Multiple responses optimization of antioxidative components extracted from distiller's grains using response surface methodology and identify their chemical compositions

摘要

Distiller's grains are a waste product in the Baijiu brewing that contains many bioactiveingredients. However, few studies on the active ingredients and biological in distillers'grains. Therefore, it is promising to study the utilization of bioactive substancesin distiller's grains. In our present study, an ultrasonic-assistedmethod was appliedto extract antioxidative components from distiller's grains. Four factors: ethanolconcentration, liquid–solidratio, extraction temperature, and ultrasonic power wereselected, and multiple responses were studied using response surface methodology(RSM). The effects of factors and the correlation between all responses (flavonoidscontent, DPPH assay, OH-assay)were investigated. The regression model indicatedthat all factors have significant effects on all responses. The model predicted a flavonoidyield of 6.53 mg/g, DPPH-RSCof 90.00%, and OH-RSCof 55.03% at an ethanolconcentration of 69%, a liquid–solidratio of 35 ml/g, an extraction temperature of61°C, and a power of 300 W. The confirmation test showed the closeness of the predictedresults with those of experimental values. The distiller's grains was separatedby LH20 glucan gel, and total flavonoid content of 79.4% was obtained. LC-HRMSanalyzed the compounds, and 24 compounds, including 7 flavonoids, were identifiedsuccessfully.