Avaliação da atividade antioxidante de extratos etanólicos de resíduos provenientes da fabricação de vinho

Abstract

The search for natural products that perform efficiently the antioxidant activity in foods is having a lot of attention in research today. The main compounds that can act with this action, are phenolic compounds, these can be found in various plants, fruits and even vegetables residues. In this way, the main objective of this work was to evaluate the antioxidant potential of the residue obtained from the manufacture of red wine (RVT) and white wine (RVB) with the intention that in future be used as a natural antioxidant in the elaboration of new food products. In this study the antioxidant activity was evaluated by the method of sequestration of DPPH * and ABTS * radicals, percentage inhibition by beta-carotene/linoleic acid system and reducing power of iron (FRAP) and compared with synthetic antioxidants sodium erythorbate, BHT (butylhydroxytoluene) and BHA (Butilihidroxianisol) and the natural antioxidant α-tocopherol used as positive control. The RVT and RVB showed content of total phenolics of 21.66 mg GAE / g of residue and 20.54 mg GAE / g of residue, respectively (EAG: Equivalent gallic acid). While the content in flavonoids found was 0.84 mg QE / g of residue and 0.65 mg QE / g of residue, respectively (QE: Equivalent quercetin). The antioxidant activity was evaluated by DPPH radical sequestration and expressed as IC50 (IC50: inhibitory concentration or minimum equivalent antioxidant to sequester 50% of the initial radicals) was 0.66 and 1.14 mg / mL, for the RVT and RVB, respectively. While for the kidnapping expressed in ABTS umol Trolox was obtained Trolox 150.68 umol / g for the RVT and Trolox 145.91 umol / g for RVB. When analyzed by the method of inhibition of beta carotene / linoleic acid, the extracts evaluated at a concentration of 5 mg / ml were inhibited by 82.92% and 81.42% for RVT and RVB, respectively and did not differ significantly by the Tukey test (p <0.05). For the analysis of the reduction of iron (FRAP), the extract was able to reduce the RVT 56.29 micromol Fe 2 + / g while the RVB 38.52 micromol Fe 2 + / g of residue. The residue of the process to obtain red wine showed superiority in all analyzes when compared to the residue of white wine. Among the commercial antioxidants used in this study, sodium erythorbate excelled in all analyzes, with the lowest antioxidant activity was presented by BHT. The residues of obtaining red wine and white wine process presented below the sodium erythorbate, BHT, BHA and α-tocopherol antioxidant activity. The results, we can state that waste from red wine and white wine may be considered an option to synthetic antioxidants mainly due to restriction of the use of these synthetic antioxidants in foods due to deleterious health effects.