(492l) Deflavoring Whey Protein Preparation Using Supercritical Carbon Dioxide

Many flavor compounds are present in powdered commercial whey protein preparations. Some flavor compounds may be additionally produced during processing or storage of powdered whey protein preparations. Although these compounds are present at extremely low concentrations, off-flavor properties may limit the application of whey proteins in certain food applications. Conventional deflavoring approaches using organic solvents may have toxicity concerns due to the residual solvent, in addition to a limited deflavoring/extraction effectiveness. Supercritical carbon dioxide (scCO2) was previously studied in our group as a green approach to modify whey protein functionalities. In this work, scCO2 was investigated for the effectiveness of deflavoring whey protein isolate (WPI) and whey protein concentrate (WPC), with the assumption that the low surface tension of scCO2 may allow the easy penetration into powders to utilize the extraction capability of scCO2. A fixed amount of WPI or WPC powder was treated with a continuous CO2 stream at 50 g/min for 1 hour, controlled at various combinations of temperature (30-65 ºC) and pressure (70-300 bar). GC/MS chromatograms of processed and unprocessed samples were obtained after adsorption of volatiles by using a solid phase microextraction fiber. Generally speaking, most peaks on the chromatograms of the unprocessed whey protein samples disappeared or were reduced very significantly at all studied conditions, even at subcritical conditions of 70 bar and 30 ºC for 1 hour. Our findings demonstrated that supercritical or subcritical CO2 is an effective and green solvent to deflavor whey proteins for novel food applications.