Effect Of Storage Temperature, Packing Mode And Low Oxygen Concentration On Postharvest Quality And Physiology Of Lycium Chinense Mill

The fresh sprout of Lycium chinense Mill produced in Shanghai after removing decay and yellow leaves was taken as experiment material to study the effect of storage temperature,packing mode,and low 02 concentration on the postharvest quality and physiology ofLycium chinense Mill.The results were as follows:1.The fresh sprouts of Lycium chinense Mill produced in Shanghai after removing decay and yellow leaves were packed in plastic bags either loosely closed or open with each sample 200 grams,and then stored at 20±5℃,10℃and 0℃.The treatment was replicated for 3times.The effect of storage temperature and packing method on the quality of Lycium chinense Mill during storage was studied.The result showed no chilling injury symptom appeared at 0℃,and 0℃together with loosely closed package had lower weight loss and alleviated the decay.0℃can also reduce the loss of reducing sugar,postpone the degeneration of the chlorophyll and inhibit the synthesis of cellulose.The Lycium chinense Mill open packed were apt to lose water compared to the other one,and the higher temperature,the more water lost.High temperature combined with the open package could aggravate the nutrition loss,stimulate the synthesis of cellulose,and accelerate the senescence of Lycium chinense Mill.Therefore,0℃is a better temperature to store Lycium chinense Mill,and 0℃together with loosely closed package is a better method to keep Lycium chinense Mill fresh.2.The effect of storage temperature and packaging method(open packed or loosely closed packed) on the postharvest physiology characteristics of Lycium chinense Mill during storage was studied.The respiratory rate was at a high level after harvest,and appreared respiratory peak at high temperature,and the packing mode of loosely closed packed can keep the respiratory rate at a low level at 0℃during storage period.MDA content grew up constantly in every treatment,and 0℃can slow down the rate,especially in loosely closed package.O₂^content showed a rising tendency in general while the activity of SOD reduced during storage period.PPO activity was weak while POD activity was at a high level,which can reach ten thousand units,so POD was the key enzyme of Lycium chinense Mill in the biochemical-physiology function.The TP and FP contents in fresh Lycium chinense Mill were 5.80 and 1.52 ug·g^-1.FW respectively,however,they changed a little due to the low contents.The main phenol in the tissue of Lycium chinense Mill was L-Tyrosine and Chlorogenic acid.3.The fresh sprouts of Lycium chinense Mill produced in Shanghai after removing decay and yellow leaves were packed in plastic bags and adjusted the V(O₂)/V(N₂) respectively to 21/79(CK),5/95,3/97 and 1/99 by ejecting O₂ and filling N₂ and then stored at 1±0.5℃.The results showed that low oxygen concentration could decrease the weight loss effectively and inhibit the decay and keep better sensory quality;low oxygen concentration has a significant effect on the loss of Vc,the degradation of Chlorophyll and the synthesis of cellulose.Low oxygen concentrationcan slow down the MDA and keep high activity of SOD.The lower V(O₂)/V(N₂) was,the better effect showed.And when V(O₂)/V(N₂) was 1/99,the the storage effect was best.4.The results showed that the storage period of Lycium chinense Mill varied from its different harvest time.The storage period of Lycium chinense Mill picked in May is shorter than that picked in March.