Study On Post-harvest Physiology And Storage Technology Of Yam

Yam has high edible and commercial value with its affluent nutrition. With people to worth the nourishment value in fresh Yam, it is consumption increased gradually, and the market foreground is vast. But after havest, Yam is inclined to lose water and crimpled, with softening, rotting and Vitamin C lose, the nutrition and the high quality is not maintained under simple condition. The report about its post-harvest physiology and storage technology are seldom until now, which influenced the development of storage and process. So in this paper, postharvest physiology and storage technology of Yam were systematically studied under different temperature and different humidity condition, including the medicalment preventing Yam from rotting. The changes of respiration intensity, firmness, weight-loss rate, Vc, titratable acid, reducing sugar, total sugar, MDA, PPO, POD were studied. The optimum storage technology of Yam was developed. The main research contents and results were as follow:1 The study on the respiration of Yam in different temperature showed that the respiration was decreased during storage after harvest and was reduced by the low temperature combined with the package of PVC film bag with holes..2 The weight-loss rate of Yam during storage was reduced markedly by the low temperature combined with the package of PVC film bag with holes.3 The firmness of Yam reduced gradually during the storage, the low temperature had a good effect on keeping firmness. This condition had the best quantity.4 During storage, Vc and titratable acid content decreased constantly; the contents of reducing sugar and total sugar increased gradually in the earlier stage then decreased during the later time; MDA content rose slowly in the whole progess; the acitivity of PPO enzyme decreased at initial stages and increased in the latter part; the variation trends of POD activity were different in each treatment.5 The firmness of Yam reduced gradually during the storage, MDA content rose slowly in the whole progess, MDA content was negatively correlated with the firmness; the Correlation cofficients was -0.805.6 During storage, the package of PVC film bag, relative humidity of 80%—85%, storage at 4℃was the best storage technology. 7 The fresh Yam used to stored over a long period time must be Prohibit Packing the wounded or infected one.8 The best storage technology was that: harvesting Yam→transporting and pre-cooling at 0℃on time→classifying and picking out the unqualified vegetable→treating with antiseptics→storage at 4℃, relative humidity of 80%～85%. After 150 days storage, the percent of gool Yam was 95.6%. The weightiness rate was 3.75%.