The Development Of Ready-To-Eat Loach Food And Extraction,Structural Analysis Of Its Byproduct Polysaccharide

A new ready-to-eat loach food was developed in this study.The polysaccharide was extracted by the byproduct loach head. Through loach processing experiment, the deodorization fluid condition（salt 0.8%, NaCO30.3%, β-cyclodextrin 0.7%）and flavoring liquid condition（salt 18g, vinegar 40g, cooking wine 40g, sucrose 75g, soy 25g, thick chilli sauce 35g, water 100g） were established.The polysaccharide structure which is closely related to functional properties was also analysed. Nowadays there are many research papers in plant polysaccharide and fungal polysaccharide.Otherwise,the research on animal polysaccharide is rarely reported.Through detecting loach nutritional index, we realized that it is a kind of high-protein and low-fat food which is beneficial to our health. Loach mucus and head contains a large number of functional polysaccharide and it provided the direction for loach high additional value product development. Therefore, the research focuses on extraction, purification and structural analysis of loach polysaccharide.The experimental method of extraction and purification mainly includes loach head drying and crushing, degreasing, water extraction and alcohol precipitation, removing protein by savage and enzyme method, water dialysis, sephadex gel column purification. On the basis of single-facter experiments, Design-Expert 8.0 statistical software was applied to optimize polysaccharide extraction condition by response surface method. Phenol sulfuric acid method was used to determine total polysaccharide content and 3,5-two nitro salicylic acid method was used to determine reducing sugar content. The polysaccharide purity was analysed by UV spectrum. The polysaccharide molecule structure was analysed by infrared spectroscopy and nuclear magnetic resonance.This experiment utilized high performance liquid chromatography to determine the molecular weight of polysaccharide. The spatial structure of polysaccharide was verified by congo red experimental method.The main conclusions of this article are as follows:The regression model was predicted in code form:Y= 0.22+0.05X₁+0.22X₂+0.03X₃+0.063X₁X₂-0.2X₁X₃+0.027X₂X₃-0.19X₁² +6.75 × 10^-3X₂²-0.15X₃²The optimum extraction conditions are as follows:NaOH 0.1 lmol/L, the concentration of ethanol 80%, leaching time 1 Oh. The highest theoretical yield of crude polysaccharide is 2.46% which matches actual yield of 2.41%. The total sugar content is 79.51%, reducing sugar content is 0.27%, so the content of polysaccharide is 79.24%. UV spectrum showd no protein and nucleic acid in the loach polysaccharide sample. Infrared spectroscopy and nuclear magnetic resonance spectra indicated that the loach polysaccharide is consist of beta and alpha pyranose without uronic acid. HPLC showed that molecular weight of polysaccharide is 7.11×105Da. Congo red experiment showed that loach polysaccharide has the three strands of the helix structure.