C-13-IRIS: An improved method to detect the addition of low levels of C-4-derived sugars to juices

A method to improve the detection of cane or corn sugar addition to fruit j uices has been developed. This involves the isolation of the individual sug ars and measurement of their carbon isotope ratios. Using the Isotopic Rela tions of Individual Sugars approach, the additions of cane sucrose or cane invert as low as 4% of the total sugars can be detected in orange juice. Th is method offers a significant improvement over the conventional carbon iso topic method that has a detection limit of about 10%.