Resumo Os mirtilos são amplamente reconhecidos por seus efeitos benéficos à saúde pelo conteúdo em compostos bioativos. Além disso, o mercado de vinagre balsâmico se desenvolveu muito rapidamente, em razão da ampla aceitação de alimentos gourmet. Neste trabalho, um novo produto foi avaliado, o vinagre balsâmico de mirtilo, produzido com bagas de segunda qualidade, mas adequado ao consumo humano. O objetivo foi analisar as variações de antocianinas totais, compostos fenólicos totais e atividade antioxidante durante o processo de obtenção de vinagre balsâmico de mirtilos, nas seguintes etapas: matéria-prima, suco de mirtilo após tratamento enzimático, substrato alcoólico de mirtilo, vinagre de mirtilo, suco concentrado de mirtilo e vinagre balsâmico de mirtilo. Além disso, para determinar o método de concentração que retém a maior concentração de antocianinas e fenóis totais no suco de mirtilo, três sistemas de evaporação alternativos foram analisados: evaporador rotativo a vácuo, forno de micro-ondas e forno de micro-ondas a vácuo. As maiores concentrações foram obtidas por evaporação em evaporador rotativo a vácuo. Por outro lado, a fermentação alcoólica e a acetificação afetaram negativamente as antocianinas totais, os fenóis totais e a atividade antioxidante durante a produção de vinagre. No entanto, misturar com suco concentrado para obter vinagre balsâmico de mirtilo permitiu equilibrar essas perdas devidas ao processamento. Este trabalho mostra que a produção de vinagre balsâmico de mirtilo abre uma possibilidade interessante de reduzir perdas por descarte de frutos e, ao mesmo tempo, obter produtos de valor agregado com características saudáveis.

Abstract Blueberries are widely recognized for their beneficial health effects due to their bioactive compounds content. In addition, balsamic vinegars trade developed quickly because of their wide acceptance in gourmet food. A novel product made with second quality berries, being suitable for human consumption, i.e., blueberry balsamic vinegar, was evaluated. This work aimed to assess changes in Total Anthocyanins (TA), Total Phenolics (TP), and antioxidant activity during production process of blueberry balsamic vinegar, at the following stages: raw material, blueberries juice after enzyme treatment, blueberries alcoholic substrate, blueberries vinegar, concentrated blueberry juice and blueberries balsamic vinegar. Additionally, three alternative evaporation systems, rotary vacuum evaporator, microwave and vacuum microwave, were evaluated in order to determine the concentration method that best retains TA and TP in blueberry juice for its further use in this process. The highest TA and TP retention was achieved by blueberry juice concentration with a rotary vacuum evaporator. On the other hand, both alcoholic fermentation and acetification negatively affected those compounds and antioxidant activity during vinegar production. However, mixing with concentrated juice to obtain blueberry balsamic vinegar allowed balancing nutrient concentration reductions due to processing. The present study showed that production of blueberry balsamic vinegar gives rise to an interesting possibility to reduce losses due to fruit waste while getting added value products with healthy qualities.

Abstract Citrus fruits are significant sources of bioactive compounds, such as ascorbic acid, polyphenols and carotenoids, due to their antioxidant properties important for human nutrition. In addition, since oranges possess high sugar content (8-15%), making vinegars from alcoholic orange substrates, with functional characteristics is a possible development of novel products. The aim of this research work was to analyze changes in ascorbic acid, total phenolics, total carotenoids and antioxidant activity during orange vinegar processing. In order to analyze the influence of acetification and aging in these characteristics, samples were taken in three stages: orange alcoholic substrate for acetification (SNA), young orange vinegar or recently obtained (Vn0) and orange vinegar after six month-aging in bottles (Vn6). Statistically significant differences (p < 0.05) were found among bioactive compounds concentrations; antioxidant activity decreased along the process, but total phenolics and carotenoids remained constant during aging period (Vn0-Vn6). The highest reduction was recorded during the acetification stage, possibly due to components oxidation caused by continuous air flow to the system. A higher contribution (p < 0.05) to antioxidant activity was associated to ascorbic acid and phenolic compounds concentration.

AbstractAscorbic acid, carotenoids and polyphenols stand out among the orange juice natural antioxidants. The winemaking process affects their bioavailability and bioactivity. Antioxidant activities (AA) were estimated in different process conditions to asses those properties. The AA and their correlation with ascorbic acid, total phenolics and carotenoids content were calculated. The variables and levels analyzed were: pasteurized and natural must (PJ and NJ), pH 3.5 and 4.0 and fermentation temperatures at 10°C and 20°C. Statistically significant differences (α=0.05) were found among bioactive compounds concentrations. Antioxidant compounds concentration was higher in raw material than in orange wine. Juice pasteurization caused the major losses while subsequent vinification affects them to a lesser extent. Highest antioxidants retention was measured in wines from JN fermented at pH 3.5 and 10 °C (JN-3.5-10) followed by wines from JP and fermented at the same conditions (JP-3.5-10). AA determined by DPPH showed a positive and close correlation with FRAP, while ABTS showed a low correlation with former assays. Juice pasteurization process and fermentation temperature influenced bioactive compound reduction which correlates with the AA variation.

El estudio de levaduras autóctonas para ser usadas en la elaboración de vino de naranja, incluye aislamiento, identificación y obtención de biomasa. Para optimizar su crecimiento se deben establecer los requerimientos nutricionales. El objetivo de este estudio fue definir las necesidades de vitaminas y factores orgánicos de crecimiento de S. cerevisiae aislada de jugo de naranja fermentado. Se formuló un medio de cultivo con sacarosa (4 g/L) como fuente de carbono y energia (FCE) y urea como fuente de nitrógeno (FN), con 6 vitaminas (pantotenato de calcio, piridoxina, tiamina, biotina, niacina, ác. fólico) e inositol y ácido p-aminobenzoico (PABA) como factores de crecimiento. El medio completo se usó como testigo, preparándose además otros tres medios: con ausencia de todas las vitaminas y factores orgánicos de crecimiento, con pantotenato de Ca, piridoxina, tiamina, biotina e inositol y con esas 4 vitaminas, pero sin inositol. Finalmente, se procedió a eliminar una vitamina. Los cultivos se realizaron en aerobiosis a 30 ºC y pH 5,0. La cepa autóctona de S. cerevisiae requiere las vitaminas pantotenato de calcio, piridoxina, tiamina y biotina para crecer adecuadamente en condiciones aeróbicas en sistema batch; en cambio, no es auxótrofa para niacina, ácido fólico, PABA e inositol.

The study of the yeasts present in the orange juice microbiota and used in the winemaking involves the isolation, identification and production of biomass. In order to optimize the yeast growth, the nutritional requirements should be determined. The aim of this work was to determine the vitamin and other growth organic factors demand for the S. cerevisiae isolated from fermented orange juice. The culture medium was formulated with sucrose (4 g/L) as carbon and energy source (CES), urea as nitrogen source (NS), six vitamins (calcium pantothenate, pyridoxine, thiamine, biotin, niacin, folic acid), and inositol and p-aminobenzoic acid (PABA) as growth factors. The complete culture medium was used as blank, and three other media were prepared: without the vitamins and growth organic factors, with calcium pantothenate, pyridoxine, thiamine, biotin and inositol and with the latter four vitamins, but for inositol. Finally, four new media were obtained by elimination of one vitamin at a time. The temperature was set at 30 ºC and the pH, at 5.0. The S. cerevisiae present in the orange juice needs calcium pantothenate, pyridoxine, thiamine and biotin to grow adequately under aerobic conditions in a batch system, not being auxotroph for niacin, folic acid, PABA and inositol.