以嗜酸乳杆菌发酵虾头虾壳回收蛋白质和甲壳素的研究

Recovery of Protein and Chitin from Shrimp Waste by Fermentation with Lactobacillus Acidophilus

利用嗜酸乳杆菌发酵虾头、虾壳,结合虾头、虾壳中内源蛋白酶的自溶作用,回收蛋白质和甲壳素。研究了影响发酵的因素并优化了发酵条件,分析了用稀盐酸脱除粗甲壳素(即发酵残渣)中的矿物质,制备食用级甲壳素的条件。研究结果表明,添加15%葡萄糖,固液比1∶2.5,接种量15%,初始pH值6.5,于40℃发酵48 h,得到的虾头、虾壳发酵液pH值低至3.79,蛋白质水解度达到21.9%;蛋白质回收率达到95.2%,发酵残渣(粗甲壳素)中仅残留2.71%矿物质,达到工业级甲壳素的纯度要求;以稀盐酸浸泡处理粗甲壳素,当浸泡温度为50℃,浸泡时间为1.5 h,粗甲壳素脱矿物质的效果最好,甲壳素中仅残留0.2%矿物质,达到食用级甲壳素的纯度要求。

In this paper, shrimp waste is fermented with Lactobacillus acidophilus in combination with the action of endoproteinase to recover the protein and chitin, the factors which influenced the fermentation process are investigated and the fermentation condition is optimized. The condition of the removal of minerals from crude chitin by the usage of dilute hydrochloric acid （the fermentation residue） are investigated to prepare food class Chitin. The results are as follows： glucose concentration 15%, solid-to-liquid ratio （1 ： 2.5）, inoculation 15%, initial pH 6.5, fermentation temperature 40 ℃ and fermentation time 48 h; 95.2% protein is recovered from fermented shrimp waste. Meanwhile, most of the minerals are dissolved out by lactic acid and only 2.71% minerals remained in the final crude chitin. In addition, the optimal conditions for removing minerals from crude chitin by dilute hydrochloric acid are as follows： soaking time 1.5 h and soaking temperature 50 ℃. Only 0.20% of minerals are remained in chitin and it reaches the food class requirements.