Identification of Fluorescent Substance in Mandarin Orange Skin for Machine Vision System to Detect Rotten Citrus Fruits

Automated Systems Based on Machine Vision for Inspecting Citrus Fruits from the Field to Postharvest—a Review

“…For this reason, it is of special importance to detect the compounds involved in the fluorescence process as it was studied by Kondo et al (2009) and Momin et al (2013a). Another problem is related with other defects that also present some degree of fluorescence and hence can confuse a potential automated system (Blasco et al 2007b;Slaughter et al 2008;Obenland et al 2010).…”

“…Table 2 summarises the different works carried out for the application of computer vision in the citrus inspection in postharvest ordered by different topics chronologically. Table 2 Reference Achievement Estimation of properties of the fruit Blasco et al (2007a) Used an unsupervised segmentation method based on region growing to separate defects from sound skin Blasco et al (2007b) Tested different colour spaces to discriminate among eleven types of defects in the citrus peel and the stem Kim et al (2009) Introduced textural features in colour images to distinguish between some serious damages and other cosmetic defects (Blasco et al 2009) Introduced spectral and morphological information to distinguish between some serious damages and other cosmetic defects Omid et al (2010) Estimated the volume of the citrus using two cameras and computing the volume by dividing the fruit in a series of discs López-García et al (2010) Used multivariate image analysis introducing textural information and PCA to separate defects from sound skin López et al (2011) Used colour and texture features extracted in the RGB and HSI colour spaces to discriminate among seven common defects of citrus fruits Vijayarekha (2012a) Used several segmentation techniques to detect defects in citrus fruits Vijayarekha (2012b) Used several segmentation techniques to identify defects in citrus fruits Li et al (2013) Used RGB image ratios to discriminate the stem from different defects in oranges Cubero et al (2014b) Developed a robust method to detect stalks in different fruits, including oranges and mandarins Iqbal et al (2016) Investigated several supervised segmentation methods based on colour information Detection of decay lesions Gomez et al (2007) Used a Mahalanobis kernel to classify pixels as decay or sound skin in hyperspectral images Gómez-Sanchis et al (2008) Used correlation analysis, mutual information, stepwise, and genetic algorithms based on linear discriminant analysis (LDA) to select the most relevant bands of hyperspectral images, and classification and regression trees and LDA for pixels classification in decay or sound skin Kondo et al (2009) Studied the compounds involved in the fluorescence process to detect decay in oranges Kurita et al (2009) Innovative technique which alternatively switched on UV and white pulsed LED, thus allowing the inspection with both types of illumination, and hence allowed both a fluorescent and a colour image to be captured Slaughter et al (2008) Detect freeze-damages in the skin of trough fluorescence imaging Blanc et al (2010) Patented a commercial sorter for decay detection in citr...…”

Detection of Chilling Injury in Pickling Cucumbers Using Dual-Band Chlorophyll Fluorescence Imaging

“…Slaughter et al (2008) detected the freeze damage of oranges by acquiring color images of the yellow-fluorescent emissions of peel oil constituents [ 25 ]. Kondo et al (2009) conducted a similar study on the detection of rotten citrus fruit and examined the fluorescent substances [ 26 ]. Researchers also developed fluorescence imaging systems in multispectral [ 27 , 28 ] or hyperspectral [ 29 ] mode for detecting foreign contaminants on horticultural products.…”

Identification of UV-Fluorescence Components for Detecting Peel Defects of Lemon and Yuzu using Machine Vision

“…Reports have noted that most organs in citrus accumulate significant quantities of flavonoids during their development, and that when these flavonoids are exited with ultraviolet (UV) light, a number of them fluorescence in the visible (VIS) region of the spectrum (Kondo et al, 2009;Benavente-Garcia, et al, 1993;Castillo, et al, 1992;Uozumi et al 1987). It has been proposed that when the oil glands of citrus are ruptured, peel oil is released, migrates closer to the peel surface, allowing it to be visible when excited by UV light (Latz, and Ernes, 1978).…”