| The flesh color and some physiological changes of green mume fruit after harvested were investigated during storage at various temperatures. The results indicated that at 10C and 1C, the respiration rate and ethyene production of fruits were low; the range of changes in firmness, acid content, pH value, flesh color, chlorophyll fluorescence parameters Fo and Fv/Fm value were no obvious; chlorophyll and carotenoid content decreased slowly; a* and Hue Angle value of flesh were about -10 and 105 respectively, and through visual assessment, the flesh color constantly appeared yellow-green under storage, while at 25 癈, the peak of the respiration rate and ethyene content appeared at the day 6 and 8 of storage respectively, which showed the climacteric pattern. The decrease of firmness, Fo and Fv/Fm value, chlorophyll and carotenoid content, and yellowing of the flesh were rapid in fruits within the first 6 days of storage. It made clear that temperature is an important influence factor for flesh color and senescence of fruits under storage. Low temperature may delay chlorophyll degradation and the senescence process and yellowing in fruits, while the degradation rate of chlorophyll, the decrease of firmness and yellowing of fruits were rapid at room temperature. So the shelf-life of fruits could be for 5 days at room temperature.The results of relations among various indexes showed that it was positive correlation between chlorophyll content of flesh and fruit firmness(R=0.9755); the ratio between chlorophyll and carotenoid content constantly increased; a* and Hue Angle value of flesh were successful in determining in the extent of yellowing process of fruits, but Fo and Fv/Fm value were failed to define the extent of senescene and yellowing process of fruits.Effects of modified atmosphere packaging, preharvest application of GAs and ethylene absorbent treatments on physiology and maintaining green in fruits were investigated at 25C. The results indicated that in three treatment fruits, the respiration rate and ethyene content were low, the content of chlorophyll and carotenoid reduced slowly, firmness were relatively maintained. But the treatment of modified atmosphere packaging was better than others. As far as the treatment of modified atmosphere packaging was concerned, it was found that atmosphere combination with 6%O2, 4%CO2 and 90%N2 turned out to be the best.Relative proportion of chlorophylls and their derivatives in fruit at 25 C was measured by means of high-performance liquid chromatography and some enzymes activities involved in the pheophorbide pathway were studied. The results presented that the pheophytin a, b and pheophorbide b were not found during the process of chlorophyll degradation. So, the Mg2+ in chlorophyll a, b could not first be removed, which illustrated that the substrate for mg-dechelatase was only chlorophyllide a and that chlorophyll b may be transformed to chlorophyll a-forms before complete degradation. The chlorophyllide a, b and pheophorbide a were detected during the process of chlorophyll degradation. Therefore, combined with previous studies, some degradation reactions for the pheophorbide pathway in green mume fruits were speculated. First, the chlorophyll a, b are dephytylated to chlorophyllide a, b by the action of chlorophyllase, and subsequently the central Mg actom is removed by mg-dechelatase, then the pheophorbide a is oxygenolytically opened to a primary chlorophyll catabolite (colorless) in a two-step reaction by the joint action of pheophorbide oxygenase and red catabolite reductase. The second or third reaction may be the key step in chlorophyll breakdown in green mume fruits. Furthermore, chlorophyllase activities had no notable change in fruits of modified atmosphere packaging and ethylene absorbent treatment, compared to the control fruits, while the activity peaks of mg-dechelatase were inhibited, but the former was better than latter. Therefore, it presumed that mg-dechelatase, not chlorophyllase plays an important role in chlorophyll breakdown...
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