Sucrose from pure orange juices and beet sugar syrups was isolated by preparative HPLC. A portion was converted to sucrose octanitrate, to remove the readily exchangeable hydroxyl hydrogens. D/H ratios were then determined on the carbon-bound hydrogen atoms by mass spectrometric stable-isotope ratio analysis. The mean D/H ratios in orange sucrose were significantly elevated compared to those in beet sucrose, the δ(D) values being -27 and -143/mil respectively. 18O/16O ratios were determined for underivatized sucrose from both soures. With a single exception, δ(18O) values were higher in orange sucrose than in beet sucrose. From these data, a discriminatory formula has been developed describing a 99.99% confidence ellipse about pure orange juices. The availability of this method to identify orange juices as pure or adulterated with beet sugar will provide a disincentive for the economic adulteration of orange juice.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)