RT Journal Article SR Electronic T1 Mass Spectral Characterization of Uva Longanesi Seed and Skin Extracts JF American Journal of Enology and Viticulture JO Am. J. Enol. Vitic. FD American Society for Enology and Viticulture SP 402 OP 406 DO 10.5344/ajev.2012.12017 VO 63 IS 3 A1 Mark A. Kelm A1 Andrea Versari A1 Giuseppina Paola Parpinello A1 John H. Thorngate III YR 2012 UL http://www.ajevonline.org/content/63/3/402.abstract AB Polyphenolics in grape seed and skin extracts of Uva Longanesi were analyzed at harvest with selected chromatography techniques. Seed extract of Uva Longanesi was characterized by high content of proanthocyanidins (average 49 g/100 g extract), of which 42% was polymeric and ~28% was oligomeric. Epicatechin comprised the primary extension subunit (~75%), whereas catechin predominated as the terminal unit (~67%); epicatechin-gallate was present in both extension (~11%) and terminal subunits (~9%). As skins matured, terminal unit galloylation decreased and extension unit galloylation increased. The mean degree of polymerization of seed proanthocyanidins was relatively constant (average 2.7 subunits) across the sampling dates.