Uso de pré-tratamento com tensoativo natural na produção de passas de BRS Vitória: influência nas características físico-químicas durante armazenamento
Carregando...
Data
2022-03-09
Autores
Shimizu-Marin, Victoria Diniz
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A atual situação do mercado mundial de produtos derivados de uva mostra um grande interesse por seus derivados não alcoólicos, tal como sucos e passas, pois esses podem representar uma fonte alternativa de compostos fenólicos na dieta. O presente estudo objetivou a produção de uvas passas a partir da cultivar ‘BRS Vitória’ pré-tratada com tensoativo natural (azeite de oliva extravirgem - AOEV) e a avaliação da manutenção de suas características físico-químicas durante o armazenamento. Para avaliar a qualidade das passas foi realizada a análise da superfície das passas por microscopia eletrônica de varredura (MEV) e a caracterização físicoquímica (umidade, sólidos solúveis (SS), pH, atividade de água (Aw), acidez total (AT) e conteúdo de açúcares redutores (ACR) e de totais (ACT)), bem como determinação do conteúdo de compostos fenólicos totais (CFT) e antocianinas totais (ANT) e poliméricas (ANP) das uvas e das passas. Para avaliar a manutenção destas características físico-químicas, as passas com e sem pré-tratamento foram armazenadas durante 180 dias sob três temperaturas distintas (4, 25 e 35 °C) e avaliadas em 9 pontos ao longo do tempo. Por MEV foi possível observar que o AOEV atua na solubilização ou dissolução da camada de cera presente na superfície da casca da uva, além de formar várias deformações e lesões na mesma (microporos, microfuros, microfissuras e rachaduras), facilitando a perda de água e, por conseguinte, o processo de desidratação. A partir da determinação das características físico-químicas das passas sem e com AOEV após a secagem, pode-se observar que por meio do efeito de concentração associado ao menor tempo de desidratação as uvas pré-tratadas possuíram maior conteúdo de ANT (337,1 e 560,7 mg mv-3,5-diglicosídeo.kg de amostra-1, respectivamente). Após acompanhamento das características físico-químicas das passas pode-se concluir, por meio das tendências observadas e pela Análise de Componentes Principais (ACP), que os parâmetros ANT, ACT, ACR, Aw, C* e L* foram os que mais refletiram a variabilidade das passas armazenadas a 35 °C e, portanto, sendo estas características potenciais indicadoras de qualidade de passas de uva BRS Vitória ao longo da sua vida útil. Por fim, considerando também que as análises não demonstraram que a aplicação do AOEV diminuiu a qualidade das passas durante o período de armazenamento e que os resultados foram próximos ao relatado na literatura para passas comercializadas, demonstra-se assim o potencial deste pré-tratamento com tensoativo natural.
The current status of the global grapes products market shows a great interest in their nonalcoholic derivatives, such as juices and raisins, as these can represent an alternative source of phenolic compounds in the diet. The present work aimed at the production of raisins from 'BRS Vitória' cultivar pre-treated with natural surfactant (extra virgin olive oil - EVOO) and to evaluate the maintenance of their physicochemical characteristics during storage. To evaluate the quality of the raisins, the following determinations were carried out: drying time, surface analysis of the raisins by scanning electron microscopy (SEM), physicochemical characterization (moisture, soluble solids (SS), pH, water activity (Aw), total acidity (AT) and reducing sugar (ACR) and total (ACT) content), as well as determination of the content of total phenolic compounds (CFT) and total (ANT) and polymeric (ANP) anthocyanins of grapes and raisins. To evaluate the maintenance of these physicochemical characteristics, the raisins with and without pretreatment were stored for 180 days under three different temperatures (4, 25 and 35°C) and evaluated at 9 points during storage. SEM was essential to evidence the good results of the reduced drying time after application of the pre-treatment to the raisins. The analysis showed that the EVOO acts in the solubilization or dissolution of the wax layer on the surface of the grape skin. In addition it forms a several deformations and lesions (micropores, microholes, microcracks and cracks), facilitating the loss of water and hence the dehydration process. About the physical-chemical analysis carried out, it can be concluded that the concentration effect associated with the shorter dehydration time resulted in pre-treated raisins with better ANT content (337,1 e 560,7 mg mv-3,5-diglycosíde.kg of raisins-1, respectively for raisins without and with pre-treatment). After monitoring raisins physicochemical characteristics it can be concluded, through the observed trends and by the Principal Component Analysis (PCA), that the parameters ANT, ACT, ACR, Aw, C* and L* were the ones that most reflected the variability of raisins stored at 35 °C and, therefore, are potential indicators of the quality of BRS Vitória raisins during its storage. Finally, also considering that the analyzes did not demonstrate that the application of AOEV decreased the quality of the raisins during the storage period and that the results were close to those reported in the literature for commercialized raisins, this demonstrates the potential of this pre-treatment with natural surfactant.
The current status of the global grapes products market shows a great interest in their nonalcoholic derivatives, such as juices and raisins, as these can represent an alternative source of phenolic compounds in the diet. The present work aimed at the production of raisins from 'BRS Vitória' cultivar pre-treated with natural surfactant (extra virgin olive oil - EVOO) and to evaluate the maintenance of their physicochemical characteristics during storage. To evaluate the quality of the raisins, the following determinations were carried out: drying time, surface analysis of the raisins by scanning electron microscopy (SEM), physicochemical characterization (moisture, soluble solids (SS), pH, water activity (Aw), total acidity (AT) and reducing sugar (ACR) and total (ACT) content), as well as determination of the content of total phenolic compounds (CFT) and total (ANT) and polymeric (ANP) anthocyanins of grapes and raisins. To evaluate the maintenance of these physicochemical characteristics, the raisins with and without pretreatment were stored for 180 days under three different temperatures (4, 25 and 35°C) and evaluated at 9 points during storage. SEM was essential to evidence the good results of the reduced drying time after application of the pre-treatment to the raisins. The analysis showed that the EVOO acts in the solubilization or dissolution of the wax layer on the surface of the grape skin. In addition it forms a several deformations and lesions (micropores, microholes, microcracks and cracks), facilitating the loss of water and hence the dehydration process. About the physical-chemical analysis carried out, it can be concluded that the concentration effect associated with the shorter dehydration time resulted in pre-treated raisins with better ANT content (337,1 e 560,7 mg mv-3,5-diglycosíde.kg of raisins-1, respectively for raisins without and with pre-treatment). After monitoring raisins physicochemical characteristics it can be concluded, through the observed trends and by the Principal Component Analysis (PCA), that the parameters ANT, ACT, ACR, Aw, C* and L* were the ones that most reflected the variability of raisins stored at 35 °C and, therefore, are potential indicators of the quality of BRS Vitória raisins during its storage. Finally, also considering that the analyzes did not demonstrate that the application of AOEV decreased the quality of the raisins during the storage period and that the results were close to those reported in the literature for commercialized raisins, this demonstrates the potential of this pre-treatment with natural surfactant.
Descrição
Palavras-chave
Uvas passas, Pré-tratamento, Armazenamento, Físico-química, Raisins, Pretreatment, Storage, Physicochemical