Study On Preparation Of Collagen Peptide Chelate Calcium

The output of freshwater fish cultured in our country occupies first place in theworld. During the processing, a large number of byproduct like fish scale, fish skin,fishbone were produced. About650thousand fish scale are produced annually in China,but it has not been completely used. Small peptides obtained from enzymatic hydrolysisof fish scale not only have lots of functional properties, but also can improve theabsorbability of calcium.It has been proved that amino acid chelating calcium has much biological activitywhich can promote animal growth and improve immunity of animals. There are manyresearches about the preparation and application of amino acid chelating calcium, butstudies on the preparation and activity of calcium chelating small peptides are verylimited.This paper studied the preparation of small peptides using controlled-enzymatichydrolysis of silver carp protein and calcium chelating small peptides as well as thebiological activity of calcium chelating small peptides in mice. The main results wereshown as follows:1. The decalcifying and degreasing process of fish scale were studied.collagen contentas indicators of evaluation off the hybrid protein technology.First single factorexperiments and orthogonal test was designed to optimize the process based on theresults.The optimal conditions of acid processing were:0.4mol/L HCl solution,substrate to solution1:20, time2h. The optimal conditions of alkali processing were:0.15mol/L NaOH emulsion, substrate to solution1:20, time10h. The scale wasbasically composed of coarse collagen under these processes, the ash content wasdecreased under2%, the extraction rate of collagen was95.93%.2. The extraction technology of scale collagen oligopeptide was investigated. Nitrogenrecovery,the degree of hydrolysis as an indicator to measure the efficiency ofproteolysis,in order to determine the best enzyme complex and to optimize the hydrolysis conditions.The complex enzyme and condition were determined: Usingalkali protease first，enzyme dosage5%；concentration of substrate6%；temperature50℃，pH11，time3h；And then，using flavor enzyme，4%，concentration of substrate6%，temperature50℃，pH6.5，time3h. We continue the enzymatic hydrolysis of coarsecollagen under these conditions, the enzymolysis liquid was clear and transparent withlight yellow in color. The bitterness and fishy smell was greatly reduced. The smallpeptide with molecular weight under1000Dal of content is88.58%.3. We removed the salinity of polypeptide enzymolysis liquid by ion exchange, underthe condition of6times elution flow rate of given column volume,25℃,the desalinization ratio reached to81.77%, the protein recovery reached to86.31%,meanwhile, resin have adsorption effect to pigment substance, which made remarkableeffect on decoloration of polypeptide enzymolysis liquid.4. The preparation of collagen peptide chelate calcium. Contrast to the solubility ofdifferent calcium sources in different solvents to determine the best source ofcalcium,collagen peptide chelated calcinm by organic solvent extraction,and determinethe amout of organic solvent.Obtained the chelated calcium content of the total calciumcontent in the reaction solution and the reaction by measuring the EDTAcomplexometric titration.The result showed that the optimal calcium was CaCl2,theoptimal reaction condition was pH value8,the molar ratio is2.1:1，Enzymatichydrolysis time is30min.Consequently,the chelate products were purified and analyzedby common chemical method. Extraction solvent was also evaluated. The effect ofvolume ratio of organic solvent to filtrate was studied. The highest recovery rate wasobtained at8:1of ethyl alcohol to distilled water. The product was testified by infrared(IR).The result shows that this chelating product is different from collagenpolypeptide, it is a new material.