DNA methods are available for determining the adulteration of orange juice by mandarin juice. Chinese researchers have developed a different approach by analysing the VOCs in the headspace of orange juice (not from concentrate) and manadarin juice, and using chemometrics to calculate if a sample of orange juice has mandarin juice in it. Juices were extracted from different cultivars of sweet orange and mandarin fruits. After being pasteurised, the VOCs in the juice samples were extracted using headspace solid-phase microextraction, and qualitatively and quantitatively analysed using gas chromatography–mass spectrometry. Thirty-two VOCs identified in both the sweet orange juice and mandarin juice, but at different concentrations, were used as variables, and the identification model for discriminating between the two varieties of juice was established by principal component analysis. Model juice mixtures were made up from different varieties of both mandarins and oranges. The model was able to identify and quantify a blend of mandarin juice in orange juice at the level of 10% or above.
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