Monitoring of rancidity of milk by means of an electronic nose and a dynamic PCA analysis

This paper reports the use of a semiconductor thin films based electronic n ose to recognise the rancidity of two different kinds of milk (UHT and past eurised) during their ageing days. The employed sensor array consists of fi ve different SnO2 thin films prepared by means of the sol-gel technology. T he data coming from the response of the sensors have been elaborated by pri ncipal component analysis (PCA) in order to obtain a classification of the data clusters related to different milk ageing days and so track the dynami c evolution of milk rancidity. The obtained results could lead to industria l applications in dairying for the quality control of starting milk and the rancidity check during the different stages of production. (C) 2001 Elsevi er Science B.V. All rights reserved.