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Chinese bayberry fruit were stored either in air (control) or pure oxygen for up to 12 days at 5°C to investigate the effects of high oxygen on fruit decay control and its relation to the induction of defense enzyme activities. The results indicated that exposure to pure oxygen significantly prevented fruit decay. At the end of the storage period, the decay rate of fruit exposed to pure oxygen was only 17% while that of control fruit reached 54%. Pure oxygen induced a significant increase in chitinase and β-1,3-glucanase activities which reached peak values at day 6 of storage. Phenylalanine ammonia-lyase and peroxidase activities as well as total phenolic content were also increased by exposure to pure oxygen, and maintained at significantly higher levels compared with the control fruit throughout the storage period. These results suggest that the inhibitory effect of high oxygen on decay incidence was correlated with the induction of defense enzyme activities. The induced disease resistance enzymes may be involved in the mechanisms by which high oxygen inhibits fruit decay in Chinese bayberry fruit.

Internal browning (IB) and flesh leatheriness (mainly manifested as increased fruit firmness and decreased extractable juice rate) are major problems of loquat (Eriobotrya japonica Lindl.) fruit during cold storage. The effects of a postharvest application of 1-methylcyclopropene (1-MCP) on internal browning and quality in loquat fruit during storage at 5°C were investigated. Freshly harvested loquat fruit were exposed to 50 nl/L 1-MCP for 24 h at 20°C, and then stored for six weeks at 5°C. Changes in internal browning, polyphenol oxidase (PPO) activity, fruit firmness, extractable juice rate, total soluble solids (TSS) and total titratable acidity (TA) contents were monitored. The results showed that fruit internal browning was effectively controlled by 1-MCP for up to five weeks during storage at 5°C. Treatment with I-MCP inhibited PPO activity, which may account for inhibited internal browning. Increase in fruit firmness and decrease in extractable juice rate were significantly inhibited by 1-MCP treatment. Treatment with 1-MCP also arrested the decline in both TSS and TA contents. Thus, a postharvest application of I-MCP effectively reduced internal browning and maintained quality in cold-stored loquat fruit. These results suggest that 1-MCP may of commercial use to control internal browning and flesh leatheriness in loquat fruit during cold storage.

Leafy vegetables generally have a very short shelf life due to rapid yellowing caused by chlorophyll degradation and decline in quality during storage at ambient temperature, which often causes significant commercial losses. Since the ethylene binding inhibitor, 1-methylcyclopene (1-MCP), has been shown to substantially prolong shelf life in various ornamentals, fruits and vegetables, the effects of different concentrations of 1-MCP on shelf life and quality of three leafy vegetables (California Burclover, India Horseorchid, and Shepherd's purse) during storage at 20°C were examined. The results indicated that the leaf yellowing of all these vegetables was significantly inhibited by treatments with 0.5μl/L or higher concentrations of 1-MCP, thus prolonged the shelf life. Treatment with 0.5μl/L 1-MCP increased the shelf life of California Burclover, India Horseorchid and Shepherd's purse by 37.5%, 23.8% and 36.8%, respectively, compared to the control. Above 0.5μl/L, increasing 1-MCP concentrations (up to 5μl/L) did not result in further increase in the shelf life of the three vegetables, indicating that the ethylene receptors were nearly saturated by 0.5μl/L 1-MCP. Therefore, the effects of 0.5μl/L 1-MCP on some quality parameters of all three vegetables were further investigated in this paper. The contents of chlorophyll and soluble protein and hue angle value in the leaves declined during storage, except for a slight increase in soluble protein content on the 4th day in the California Burclover, possibly due to the synthesis of some hydrolases. 0.5μl/L 1-MCP treatment significantly delayed the decrease in chlorophyll and soluble protein contents and hue angle value, especially in California Burclover and India Horseorchid. These results suggest 1-MCP may of commercial use to increase shelf life and maintain quality of the three leafy vegetables.

1-Methylcyclopene (1-MCP) prevents ethylene action and extends postharvest life of many fruits and vegetables. It has been shown that treatment concentration and temperature are two important factors affecting the efficacy of 1-MCP. Considering the very short shelf life of Chinese bayberry fruit at ambient temperature, this work was carried out to investigate the effects of 1-MCP treatment at low and high temperatures on fruit decay and quality in this fruit. The fruit (cv. 'Wuwei') were harvested at ripe stage and exposed to 0.5, 1.0, and 5 μL/L 1-MCP at 5°C for 12 h or at 20°C for 4 h. Following treatment, fruit were stored either at 0 °C for 12 days or at 20°C for 3 days. Treatment with 1-MCP at 5°C significantly reduced decay incidence during storage at both temperatures. The lowest concentration of 1-MCP was most effective in inhibiting fruit decay when stored at 0°C, having a decay index of 5% after 12 days of storage. In contrast, control fruit had a decay index of.15%. For fruit stored at 20°C after a treatment at 5 °C, 5 μL/L 1-MCP was most effective in reducing fruit decay. The decay index of those treated fruit was 12% at 3 days, compared with 20% in control fruit. In complete contrast, 1-MCP treatment at 20 °C led to increased fruit decay at either 0 or 20 °C storage. Treatment with 1-MCP at both temperatures maintained higher total soluble solids (TSS) content during storage at 0°C, however, no significant differences were observed among any of the 1-MCP treatments. There was no significant effect of 1-MCP on TSS content when the fruit were stored at 20°C. Total titratable acidity content was not significantly influenced by 1-MCP treatment. These results suggest that low temperature for 1-MCP treatment has the potential to extend the post-harvest life of Chinese bayberries by inhibiting fruit decay.