In Vivo Evaluation of the Cardiometabolic Potential of Grape Pomace: Effect of Applying Instant Controlled Pressure Drop

Grape pomace (GP) is a source of polyphenols which may be present as free structures or associated with dietary fiber. Instant controlled pressure drop (DIC) is a technology which can modify the association of polyphenols with food matrixes, but how these modifications affect the health benefits associated with GP remains to be elucidated. In this study, in rats fed a high-fat-fructose diet (HFF), we evaluated the in vivo cardiometabolic effects of the modification of polyphenols in GP caused by DIC at 0.2 MPa for 60 s (DIC1) and 0.4 MPa for 120 s (DIC2). These treatments increased anthocyanin and total flavonoid contents, respectively, while all the supplementations caused significant improvements in insulin resistance and plasma triacylglycerols. Thus, the bioactive compounds present in GP (including a major fraction of non-extractable proanthocyanidins) caused these modifications independently of the specific polyphenol profiles which may have resulted from these DIC treatments. Additionally, only intact GP led to an increase in HDL cholesterol, while only DIC2-treated GP improved hepatic steatosis. In conclusion, GP always improves insulin sensitivity in this animal model of obesity, while the different compositions of GP modified by DIC may be associated with other cardiometabolic parameters.