Journal of Food Processing & Technology

Abstract

Enzymolysis-Assisted Treatments for Improved Phytochemical Contents and Bioactivities Levels from Unfertilized Corn Silk Extracts

Kim HS, Kim SL, Kang HJ, Kim WK and Kim MH

Corn silk is an excellent source of many bioactive compounds, which is well known functional food and traditional herbal medicine. The aim of this study was to evaluate the effects of Novozym 33095 treatment to improve the phytochemical contents and bioactivities in unfertilized corn silk ethanol extracts. Furthermore, the treatment conditions were simultaneously optimized using a response surface methodology with a central composite design. The influence of Novozym 33095 concentration, reaction temperature, and reaction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl- 1-picrylhydrazyl radical scavenging activities, and tyrosinase inhibition was analyzed. The following optimal conditions were determined by simultaneous optimization of several responses with the Derringer’s desirability function using the numerical optimization function of the Design-Expert program: Novozym 33095 concentration 0.11 ml/L, reaction temperature 20°C, and reaction time 120 min. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and tyrosinase inhibition were 5462.26 μg GAE/g dried sample, 3932.03 μg QUE/g dried sample, 3213.64 mg/100 g dried sample, 87.57%, and 75.78%, respectively, and the overall desirability (D) was 0.73. Those values of unfertilized corn silk ethanol extracts were 2921.32 μg GAE/100 g dried sample, 1703.69 μg QUE/g dried sample, 801.40 mg/100 g dried sample, 62.34%, and 48.21%, respectively, demonstrating significant improvement from Novozym 33095 treatment.