IMPACTS OF SUPERCRITICAL EXTRACTION ON GC/MS PROFILES OF VOLATILES IN WHEY PROTEIN ISOLATE SAMPLED BY SOLID-PHASE MICROEXTRACTION

Whey protein isolate (WPI) contains >90% protein but has flavors that are disliked by some consumers. Supercritical carbon dioxide (scCO2) extraction, although principally feasible, has not been reported for the impacts on volatile profiles of WPI. In this work, adsorption conditions in a headspace solid-phase microextraction method for subsequent gas chromatography/mass spectroscopy (GC/MS) analysis were first established for assessment of extraction efficiency by scCO2. GC/MS profiles of WPI were then compared after scCO2 extraction at various combinations of temperature (3065C), pressure (7.030.0 MPa) and duration (1090 min). Overall, extractions with a higher temperature and a higher pressure for a longer time were more effective in removing volatiles, and most peaks on the chromatogram of unprocessed WPI sample disappeared or were reduced significantly after scCO2 extraction at all studied conditions. Our findings demonstrated that scCO2 may provide a green approach to improve flavor quality of whey protein ingredients for novel food applications.