Study on extraction of crude polysaccharide from Ulva prolifera

Crude polysaccharide was extracted from Ulva prolifera cultivated in Jiangsu using alcohol sedimentation, and some technological parameters were studied. The process of crude polysaccharide extraction was as follows:U. prolifera was submerged in 95% alcohol before filtration, the dried frond was swelled in distilled water at ratio (g/mL) of 1∶40, followed by homogenising, the suspension liquid was heated to 95℃ follow by constant temperature stirring for 15min, then separated with bolting-silk, the filter liquor was concentrate to 95% water content using constant temperature stirring, followed by centrifugalization. The supernatant was gathered and precipitated in 80% ethanol for 24h, then separated with bolting-silk. The filter residue was gathered for freeze drying of crude polysaccharide with yield of 20.1%, in which the polysaccharide content was 51%.