Steam explosion (SE), as a high-efficient and environment-friendly pretreatment technology, was applied to pretreat the grape pomace. The results showed that SE increased the yield of free phenolics and flavonoids, but decreased the yield of bound phenolics and flavonoids. The content of total phenolics from grape pomace was much higher than that of total flavonoids. SE significantly decreased the contents of total monomeric antho-cyanins and non-extractable proanthocyanins. (-)-Epicatechin and catechin were the most abundant ingredients in free extracts. After SE, most phenolic acids and flav...
