Study On Impact Factors Of Quality Change Of Pepper During Cold Chain Circulation

The effects of 5℃, 5℃+heat treatment, 5℃+ intermittent warming, 7℃, 7℃+heat treatment, 7℃+1-MCP, 9℃, 9℃+ 1-MCP, 9℃+control atmosphere on the post-harvest physiological changes of pepper during cold chain circulation were studied,The main results were as follows:1. The effects of 5℃, 7℃and 9℃on the post-harvest physiological changes of pepper were studied. The results showed that 9℃was the safe temperature for the pepper, there was no chilling injure at 9℃. The respiration rate increased on 15 days of storage at 5℃and 20 days storage at 7℃, and the abnomal reaction happened for the chilling injury at low temperature. The chilling injury happened after 15 days of storage at 5℃and 20 days storage at 7℃, and chilling injury index were 4.33% and 2.67%, respectively. Therefore, 15 days of storage at 5℃and 20 days storage at 7℃were safe days for pepper during cold chain circulation. After 35d, the content of Vc and chlorophyll and CAT activity of pepper of storage at 9℃were higher than storage at 5℃and 7℃, and MDA and cell membrane permeability were lower. The CAT, VC, chlorophyll, the weight loss and decay index of pepper storaged at 9℃after 35d, were 211U/g·min, 317mg/100g, 4.13mg/100g, 8.33%, 3.61%, respectively.2. The effects of 5℃+heat treatment, 5℃+ intermittent warming on the post-harvest physiological changes of pepper were studied. The respiration rate of the pepper which was treated by heat treatment and intermittent warming was increased, was higher than the control treatment. But heat treatment and intermittent warming postponted the happening of chilling injury, decreased the chilling injury, and improved the commodity, and extended the time of circulation of pepper. The chilling injury happened after 15 days of treatment by heat treatment and 20 days of treatment by intermittent warming, and chilling injury index were 2.33% and 3.67%, and the safe days for pepper during cold chain circulation were 15d and 20d.respectively. The weight loss, respiration rate, CAT activity, and decay index of pepper treated by heat treatment was higher than treated by intermittent, and MDA and cell membrane permeability, the content of Vc and chlorophyll, chilling injury index were higher. The intermittent warming postponed effectively the happened time of chilling injury, decreased the chilling injury. But the weight loss and decay index is higher, and the loss of Vc and chlorophyll was higher. 3. The effects of 7℃+heat warming, 7℃+1-MCP on the post-harvest physiological changes of pepper were studied. Heat warming promoted the respiration rate, and 1-MCP inhibited the respiration rate. For preserving green, 1-MCP was better than 1-MCP. But in general, the heat treatment was better than 1-MCP. The chilling injury happened after 25 days of treatment by heat treatment and 1-MCP, and chilling injury index were 2.33% and 3.67%, and the safe days for pepper during cold chain circulation were 20d.respectively. The chilling injury index, respiration rate, cell membrane permeability, the content of MDA, VC, chlorophyll, the CAT activity, the weight loss and decay index of pepper which was treated by heat treatment after 49d, were 19.33%, 43.04mg/kg·h, 36.01%, 6.9nmol/g, 290mg/100g, 3.53mg/100g, 154U/g·min, 4.61%, 21.33%, respectively.4. The effects of 9℃+control atmosphere, 9℃+1-MCP on the post-harvest physiological changes of pepper during cold chain circulation were studied. The results showed that 9℃was safe temperature, and there is no chilling injury happened during transportaion at 9℃. Compared with 1-MCP, the quality of pepper which was treated by control atmosphere was better. The respiration rate, cell membrane permeability, MDA, VC, chlorophyll, CAT, the weight loss and decay index of pepper which was treated by control atmosphere after 49d, were 31.09mg/kg·h, 28.16%, 5.31nmol/g, 370mg/100g, 4.54mg/100g, 269U/g·min, 2.7%, 7.67%, respectively.5. The paper showed the main points of the preservation techniques for pepper during cold chain circulation. Pepper harvested by classification, and eliminated unqualified pepper （mechanical injury, damaged by insect）, and storage with control atmosphere （O₂ was dropped to 6 % to 8%,CO₂ was controlled in 1% to 2%） at （9±0.5）℃with the relative humidity of 85%⁹5%.After 49 days, the decay rate of pepper was 7.67%.