Application Of Precise Temperature Control Fresh-keeping Box And Cold Storage Agent In The Storage Of Daylily

Daylily is a precious vegetable with the same origin of medicine and food.It is rich in nutrition,fresh and tender.Especially fresh daylily is loved by consumers.However,fresh daylily after harvesting is extremely intolerant of storage at room temperature and has a short shelf life.Precise temperature control fresh-keeping box and cold storage agent are simple,economical and effective fresh-keeping methods in postharvest storage of daylily,and can provide technical support for promoting the industrialization of daylily.Gansu Qingyang daylily was used as the experimental material,and two kinds of fresh-keeping technologies,precision temperature-controlled fresh-keeping box and cold storage agent,were used to determine various sensory indexes,physiological indexes,nutritional indexes,volatile substances and related enzymes of daylily.The effect of the two on the postharvest storage effect of daylily,and the temperature storage and preservation effect that can be achieved after the combined use of the two,in addition,this experiment further analyzes the diversity of microorganisms based on high-throughput sequencing.The strains that account for a key proportion are summarized to provide a reference for the preservation strategy of daylily.The experimental results are as follows:(1)The storage temperature of the ordinary incubator is 0.9±0.3?,and the precision temperature-controlled fresh-keeping box is 0.6±0.1?.The V_C,reducing sugar,total phenols,flavonoids,respiration intensity,ethylene production rate,carotenoids,chlorophyll,pH value and other indicators of the two groups of daylily were detected,and the SPSS comprehensive scoring method was used to obtain that the preservation effect of the precise temperature-controlled fresh-keeping box was better than that of the ordinary fresh-keeping box.Through OPLS-DA analysis,it was concluded that the difference indicators of different fresh-keeping box treatments were total difference?E and chlorophyll b content.Precise temperature-controlled fresh-keeping box can effectively delay the rise of polyphenol oxidase activity,maintain peroxidase activity,and this treatment significantly reduces the browning speed of daylily.(2)The temperature fluctuation range of the foam box group during storage was about 1.0±0.1?,while that of the foam box+cool storage agent group was about0.4±0.1?,and the pH value and carotenoid were significantly different between the two treatments(p<0.05).The carotenoids,respiration intensity,ethylene production rate,pH value,chlorophyll content,V_C content,total phenols,flavonoids and other indicators were measured in the two groups,and the SPSS comprehensive scoring method was used to obtain the cold storage agent+foam box group>foam box group.In addition,it was also measured that the POD activity in the two groups of daylilies gradually increased,and the PPO activity was relatively stable.Through the detection of volatile components in different storage periods,high levels of linalool and trans-orange were found in both groups.Anthocyanin,and the use of cold storage agent can promote the release of alcohols and esters in daylily.(3)To explore the effect of the relative temperature environment achieved by the combined use of the cold storage agent and the precise temperature control fresh-keeping box on the storage quality of daylily,the refrigerator group and the cold storage group were set as the control group,and the skin color,ethylene production rate,Respiration intensity,carotenoid content,flavonoid content,chlorophyll,V_Ccontent,total phenolic content,pH value and other indicators were detected.SPSS comprehensive scoring method showed that the phase temperature group had the best preservation effect,and the storage period was 21 days.There was a significant difference(p<0.05)in pH value between the two groups.In addition,the measured POD in the phase-temperature group has been tending to be stable,and the PPO activity in the refrigerator group and the cold storage group increased faster than that in the phase-temperature group reduce.(4)On the basis of the storage experiments of the refrigerator group,the cold storage group and the phase temperature group,the daylily of each group stored for 7days was selected as the experimental material.Discovered by high-throughput sequencing results,At the genus level,Dothideomycetes,Microbotryomycetes,Tremellomycetes,Eurotiomycetes,and Sordariomycetes are the dominant flora of daylily fungal communities,and Cyanobacteriia,Gammaproteobacteria,Alphaproteobacteria,Bacilli,and Clostridia are the dominant flora of the daylily bacterial community.From the perspective of the number of OTUs in the dilution curve,the diversity of fungi and bacteria on the surface of daylily stored at phase temperature is the lowest,which proves that storage at phase temperature can effectively inhibit the diverse growth of surface microorganisms.