Combined effects of hot water vapor, sodium chlorite, and PVC film on postharvest decay and browning of trimmed aromatic coconut
Postharvest deterioration of trimmed aromatic coconut is a problem due to fungal infection and browning of coconut mesocarp. The two major fungi found in the mesocarp were Aspergillus niger and Penicillium spp. The effect of sodium chlorite (SC) solution combined with hot water vapor (HV) and PVC film wrapping was investigated for the control of fungal infection and browning. Trimmed coconut fruit were dipped in filtrated water, 3% sodium metabisulfite (SMS, commercial agent) for 5 min, and exposed to HV for 90 s followed by dipping in 250 mg L-1 SC for 5 min, after which they were wrapped with PVC film. The fruit dipped in filtrated water and non-wrapped served as the control. All fruit samples were stored at 4°C for 25 days. Results showed that HV combined with SC and PVC film (HV+SC+PVC) was able to suppress fungal infections and browning relative to the controls but its efficiency was not equal to commercial SMS. HV+SC+PVC treatment of fruit which exhibited less brown pigment and o-quinone than filtrated water treated fruit (both wrapped and un-wrapped with PVC). these results were correlated with low activities of browning enzymes, such polyphenol oxidase (PPO) and peroxidase (POD). Treatment with HV+SC+PVC did not affect titratable acidity, total soluble solids, percentage of transmittance and the thiobarbituric acid (TBA) value of coconut juice. Therefore, it is suggested that HV+SC+PVC can reduce fungal infection and browning of coconut even though its effectiveness was not equal to the SMS treatment.
Payuhamaytakul, K., Sripong, K., Uthairatanakij, A., Renumarn, P. and Jitareerat, P. (2021). Combined effects of hot water vapor, sodium chlorite, and PVC film on postharvest decay and browning of trimmed aromatic coconut. Acta Hortic. 1325, 109-118
enzymatic browning, heat treatment, sodium chlorite, sodium metabisulfite