Physicochemical Composition and Sensory Analysis of Whole Juice Extracted From Grapes Irradiated With Ultraviolet C

Abstract

-Grape juice has been widely studied due to the presence of phenolic compounds and its beneficial effects on human health. Ultraviolet irradiation C (UV-C) can increase the content of phenolic compounds and anthocyanins and contribute to sensory acceptability. The aim of this study was to evaluate the effect of different doses of ultraviolet irradiation C (UV-C) on 'Trebbiano', 'Niagara Branca', 'Isabel' and 'Cabernet Sauvignon' grapes, as well as effect of the storage period. Juices were elaborated and evaluated for physicochemical analyses, and for the sensorial analysis in irradiated samples. In 'Niagara Branca' and 'Trebbiano' cultivars, storage and irradiation promoted few physicochemical alterations, and sensorially, irradiation reduced the intensity of flavor and color attributes. In juices from 'Isabel' and 'Cabernet Sauvignon' cultivars, the storage period led to the concentration of sugars and irradiation influenced physicochemical parameters and increased the intensity of aroma attribute at dose of 2 kJ m -2 . Thus, UV-C irradiation contributes little for the improvement of white grape juices; however, it favors some sensory attributes in red grape juice, requiring further studies to elucidate the influence of UV-C irradiation on the phenolic and volatile composition of grape juice. Index terms: Vitis labrusca, Vitis vinifera, abiotic elicitor, postharvest, total polyphenols, ordering test. COMPOSIÇÃO FÍSICO-QUÍMICA E ANÁLISE SENSORIAL DO SUCO INTEGRAL DE UVAS IRRADIADAS COM LUZ ULTRAVIOLETA DO TIPO CRESUMO -O suco de uva vem sendo amplamente estudado pela presença dos compostos fenólicos e seu efeito benéfico para saúde humana. A irradiação ultravioleta do tipo C (UV-C) pode aumentar compostos fenólicos, antociânicos e contribuir com a aceitabilidade sensorial. Este trabalho teve como objetivo avaliar no suco o efeito da aplicação de diferentes doses de irradiação ultravioleta do tipo C (UV-C) sobre as uvas 'Trebbiano', 'Niágara Branca', 'Isabel' e 'Cabernet Sauvignon', bem como o efeito do período de armazenamento. Os sucos foram elaborados e avaliados quanto às análises físico-químicas, e quanto à análise sensorial em amostras irradiadas. Nos sucos das cultivares 'Niágara Branca' e 'Trebbiano', o armazenamento e a irradiação promoveram poucas alterações físico-químicas, e sensorialmente a irradiação reduziu a intensidade dos atributos sabor e cor. Nos sucos das cultivares tintas 'Isabel' e 'Cabernet Sauvignon', o armazenamento levou à concentração de açúcares e a irradiação influenciou tanto os parâmetros físico-químicos quanto favoreceu o aumento da intensidade do atributo aroma na dose de 2 kJ m -2 . Sendo assim, a irradiação UV-C pouco contribui para a melhoria dos sucos de uvas brancas, no entanto, favorece alguns atributos sensoriais nos sucos de uvas tintas, sendo necessários estudos mais amplos para elucidar a influência da irradiação UV-C na composição fenólica e volátil. Termos para indexação: Vitis labrusca, Vitis vinifera, elicitor abiótico, pós-colheita, polifenóis totais, test...

Phenolic Compounds and Antioxidant Activity in Grape Juices: A Chemical and Sensory View

“…Other physical treatments, applied to grape juices, can also interfere with their sensory quality. According to Treptow et al [88], the storage period and irradiation promoted few physicochemical changes in juices from 'Niagara Branca' and 'Trebbiano' grapes, whereas, sensorially, irradiation reduced the intensity of flavour and colour attributes for both cultivars. While in juices made from white grapes, UV-C irradiation does not improve juice quality, in juices from red grapes UV-C irradiation influenced the physicochemical parameters of 'Isabel' cultivar.…”

“…Good results were obtained with dosages of 2 kJ m −2 (improved of aroma and colour intensities). According to these authors [88], UV-C irradiation can keep the juices microbiologically stable, without spoiling their sensory quality.…”

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

“…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.…”