| The fresh-keeping of peach is a technology problem needed to solve currently especially at ambient temperature condition. In this experiment we do four teams of tests with the peach named P.persica.cv ’Baihua’ picked from Zhangjiagang city. The research contents are as follows:(1) Test the physiological indexes such as sound fruit rate, respiration rate, weight loss rate, membrane, firmness, TSS, MDA, PPO that indicate the condition of peach.(2). Analyze the security, effectiveness, economy and feasibility of four teams of treatments. The first team was UV-C, VP and Pul; the second team was CaCl2, GA3 and SA; the third team was UV-C+VP, UV-C+Pul and TBZ+Pul; the last team was SA+GA3,1-MCP+GA3 and 1-MCP+SA. After three years of experiments, the main results showed as follows:(1) Post-harvest physiology and mechanism of decay. From outward appearance, water content changed significantly during storage and this lead to a series of change. First the peel became crimpled and shriveled then came out spots at last the peaches were invaded by pathomycete. From the physiological indexes, respiration rate is the most important one. Experimental data showed that the honey peach is one kind of respiratory climacteric fruit. The second day after harvested it will show a small respiration climacteric, and it will came out a second respiration climacteric before the large-scale decay started. Before the respiration climacteric, physiological indexes of fruits changed seldom. At the beginning of respiration climacteric, weight loss ratio, numbers of spot accelerate significantly and respiration rate came to the peak quality. After respiration climacteric, firmness decrease rapidly, MDA and PPO came to the peak.The mechanism of decay:From the internal of fruit, the respiration rate keep at a high level after harvest, this kind of respiration rate lead to a series of physiological changes. It may the main reason caused corrupt of peaches. As to the conditions of storage, high temperature, high relative humidity and invade of pathomycete all can lead to decay of fruit. So depress respiratory action, optimize storage conditions and prevent pathomycete invade are the key way to extend shelf life of honey peach.(2) The results showed that 1.0kJ/m2 UV-C treatment was effectively to maintaining firmness (152%) and reducing respiration rate (-58.6%), relative conductivity (-23.7%) and MDA (-49%). This treatment also had good effects on maintaining TSS (48.4%) and inhibiting the increase of PPO (-21.8%). However, there were no obvious effects on good fruit rate and weight loss (-22.4%). Vacuum packaging was good at maintaining firmness (214%), TSS (27.8%), reducing relative conductivity (-51%) and MDA (-12.9%). But only have modest effects on maintaining good fruit rate (41.9%), reducing weight loss (-19.5%) and inhibiting the activity of PPO (-7%), at the same time vacuum packaging may lead to an increase of anaerobic respiration which cause flavor change. The results showed that there were positive effect on good fruit rate (125%), respiratory rate (-27.3%), relative conductivity (-22.9%), TSS (8.1%), weight loss (-13%), MDA (-46.4%) and PPO (-32.7%) after 2%Pullulan coating. However, there were no obvious effects on firmness. The 1.0kJ/m2 UV-C treatment was the best one in this team.(3) The results showed that after 2%CaCb treated there were positive effects on good fruit rate (73.5%), respiratory rate (-32.58%), relative conductivity (-20.2%), firmness (246%), TSS (19.5%). However, on MDA (-16.0%), weight loss (-37.7%) and PPO (-7.6%) activity there were no obvious effect. The sound fruit rate kept at 50%after 7 days storage.0.3g/L SA treated has positive effect on good fruit rate (76.5%), respiration rate (-28.6%), MDA (-30.0%), firmness (90.5%), TSS (16.5%) and PPO (-22.1%), but there were no obvious effect on the control of weight loss (16.7%) and relative conductivity (7.9%). After 0.6g/L GA3 treated there were positive effects on sound fruit rate, respiratory rate (-27.5%), relative conductivity (-21.3%), TSS (21.3%), firmness (157.0%), MDA (-35.4%) and PPO (-35.1%). However, it did not have obvious effect on weight loss (-26.0%). The 0.6g/L GA3 treatment was the best one in this team.(4) The results showed that the 1.0kJ/m2UV-C+2%Pul treatment has significant effects on good fruit rate (64.0%), weight loss (-52.6%), firmness (83.2%), TSS (36.9%), relative conductivity (-25.3%), MDA (-44.9%) and PPO (-37.7%). However, there were no obvious effects on respiration rate (10.16%). This treatment may extend shelf-life to 6 days. 1000ppm TBZ+2%Pul treatment has significant effects on good fruit rate (52.9%), weight loss (-57.3%), firmness (99.5%), relative conductivity (-36.3%), MDA (-13.1%) and PPO (-30.4%), but there were no obvious effects on TSS (16.7%) an respiration rate (-3.7%); 1.0kJ/m2UV-C+VP treatment has significant effects on good fruit rate (56.9%), weight loss (-39.0%), firmness (127.3%), TSS (36.0%), relative conductivity (-22.1%) and MDA (-16.4%). However, there were no obvious effects on respiration rate (135.2) and vacuum packaging may lead to an increase of anaerobic respiration which cause flavor change. The 1.0kJ/m2UV-C+2%Pul treatment was the best one in this team.(5) 0.3uL/L 1-MCP+0.6g/L GA3 treatment was good at good fruit rate (76%), respiration rate (-17.1%), relative conductivity (-5.2%), MDA (14.4%) and PPO (-5.3%). But there were no obvious effects on weight loss (-8.7%), firmness (33.6%) and TSS (5.0%). The respiration rate (62.0%) and MDA (-28.2%) of peach fruits treated by 0.3uL/L 1-MCP+0.3g/L SA were decreased compared with the control, at the same time there were significantly effects on good fruit rate (62%). However, there were no obvious effects on weight loss (-16.5%), firmness (29.0%), relative conductivity (-2.4%), TSS (18.7%) and PPO (-1.7%). Compared with the control, the good fruit rate (68.0%) of peach fruits treated by 0.3g/L SA+0.6g/L GA3 was good maintained, and the respiration rate (-16.3%) MDA (-24.9%) and PPO (-28.6%) were decreased significantly. However there were no obvious effects on weight loss (-21.4%), firmness (20.9%), relative conductivity (-9.3%), and TSS (14.8%). The 0.3g/L SA+0.6g/L GA3 treatment was the best one in this team.Taken together, these researches take advantage of UV-C, Pul, VP and 1-MCP as methods for the fresh-keeping of Fenghuang honey peach. After an intensive study we choose the UV-C as the best ways to preservation peaches. It has great popularization and application on the preservation of’baihua’honey peach.On the foundation of single method research we used combination methods to preservation peaches. Based on the analysis result of single method we picked up the optimum concentration and use two of the optimum concentrations to treated peaches. So those researches analyze the effects of single method and combination methods on honey peach preservation, there were no reports in former document literatures.In this paper, with the innovative and deep analysis of postharvest physiology, decay mechanism of honey peaches and different combinations of concentrations, treatments time and preparation experiments of different methods. UV-C and UV-C+Pul were chosen compared along the eight physiological indexs. The put forward of preservation methods suitable for fruit growers and industrial-scale production made this subject had strong application value. |
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