Detection of Grain Weevils inside Single Wheat Kernels by a Very near Infrared Two-Wavelength Model

Abstract

Near infrared reflectance spectroscopy in the very near infrared region (700 nm to 1100 nm) has been investigated for the detection of grain weevil larvae and pupae inside single wheat kernels. Using a total of 80 samples, simple, two-wavelength classification models have been identified, based on either log 1/R (982 nm)-log 1/R (1014 nm) or log 1/R (972 nm)-log 1/R (1032 nm). Both models correctly classified over 96% of samples as uninfested or infested. Detection performance equalled that obtained using the full-spectrum approach of principal components analysis. In a separate experiment, repeatedly scanning samples over time demonstrated detection of younger larvae as well as later developmental stages. This experiment confirmed that the observed spectral differences arise from the actions of the developing insect, rather than from any feature specific to kernels selected by adult females for egg-laying. The origins of the spectral differences are almost certainly decreasing grain starch, for log 1/R (982 nm)-log 1/R (1014 nm), or increasing grain moisture, for log 1/R (972 nm)-log 1/R (1032 nm), with infestation. These results indicate that the future incorporation of the wavelength pair, 982 nm and 1014 nm, as camera lens filters in a very near infrared imaging system, could lead to an inexpensive, rapid and reliable machine-vision method for detecting internal insects in grain.

Identification of species and geographical strains ofSitophilus oryzaeandSitophilus zeamaisusing the visible/near-infrared hyperspectral imaging technique

“…NIR spectroscopy is based on the molecular overtone and combination vibrations in organic compounds. In a previous study, by Ridgway et al, 28 wavelengths of 982 and 1014 nm were selected to develop a two-wavelength classification model for insect-damaged wheat kernels with NIR reflectance spectroscopy. Furthermore, Perez-Mendoza et al 29 found 890 nm to be one of the significant wavelengths for detecting insect fragments in wheat flour.…”

Assessment of Heat‐Damaged Wheat Kernels Using Near‐Infrared Spectroscopy

“…Recent research on single wheat kernel quality measurement using NIR spectroscopy has successfully measured protein content (Delwiche 1995(Delwiche , 1998; wheat class (Song et al 1995;Delwiche and Massie 1996); color class (Dowell 1997(Dowell , 1998Wang et al 1999a-c); and insect damage Baker et al 1999;Ridgway et al 1999). However, the use of NIR spectroscopy to measure kernel heat damage, especially in combination with other quality measurements, has not been studied.…”

Monitoring water uptake in whole barley (Hordeum vulgare L.) grain during steeping using near infrared reflectance spectroscopy

“…The region between 2200 and 2300 nm is related with C-H and CONH 2 associated with several compounds including protein, starch and cell wall constituents (e.g. lignin) (Gergely and Salgo, 2005;Jacobsen et al, 2005;Ridgway et al, 1999;Workman and Weyer, 2008). Table 3 shows the calibration statistics for the PLS models developed for water uptake and steeping time using whole barley samples and NIR spectra after second derivative as pre-processing.…”