N-glycan profiles as a tool in qualitative and quantitative analysis of goat milk adulteration

Goat milk is closer to human milk in some respects than cow milk, and therefore preferred by many consumers. Because of the short lactation period and consequently less milk production of goats, the price of goat milk is often higher than that of cow milk, so that adulteration of goat milk is common. N-glycans have stability and thus have a good potential for acting as a new biomarker for identifying dairy adulteration. In this study, the N-glycan structures of goat milk and cow milk were analyzed by Ultra-high performance liquid chromatography (UPLC) and MALDI-TOF-MS. Based on the high species specificity of N-glycans, a method for identifying goat milk mixed with cow milk was established. The adulteration content of 5% cow milk in goat milk could be qualitatively and quantitatively detected. A prediction model of adulteration in goat milk was established by using partial least squares (PLS).