| In this essay,polyethylene spontaneous gas packaging-film pretreatment com-bined with electron beam irradiation technology had been used to effectively inhibit the quality deterioration of fresh fruits of Hainan local species Areca catechu L.in storage process,compared with the fresh fruit preservation period of 7 days after leaving the tree at 25℃,the preservation method used in this essay can effectively extend the fresh fruit preservation period to 40 days.The main elements and research results are as follows.（1）The pathogenic microorganisms promoted in fresh betel nut fresh were isolated and purified at 13℃and 90%relative humidity,and the main pathogenic micro-organism was initially identified as mold.The minimum inhibitory concentration of thymol,an essential oil extract of the plant,was 0.08 g/m L,and the actual concentration used was 1.750 g/L,which has a good inhibitory effect.（2）After the surface disinfection of betel nut fresh fruits,CK coating agent,T1coating agent and T2 coating agent were used to soak and coat the fresh fruits respectively,and then placed in polyethylene self-generating air condition bags,stored at 13℃with 65%relative humidity in a light-proof environment.The results showed that the T2 coating treatment alone significantly improved the glossiness of the peel,and the irradiation treatments from 1.0 k Gy to 2.0 k Gy in the T1 group effectively delayed the fruit color change,while the 0.3 k Gy treatment significantly delayed the decline of fruit hardness;the 1.0 k Gy treatment in the T2 group significantly inhibited the increase of weight loss and decay rate,thus maintaining the respiratory metabolism and tissue integrity of fresh fruits and significantly inhibiting the accumulation of malondialdehyde in the peel.Compared with the CK group,the combined irradiation of T1 and T2 treatments had a significant effect on the respiratory metabolism of fresh fruits,which showed a respiratory jump after irradiation,with the initial respiratory intensity higher than that of the dose 0 group,and then stabilized.Also,irradiation combined with T2 treatment had delayed the peak respiration from day 12 to day 23,and the physiological and metabolic activity of fresh fruits was maintained and the resistance to stress was greatly increased.（3）E-beam irradiation had significantly increased the content of secondary meta-bolites such as polyphenols and flavonoids in kernels and pericarp,which led to an increase in fresh fruit active substance content and optimized quality.The irradiation browning of kernels was effectively curbed by the combined effect of the coating agent and other factors,and the degree of kernel browning was significantly lower in the T1group at 0.5 k Gy and T2 group at 0 k Gy on day 25 than other treatments in group.CK conducting with 2 k Gy and T2 group with 1 k Gy showed no significant kernel browning on day 35.At day 40,the browning of kernels in CK group 0.4 k Gy and 2 k Gy,T1 group0.4 k Gy and 0.5 k Gy,and T2 group 0.4 k Gy were significantly lower than that in the uncoated and unirradiated group.（4）T2 coating treatment combined with electron beam irradiation had significantly increased the activity of peel polyphenol oxidase,which can promote lignin production in addition to the oxidative polymerization of phenols to quinones under certain conditions.In this essay,it had been verified that electron beam irradiation had a significant correlation with the lignin content of peel,indicating that electron beam irradiation has caused an effect on the lignin production-related pro-enzyme system.Combined with the trend of lignin content,phenolic substrates such as chlorogenic acid and coumaric acid should tend to convert to caffeic acid,a lignification precursor,under the action of polyphenol oxidase.The accumulation of substrates facilitates lignin production and maintains a stable content,which can effectively maintain the integrity of peel tissue and better resist the invasion of pathogenic bacteria for long-term freshness.In contrast,the activities of PPO enzyme and PAL enzyme,the initiating enzyme of lignification metabolism in kernels,were inhibited,and the activity of 4-CL enzyme had decreased within a certain range,while the activities of CAD enzyme and POD enzyme increased,indicating a relative increase in the physiological metabolic capacity of fresh kernels.Collectively,the best preservation treatments at 13°C and 65%relative humidity for 25 days were T2 pretreatment combined with 0.1 k Gy,0.2 k Gy,0.3 k Gy and 0.5k Gy irradiation,and for 40 days were CK pretreatment combined with 0.2 k Gy irradiation,T1 pretreatment combined with 0.5 k Gy irradiation,T2 pretreatment combined with 0 k Gy,0.1 k Gy,0.1 k Gy,and 0.2 k Gy,0.3 k Gy,0.4 k Gy irradiation. |
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