Print version ISSN 0102-0536
MORETTI, Celso Luiz; SARGENT, Steven Alonzo; BALABAN, Murat O and PUSCHMANN, Rolf. Electronic nose: a non-destructive technology to screen tomato fruit with internal bruising. Hortic. Bras. [online]. 2000, vol.18, n.1, pp. 20-23. ISSN 0102-0536. http://dx.doi.org/10.1590/S0102-05362000000100005.
Tomato (Lycopersicon esculentum Mill) fruits, 'Solar Set', were harvested at the mature-green stage (green color in 100% of the fruit surface) and gassed with 100mL.L-1 of ethylene at 20°C. At the breaker stage (less than 10% of the fruit surface is red or tannin-yellowish), fruit were dropped from a 40 cm height onto a smooth surface. Following impact, fruits were stored at 20°C and 85-95% relative humidity until table-ripe stage. Bruised and unbruised fruit were then placed individually inside the electronic nose-sampling vessel and the twelve conducting polymer sensors were lowered into the vessel and exposed to the volatile given off by the fruit. Data were analyzed employing multivariate discriminant analysis (MVDA), which maximizes the variance between treatments. The degree of dissimilarity was defined using the Mahalanobis distance The differences found between bruised and unbruised fruit were highly significant (P<0.0041). The Mahalanobis distance between groupings (28.19 units) was a dramatic indicative of the differences between the two treatments. The electronic nose proved to be a useful tool to nondestructively identify and classify tomato fruit exposed to harmful post-harvest practices such as mechanical injuries.
Keywords : Lycopersicon esculentum; mechanical injury; postharvest; storage.