• Journal of Biosystems Engineering
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• v.38 no.3
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• pp.199-207
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• 2013

Purpose: Tomatoes, an important agricultural product in fresh-cut markets, are sometimes a source of foodborne illness, mainly Salmonella spp. Growth cracks on tomatoes can be a pathway for bacteria, so its detection prior to consumption is important for public health. In this study, multispectral Visible/Near-Infrared (NIR) reflectance imaging techniques were used to determine optimal wavebands for the classification of defect tomatoes. Methods: Hyperspectral reflectance images were collected from samples of naturally cracked tomatoes. To classify the resulting images, the selected wavelength bands were subjected to two-band permutations, and a supervised classification method was used. Results: The results showed that two optimal wavelengths, 713.8 nm and 718.6 nm, could be used to identify cracked spots on tomato surfaces with a correct classification rate of 91.1%. The result indicates that multispectral reflectance imaging with optimized wavebands from hyperspectral images is an effective technique for the classification of defective tomatoes. Conclusions: Although it can be susceptible to specular interference, the multispectral reflectance imaging is an appropriate method for commercial applications because it is faster and much less expensive than Near-Infrared or fluorescence imaging techniques.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.87-89
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• 2008

A blue mold on tomato fruit caused by Penicillium oxalicum occurred sporadically in a greenhouse at Gyeongsangnam-do Agricultural Research and Extension Services. Infection usually occurred through wounds or cracks on the fruits. Symptoms began with water soaking lesions, then became watery and softened eventually. Colony of the causal fungus was white at the early growing stage, turned green on Czapek yeast extract agar and malt extract agar. Conidia were ellipsoidal in shape and $2-6{\times}2-4{\mu}m$ in size. Stipes were septate, smooth, thin walled, and $90-280{\times}3-4{\mu}m$ in size. Penicilli were mostly biverticillate. Ramuli were 1-3 groups, smooth, and $10-16{\times}2-3{\mu}m$ in size. Rami were 1-2 groups and $6-30{\times}2-4{\mu}m$ in size. Metulae were 2-3(5) verticils, smooth, and $12-20{\times}3-4{\mu}m$ in size. Phialides were 5-7 verticilate, ampulliform to cylindroidal, smooth, and $8-12{\times}2-3{\mu}m$ in size. Optimum temperature for growth was about $25^{\circ}C$. Pathogenicity of the fungus was proved on tomato fruit according to Koch's postulation. On the basis of mycological and pathological characteristics, the fungus was identified as P. oxalicum Currie & Thom. This is the first report of the blue mold on tomato fruit caused by P. oxalicum in Korea.