title: Effect of UV-C irradiation and low temperature storage on bioactive compounds, antioxidant enzymes and radical scavenging activity of papaya fruit.
abstract: Mature green 'Maradol' papaya fruits were exposed to ultraviolet (UV)-C irradiation (1.48 kJ·m(-2)) and stored at 5 or 14 °C. Changes in total phenols, total flavonoids, enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), as well as the scavenging activity against 2,2-diphenyl-1picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals were investigated in peel and flesh tissues at 0, 5, 10 and 15 days of storage. UV-C irradiation increased significantly (P < 0.05) the flavonoid content (2.5 and 26 %) and ABTS radical scavenging activity (5.7 and 6 %) in flesh and peel at 14 °C respectively; and CAT activity (16.7 %) in flesh at 5 °C. Flavonoid contents, CAT and SOD activities were positively affected under low storage temperature (5 °C). DPPH and ABTS radical scavenging activities increased in both control and UV-C treated papaya peel during storage at 5 °C. UV-C irradiation effect on radical scavenging of papaya peel could be attributed to increased flavonoid content. Papaya antioxidant system was activated by UV-C and cold storage by increasing phenolic content and antioxidant enzymatic activities as a defense response against oxidative-stress.
authors.affiliation: Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N, Juriquilla, Querétaro, 76230 Mexico.
authors.forename: Dulce M
authors.initials: DM
authors.lastname: Rivera-Pastrana
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo A.C., Carretera a la Victoria km. 0.6, Apartado postal 1735, Hermosillo, 83304 Sonora Mexico.
authors.forename: Alfonso A
authors.initials: AA
authors.lastname: Gardea
authors.affiliation: Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias S/N, Juriquilla, Querétaro, 76230 Mexico.
authors.forename: Elhadi M
authors.initials: EM
authors.lastname: Yahia
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo A.C., Carretera a la Victoria km. 0.6, Apartado postal 1735, Hermosillo, 83304 Sonora Mexico.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Martínez-Téllez
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo A.C., Carretera a la Victoria km. 0.6, Apartado postal 1735, Hermosillo, 83304 Sonora Mexico.
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: González-Aguilar
keywords: Antioxidant capacity; Antioxidant enzymes; Carica papaya L.; Hormesis; UV-C