Quantitative H-1 NMR Analysis of Egg Yolk, Alcohol, and Total Sugar Content in Egg Liqueurs

摘要

Analyzing egg liqueurs for compliance with legal requirements means several different time-consuming preparations and analytical processes. In this paper, we describe the approach-to use quantitative H-1 NMR spectroscopy as an accurate alternative technique. H-1 NMR analysis comprised two different rapid sample preparations for water-soluble or nonpolar ingredients: Fifteen egg liqueurs-were analyzed for alcoholic strength and content of total sugar and egg yolk (estimated by cholesterol as a marker substance) with both classical methods and quantitative H-1 NMR spectroscopy. The. results of both methods. Showed excellent correlations for alcoholic strength (R = 0.996, p < 0001) and content of total sugar (R = 0.989; p < 0.001) and cholesterol (R = 0.995, p < 0:001). Besides, NMR spectra revealed further information: a signal of phosphatidylcholine at about delta = 3.20 ppm served as a second marker for the egg yolk content, and characteristic signals-Of lactose at delta = 4.46 ppm and butyic acid at delta = 0.97 ppm indicated the use of milk products, which has to be declared for lactose: intolerant consumers.