海带岩藻聚糖硫酸酯电渗析分离工艺

摘要

Fucoidan is a type of heteropolysaccharides that contains the sulfate group. It has gradually become a hotspot of research on the marine bioactive ingredients because it has various biological activi-ties. Fucoidan is commonly found in brown algae such as Laminaria japonica. Fucoidan can be separated from L. japonica with the ethanol method. However this method costs a large amount of ethanol and re-quires special safety facilities during the precipitation process. In order to establish a more practical and efficient technology, here we explored the separation of fucoidan from pretreated L. japonica enzymatic hydrolysate using electrodialysis technology. We used salt removing and carbohydrate retention rates as the indicators and optimized the electrodialysis with the response surface method. The contents of each component in the fucoidan crude (on dry basis) were determined before and after the electrodialysis. The results suggested that the optimal conditions were:voltage 80 V, pH 5, flow 3.2 L/min, and solids content 10 mg/ml. Under these conditions, the salt removing rate was 60.32%and the carbohydrate retention rate was 100%. After continuous electrodialysis for three times, the polysaccharide content in the dry matter increased from 40.17%to 47.11%and the level of SO42-increased from 3.36%to 4.97%. Some metal ions and heavy metal ions decreased after electrodialysis, which were Ca 0.13 mg/g, Mg 16.04μg/g, Cu 0.29μg/g, Se 11.7μg/g, and Cr 8.06μg/g on the dry basis, and Pb was not detected. These results suggested that electrodialysis technology could be an efficient and practical method for desalination and fucoidan purification from alginate-free kelp enzymatic hydrolysate. This method should help optimize the pre-treatment process in the industrial mass production of fucoidan, and provide a new idea and theoretical foundation on fucoidan separation from L. japonica. Moreover it follows the trend in current food indus-try:high efficiency, high quality, and environmental protection.%采用电渗析法对盐沉后的海带酶解液中岩藻聚糖硫酸酯进行分离，探索工业化分离生产岩藻聚糖硫酸酯的方法，以解决目前乙醇沉淀法存在的安全性和高成本等问题。以脱盐率、糖保留率为检测指标，采用响应面法优化了电渗析工艺参数。结果显示，在操作电压80 V、料液流量3.2 L/min、固形物浓度10 mg/ml、pH=5的条件下，电渗析连续循环3次，海带酶液解干基中多糖含量由40.17%提高至47.11%，硫酸根含量由3.36%提高至4.97%。电渗析后海带酶解液干基中的金属离子含量为Ca 0.13 mg/g、Mg 16.04μg/g、Cu 0.29μg/g、Se 11.7μg/g、Cr 8.06μg/g，Pb未检出，较电渗析前均有降低。电渗析对脱除褐藻胶的海带酶解液进行脱盐纯化处理，可有效地分离纯化出岩藻聚糖硫酸酯。