Postharvest aqueous ozonation alleviates chilling injury by upregulating ascorbate-glutathione (AsA-GSH) cycle and associated antioxidant enzymes in cold-stored ‘kensington pride’ mango fruit

Abstract

Chilling injury (CI) hinders prolonged cold storage of mangoes (Mangifera indica L.). Hence, the influence of postharvest aqueous ozonation (PAO) (1 mg ozone s− 1) of mature green ‘Kensington Pride’ mangoes for 10, 20 and 30 min preceding storage at 5 °C for 21 and 28 d on modulating CI, cell membrane integrity, ascorbate-glutathione (AsA-GSH) cycle, antioxidant enzymes and fruit quality were investigated. Compared to control, 10 min PAO significantly reduced CI index (62.5% and 42.9%), CI incidence (40.5% and 41.4%), weight loss (18.4% and 21.8%) and malondialdehyde (MDA) in peel (61.8% and 71.7%) in 21 and 28 d cold stored mangoes respectively. Lipoxygenase (LOX) activity was 71.2% and 43.6% lower under 30 min PAO preceding 21 and 28 d cold storage respectively. Hydrogen peroxide (H2O2) in pulp (65.3%, 53.8%, 69.2%) and peel (26.5%, 37.2%, 41.1%) were reduced by 10, 20 and 30 min PAO respectively. Moreover, PAO significantly enhanced the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and maintained fruit quality with no significant influence on the soluble solids content (SSC) and titratable acidity (TA). This study for the first time revealed that PAO extends both cold storage and shelf life of ‘Kensington Pride’ mangoes up to 28 d increasing the potential for distant market opportunities. Based on higher practicality and overall performance, 10 min PAO was selected as a feasible strategy for improving chilling tolerance in ‘Kensington Pride’ mangoes stored at 5 °C up to 28 d.