Effects Of Preservative Agent And Storage Temperatures On Postharvest Physiology And Quality Of Pepper Fruit

The objective of this study is to understand the ripening and senescence mechanisms of pepper fruit. The effects of preservative agent and storage temperatures on postharvest physiology and quality of pepper fruit were studied. The main results were as follows:1. During the period of storage, both vitamin C (Vc) and chlorophyll (Chl) contents tended to go down in pulp, stalk and sepal; fruit rot index and red fruits percent tended to go up, resulting in bad preservation scale. Either room temperature(20-25℃) or low temperature(9-10℃) was given, application of preservative agent hampered Vc and Chl degradation in pulp, stalk and sepal, meanwhile, fruit rot index and red fruits percent aslo be decelerated, thus leading to a longer storage phase. When stored at room temperature for 5~30 days, the Vc and Chl contents were higher 23.60%-181.18% and 8.83%-50.69% in pulp of preservative agent-treated fruits than CK fruits, respectively, and, by the time of 30 days, commercial fruits rate was bigger by 41.71%. Similarly, at low temperature for 10~60 days, the Vc and Chl contents were higher by 11.39%-107.69% and 5.00%-106.15%, respectively, also, on 50th day, commercial fruits rate was bigger by 7.13 times.2. Regardless of room or low temperature, preservative agent could significantly reduce the respiration rate and the ethylene production rate. When stored for 30 or 60 days at room or low temperature after treatment, respiration rate was lower by 44.06% and 64.24% in preservative agent treated fruits than that in CK fruits, respectively. With preservative agent treatment at room temperature, the peak of ethylene production rate was delayed by 5 days, and the peak value was smaller by 23.88% than that of CK; while at low temperature condition, respiration peak disappeared in treated fruits, however, the CK fruits have a small peak on the 20th day.3. Preservative agent prolonged the storage period by keeping the relative higher contents of IAA and GA , and the lower content of ABA in pulp, stalk and sepal of pepper fruits. When stored at room temperature for 30 days, IAA,and GA contents were 2.77 and 1.41 higher in pulp in treated fruits than that in CK fruits, respectively; in contrast, treated fruits only held 37.15% ABA content of CK fruits. At low temperature for 60 days, these numbers ran to 3.25, 2.21, 1.41 and 8.37%, respectively.4. Under room and low temperature, preservative agent minimized the membrane injury by maintaining the higher activities of SOD,POD,CAT,APX, and decreasing the MDA content.