Detection of orange juice adulteration by tangelo juice using multivariate analysis of polymethoxylated flavones and carotenoids

Reverse phase HPLC has been applied to quantify levels of polymethoxylated flavones and carotenoids in orange and tangelo juices. Lower levels of sinensetin and tetramethyl-o-scutellarein and higher levels of heptamethoxyflavone and tangeretin relative to nobiletin indicated the addition of tangelo to orange juice. beta-Cryptoxanthin and its esters, identified by, positive ion electrospray mass spectrometry, were present in larger amounts relative to beta-carotene in tangelo than in orange juice. Using canonical discriminant analysis, the addition of 100g kg(-1) tangelo to orange juice can be detected. (C) 2002 Society of Chemical Industry.