title: Gamma irradiation inhibits wound induced browning in shredded cabbage.
abstract: Gamma-radiation induced browning inhibition in minimally processed shredded cabbage stored (10 °C) for up to 8 days was investigated. γ-irradiation (2 kGy) resulted in inhibition of browning as a result of down-regulation (1.4-fold) in phenylalanine ammonia lyase (PAL) gene expression and a consequent decrease in phenylalanine ammonia lyase (PAL) activity. Activity of polyphenol oxidase and peroxidase, total and individual phenolic content as well as o-quinone concentration were, however, unaffected. In the non-irradiated samples, PAL activity increased as a consequence of up-regulation of PAL gene expression after 24 and 48 h by 1.2 and 7.7-fold, respectively, during storage that could be linearly correlated with enhanced quinone formation and browning. Browning inhibition in radiation processed shredded cabbage as a result of inhibition of PAL activity was thus clearly demonstrated. The present work provides an insight for the first time on the mechanism of browning inhibition at both biochemical and genetic level.
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: Aparajita
authors.initials: A
authors.lastname: Banerjee
authors.affiliation: Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: Penna
authors.initials: P
authors.lastname: Suprasanna
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India. Electronic address: prasadpsv@rediffmail.com.
authors.forename: Prasad S
authors.initials: PS
authors.lastname: Variyar
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Sharma
mesh_terms: D001937:Brassica / Q000378:metabolism / Q000528:radiation effects*; D004156:Catechol Oxidase / Q000378:metabolism; D005720:Gamma Rays; D009195:Peroxidase / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism
chemical_list: D010636:Phenols; D004156:Catechol Oxidase; D009195:Peroxidase; D010650:Phenylalanine Ammonia-Lyase
keywords: Brassica oleracea; Browning; Gamma irradiation; Gene; Peroxidase; Phenylalanine ammonia lyase; Polyphenol oxidase