Detection of High Fructose Corn Syrup in Apple Juice by Mass Spectrometric 13C/12C Analysis: Collaborative Study

Abstract

The addition of high fructose corn syrups (HFCSs) to apple juice can be detected by mass spectrometric determination of 13C/12C ratios. Forty-one pure apple juice samples, representing 18 varieties, gave a mean value for δ13C of −25.3‰ (parts per thousand), while 4 HFCSs averaged −9.7‰. In a collaborative study, 1 pure apple juice and 4 apple juice-HFCS mixtures containing from 25 to 70% apple juice were properly classified by 6 laboratories. Samples with δ13C values less negative than −20.2‰, 4 standard deviations from the mean of pure juices, can, with a high degree of confidence, be classified as adulterated. Because of the range of values for pure apple juices, other interpretations of δ13C data on suspect samples are meaningless (i.e., samples with values more negative than −20.2‰ must be considered unadulterated with HFCS). The 13C/12C mass spectrometric method for corn syrup products, 31.150-31.153, has been adopted official first action for detecting HFCS in apple juice.