Effects Of 1-MCP Treatment Combined With Cold Storage On Postharvest Physiological Quality And Lignification Of Common Bean

During the storage of common Bean,with the elongation of cell and the thickening of Secondary Wall,cellulose was synthesized and formed fiber bundle,Lignin was also synthesized and deposited in the fiber bundle grid,and the tissue became rough and fibrous,the mechanical strength of cells and tissues increased greatly,and the edible quality became worse.The contents of Soluble solids(TSS),reducing sugar,total phenolics,ascorbic acid(Vc)and cellulose during storage of Clematis Guiyang were determined,the changes of firmness,cell membrane permeability,rot rate,relative thickness of pod and length of bean tendon were studied.At the same time,the key enzymes of lignin synthesis in postharvest physiology of Phaseolus vulgaris were determined: cinnamyl alcohol dehydrogenase(CAD),Phenylalanine ammonia-lyase enzyme,cellulase,active oxygen scavenging system,ascorbic acid Peroxidase enzyme,and the activity of Peroxidase,a key enzyme involved in Lignin synthesis and active oxygen scavenging,to study the process of post harvest fibrosis in common Beans.At the same time,1-MCP of 0.5ul/l,1.0 ul/l and 1.5 ul/l was used to study the regulation mechanism of 1-MCP on postharvest fibrosis of common Bean,the effects of 1-MCP treatment on fresh-keeping of common Bean under cold storage were analyzed in order to provide theoretical basis and technical support for 1-MCP treatment.The results show that:1.Under the condition of cold storage,the contents of TSS and edible hardness of common Bean increased at first,then decreased,then increased,the contents of reducing sugar decreased,the contents of cellulose and ascorbic acid(VC)increased The total phenol content decreased at first and then increased,the hardness of common Bean decreased continuously,the respiratory intensity reached the peak on the 9th day,the length of bean tendon increased continuously,the relative thickness of Bean pod decreased continuously,the permeability and rot rate of cell membrane increased continuously.2.1-MCP combined with cold storage at 0.5 ul/l could keep the total phenol content in common Bean at a high level for 0-9 days,and the cellulose content in common Bean at a low level for the whole storage period 1.1-MCP combined with cold storage at 1.5 ul/l level can maintain the relatively stable level of TSS and the relatively low level of ascorbic acid in common Beans The effect of 1-MCP combined with cold storage on reducing sugar content of common Bean was not significant.1.0ul/l and 1.5 ul/l 1-MCP treatment combined with cold storage could significantly maintain the hardness of common Bean during 0-9 days.However,1-MCP combined with cold storage could not maintain the edible hardness of common Bean during storage.1-MCP treatment combined with cold storage could inhibit the absorption of common Bean,and the concentration of 1.5 ul/l was the best,and the permeability of common Bean cell membrane was also inhibited,the effect was obvious in 15-21 days.1-MCP treatment combined with cold storage had no obvious effect on the relative thickness of pod and the length of bean gluten,but it could effectively reduce the rate of bean rot.3.Under the condition of cold storage,the activity of APX decreased continuously,the activity of PAL increased as a whole,the activity of CAD increased significantly,and the activity of POD changed little,the key enzymes in Lignin synthesis pathway are active.4.1-MCP treatment at 0.5 ul/l combined with cold storage significantly inhibited APX activity in common Bean at 0-9 days,and 1-MCP treatment at 1.5 ul/l showed this effect at 9-15 days,however,1-MCP treatment at all levels significantly increased APX activity at 15-21 days.1-MCP treatment at 0.5 ul/l and 1.5 ul/l combined with cold storage could effectively inhibit PAL activity in common Bean from 0 to 21 days,1-MCP treatment at all concentration levels could inhibit CAD activity in common Bean from 0 to 15 days,and 1-MCP treatment at all concentration levels could inhibit CAD activity in common Bean from 0 to 15 days,1-MCP treatment combined with cold storage could inhibit POD activity in common Bean,but this effect was not significant in 15-21 days.The results showed that 1-MCP treatment combined with cold storage could delay the synthesis of Lignin in common Bean.In addition,1-MCP treatment at 1.0 ul/l level combined with cold storage at 9-21 days significantly inhibited cellulase activity in common Bean.