Quality Characteristics and Antioxidant Activity of Juices Produced With Irradiated Grapes

Abstract

ABSTRACT-The aim of this study was to evaluate physicochemical characteristics, antioxidant activity, total phenolic, vitamin C and anthocyanins content of grape juices from cv. Isabel submitted to different UV-C doses. The fruits were harvested, sanitized and inserted into a UV-C radiation chamber, where different doses were applied: 0 kJ/m 2 (0 minutes); 0.68 kJ/m 2 (2 minutes); 2.73 kJ/m 2 (4 minutes); 4.10 kJ/m 2 (6 minutes). The grape juice was extracted at 75±5°C for 1 hour, using an equipment with steam extraction and submitted to evaluations after 0, 30, 60 and 90 days of cold storage. No significant differences were observed in grape juices submitted to radiation doses regarding the antioxidant activity and phenolic compounds. However, the vitamin C content was affected by different UV-C doses, where there was an increase in the values of the treated fruits during storage. Index terms: Vitis labrusca, phenolic compounds, vitamin C, quality, irradiation. CARACTERIZAÇÃO FÍSICO-QUÍMICA E ATIVIDADE ANTIOXIDANTE DE SUCOS ELABORADOS A PARTIR DE UVAS IRRADIADASRESUMO-O presente trabalho teve como objetivo a caracterização físico-química, bem como a avaliação da atividade antioxidante, teor de fenólicos totais, vitamina C e antocianinas de sucos elaborados a partir de uvas cultivar Isabel submetidas a diferentes doses de radiação UV-C. Os frutos foram colhidos, sanitizados e inseridos em uma câmara de radiação UV-C, onde diferentes doses foram aplicadas: 0 KJ/m 2 (0 minutos); 0,68 KJ/m 2 (2 minutos); 2,73 KJ/m 2 (4 minutos); 4,10 KJ/m 2 (6 minutos). A elaboração dos sucos de uva foi realizada a 75º±5ºC durante 1 hora, usando um equipamento artesanal por arraste de vapor e os mesmos foram analisados após 0, 30, 60 e 90 dias de armazenamento. Os sucos de uva não apresentaram diferenças significativas com relação às doses de radiação para atividade antioxidante e compostos fenólicos. Porém, o teor de vitamina C foi afetado pelas diferentes doses, onde observou-se um aumento dos valores dos frutos tratados ao longo do armazenamento. Termos para indexação: Vitis labrusca, compostos fenólicos, vitamina C, qualidade, irradiação.

Productivity and quality of juices from different genotypes of ‘Bordô’ grape (Vitis labrusca) in the Vale do Rio do Peixe -SC region

“…The lowest mean for this variable was found in G10, being the only one that had values below the 15 -45 range mentioned by Mota et al (2018) as desired for this variable. Vilas Boas et al (2016b) also refer to the aforementioned range as a reference and explain that the ratio expresses the balance between sweet and acidic flavors. Treptow et al (2016) evaluated juices from different grape cultivars, with 'Cabernet Sauvignon' juices showing values above 60, and being described as sensorially unbalanced and with excessive sweetness.…”