Abstract: This paper was aimed at using ultra high performance liquid chromatographic to determine hydroxyproline (Hyp) content in raw milk. Determination of Hyp in various conditions in raw milk on the effect of determination results obtained better conditions. The recovery rates of this method were 94.7% to 98.6%,1 to 16 μg/mL regression equation of standard curve was y=3286.5x+87.943,the correlation coefficient was r=0.9999,RSD less than 2.36%. The minimum detection limit was 1.0 mg/kg. The method had the simple operation,chromatographic separation speed,high accuracy,good precision, and could be used for quantitative determination of Hyp in raw milk,so as to determine whether hydrolyzed animal protein was added in raw milk.

Key words: hydroxyproline (Hyp); raw milk; ultra high performance liquid chromatography; determination