Investigating the potential of a humidification system to control moisture loss and quality of ‘Crimson Seedless’ table grapes during cold storage

Abstract

The potential of humidifying cold storage rooms to control moisture loss and quality of table grapes in different package designs was studied. Fruit were stored in cold rooms (−0.33±0.32°C or −0.12±0.32°C) with humidifier (95.0% RH) or no humidification (90.3% RH) respectively. Room humidification resulted in a 7.5% and 9.0% increase in RH inside the clamshell and open-top punnets multi-scale packages respectively in comparison to non-humidified storage, while there was no significant change in RH inside the 4.5kg carry bag multi-packaging. The grapes were assessed for weight loss and SO2 injury at intervals during a 35d period. After 21d of cold storage under humidification, weight loss of grapes was significantly higher (P<0.05) in packages with open-top punnets than clamshell punnets and carry-bags. After 35days in non-humidified cold storage, grape weight losses were 1.45±0.32%, 1.62±0.21% and 2.01±0.57% for the 4.5kg carry-bag, 5kg clamshell punnet and 5kg open-top multi-packages, respectively. When fruit were stored inside the same types of multi-packages under humidification, the corresponding weight losses were 0.97±0.34%, 1.08±0.27% and 2.00±0.57%. Cold storage humidification reduced the rate of stem dehydration and browning; however, it increased the incidence of SO2 injury in table grape bunches and caused wetting of the packages.