Study On Enzyme Activity In The Fresh-keeping Process Of Lilium Davidii Var

Lily is a perennial herb which belongs to the genus of Liliaceae Lilium.China is the origin of lily and the distribution center of Liliaceae in the world.It is also the earliest country to develop and utilize lilies.In china,a large number of lily bulbs are exported and sold each year,which has made a significant economic benefit.Lily contains not only nutrients such as fat,protein,polysaccharides,crude fiber,vitamins,et al.but also an important source of active ingredients such as assaponins,alkaloids,flavonoids,et al.Therefore,it has a high pharmacological activity and nutritional value,and it is highly favored by consumers,which shows the great development potential.Fresh lily has high moisture content,respiratory intensity and active metabolism,which causes a series of problems such as color change,quality loss,quality deterioration,rapidly declining nutritional quality,short shelf life,storage and transportation after harvest and so on.All these problems seriously affect the quality,value,sales of Lanzhou lily,which results in considerable economic losses.With the purpose of improving storage and preservation of Lanzhou lily,this paper examines the use and effects of different preservation techniques,including the effect of low temperature preservation technology,the effect of ozone water preservation technology and the effect of ultraviolet radiation preservation technology.In the end,this paper investigates the application of modified atmosp Here preservation technology to Lanzhou Lily,getting the optimal gas ratio(O2,N2,CO2)of Lanzhou Lily preservation.The major findings are as follows:1.Lanzhou Lily was stored at(4±0.5)°C,(10±0.5)°C and(20±0.5)°C,respectively,and the enzymes related to browning and browning of Lilium lantus during storage were determined.(PAL,POD,PAL)activity,MDA content.The results showed that under the storage conditions of(20 ± 0.5)°C,with the increase of storage time,the browning degree and activity of PPO,POD and PAL in Lanzhou Lily rose sharply.Lanzhou lily began to brown,and its quality decreased.The shelf life of Lanzhou lily is only a few days,while the low temperature of(4±0.5)°C is favorable for delaying the increase of browning degree of lily,inhibiting the activities of related enzymes(PPO,POD,PAL),inhibiting browning,and maintaining low MDA content inhibits peroxidation of membrane lipids.Lanzhou lily stored at(4±0.5)°C was better than(10±0.5)°C and(20±0.5)°C in storage as a whole,indicating that low temperature film packaging can effectively inhibit the browning of Lilium lantus andinhibit browning.The activity of enzymes(PPO,POD,PAL)delays the increase of MDA content and prolongs the shelf life of lily.2.The storage test of Lanzhou Lily scales washed with ozone water with concentrations of 0.5 mg/L,1.0 mg/L,1.5 mg/L and 2.0 mg/L for 5 min showed that the ozone water treatment was better for Lanzhou lily.The good preservation effect can restrain the browning of Lanzhou lily and maintain good storage quality.The increase of ozone water concentration has better preservation effect on the storage period of Lanzhou lily,but when the concentration of ozone water reaches a certain value,the effect on Lanzhou lily changes little,and the comprehensive analysis from various physiological indexes and quality indexes is 1.5mg/L.The effect of oxygenated water treatment is better than that of other groups.3.The storage of Lanzhou lily under irradiation of ultraviolet germicidal lamp for 5 min,10 min and 15 min respectively was found.The 10 min irradiation treatment had better preservation effect on the color of Lanzhou lily,and it could effectively reduce the respiration rate of Lanzhou lily.It inhibits the activities of browning enzymes(PPO,POD,PAL),delays the increase of MDA content,and reduces the damage degree of cell membranes,thereby delaying the aging process of Lilium lancifolium,increasing the commercial value of fruits,and prolonging its shelf-life.4.The study found that with the prolongation of storage time,it was compared with5%CO2+5%O2+90%N2,10%CO2+5%O2+85%N2,10%CO2+10%O2+80%N2,the treatment with 10%CO2+5%O2+85%N2 can maintain better sensory quality,including browning degree,PPO,POD and PAL activity,and can effectively inhibit MDA content.Accumulation,taking into account changes in various indicators,the optimum gas ratio during storage of Lanzhou lily is 10%CO2+5%O2+85%N2.5.the Lanzhou Lily was cleaned with 1.5 mg/L ozone water.After draining,the ultraviolet radiation was 10 min,and the gas was stored at 4 centigrade for a period of time with the gas ratio of 5%CO2+10%O2+85%N2.The results showed that,compared with the control,the activity of PPO,POD,PAL,the accumulation of MDA content,the damage degree of the cell membrane,the browning of the Lanzhou Lily scale and the fruit commodity were improved.To extend the shelf life of the shelf.Correlation analysis showed that the browning degree of Lanzhou Lily was closely related to PPO activity,POD activity,PAL activity and MDA content.