洋葱多糖不同提取工艺的提取效果研究

Comparison of Different Technology for Polysaccharides Extraction from Onion

目的比较不同提取方法对洋葱中多糖的提取效果。方法采用热水浸提法、微波辅助冻融法和超声波法从新鲜洋葱和洋葱皮中提取多糖,用DNS法测定多糖含量。结果以葡萄糖为标准品,采用DNS法测定多糖含量是可行的,平均回收率达到了98.5%,RSD为2.65%。不管是新鲜洋葱肉质部分还是洋葱皮干粉,微波辅助冻融法提取的多糖的得率最高,超声波法提取的多糖的含量最高,其中微波辅助冻融法提取洋葱皮中多糖得率为3.58%(含量为63.9%);肉质部分多糖得率为3.15%(含量为62.0%)。结论微波辅助冻融法是提取洋葱多糖较为合适的方法,该法提取洋葱多糖得率高,且多糖含量也较高。

Objective To compare the effects of different extraction methods on extraction of the polysaccharides from onion. Methods Polysaccharides was extracted from fresh onion and onionskin by hot water leaching method, microwave - assisted freeze thawing method and ultrasonic wave method. The content of polysaccharides was determined by DNS method. Results Under the condition that the glucose was confirmed as standard, it was accurate and feasible to determine the content of polysaccharides in onion by DNS method ; the average recovery rate reached 98.5% with RSD of 2.65%. Weather fresh onion or onionskin dry powder, the yield of polysaccharides obtained by microwave - assisted freeze thawing was the most, and the content of polysaccharicle obtained by utrasonic wave was the most. The yield of polysacchalides obtained by microwave - assisted freeze thaucing in onionskin was 3.58% （the content of polysaccharides was 63.9% ） ; and its yield in fleshy parts was 3.15% （the content of polysaccharides was 62： 0% ）. Conclusion Microwave - assisted freeze thawing method is an appropriate method for extracting polysaccharides from onion. The polysaccharides obtained by microwave 2 assisted freeze thawing method, and its yield and content were the most.