Research On Preparation And Quality Of Duck Oligopeptide

Duck meat have abundant nutrition so that there are a lot products made from duck meat in our country.But further processing products from duck meat didn't appear a lot in market,and so many leftover bits and pieces that left from processing of duck meat were not used effectively.This research studied many manufacture pathways including hydrolysis,using powdered activated carbon to decolor,using the macroporous resin DA201-C to desalt and isolating by sephadex etc,which used duck meat as material to produce low molecular weight duck oligopeptide.Meanwhile,we studied the properties of duck oligopeptide.In the study of enzyme hydrolysis,we use single-enzyme hydrolysis method to hydrolysis duck meat,by comparison and analysis,alkaline protease was proved to be the best hydrolysis enzyme.The optimal conditions have been found by response surface method:temperature 54.7℃,enzyme/substract 2.03%,substrate concentration 3.78%,pH9.86,time120min.Under these conditions,the content of peptide is 57.87%.Second,we studied the effect of complex-enzyme hydrolysis method,the best conditions of complex-enzyme hydrolysis method were:substrate concentration was 4%,alkaline protease hydrolyzed for 2h on the condition of temperature 55℃,enzyme/substract1%,pH10,then flavor enzyme hydrolyzed for 2h on the condition of temperature 45℃,enzyme/substract 1.5%,pH7.Under these conditions,the content of peptide is 60.45%,the effect was better than single-enzyme alkaline protease,and the molecular weight distribution of 89.73% duck oligopeptide is under 1000u.So,we chose complex-enzyme hydrolysis duck meat to get duck peptide.Use powdered activated carbon to decolor duck peptide.We got the optimum decolorization conditions by single-factor experiment and orthogonal : quantity of powdered activated carbon is 0.03g/mL,pH3,temperature 50℃,time 20min.Under these conditions,decolorization was 93.81%,the loss rate of duck peptide was 14.83%.Use the macroporous resin DA201-C to desalt duck peptide,the sample concentration was 30mg/mL,the flow rate was 2mL/min.First,the column was eluted by water until electric conductivity of outflow liquid was near to water,then the duck peptide were desorbed by 70% ethanol with flow rate at 1mL/min.Duck peptide was desalted by the macroporous resin DA201-C,Its desalination rate was 83.15% while the peptide recovery rate was 86.27%.The duck peptide was isolated by Sephadex G-25,and got three isolates,there are 98.76% of the molecular weight distribution of the second isolate is under 1000u.This study is the basis of the future study.The constitution,amino acid composition,the molecular weight distribution and property were studied.The amino acid composition is abundant,it contains many essential amino acids.The molecular weight distribution of 98.76% duck oligopeptide is below about 1000u.The duck peptide has good solubility,low viscosity and antioxidant,it is good for food.