Shelf life of fresh cut vegetables as measured by an electronic nose. Preliminary study

Evaluation of the shelf life of fresh vegetables is very important and there is a need for rapid non-destructive methods for the determination of freshness and spoilage during their commercial life. For this purpose an electronic nose was evaluated to determine its usefulness in measuring the shelf life of fresh cut vegetables. Volatile changes in samples of cicorino and shredded carrots packaged with cling films were analysed by an electronic nose equipped with 10 MOSFET and 5 MOS sensors. Microbial spoilage and colour evolution were also evaluated. A pattern recognition software program was used to evaluate the sensor signals. The response of 5 sensor signals was used to classify the degree of freshness of both vegetables. The first principal component of PCA was correlated to the microbial population in the samples and to their colour index, showing that the electronic nose is a suitable tool to study the storage life of these products. L'evaluation de la duree de conservation des legumes frais tranches est importante, il est necessaire d'avoir des methodes d'evaluation non destructives et rapides. Un nez electronique a ete teste: les modification dans la composition des composes volatils des carottes rapees emballees ont ete mesurees. L'alteration microbienne et la couleur ont egalement ete etudies. 5 signaux ont ete utilises pour classer les produits. L'analyse en composantes principales permet de correler la premiere composante a la population microbienne et la deuxieme a la couleur.