Detection of fruit fly infestation in pickling cucumbers using a hyperspectral reflectance/transmittance imaging system

Innovative Hyperspectral Imaging-Based Techniques for Quality Evaluation of Fruits and Vegetables: A Review

“…Most research on hyperspectral imaging has focused on the reflectance measurement, which is appropriate for evaluating surface or subsurface quality characteristics but not for internal defects in food products. Our group proposed a new concept of integrating reflectance and transmittance measurements in one hyperspectral imaging system for detecting both external quality attributes (e.g., color and size) and internal defects [28,[82][83][84][85][86][87][88]. The concept is based on the fact that the visible light in the region of 400-675 nm, which is relatively poor in penetrating biological tissues, is more suitable for assessing surface features of the product, while the red and NIR light in the region of 675-1000 nm has better penetration capabilities and can thus be used for internal quality assessment in transmittance mode.…”

“…A typical s value is 1.3 for cucumbers [86]. However, no diameter correction is needed for the reflectance measurement.…”

“…The infestation is generally hidden in the product and cannot be easily detected from outside. Lu and Ariana [86] In another study using LEDs replacing broadband QTH lamps as illumination sources, Cen et al [87] acquired hyperspectral reflectance images (400-700 nm) by using two white LEDs, and transmittance images (700-1000 nm) by using four 830-nm and four 890-nm infrared LEDs, from 'Journey' pickling cucumbers at two conveyor speeds of 85 and 165 mm/s. Reflectance images below 700 nm carried surface or color features information, while transmittance images above 700 nm contained information about the internal features of the cucumbers (Figure 17).…”

“…The infestation is generally hidden in the product and cannot be easily detected from outside. Lu and Ariana [86] Pest/insect infestation can pose a serious quality and safety problem for the pickle processor, as many countries have zero tolerance for importing pest-infested pickled products. The infestation is generally hidden in the product and cannot be easily detected from outside.…”

“…The infestation is generally hidden in the product and cannot be easily detected from outside. Lu and Ariana [86] reported on the detection of fruit fly infestation in pickling cucumbers ( Figure 18) using hyperspectral reflectance and transmittance imaging. Three sensing modes, reflectance (450-740 nm), transmittance (740-1000 nm) and their combination were compared for differentiating infested cucumbers from normal ones by PLS discriminant analysis.…”