Reflectance and Transmittance Spectroscopy Applied to Detecting Fumonisin in Single Corn Kernels Infected with Fusarium verticillioides

Abstract

Reflectance and transmittance visible and near‐infrared spectroscopy were used to detect fumonisin in single corn kernels infected with Fusarium verticillioides. Kernels with >100 ppm and <10 ppm could be classed accurately as fumonisin positive or negative, respectively. Classification results were generally better for oriented kernels than for kernels that were randomly placed in the spectrometer viewing area. Generally, models based on reflectance spectra have higher correct classification than models based on transmittance spectra. Statistical analyses indicated that including near‐infrared wavelengths in calibrations improved classifications, and some calibrations were improved by including visible wavelengths. Thus, the color and chemical constituents of the infected kernel contribute to classification models. These results show that this technology can be used to rapidly and nondestructively screen single corn kernels for the presence of fumonisin, and may be adaptable to on‐line detection and sorting.

Development of a Single Kernel NIR Barley Protein Calibration and Assessment of Variation in Protein on Grain Quality

“…A number of applications have been reported using SKNIR in wheat and maize for quality and fungal infection [4][5][6][7][8]14,21,22,25 , as well as for protein 4,26 and hardness 4,17 in wheat. In barley, there have been a number of recent reports on SK measurements for grain hardness 2,13,[15][16][17]19 .…”

Development of Physical and Optical Methods for In-shell Brazil Nuts Sorting and Aflatoxin Reduction

“…For the rejected nuts, they were 9.94 g (min 4.8, max 12.8) and 7.26 g (min 13.2, max 15.8) with SD and %RSD of 4.96 & 3.36% and 6.88 & 4.53% for the two air speeds, respectively. In fact low density (S/N<1.5) nuts may be more prone to aflatoxin contamination than the high density ones (De-Mello and Scussel, 2007) and have been reported by other authors for grains and nuts (Dowell et al, 2002;Huff, 1980;Pearson and Wicklow, 2006). It is important to emphasize that, although, the lightest nuts blew off with the air stream, some heavy (healthy) nuts were also rejected (blown off) during the density sorting.…”

“…Those tissue alterations scatter the NIR beam reducing its transmittance when it crosses the entire in-shell nut material giving readings different of that obtained in the healthy nuts (Dowell et al, 2002;Wicklow and Pearson, 2006;Pearson, 1999;Pearson and Young, 2002).…”

“…Corn contaminated with mycotoxins showed lower density than non-contaminated ones (Dowell et al, 2002;Huff, 1980;Pearson and Wicklow, 2006), therefore, they could be separated by flotation in water or sucrose/salt solutions (Huff, 1980;Huff and Hagler, 1982;1985;Rotter et al, 1995;Shetty and Bhat, 1999) or by air stream to sort the lighter corn from the heaviest ones (Huff, 1980). Pearson et al, in 1994 showed that early split pistachio which is more exposed to fungi and aflatoxin contamination is significantly different in relation to length, width and weight.…”

“…From these characteristics it was possible to develop an image system for sorting earlier split pistachio nuts (Pearson and Slaughter, 1996). Dowell et al (2002), reported that the presence of fungi can affect some grain characteristics such as color, protein structure and oil content. Contaminated grains were rejected by color sorting machines and reduced 51% of the aflatoxin contamination in peanuts followed by hand sorting (Dickens and Whitaker, 1975;Zovico et al, 1999).…”