| Collagen peptides can not only provide the body with the nutrients required for growthand development, but also have the antioxidant activity, ACE inhibitory activity and otherbiological activity. Therefore, in recent years, there are lots of researchers focused on thecollagen peptide foods. China is a big poultry country and the production of chicken rankssecond in the world. However, in the poultry processing, the by-products such as skin arewasted or used to produce poor meat products. Therefore, in order to improve the efficiencyof resource utilization and bring economic benefit for the enterprise, the objectives of thisstudy were to prepare collagen peptides and to develop a new processing technology for thehigh value-added collagen peptide beverage.Firstly, in order to improve the purity and the molecular weight of collagen peptides, thebasic components of the skin, the content of hydroxyproline and the extraction technologywere studied, the molecular weight distribution and amino acid composition of the peptideswere determined. The result showed that the content of fat in the chicken skin was37.62%and the protein was containing collagen protein and about14.27%other proteins. So, in orderto improve the purity of collagen peptides, it needs to remove some fat and other proteins.The collagen peptides were prepared from chicken skin and the extraction conditions wereoptimized by orthogonal experiment. The results showed that the optimum enzyme werepapain, trypsin, flavorzyme (w: w: w=1:1:1) and the optimum concentration of enzyme was0.45%, the time of enzyme hydrolysis was3hours, the temperature of enzyme hydrolysis was45°C and pH was7. The molecular weight distribution and amino acid composition of thepeptides were determined and the result showed that the collagen peptides had a molecularweight distribution of180~2000Da (69.74%) and the purity were high.Secondly, in order to determine the drying method of collagen peptides, the effects offreeze drying and spray drying methods on the physicochemical and functional propertieswere investigated. The freeze-dried collagen peptide powders were superior in terms of color,solubility, emulsifying stability, water holding capacity, oil and water absorption capacity andantioxidant activity than spray-dried peptide powders. But, it appears spray drying can still bepreferred if low cost and higher production throughput are required.Thirdly, in order to make the beverage easily acceptable to consumers, the method offuzzy comprehensive evaluation was used in this study, and the formula was determined atlast: collagen peptides0.15%, Orange juice35%, sugar15%and Lemon juice2%. The singlefactor test was used on the basis of the formula to choose suitable stabilizer and then useorthogonal experiment to determine the level of added amount:0.1%pectin,0.06%xanthangum and0.06%CMC-Na.Finally, in order to study the storage stability of collagen peptide beverage, during180d,the suspension, flavor and color stability of collagen peptide beverage were studied under thestorage condition of4°C,25°C and37°C. In180d storage, the changes of beverageturbidity were relatively flat, stability difference increase gradually, but there is no visibleprecipitation and stratification. The flavor of collagen peptide beverage was good at4°C, sensory evaluation of flavor difference was less than5%. The sensory evaluation ofdiffercence was less than6%at25°C and the sensory evaluation value was greater than10%under37°C storage temperature, but it was acceptable for consumer. Color deterioration ofcollagen peptide beverage was slow during storage at4°C storage temperature, but at25°Cand37°C storage temperature, the change of beverage color was obvious, especially at37°Cstorage temperature. After180d storage, b*values increased by1.93, L*value is increasedby1.11. |
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