超声波辅助EDTA法提取淡水小龙虾壳中甲壳素的工艺研究

Extracting chitin in freshwater crayfish shell with ultrasonic assisted EDTA method

以烹饪前后淡水小龙虾壳为原料,研究超声辅助EDTA法提取淡水小龙虾壳中甲壳素的最佳工艺条件,采用EDTA法提取甲壳素,以提取物的灰分含量为评价指标,通过单因素试验和正交试验选择最佳的EDTA浓度、料液比、反应p H值、反应时间,结果表明:EDTA法提取甲壳素的最佳条件为,料液比1∶26(W/V)、EDTA浓度18%、反应时间2.5 h、反应p H值13。在此最佳提取条件下辅助超声波法提取甲壳素,以提取物灰分含量和含氮量作为提取效果的评价指标,筛选最佳超声时间、料液比和超声处理温度,结果表明:超声波辅助EDTA提取甲壳素的最佳工艺条件为处理温度30℃、p H值13、EDTA浓度18%、料液比1∶24(W/V)、超声处理时间45 min、超声频率60k Hz、功率180 W。在此条件下,烹饪后甲壳素提取物灰分含量和含氮量均较烹饪前低,分别为0.13%和3.51%。

Using cooked and uncooked freshwater crayfish shell as raw material, the optimum technological conditions of extracting chitin in freshwater crayfish shell by ultrasonic assisted EDTA method was studied. Chitin was extracted by using the EDTA method, taking the ash content of extract as the index of evaluation, the best conditions of EDTA concentration, material to liquid ratio, reaction p H, reaction time were selected through the single factor and orthogonal tests. The results showed that the optimum conditions for the extraction on chitin by EDTA method were solid-liquid ratio1∶26（W/V）, the concentration of EDTA 18%, reaction time 2.5 h, reaction p H 13. Chitin was extracted under the optimum extraction conditions assisted by ultrasonic method, and the best material to liquid ratio and ultrasonic treatment time,temperature were selected, taking the nitrogen content and the ash content of extract as the indexes of evaluation for extraction effect. The results showed that the optimum conditions of ultrasonic assisted extraction of chitin were that EDTA at 30℃, p H 13, EDTA concentration 18%, ratio of solid to liquid 1∶24（W/V）, ultrasonic reaction time in 45 min, ultrasonic frequency 60 k Hz, and power 180 W. Under these conditions, the nitrogen content and the ash content of cooked chitin were lower than those of the uncooked chitin, which is 0.13% and 3.51%, respectively.