Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the effects ...Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the effects of processing variables （extraction temperature, pH, extraction time, and liquid-to- solid ratio） on the yield of Jerusalem artichoke pectin. Under the optimal extraction conditions： pHl .52, 63.62 min, 100℃ and a liquid-to-solid ratio of 44.4 mL/g, the maximum pectin yield was predicted to be 18.76%. Experiments were conducted under these optimal conditions and a pectin yield of 18.52＋0.90% was obtained, which validated the model prediction. The effects of different drying methods （freeze drying, spray drying and vacuum drying） on the properties of Jerusalem artichoke pectin were evaluated and they were compared with apple pectin. FTIR spectral analysis showed no major structural differences in Jerusalem artichoke pectin samples produced by various drying treatments. The antioxidant activities of pectin dried by different methods were investigated using in vitro hydroxyl and DPPH radical scavenging systems. The results revealed that the activities of spray dried pectin （SDP） and apple pectin （AP） were stronger than those of vacuum oven dried pectin （ODP） and vacuum freeze dried pectin （FDP）. Therefore compared with the other two drying methods, the spray drying method was the best.展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA021205)the National Key Technology R&D Program of China(No.2011BAC02B04)
文摘Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the effects of processing variables （extraction temperature, pH, extraction time, and liquid-to- solid ratio） on the yield of Jerusalem artichoke pectin. Under the optimal extraction conditions： pHl .52, 63.62 min, 100℃ and a liquid-to-solid ratio of 44.4 mL/g, the maximum pectin yield was predicted to be 18.76%. Experiments were conducted under these optimal conditions and a pectin yield of 18.52＋0.90% was obtained, which validated the model prediction. The effects of different drying methods （freeze drying, spray drying and vacuum drying） on the properties of Jerusalem artichoke pectin were evaluated and they were compared with apple pectin. FTIR spectral analysis showed no major structural differences in Jerusalem artichoke pectin samples produced by various drying treatments. The antioxidant activities of pectin dried by different methods were investigated using in vitro hydroxyl and DPPH radical scavenging systems. The results revealed that the activities of spray dried pectin （SDP） and apple pectin （AP） were stronger than those of vacuum oven dried pectin （ODP） and vacuum freeze dried pectin （FDP）. Therefore compared with the other two drying methods, the spray drying method was the best.
