ResumoO suco de uva no Brasil é um produto amplamente consumido por suas características sensoriais e nutricionais; porém, tratamentos durante o seu processamento podem ocasionar perdas de compostos fenólicos importantes na definição dessas características. O ultrassom é apontado como um possível elicitor desses compostos, visto que o estresse mecânico provocado por cavitação acústica e microagitação estimula respostas de defesa na planta que levam à síntese dessas substâncias. Neste estudo, diferentes densidades de potência (53 e 113 W.cm -2 ) e tempos de exposição (1, 5 e 10 minutos) de ultrassom foram aplicados em uvas Isabel e seu efeito sobre o conteúdo de polifenóis totais e o aspecto sensorial dos sucos foi avaliado. O ultrassom causou um acréscimo de até 83% no teor de polifenóis totais, melhorando também as características sensoriais dos sucos, tendo sido estes os preferidos pelos provadores. Palavras-chave:Ultrassom; Elicitor; Fitoalexinas; Polifenóis; Suco; Uva. SummaryGrape juice in Brazil is a product widely consumed for their sensory and nutritional characteristics, however, treatments during processing can cause loss of phenolic compounds important in defining these characteristics. Ultrasound is cited as a possible elicitor of these compounds, since the mechanical stress caused by acoustic cavitation and microstreaming stimulates the plant defense responses that lead to synthesis of these substances. In this study, different power densities (53 and 113 W.cm -2 ) and exposure times (1, 5 and 10 minutes) of ultrasound were applied in Isabel grapes and its effect on the total polyphenols content and sensory aspect of the juices was evaluated. The ultrasound caused an increase of up to 83% in total polyphenols content, improving the sensory characteristics of juices, being chosen as preferred by the tasters.

PurposeThe aim of this study was to evaluate the effect of ultrasound (US) treatment on the postharvest of “Isabella” grapes and the consistency of the obtained results regarding the composition of anthocyanins in grape juice over three successive harvest years using a combination of analytical techniques.Design/methodology/approachJuices produced from “Isabella” grapes sonicated for different durations (3, 5, 7 and 10 min) were analysed. The grapes were harvested and sonicated in 2013, 2014 and 2015, and each treated sample was stored for 1, 3 and 5 days in order to verify the time necessary for the development of the US response. The juices were analysed through physicochemical analysis (total monomeric anthocyanins). The anthocyanin profiles were quantified and identified using high performance liquid chromatography coupled to photodiode array and mass spectrometry detectors (HPLC-PDA-MSn).FindingsThe results demonstrated the potential of US in improving the quality of grape juice. In all three harvests, it was observed that the treatments were effective in increasing the concentration of anthocyanins. For the 2013 harvest, the application of US for 5 min led to a 103% increase in juice pigments. However, the US response profile varied among the three harvests, indicating that the US effect was influenced by the ripening conditions of the fruit. In total, 33 anthocyanins were identified in the grape juice. For the first time, peonidin-3-p-coumaroyl glucoside-5-glucoside was identified in “Isabella” juice.Originality/valueThe results of this study validated US treatment as a simple and effective physical method that can be used as an alternative technology for improving the general quality of products such as juice by increasing the pigment concentrations that are linked to the colour and antioxidant potential of drinks. Moreover, the results demonstrate that US treatment may be less effective in the case of a sample with distinct phenolic maturation.

Ultrasound has gained attention from the food industry because its properties, including chemical and physical reactions, enable a wide range of commercial applications. One of the most popular applications is the optimization of extraction of bioactive substances. Among the most recent applications is its use in postharvest of fruits and vegetables, wherein ultrasound functions as a possible elicitor agent promoting the synthesis of phenolic compounds. These substances are important in defining the chemical and sensory characteristics of juices, wines and other grape products because the concentration and extraction capacity of these compounds in grapes directly influence the product quality. Thus, this study aimed to evaluate the application of ultrasound in American and vinifera grapes of different harvests with regard to its effects on fruit extractability and concentration of phenolic compounds in elaborated juice and wine. The results indicated that, under certain conditions, ultrasound could lead to a significant increase in the anthocyanin concentration in 'Isabella' grapes and its juice. On the other hand, in 'Cabernet Sauvignon' grapes, most of the treatments did not indicate positive results in the tested parameters and tended to promote degradation of anthocyanins at significant levels. However, the observed effects varied depending on the harvest conditions and cultivar characteristics. Key words: Acoustic cavitation. Anthocyanins. Extraction. Sonication. ResumoO ultrassom tem despertado interesse na indústria de alimentos uma vez que suas propriedades, as quais envolvem reações químicas e físicas, possibilitam uma larga escala de aplicações comerciais. Uma das mais exploradas é a otimização da extração de substâncias bioativas, e entre as mais recentes esta sua utilização na pós-colheita de frutas e vegetais, onde o ultrassom vem sendo testado como possível agente elicitor capaz de promover a síntese de compostos fenólicos. Estas substâncias são importantes na definição das características químicas e sensoriais de sucos, vinhos e outros produtos da uva, de forma que a concentração e a capacidade de extração destes compostos na uva influenciam diretamente a qualidade de seus produtos. Dessa forma, este estudo teve o objetivo de avaliar a aplicação do ultrassom em uvas americanas e viníferas de diferentes safras em relação aos efeitos sobre a extratibilidade no fruto e concentração de compostos fenólicos no suco e vinho elaborados. Os resultados revelam que em determinadas condições, o ultrassom pode levar a um aumento significativo da concentração de

Thermal pest control (TPC) is a technology that applies heated air in the vineyard to reduce pests. However, it can also alter grape anthocyanin synthesis in answer to temperature stress. The aim of this work was to determine the impact of TPC in 'Tannat' grape vineyards on wine quality. The major makers of quality considered in this study were the wine anthocyanin characterization by HPLC-PDA-MS, beverage's sensory evaluation by descriptive analysis, and color parameters by instrumental analysis. A total of three experiments were performed in different harvesting years. In 2011/12 (Experiment I), four applications were performed from the flowering to fruiting. For the second experiment (2012/13), five applications were used only during fruiting. TPC treatment performed in 2013/14 (Experiment III) had a total of 19 applications from the flowering to harvesting. In the first experiment, TPC had increased wine pigments, color, and sensorial descriptors for visual (translucence) and gustatory (woody and body) perceptions. However, in the second experiment none of the evaluated wine quality parameters was affected by TPC (p≤0.05). In the last and longest experiment (19 applications), TPC has significantly increased some wine pigments content. Nonetheless, wine sensorial parameters were not affected. Since the climate was different among the years, it seems that TPC effect does not depend on the applications number and vegetable cycle period only, but also it can be affected by the weather conditions in which the vine is being cultivated. However, when TPC treatment has resulted in the greatest anthocyanin increment (Experiment I) some wine sensory descriptors were also improved.

O presente trabalho teve por objetivo determinar a composição centesimal do tubérculo de batata in natura a ser utilizado no processo de destilação para a produção de etanol e do resíduo sólido resultante da fermentação deste tubérculo. Com base na composição do resíduo, avaliou-se o efeito da sua utilização na substituição de diferentes teores de fibra alimentar de uma dieta padrão, na resposta biológica de ratos. Para a avaliação dos efeitos biológicos, foram utilizados 32 ratos Wistar divididos em quatro grupos. Um dos grupos de animais recebeu a dieta padrão para ratos em crescimento, e os demais grupos receberam esta dieta com substituição de 25, 50 ou 100% de sua fibra alimentar pela fibra do resíduo. Durante o período experimental (23 dias), foram avaliados o consumo, o ganho de peso, o coeficiente de eficiência alimentar (CEA), a produção de fezes secas e úmidas, pH e excreção de nitrogênio fecal. No final do ensaio, foram avaliados o peso do fígado e da gordura epididimal, níveis sanguíneos de triglicerídeos, colesterol total, colesterol HDL e proteínas totais. O resíduo apresentou uma composição centesimal de 8,2% de proteína, 16,7% de fibra alimentar, 62,8% de carboidratos e 288Kcal. Os resultados obtidos no ensaio biológico sugerem que o resíduo sólido da fermentação de tubérculos de batata pode ser empregado como fonte de nutrientes, com base na substituição da fração fibra de uma dieta padrão AIN-93, sem comprometer o desenvolvimento dos ratos e os parâmetros bioquímicos analisados.