Study On Inspection Technologies Of Hydrolyzed Animal Protein (HAP) In Goat Milk Powder

In order to ensure Chinese dairy industry development to be rapid, healthy and benign,adulteration of dairy is always the problem that quality safety focused on to solve,especiallythe illegal addtions is key to prevent. Melamine and HAP are illegal additions.Melamine isestablished some measures of prevention, controlling and detection.So far detection methodof HAP in milk product has not yet formed a standard. We need to build up a rapid, simple,and effective detection method. Goat milk,as the characteristic of Shaanxi provinceresource,is paid extensive attention and protection. Goat milk powder is the main basematerial of the infant formula milk powder. Related department should improve the means ofdetection and quality safety system construction.In the study considering L-hydroxyproline(L-HYP) as hydrolysis features things of hydrolyzed animal protein, we study amicrowave-aided hydrolysis method based on UV spectrophotometer to quickly detectwhether hydrolyzed animal protein is added to goat milk powder. Referring to relatedmethods, using the single factor and orthogonal test to optimize the colorimetric conditionsand microwave assisted hydrolysis pretreatment conditions. Ultimately we want to determinea feasible and rapid detection technology for sheep milk powder of HAP. The results showthat,(1) It is feasible that L-HYP is regarded as characteristic amino acids of HAP.Thecontent is about ten percent. But the protein of the milk almost has no this compsition.So wecan distinguish milk protein and other animal protein.If L-HYP is detected,we can qualitativeand quantitative HAP of the sample.(2)Comparation of two different material HAP.HAP of different material containsdifferent quantity of protein and HYP. The quantity of HYP in skin-bone mixed HAP andboned HAP is10.02%and7.83%.(3) Optimization of detecting conditions. The best conditions in use of UVspectrophotometer is: hydrolysate liquid pH7.0, oxidation temperature20℃, oxidation time 20min, addition of chromogenic agent2.0mL, color developing time20min.(4) Optimization of Microwave aided hydrolysis conditions.When sulphuric acidconcentration4mol/L, volume6mL,power720w, time40~45min, compared withtraditional method, we can figure out the RSD range is-4.5~1.6%, the measurement ofhydroxyproline content is basically same with that of traditional heating hydrolysis16h. Thatis, Sample preparation time is reduced to40~45min.(5)This techonology can replace the traditional hydrolysis methods to detect HAP in goatmilk powder. This method can quickly inspect qualitative and quantitative addition of HAP ingoat milk powder. The result has high accuracy and reproducibility, Hydroxyprolineconcentration and absorbency has good linear relationship, decided to coefficient is0.9968,recovery is92.24%~100.56%, RSD is2.16%. Precision and repeatability is good.Verificationis effictive. The method has advantages of simple operation,economic and feasibility.the resultcan provide technical basis for dairy enterprises and related departments.