Analysis of the amino acid profile of red and white graphs winery by-products from western Sicily

Nowadays, research addressing the composition of nutrients and bioactive compounds in waste from the agri-food industry has increased due to environmental and economic interests. The wine industry produces enormous quantities of by-products every year along the production chain. The nitrogen content in wine grapes is important for the yeast's metabolism and growth, playing a key role in both grape and wine quality. Besides research in grapes and derived products, few studies are present in the literature on the characterization of the amino acid content of wine industry by-products. In this context, this preliminary research aims at the application of a methodological approach for the identification and quantification of amino acids profile from grape by-products (red and white skins, red and white defatted grape seeds) by HPLC-FLD analysis. The most abundant amino acid in red skins was leucine (3.163 g/100 g), while in white skins was histidine (1.886 g/100 g). Higher amounts of leucine, histidine and phenylalanine were found in red seeds, compared to white seeds. By-products of the wine industry, due to the presence of essential amino acids, together with other bioactive substances contained, can be used as functional ingredients for food fortification.