Postharvest UV-C irradiation stimulates the non-enzymatic and enzymatic antioxidant system of ‘Isabel’ hybrid grapes (Vitis labrusca×Vitis vinifera L.)

• Published in: Food research international 2017-12, Vol.102, p.738-747
• Main Authors: Maurer, Luana Haselein, Bersch, Andriely Moreira, Santos, Roberta Oliveira, Trindade, Simone Cezar, Costa, Eduarda Lasch, Peres, Marcelle Moreira, Malmann, Carlos Augusto, Schneider, Mauricio, Bochi, Vivian Caetano, Sautter, Claudia Kaehler, Emanuelli, Tatiana
• Format: Article
• Language: English
• Subjects: Abiotic stress; Anthocyanin; Hormesis; HPLC; Isabel grapes; Polyphenol
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2017.09.053

Ultraviolet light type C (UV-C) was studied as a tool to increase enzymatic and non-enzymatic antioxidant defenses and phytochemical levels in ‘Isabel’ grapes (Vitis labrusca×Vitis vinifera L.). Grapes were exposed to 0, 0.5, 1.0, 2.0, or 4.0kJm−2 UV-C and stored for 1, 3, or 5days post-treatment. One day after UV-C irradiation, the activities of grape antioxidant enzymes and thiols were increased, especially at 1.0 and 2.0kJm−2. These doses increased total phenolic content by almost 20%, while 0.5 and 4.0kJm−2 had no effects. Total monomeric anthocyanin content was increased by >35% by UV-C at 1.0kJm−2; however, anthocyanin profile was unchanged. Grape skin antioxidant capacity was also improved by UV-C irradiation. The 1.0kJm−2 UV-C was considered the hormetic dose. Postharvest UV-C had an elicitor effect on ‘Isabel’ grapes, positively impacting the antioxidant capacity and phytochemical content. [Display omitted] •UV-C increases antioxidant enzymes activity and thiol content of ‘Isabel’ grapes.•UV-C increases total phenolics and anthocyanin content in grape skin.•Anthocyanin profile of ‘Isabel’ grapes was not modified by UV-C irradiation.•Antioxidant capacity of grape skin was improved after UV-C irradiation.•The hormetic UV-C dose was1.0kJm−2.