Effects Of Heat Shork Treatment, Cysteine, GA₃ And Vacuum Treatment On Quality And Epidermis Browning In Lotus Root During Storage

Effects of heat shork treatment, L-cys (L-cysteine), GA₃ (gibberellins) treatment, and vacuum packaging treatment on postharvest charactors, qualities and browning in louts root (Nelumbo nucifera Gaertn) were studied in this paper. The results provided some useful information on how to effectively delay the senescence of louts root after harvest, on how to improve the quality of louts root, and on how to control the postharvest browning of louts root without pollution to environment and harmfulness to human healthy. The results also provided some clues to reduce epidermis browning in Lotus Root and postharvest charactors.Louts root was treated with temperature (35 ℃, 45 ℃, 60 ℃) for 30 min, and then enclosed with LDPE bag packaged and stored at 4℃ ± 1℃ with 85%-95% RH. The results indicated that different heat shorking treatment reduced epidermis browning of lotus root and effectively inhibited activities of POD, PPO, but enhanced CAT in epidermis. The most significant inhibition of lotus root was obtained by the treatment with 45 ℃ treatment.The results of postharvest L-cys (0.1 g/L, 0.5 g/L, 1 g/L) treatment in lotus root and stored at 4℃ ± 1℃ with 85%-95% RH, showed that 0.5 g/L L-cys effectively reduced browning index of lotus root epidermis, and effectively inhibited the activities of POD and PPO during storage, but enhanced the activity of CAT in it.Louts root was treated with GA₃ (0.02 g/L, 0.1 g/L, 0.5 g/L) after harvest at 4℃ ± 1℃ with 85%-95% RH before storage. Results indicated that GA₃ delayed the senescence of lotus root during storage and effectively inhibited respiration rate, and 0.1g/L GA3 and 0.5 g/L GA3 treatment effectively reduced browninging index of lotus root epidermis.Lotus root was treated with intermixture of 0.5 g/L L-cys and 0.1 g/L GA₃ under a low pressure (0.05 MPa) for 5 min, and vacuumed packing with LDPE, HDPE, PA and aluminum foil bags, and stored at 4℃ ± 1℃ with 85%-95 % RH. Results showed that PA and aluminum foil vacuumed packing treatment effectively inhibited respiration rate and content of AsA, and reduced relative electrical conductivity and MDA content of lotus root, There were no notable change on SSC content, but marked effect on the incidence of browning index of lotus root (P < 0.05). Furthermore, PA and aluminum foil vacuumed packing treatment effectively enhanced GSH content and inhibited the decrease of SOD, CAT activity, but reduced activities of POD, PPO and phenolic compounds significant difference in lotus root epidermis during storage.