Fast detection of rancidity in potato crisps using e-noses based on mass spectrometry or gas sensors

Well-established methods to assess rancidity in potato crisps such as the Rancimat or the acid degree value are time-consuming and labour-intensive. Here, we report on alternative methods, based on e-nose technology, to assess rancidity directly from potato crisps without any previous oil extraction step. This simplifies sample preparation, avoids the use of solvents or high temperatures and significantly speeds up the measurement process (from several hours down to 25 min). Two different e-noses were implemented. One was based on SPME coupled to fingerprint MS and the other one was based on dynamic headspace sampling and an array of metal oxide gas sensors. The two e-noses were used to classify crisps according to four stages of oxidative rancidity. While the MS e-nose reached a 100% success rate in this classification, the success rate of the GS e-nose was 68%. These results show that e-nose technology can be a useful tool for the crisp industry. We show that it is possible to reliably assess rancidity in potato crisps by either a mass spectrometry or a gas sensor-based electronic nose. The two approaches are presented and their performance compared in the framework of this application. (c) 2004 Elsevier B.V. All rights reserved.