Citrus juice classification by SPME-GC-MS and electronic nose measurements

According to suppliers indications, 76 commercial and 120 self-prepared citrus juices were grouped corresponding to fruit type, cultivar and treatment by linear discriminant analysis of the volatile compounds measured by an electronic nose (EN) instrument and solid-phase micro extraction gas chromatography mass spectrometry (SPME-GC-MS) from the headspace. While the number of available variables for SPME-GC-MS with 311 was rather high and always allowed for reasonable group separation, the number of variables for the EN instrument was limited to 12. Nevertheless, wrong and misleading supplier information was uncovered especially by EN data. Analysis revealed a commercial orange juice grouped close to grapefruit and two pummelos declared as grapefruits, while further conspicuous samples were noted but require more detailed investigations. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.