| Electron beam irradiation is a kind of preservation technology using the eletron beam rays induced by electron accelerator to kill microorganisms on the surface of fruits and vegetables,inhibit the physiological activities of fruits and vegetables,and thus prolong the shelf life of fruits and vegetables.Compared with the conventional methods,electron beam irradiation is a cold sterilization technology with short processing time,and high sterilization efficiency.It can maintain the fruits' original sensory quality,nutrition and flavor,which has the advantages of safety,efficiency,pollution-free and additives-free.Since chitosan preservation has obvious inhibitory effect on mango browning,the combination of electron beam and chitosan coating preservation technology is used to study the preservation and preservation technology of Kate mango.The result shows:(1)Electron beam irradiation has a good preservation effect on mango.A dose of 0.5 k Gy can kill most microorganisms on the surface of mango,reducing the total number of molds and yeasts by two orders of magnitude.Electron beam irradiation of 0.5-2.0 k Gy can inhibit the hardness decrease of mangoes,and 0.5 k Gy has the best effect on suppressing the hardness decrease.Electron beam irradiation of 0.5-1.0 k Gy can reduce the weight loss rate of mango and reduce the decay rate of mango without affecting the epidermis and nutrients.Electron beam irradiation of kiwi fruit can significantly reduce the total number of colonies.When the irradiation dose reaches 1.5 k Gy,it has a good killing effect on mold and yeast.Electron beam irradiation of 0.5-1.0 k Gy can inhibit the softening of kiwi and the increase of weight loss rate,but irradiation can cause the skin of kiwi to dry and brown.For sweet cherries,the 1.0 k Gy irradiation treatment can almost achieve complete sterilization,but the growth rate of irradiated microbe in the storage period is greater than that of the control group.Electron beam irradiation of 0.5-2.0 k Gy has no significant effect on its weight loss rate and TSS content,but it will cause epidermal damage and accelerate its decay,and the damage degree is positively correlated with the radiation dose.For all these reasons,mango was selected as the research object in the follow-up storage period research.(2)The effects of electron beam treatment with different irradiation doses on the quality of Kate mango was studied.The results showed that,in the range of 0.5-1.5 k Gy,the higher the dose,the better the inhibition effect on the hardness decline of Kate mango,but there was no significant effect on the weight loss rate and taste.However,if the radiation dose isgreater than 0.8 kGy,the skin of mango will produce small brown spots,and the appropriate dose of 0.5-0.8 k Gy can not only reduce the decay rate but also have no impact on the skin.(3)The preservation effect of chitosan coating on mango Kate was studied.The results show that 0.5-1.25 % of chitosan coating can significantly reduce the weightlessness rate of Kate mango and inhibite ripen-softening,but when the coating concentration is greater than1.0 %,it will accelerate the mango to yellow.And 0.75-1.0 % of chitosan coating has a significant inhibitory effect on the total acid and reducing sugar of Kate mango,that is to delay its ripen-softening.(4)The comprehensive preservation results of Kate mango by electron beam irradiation combined with chitosan coating showed that the deodorant of Kate mango was mainly terpenes,and the coating with high concentration at the same irradiation dose could reduce the loss of aroma substances.With same film concentration,low dose of irradiation can reduce the reduction of aroma components of mango.To be specific,the treatment of 1.0 %chitosan + 0.5 k Gy has the best effect on maintaining mango aroma,inhibiting mango aging and decreasing Vc content,and has a significant effect on comprehensive preservation in weight loss rate and inhibiting after-ripening and yellowing.The effect of storage temperature on the quality of irradiated mango was different.The results showed that the storage temperature of 10-15 ? had a better effect on the inhibition of yellowing and decay,and the most obvious effect was at 10 ?.Through the comparison of different preservation methods,it was found that irradiation preservation had the best effect on killing microorganisms of Kate mango,and chitosan coating had a good effect on microbial inhibition.the comprehensive preservation method of 1.0 % chitosan + 0.5 k Gy + 10 ?storage not only can effectively kill microorganisms,inhibit the growth of microorganisms during the period of storage at the same time,keep the fruit taste and the rate of fruit decay was reduced by more than 30 % compared with the control group. |
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