Study On Extraction Of Polysaccharides From Laver (Porphyra Yezoensis Ueda) And Utilization Of The Residue

Porphyra yezoensis Ueda is one of the plentiful red seaweed in east china sea. Its various biological activities ( antitumoral , anticoagulant, antioxidative and so on) have been reported in the literature.To make best use of the precious marine resources, three fields have been studied in this paper,including, l):the methods of extraction, separation, purification, components and properties of polysaccharides (PYP) from Porphyra yezoensis Ueda, 2) antioxidative Activities of PYP, 3) utilization of the residue.Traditional polysaccharide extraction method that is being extracted by hot water have been studied, but the report about the extraction technology on freeze combined with microwave and impoving extraction rate are even less. In the course of drawing, the effects of several main factors on extraction rate, e.g: microwave power, solvent and solute radio and extraction duration have been investigated. Through orthogonal design, several main affecting factors and levels are discussed, and then the optimization condition of extraction of Porphyra yezoensis Ueda polysaccharides were as follows: 200W microwave power, 8 minutes extraction duration, 50/1 (g/g) solvent and solute weight ratio. The removal of protein in the pruduct was compared by two different methods, Sevag method and enzyme combined with Sevag method. The second method has its own obvious advantage. It may increase the removal rate of protein. At the same time, the loss rate of polysaccharides is reduced greatly. Enzyme can cut off the protein chain, then use classical chemical method( Sevag method ) to deal with two times. The method is an ideal method for eliminating protein. Polysaccharide after removing protein is dialysed, we obtain part-pure product of polysaccharide—PYP.PYP are separated and purified into three fraction (PYP₁, PYP₂, PYP₃) by DEAE-Sephadex A-50 and Sephadex G-200 gel chromatography. The identification ofpurify implies that they are homogeneous components. Typical absorption of nucleic acid or protein can not be observed in UV spectrum. PYPi, PYP2, PYP3 are hydrolyzed by 2mol/Lsulphuric acid, then their component and sructure are measured by means of GC/MS. The result shows PYPi is composed of mannose and xylose; the component of PYP2 is consisted of galactose and mannose; the main compositions of PYP3 are galactose, mannose and glucose. The experiment studies antioxidative of PYP and analyses effects of clearing oxygen radical. Hydroxid radical (*OH )and superoxide anion radical (02'*) are produced respectively by H2O2/Fe2+ system and AP-TEMED system. The result showed that *OH and O{' can be inhibited by PYP, their activities and amount are relative.Influence of major factors, including deodorization technics and formula of products, on the quality of laver sauce was studied. Results revealed that the best combination of natural spices, which was 0.4%cinnamon+0.4%nutmeg+0.2%pepper, and the best combination of flavouring , which was 3.0%garlic + 2.0%ginger + 2.0%onion , were the best combination of deodorization. The results of orthogonal experiments Lg (34) showed that the effect of the moment of laver (* Fa) on sensory quality of laver sauce was prominence, but acidifier (Fc) and CMC-Na (Fd) were not. The formula of laver sauce included laver 8.(h sugar 5.0, citric acid 0.2, acetic acid 0.15, CMC-Na 0.4, capsicum 1.0, salt 1.5, monosodiun glutamate 0.05.The research offered some scientific basis for comprehensive utilization of Porphyra yezoensis Ueda.