Studies On The Technology And Mechanism Of Green Asparagus During Three-stage Hypobaric Storage

The senescence mechanism and the hypobaric storage condition of postharvest green asparagus was researched in order to solve the questions of weight loss, green colour degeneration and aging by investigation on the physical, chemical and physiology changes during hypobaric storage with green asparagus (Asparagus officinalis L.,) UC800 as the material and suing JZ2 hypobaric storage chamber in this paper. It can provide the theoretical guide for the application of hypobaric strorage technology.The hypobaric storage condition of green asparagus was optimized and optimal parameters of the storage condition(The vacuum pressure, storage temperature and relative humidity were respectively about 35⁴0kPa,2⁴℃and 85%⁹5%.)were confirmed by analyses of respiration metabolism, weight loss rate, nutrition index, colour and decay index. The three-stage hypobaric storage technology of green asparagus (The vacuum pressure were respectively 10²0 kPa in the first stage, 20³0 kPa in the second stage and 35⁵0 kPa in the third stage) was proposed to solve the contradiction between vacuum pressure and weight loss rate during the hypobaric storage. The effect of keeping green asparagus fresh was quantitatively evaluated from the view of mathematics which makes use of fuzzy mathematics theory. The result showed that the effect of three-stage hypobaric storage was obviously better than the normal hypobaric storage.Atmosphere cold storage used as the control, the nutritional quality and sensory quality changes of green asparagus were studied respectively after making the three-stage hypobaric storage technology clear. The result indicated that the three-stage hypobaric storage condition could significantly(P<0.05)inhibit the degradation of nutritional components such as sugar, soluble protein, ascorbic acid and total acid et al, decrease the senescence index and improve the commodity rate of green asparagus.Compared with the atmosphere cold storage, the physiology changes and chlorophyllase degradation mechanism of postharvest green asparagus were investigated under three-stage hypobaric storage condition. The result indicated that the weight loss of green asparagus was closely related with the epidermal stoma distribution as stoma was an important channel of water loss. The chlorophyll degradation process of green asparagus might involve two pathways, namely the chlorophyllase degradation and chlorophyll oxidation, which were both related to the accumulation of activated oxygen. The three-stage hypobaric storage condition could significantly(P<0.05)inhibit respiratory intensity and ethylene emission, increase the activities of superoxide dismutase (SOD) and catalase (CAT), decrease the accumulation of superoxide anion (O₂^-·) and hydrogen peroxide (H₂O₂), reduce the damage of cell membrane. Meanwhile, this storage technique could significantly(P<0.05)improve SOD and CAT...