Physiological And Biochemical Changes In Fresh-cut Bamboo Shoots (Phyllostachy Pubescens) During Preservation

Batatas(Ipomonea batatas(L.)Lam.) are popular in China because of the good taste and nutritional value, appropriate price. However the technology of preservation and freshness still perplexes people, because of the high rotting rates(usually above 30 %) and the short freshness dates(only about 120 days),which limits its development and use. The purpose of this paper to analyze the nascence and control mechanism of cold damage is from the study of glycometabolism、energy metabolism and phenol metabolism, and want to conform a protective measure to protect batatas from cold damage by using UV-C treatment、Ethephon treatment and cold acclimation treatment(CAT). Shoots of batatas(Ipomonea batatas(L.)Lam.)were grown in Lin’An. After selecting and grouping, the batata shoots are treated by 6 k J/m2 UV-C, 1:400 aethylenum and cold acclimation.The research contents and conclusions are shown as follows:(1) The effect of chilling stress on extrinsic feature of batatas after harvest, the results show that chilling stress will lead to chilling injury index、relative conductivity、malondialdehyde(MAD) content and browning degree getting rapid rise.(2) The effect of chilling stress on glycometabolism of batatas after harvest, the results show that chilling stress will lead to starch content decreasing、amylase activity and soluble sugar increasing, while fructose content and sucrose content increasing, but glucose content is decreasing.(3) The effect of chilling stress on energy metabolism of batatas after harvest, the results show that chilling stress will lead to the inhibition of succinate dehydrogenase(SDH) and cytochrome oxidase(CCO) activity and the promotion of H+-ATPase activity,while ADP and AMP content increasing, but ATP content is decreasing.(4) The effect of chilling stress on phenol metabolism of batatas after harvest, the results show that chilling stress will lead to promoting the total phenol content and inhibiting phenylalanine ammonialyase(PAL) and polyphenol oxidase(PPO) activity, meanwhile, peroxidase(POD) activity decreasing first then increasing last;while chilling stress will lead to reducing the clearance rate of hydrogen peroxide(H2O2) while enhancing ability to scavenge superoxide radicals(O2·-) and reductive ability.(5) The results of different treatments on extrinsic feature of batatas indicated that the UV-C treatment、Ethephon treatment and CAT can delay the increase of the relative conductivity, the UV-C treatment can also reduce the accumulation of MAD.(6) The results of different treatments on glycometabolism of batata shoots indicated that the UV-C treatment can promote starch content、soluble sugar content andamylase activity, but inhibit the glucose、fructose and sucrose content; CAT can promote soluble sugar、fructose and glucose content,but effect of sucrose content is not obvious; the Ethephon treatment for all these indicators are not significant role.(7) The results of different treatments on energy metabolism of batata shoots indicated that CAT can accelerate the decrease of ATP content and Ethephon treatment can accelerate the increase of AMP、ADP content,meanwhile, the effect of the UV-C treatment、Ethephon treatment and CAT treatment on the energy charge is not obvious.(8) The results of different treatments on phenol metabolism of batata shoots indicated that the UV-C treatment、Ethephon treatment and CAT can increase the total phenol content and the activity of PPO, Ethephon treatment and CAT can also increase the activity of PAL, but UV-C treatment can inhibit the activity of PAL,as for the activity of POD, UV-C treatment and CAT can improve the activity in the prophase of storage;while UV-C treatment、Ethephon treatment and CAT can promote the clearance rate of superoxide radicals(O2·-), CAT also can promote the reductive ability.