| Fresh-cut fruits and vegetables are favored by consumers for their convenience,freshness and nutrition.The emerging of the central kitchen has further promoted the development of the fresh-cut fruits and vegetable industry.However,fresh-cut processing will aggravate the quality deterioration of fruits and vegetables and shorten their shelf life.Taking fresh-cut asparagus as the research object,aiming at the problems of microbial contamination,vigorous respiration,decline in nutritional and sensory quality,and lignification during cold storage,in this paper,we investigated the effects of ultrasonic-composite cleaning agent/cinnamon fumigation,1-methylcyclopropene（1-MCP）/chitosan coating treatment,1-MCP/modified atmosphere packaging and ultrasonic-composite cleaning agent/cinnamon fumigation combined with 1-MCP/modified atmosphere packaging on the microbial population,respiration intensity,weight loss,nutritional quality,lignification and sensory quality of fresh-cut asparagus during cold storage,aiming to provide a theoretical basis for the preservation of fresh-cut fruits and vegetables.（1）Aiming at microbial contamination of fresh-cut asparagus,the effects of citric acid and Nisin compound cleaning agent treatment（CN）,ultrasonic-composite cleaning agent treatment（USCN）,cinnamon essential oil fumigation（CEO）,and ultrasonic-composite cleaning agent/cinnamon fumigation treatment（USCN/CEO）on fresh-cut asparagus preservation during cold storage were investigated.The results showed that the USCN/CEO treatment was more effective in reducing the initial total number of colonies,moulds and yeasts counts,inhibiting microbial growth,and keeping the microbial counts below the microbiological safety limits of fresh-cut asparagus during 20 days of cold storage compared with the USCN and CEO treatments alone.Meanwhile,USCN/CEO treatment inhibited phenylalanine aminolytic enzyme（PAL）and peroxidase（POD）activities and delayed the rise of lignin content.（2）For the problem of vigorous respiration of fresh-cut asparagus,the effects of 1-MCP treatment,chitosan coating treatment and 1-MCP/chitosan treatment on fresh-cut asparagus during cold storage were studied.The results showed that the respiratory intensity of each test group during cold storage was as follows:1-MCP/chitosan group<1-MCP group<chitosan group<control group,and both 1-MCP and 1-MCP/chitosan treatments delayed the peak respiration time.The respiration peaks of fresh-cut asparagus treated with 1-MCP/chitosan,1-MCP and chitosan decreased by 25.01%,18.62%and 10.58%,respectively,compared with the control.（3）In view of the fact that 1-MCP treatment could reduce the respiration intensity to a certain extent and delay the appearance of respiration peaks,the effect of 1-MCP/modified atmosphere packaging on fresh-cut asparagus preservation was investigated to further solve the problem of vigorous respiration in fresh-cut asparagus.Meanwhile,the effects of 1-MCP combined with different modified atmosphere packaging conditions MAP1（5%O2+10%CO2）,MAP2（10%O2+10%CO2）and MAP3（10%O2+15%CO2）on the respiration of fresh-cut asparagus were studied.The results showed that the 1-MCP/MAP3 treatment was the most effective,resulting in a 29.31%and 35.73%decrease in peak respiration and weight loss,respectively,compared to the 1-MCP treatment.In addition,1-MCP/MAP3 treatment also significantly reduced nutrient loss,inhibited PAL and POD activities,and delayed the increase of lignin content in fresh-cut asparagus.（4）In order to solve the problems of microbial contamination,vigorous respiration,decreased nutritional quality and lignification of fresh-cut asparagus more effectively,the effect of USCN/CEO+1-MCP/MAP3 treatment on fresh-cut asparagus was investigated.The results showed that USCN/CEO+1-MCP/MAP3 treatment effectively reduced the number of surface microorganisms,inhibited microbial growth,reduced respiration intensity,weight loss rate and nutrient loss,inhibited PAL and POD activities,delayed the process of lignification,maintained better color and sensory quality,and extend its cold storage shelf life to 20 days. |
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