Study On Preservation Of Lotus And Vacuum Frying Technique Of Lotus Seeds

Postharvest fresh lotus of Hangzhou JIANDE has been treated with film packaging, antiputrefactiva and antioxidants to go with dipping treatment and stem injection treatment. The quality and pHysiological indexes of lotus during storage were measured and the application of effective preservation in lotus storage was studied. The experiment on vacuum frying of steamed lotus seeds has been studied, by studying on single factor and orthogonal experiment, the best vacuum frying technique has been found out.And effects on shelf life of lotus seeds by different storage treatments have been studied.The film packaging treatments were applied to preservate lotus storage at2℃for20days. The results demonstrated that:the treatment that lotus was bound up by PE fresh-keeping film, first storage at8℃for1day and later storage at2℃, effectively improve the score of the sensory quality of the exterior of lotus and lotus seeds, effectively control the browning,improve the value of L*and b*. Reduce the value of a*, and control the reduce of the content of chloropHyll, Vc, TSS and total acid, induce the raisment of the content of starch. This treatment showed a good function to stain the quality of lotus, and was applied to later experiment.The treatment was applied to preservate lotus storage at(37±3℃)for7days, electrolyzed-oxidizing water and ozone effectively improve the score of the sensory quality of the exterior and the inside of lotus and lotus seeds, because effectively control the growth and infection of bacteria. And the stem injection treatment was applied to preservate lotus storage at(39±4℃)for4days, the results demonstrated that:potassium sorbate, arginine, citric acid, arginine+potassium sorbate+citric acid+BHT effectively contain the external sensory quality of lotus, control the reduce of the content of chloropHyll, Vc, induce the raisment of the content of starch, and was applied to later experiment.The best two treatments were applied to preservate lotus storage at39±4℃and6℃severally. The results demonstrated that:the best two treatments can effectively maintain the external and the inside of sensory quality of lotus, control the browning, and have a good function to stain the quality of lotus, control the reduce of the content of chloropHyll, Vc, TSS and total acid, induce the raisment of the content of starch, and incraise the content of flavonoid. The best two treatments also show a good function in the effects on pHysiological activity of the postharvest lotus, reduce respiration intensity, relative conductivity rate, the concent of MDA, observably restrain the activity of PPO and POD, increase the activity of PAL, increase of the concent of total pHenolic.The experiment has found out the best vacuum frying technique, by studyng on single factor and orthogonal experiment of five factors and three levels, and the best technique is that the half of the lotus seeds,60%water content,120℃for frying temperature,20min for frying time,-0.09MPa for vacuum degree. And effects on shelf life of lotus seeds by different storage treatments have been studied, and it is demonstrated that:the treatment of BHT can effectively control the rancidity of oil,maintain the taste, the color and the crunchiness of the lotus seeds,reduce the increase of water content.