(+)-catechin, (-)-epicatechin, and gallic acid content of seeds of hybrid grapes hardy in Missouri

Pure Vitis vinifera cultivars do not grow well in the midwestern United States. The expanding wine industry in this region relies on European hybrid grapes or on native grapes and hybrids such as Norton and Cynthiana. Very little is known regarding the content of beneficial phytochemicals in these hybrids. Such compounds include monomeric flavan-3-ols (e.g., (+)-catechin) and oligomeric and polymeric compounds derived therefrom, which are concentrated in the seeds; grape seed extracts are therefore used as antioxidant dietary supplements. Eight European hybrid grapes and Norton grapes, all grown at the same location in eastern Missouri, were screened for seed (+)-catechin, (-)-epicatechin, and gallic acid content. A broad range of variation was observed; the best-yielding hybrid cultivar, XI 1-86, contained 6.12 mg/g dry defatted seed weight (+)-catechin and 5.48 mg/g (-)-epicatechin, significantly more than found in Chardonnay seed using similar methods. Use of cultivars that display superior phytochemical content in a given region may increase the opportunity to supply raw materials to the dietary supplement industry.