EFFECTS OF HIGH O2 PRETREATMENT AND HIGH O2 MAP ON QUALITY OF CUCUMBER FRUIT

Abstract

The responses of cucumber fruit to high O 2 (100%) MAP (HO-MAP) and high O 2 pretreatment with 100% O 2 for 48 hours were investigated at 5°C. The fruit stored in HO-MAP observed no weight loss through the storage. The weight loss of air-stored fruit was 2 times higher than the fruit pretreated with 100% O 2 . The desiccation of cucumber fruit was concomitant with the reduction of fruit weight. The shrivel appearance was detected in control fruit and in fruit pretreated with 100% O 2 on day 4 and day 8, respectively. The onset on chilling injury was inhibited by HO-MAP. Fruit pretreated with 100% O 2 found to have less severity of chilling injury compared to air-stored fruit. The severity of chilling injury was related with the percentage of weight loss. The concentrations of CO 2 in HO-MAP increased to 20% while O 2 levels decreased to 50% at the end of storage. Fruit in the HO-MAP did not detect any abnormal visual quality throughout storage. On day 8, however, off-flavor was detected in fruit stored in HO-MAP, furthermore, the percentage of ion leakage from flesh tissues also increased over those receiving other treatments. The ion leakage of control and 100% O 2 pretreated fruit showed similar level during the first week of storage. The sharply increase of ion leakage from control fruit to a higher level than those of 100% O 2 pretreated fruit was observed after day 8 till the end of storage. Fungal decay was showed in control fruit and fruit pretreated with 100% O 2 on day 13 and dayl5, respectively. Pretreatment with 100% O 2 lowered the respiratory rate in cucumber fruit compared to control.