The adsorption capacity of Pb(Ⅱ) on litchi pericarps was investigated as a function of temperature,pH,and adsorbent dose using batch experiments.The experimental data obtained were evaluated using adsorption equilibr...The adsorption capacity of Pb(Ⅱ) on litchi pericarps was investigated as a function of temperature,pH,and adsorbent dose using batch experiments.The experimental data obtained were evaluated using adsorption equilibrium isotherms and a kinetic model.Additionally,the removal of Pb(Ⅱ) in leachate of litchi pericarps was also evaluated.The results show that litchi pericarps exhibit a high adsorption capacity to Pb(Ⅱ),with the maximum removal efficiency occurring at a temperature of 25 ℃,a pH of 6.0-7.0 and an adsorbent dosage of 10 g/L.Langmuir and Freundlich isotherms and the pseudo-second-order kinetic model can all fit the equilibrium adsorption satisfactorily,with correlation coefficients(R^2) of 0.9935,0.9918 and 1.0,respectively.An average removal efficiency of 66.65% is found for Pb(Ⅱ) in leachate of litchi pericarps.展开更多
[ Objective] This study aimed to optimize the conditions for purification of total flavones from litchi pericarp by macroporous absorption resin. E Method] The flavones adsorption rates and desorption rates of macropo...[ Objective] This study aimed to optimize the conditions for purification of total flavones from litchi pericarp by macroporous absorption resin. E Method] The flavones adsorption rates and desorption rates of macroporous absorption resins （AB-8, HPD-600, D101 ） were compared, and the technological parameters of D101 during the purification process were investigated. E Result] D101 macroporous absorption resin was ap- propriate for the purification of total flavonoids from litchi pericarp. The optimal technological conditions were selected .. the pH of sample solution was 5.0; concentration of sample solution was 4 mg/ml, with a volume of 2.5BV; 80% ethanol was used as elution solution, with a volume of 2.0BV. [ Condusion] The content of total flavones achieved 83% after separation by D101 macoporous absorption resin.展开更多
[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determ...[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.展开更多
基金Project(51208173)supported by the National Natural Science Foundation of ChinaProject(ZR2014EEM005)supported by the Natural Science Foundation of Shandong Province,China
文摘The adsorption capacity of Pb(Ⅱ) on litchi pericarps was investigated as a function of temperature,pH,and adsorbent dose using batch experiments.The experimental data obtained were evaluated using adsorption equilibrium isotherms and a kinetic model.Additionally,the removal of Pb(Ⅱ) in leachate of litchi pericarps was also evaluated.The results show that litchi pericarps exhibit a high adsorption capacity to Pb(Ⅱ),with the maximum removal efficiency occurring at a temperature of 25 ℃,a pH of 6.0-7.0 and an adsorbent dosage of 10 g/L.Langmuir and Freundlich isotherms and the pseudo-second-order kinetic model can all fit the equilibrium adsorption satisfactorily,with correlation coefficients(R^2) of 0.9935,0.9918 and 1.0,respectively.An average removal efficiency of 66.65% is found for Pb(Ⅱ) in leachate of litchi pericarps.
基金Supported by Key Project of Science and Technology of Luzhou City(651)
文摘[ Objective] This study aimed to optimize the conditions for purification of total flavones from litchi pericarp by macroporous absorption resin. E Method] The flavones adsorption rates and desorption rates of macroporous absorption resins （AB-8, HPD-600, D101 ） were compared, and the technological parameters of D101 during the purification process were investigated. E Result] D101 macroporous absorption resin was ap- propriate for the purification of total flavonoids from litchi pericarp. The optimal technological conditions were selected .. the pH of sample solution was 5.0; concentration of sample solution was 4 mg/ml, with a volume of 2.5BV; 80% ethanol was used as elution solution, with a volume of 2.0BV. [ Condusion] The content of total flavones achieved 83% after separation by D101 macoporous absorption resin.
基金Supported by National Science Foundation of China ( GrantNo.30460085, 30960233)Open Foundation of Provincial Key Laboratory for Fruit and Vegetable Preservation of Hainan ( GrantNo. CH001)National Non-profit Institute Grant (ITBBZD2007-3-1)~~
文摘[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.
