Abstract
Use of microwave and pulsed electric field (PEF) technologies for optimization of polyphenol extraction from defatted flax seed cake was attempted using a Box-Behnken response surface design. Polyphenols were extracted after microwave or PEF treatments using ultrasound under fixed variables of 200 W of ultrasonic power, a 70A degrees C water bath, and 20 min of extraction time. Measured responses were total phenolic and total flavonoid contents, and 2,2,-diphenyl-1-picrylhydrazyl radical (DPPH center dot) scavenging activity and ferric reducing/antioxidant power activities. Maximum yields of all responses were achieved under optimum conditions for microwave processing=5 min, a liquid to solid ratio=6, and at 644 W, and for PEF-assisted extraction for 30 V at 30 Hz with a 10% ethanol concentration, and a treatment time=10 s. Under optimized microwave or PEF processing conditions, yields of polyphenols from defatted seed cake were maximized.