GRAPE POMACES ANTHOCYANINS AND NON-ANTHOCYANINS PHENOLICS PROFILING: VALORIZATION OF FOOD INDUSTRY BY-PRODUCTS

D´AMARIO FERNÁNDEZ, A.; FONTANA, A.; BOTTINI, R.; ANTONIOLLI, A.

Rosario

Simposio; 2nd Latin American Metabolic Profiling Symposium 2016; 2016

IBR-Universidad de Rosario

Grape pomace is a rich source of phenolic compounds and represents an important underused residue of the winemaking process. The dry grape by-product consists of pressed skins, seeds and stems and accounts for about 20% of the weight of the grapes used to make wine1. Grape pomace, thus, potentially constitutes a very abundant and relatively inexpensive source of a wide range of phenolic compounds including monomeric and oligomeric flavonols, flavanols, stilbenes and a diversity of anthocyanin glycosides which could be used in pharmaceutical and food industries. In this way, it is of utmost significance to determine their composition. These data may provide valuable information for the characterization of samples and likewise increase the value of the product.The main objective of the present study was to determine the profiles and amounts of individual phenolic compounds of grape pomaces coming from different grape varieties cultivated in Mendoza, Argentina (vis. Malbec, Cabernet Sauvingnon, Cabernet Franc, and Merlot). A total of 13 anthocyanins and 18 non anthocyanin compounds of different chemical classes (phenolic acids, flavanols, flavonols, stilbenes and phenylethanol analogs) were quantified. Different chemical profiles for studied grape pomaces were observed. The maximum concentrations of non-anthocyanins corresponded to the flavanols (+)-catechin (5340 µg g-1), (-)-epicatechin (3966 µg g-1), procyanidin B1 (3507 µg g-1) and syringic acid (6664 µg g-1) whereas malvidin-3-glucoside was the most abundant anthocyanin. Malbec and Cabernet Sauvignon presented the highest content of studied non-anthocyanins phenolic compounds with concentrations ranging between 2806 to 14565 µg g-1. Thus, these data may contribute to the selection of suitable plant materials for the extraction of phytochemicals as ingredients of functional foods or other biotechnological applications, as a strategy for sustainable oenology. Knowing the profiles of grape pomaces will give a valuable database for choosing the most appropriate grape variety depending on the phenolic compounds required for a particular use.