| The green bamboo(Dendrocalamus oldhami(Munro)Kengfi) belongs to the grass green bamboo subfamilies of bamboo, mainly planted in Zhejiang, Fujian, Guangdong and Taiwan provinces. Dendrocalamopsis which has the advantages of rapid growth, quick forest, and a short rotation, big gains, etc., is an excellent shoot of bamboo species. The bamboo shoot was called "green shoot", because of its horseshoe-type like, also known as "Horseshoe shoot." The bamboo shoot has a crisp flesh, delicious taste, unique flavor and rich nutrition. However, it so called green bamboo shoot, for it metabolism is so exuberant that easy to lignification. Their flavor started to change after harvesting 4 ~ 5 hours, generally, under normal temperature only can preserve one day. And the bamboo shoots is summer-type, it's period generally in the 5 ~ 10 month. The period of production is centralized, and the processing capacity is limited. So the study of preservation method to delay bamboo's lignification and maintain a good quality to facilitate the transportation and processing of green bamboo shoot, and promote the development of dendrocalamopsis industry has the extremely vital significance.The Konjac glucomannan (KGM) is an ideal, natural and biodegradable polymers, has a biodegradable, non-toxic and excellent film-forming. The molecule of KGM contains a large number of hydroxyl and acetyl groups which are modified, that make it can for chemical compound through the green technology. After compounding, KGM had much better performances, which made it can be widely used in fruits and vegetables, food packaging, and edible packing materials, etc.In this study, the use of KGM film on bamboo shoots storage processing, research the impact of KGM film compound on the quality of bamboo during storage and slowing down the aging, and provide a reference of living body refreshing technology of bamboo shoots in-depth study. In this study, we use the concentration of 0.4% and 0.6% of KGM coating liquid to applied to dendrocalamopsis at the cross-section, and the control group does not use film processing. The three experimental groups of bamboo shoots placed in 5℃, regularly measured physiological and biochemical indicators of quality of the bamboo shoots and to observe the impact of the KGM film treatment on the indicators of green bamboo shoots. Test results obtained by the following:1. The impact of KGM coating treatments on postharvest quality of green bamboo shoot changesKGM coating process can inhibit bamboo shoot body respiratory rate, reduce their water evaporation, weight loss and decay rate of bamboo shoot body ; with the extension of storage time, the bamboo body nutrients such as protein, sugar and so on show a downward trend in general and the the quality of bamboo body deteriorates gradually, but the KGM film processing can slow the decline in these indicators, compared with the control group, the bamboo body can maintain a good quality and a good body sensory partten. Overall, the effect of 0.6% KFM film processing is better than 0.4% KGM coating treatment.2.The picked bamboo shoots'anti-aging effects of coating ways on konjac glucomannanAfter bamboo shoots are picked, their internal PAL and POD have consistent activity change trend, that is, their activity increases rapidly in prophase of storage period and decreases gradually in the latter period. The content of fibrin and lignin increases constantly, whose change rule is related to that of PAL and POD's activity. Coating ways on konjac glucomannan can delay the increase of lignified related enzymes in the bamboo shoos such as PAL and POD, especially the bamboo shoots, with coating ways of 0.6%KGM,has slight changing amplitude in its PAL and POD's activity during the experiment. The content of fibrin and lignin has the slightest increase and the highest score of sensory evaluation, which is the better ideal preservation methods. |
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