Green color and texture are important attributes for the perception of freshness of wild rocket. Packaging of green leafy vegetables can postpone senescence and yellowing, but a drawback is the risk of anaerobic respiration leading to loss of tissue integrity and development of an olive-brown color. The hypothesis underlying this paper is that color and textural quality of packaged wild rocket leaves can be predicted by multispectral imaging for faster evaluation of visual quality of leafy green vegetables in scientific experiments. Multispectral imaging was correlated to sensory evaluation of packaged wild rocket quality. CIELAB values derived from the multispectral images and from a spectrophotometer changed during storage, but the data were insufficient to describe variation in sensory perceived color and texture. CIELAB values from the multispectral images allowed for a more detailed determination of color compared to measurement with a spectrophotometer with an 8 mm aperture. Furthermore, the multispectral images enabled subtraction of background information of the sample and gave more accurate results on visual color of wild rocket leaves. The combination of wavelengths in the NIR range describing textural changes, and wavelengths in the VIS range describing color changes was optimal for quantification of sensory perceived color and textural quality of packaged wild rocket.
Postharvest Biology and Technology, 2013, Vol 75, p. 86-95
rucola; wild rocket; multispectral imaging; NIR; Quality; green leafy vegetable