Study On Binding Capacity To Cholate Of Water-soluble Proteins From Major Food Crops And Immunoassay Methods Of Cholate

Water-soluble proteins from rice, wheat, soybean, corn, potato and sweet potato wereextracted, and their compositional characteristics and binding capacity to cholate in vitrowere analyzed. The content of water-soluble proteins in soybean was the highest, followed bywheat and that in potato was the lowest. In composition, rice, soybean and wheat containedmore water-soluble protein species and sweet potato possessed the least. Those obtainedwater-soluble proteins all had the binding capacity to cholate. In the case of the same proteinquality, wheat had the maximum binding capacity to cholate and was significantly higherthan the other five food crops. But the binding capacity to cholate acted by potato and sweetpotato were significantly lower than the other samples. The difference of binding capacity tocholate among those water-soluble protein samples was due to their difference in composition.The binding capacity to cholate acted by lower molecular weight proteins may be higher thanthat of higher molecular weight proteins.Soluble starch and vitamin C have a certain impact on the binding capacity of bile saltsin food. On the same quality, except wheat, the adsorption capacity of the other five grainmixed with soluble starch are enhanced. Besides, adsorption capacity of the six grainswater-soluble proteins after mixing with vitamin C were increased significantly. But all of theadsorption capacity less than the adsorption capacity of vitamin C, except wheat. Solublestarch and water-soluble vitamin C have an affect on potato protein most significantly.Soluble starch potato makes the ability of water-soluble protein binding to make bile saltsraise3.73times; while vitamin C significantly improved its ability to bind bile salts is its6.3-fold. Soluble starch makes the binding capacity of wheat protein to bile salt reduction45.9%.Using the carbodiimide method to synthesiz the immunogen STC-BSA and the coatingantigen STC-OVA successfully. UV was used to identify STC-BSA and STC-OVA. Balb/c mice was immunized with STC-BSA, the titre of polyclonal antibody was6.4104byindirect ELISA, The linear range of calibration curves to detect STC was9.33-30200μg/L,The curve equation is y22.8x112.3, coefficient correlation R2=0.9888, and the limit ofdetection was9.33μg/L; The recoveries ranged from76.2%～108.5%for detecting STCresidues in milk and the coefficients of variation was1.9%-3.7%. Primarily establish indirectcompetitive enzyme-linked immunoassay (ciELISA) for the detection of STC, and make abasis for the ultimate establishment of ciELISA detection methods for STC.