CARACTERIZAÇÃO FÍSICO-QUÍMICA, COMPOSTOS BIOATIVOS E ATIVIDADE ANTIRADICALAR EM RESÍDUOS VINÍCOLAS DE CULTIVARES DE UVAS

Abstract

This study proposed the characterization of flours and oils from seeds obtained from grape pomace from the winemaking process, with regard to nutritional and technological parameters for possible use in human or animal food. The pomace of the commercial vinification of Pinot Noir, Malbec, Tannat, Ancellotta, Merlot, Cabernet Sauvignon, Cabernet Franc, Merlot, Sauvignon Blanc, Sangiovese (Vitis vinifera), Seibel 2 and Ives (Vitis labrusca) were evaluated in relation to the dehydration method (stove or lyophilizer), type of flour (shell or pomace) and vinification process (whether or not subject to maceration). Flours were submitted to the following analyzes: moisture content, ash, protein, lipids, gross fiber and carbohydrates, minerals (N, P, K, S, Ca, Fe, Mg, Mn, Fe and Zn), total phenolic compounds and individual, and anthocyanins. Additionally, the microbiological determinations of coliforms at 45 ° C and molds and yeasts in the flours of the Ives and Ancellotta varieties were carried out. The seed oils were cold extracted. Based on the results it was possible to verify that the samples showed absence of the microorganisms investigated, characterizing product safety, as well as high fiber and protein contents for all cultivars evaluated. The lyophilization method significantly preserved the content of total, phenolic and anthocyanin compounds when compared to the dehydrated flour in the greenhouse, for all varieties studied. Among the polyphenols, the catechins, the epicatechins, quercetin and rutin, with statistical superiority in cvs. Cabernet Franc and Sauvignon Blanc. The efficacy of lyophilization was also verified by the measurement of the antiradicalar activity. All the samples dehydrated in stove had less capacity of inhibition of the free radicals, by both methods of IC50. The IC50 activity for the ABTS radical showed the best results for the lyophilized samples, in this way, smaller quantities of the flours are able to inhibit at least 50% the activity of the free radicals ABTS and HOCl-, with emphasis on the Merlot cultivar. These results reinforce the information that temperature conditions influence the preservation of antioxidant compounds. The chromatographic analysis of grape seed oils identified four fatty acids (oleic acid, linoleic acid, stearic acid and palmitic acid) and statistically superior vitamin E indices in the Merlot and Malbec cultivars. The thermogravimetric analysis showed that the samples present similar curves, whose degradation point of fatty acids is higher than 280 ° C, representing good prospects of using this oil for cooking preparations that require high temperatures (oven or deep fryer), but with preservation of fatty acids that makes it up. Due to the nutritional enrichment and to add value to the agroindustrial residue discarded by the wineries, the addition of the flour obtained from the grape marc and the oils extracted from the seeds are viable alternatives in the food industry and in the daily cooking.