) on the Flavor Profile of Conjugated Linoleic Acid (CLA)-Enriched Milk.

摘要

The effect of Ultra-Pasteurization (125°C/2-15 s), Ultra High Temperature (UHT) (135°C/4-10 s and 145°C/4-20 s) and Pressure Assisted Thermal Processing (PATP) (200-600 MPa, 80-120°C for 3-30 min) on formation of flavor compounds in Conjugated Linoleic Acid (CLA)-enriched milk was studied and analyzed using headspace solid-phase microextraction gas-chromatography and mass-spectrometry. The addition of catechin (0.5 g/kg) in milk treated by PATP (400 MPa/120°C/15 min) was evaluated. Additionally, volatiles after UHT processing were investigated during storage (0-30 days at 25°C and 4°C). Overall, UHT processing had more effect on the formation of flavor compounds than with PATP. Heptanal, 2-heptanone and octanal were the main compounds found in processed CLA-enriched milk. Catechin effectively inhibited the formation of aldehydes and ketones. Finally, hexanal and heptanal decreased over storage time regardless of the storage temperature.;Key words: catechin, Conjugated Linoleic Acid (CLA), enriched milk, gas-chromarography, milk, UHT, UP, PATP, solid-phase microextraction, flavor compounds..