| Yam, a vegetable used both as food and medicine origin, is one favorite agricultural produce of consumers. Yam tubers are easy to get brown and decay during storage and processing, which limits consumption of yams and the development of processing products. The storage condition had great effect on quality change and storage life of yam tubers. Yams of"Tiegun"are needed as tested materials for all experiments. The optimum storage temperature and the time of tubers placed in cold store at 4℃for storing whole yam tubers, were selected. Some The keeping fresh of different concentration CIPC treatment on cellaring yam and formula of chitosan compound films were analysed. The results illustrated that:1. The quality of"Tie gun"yam, stored at 4℃, was optimum."Tiegun"yams, stored at 4℃and 10℃, could be obviously restrained the respiration rate, reduced the decay rate, weight-losing and germination rate, depressed the active climax of PPO activity and POD activity and delayed the increase of the two enzymes'activity as well, inhibited the rising of and MDA content, reduce the decomposition of soluble sugar, water-soluble protein and polysaccharide, enhanced the transformation from starch to soluble sugar. The quality of yam could be kept well during 270 days(Sep.14th), while yams stored at 4℃were better. The yams, stored in cellar, maintained good quality at the first days. With the temperature increasing outside, the germination rate, weight-losing rate and the content of MDA increased sharply, while the nutrients decomposition aggravated. Yams stored at room temperature had the same problems. But the quality was better than the yams stored in the cellar at the same time.2.Considering the cost inputs, the quality of yams, stored 90 d(Mar.23rd) in cellar and then transferred to 4℃,was better than other translation time.Yams that storage at cellar 52 d(Feb.14th) and then transferred to 4℃, reduced the increasing trend of PPO activity and the content of MDA, maintained higher water-soluble protein, soluble sugar and polysaccharide. POD and PPO activity increased at first and then overall downward trend. The content of protein and soluble sugar had the same trends. The content of MDA increased all the time. But the content of starch and polysaccharide has the opposite trends. Considering the costs ,the effects of yams, which stored 90 d(Mar.23th) in the cellar and then transferred to 4℃is better than the yams stored 52 d(Feb.14th) in the cellar. The metabolism of yams which stored 135 d(May 7th) in the cellar and then transferred to 4℃had been emerged. Their abilities of recovering had been destructed. So it was difficult to slow the downwards of yams'quality.3. The germination rate of yams which stored in the cellar, could be inhibited effectively at the first days, but ineffectively during the following days. Being treated with 2.0 g·kg-1,2.5 g·kg-1 CIPC. The qualities of yams which maintained lower decay rate, weight-losing rate, germination rate , the content of MDA and higher POD activity were better than others. The yams treated with 2.0 g·kg-1 CIPC had the best quality. The germination of 0 g·kg-1 (CK) reached 71.48 %,while other treatments which were treated with CIPC reached (18.52 %～54.44 %) at 151 d(May 23rd).But the germination of 0 g·kg-1 reached 18.52 %.4. The color got darker, and the browning degree increased gradually, while the PPO activity was decreased during the first two days and then increased, the content of water-soluble sugar increased and then decreased at 4℃. Fresh-cut yam treated with the mixed solution of 0.5 % chitosan and 1 % Vc solution was optimum. The lives of fresh-cut yams could be lasted 5～7 d.
|
PDF Full Text Request