| "Wan Cui" is the province's fine selection of green meat Kiwi Large Fruit , quality and appearance are better than the market's "Qinmei".At present, the province is still a lack of new varieties of physiological and biochemical storage, preservation technology system, Wan Cui on the storage and preservation of kiwi fruit is also concentrated in the modified atmosphere and cold, in the treatment of research has not been reported.In this paper, Using "Wan Cui" as the raw material, and the kiwi fruit was treated with hot waters at different temperatures and time before storage, that is 38℃(8min, 16min, 24min), 46℃(8min, 16min, 24min), 54℃(8min, 16min, 24mim).The control is treated in ordinary temperature water.Study the effect of heat treatment on "WanCui" Kiwi fruit quality of physiology and biochemistry and quality when placed at 0~1℃, and to explore new methods of preservation treatment as well as the feasibility of heat treatment on "Wan Cui" kiwifruit; Study the physiological and biochemical effects of heat treatment and the mechanism of preservation, selection of suitable heat treatment conditions for Wan Tsui kiwifruit Storage provide a theoretical basis and technical basis for production applications.The main conclusion are followed:1. The ethylene production of kiwi fruit have the same overall trend between different combinations of heat treatment and the control. In the eighth week, the control group and treatment group were shown a significant ethylene peak and then decline rapidly. 38℃heat treatment combined ethylene production overall lower than the control, the minimum peak to deal with 16min is only 66.74 percent for the control. Shows a lower temperature heat treatment can reduce the peak of ethylene during the kiwi fruit storaged in cold, inhibit endogenous ethylene production, thus delay the process of fruit ripening and softening.2. The treated fruit was storaged on 0 ~ 1℃for 10 weeks , respiration declined significantly with the treatment temperature increased, the respiration rate has differences between the different treatment combinations,the lowest respiration rate is the combination of hot water treatment under 54℃/ 24min. It is significant that the respiration rate was significant inhibited after heat treatment.3. During storage, fruit firmness were decreased, the decline is rapid in the early and relatively slow in the late. The PG activity of kiwi fruit have the same overall trend between different combinations of heat treatment and the control., it was significantly increased from the second week, and soon reached the peak activity at the sixth week, and then decreased; PG activity increased is the firmness declined period. Under 38℃/8min heat treatment , firmness of kiwi fruit maintain better than the control, and PG activity peak is minimum, only have 87.90% of the control. Appropriate temperature suitable for heat treatment can reduce PG enzyme activity, which delayed the hydrolysis of pectin substances and the decrease of hardness.4. During storage in the 0 ~ 1℃, kiwifruit LOX activity increased with storage time showed an increasing tendency, SOD activity increased firstly and then decreased. 54℃and 46℃LOX activity of the treatment combination of the overall higher than control; The treatment combination of LOX activity was significantly lower than control at 38℃, especially in 38℃/ 24min treatment.Heat treatment of various combinations at 54℃, the SOD activity in the whole lower than the control; By 38℃and 46℃heat treatment ,the SOD activity higher than the control with treatment time, 38℃have significant differences between treatment combinations and better than 46℃. Thus,each treatment combination of 38℃maintained low levels of LOX activity and higher levels of SOD activity, it is important to maintain the integrity of membrane system , maintain normal cell function and ease fruit softening .5. With storage time, the total sugar content is upward trend , the total acid content is downward trend , and sugar acid ratio is risetrend, fruit flavor need a certain acidity and the regulation of sugar acid ratio. VC content was decreasing trend. The total soluble sugar content,the titratable acid content and the loss of vitaminC(VC) content is better than control ,the best is 38℃/ 24min .6. During storage, the weight loss and changes have significant difference in the different treatment combinations, the higher temperature, the higher rate of weight loss. At the appropriate temperature, processing time is too long or too short, so that fruit weight loss not reach the best control effect. 54℃heat treatment in different time, kiwifruit have the maximum weight loss rate, and each treatment combination of 46℃and 38℃have significantly weight loss rate and good fruit rate than the control. By different combinations of weight loss and good results, we can get 54℃treatment is not suitable for long-term storage of fruit.7. 54℃heat treatment combination damage heavily on physiological and biochemical of kiwi, not suitable for long-term storage; 46℃treatment stimulated ethylene production, accelerated senescence, lowed VC content and hardness, also not suitable for long-term storage; 38℃heat treatment combination maintained a good physiological and biochemical indexes, flavor quality and storage effects, although effects have some differences, but taken into account that 38℃/ 16min of heat treatment is relatively good combination. |
