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ABSTRACT
Sprout damage which results in poor breadmaking quality due to enzymatic activity of a-amylase is one of the important grading factors of wheat in Canada. Potential of near-infrared (NIR) hyperspectral imaging was investigated to detect sprouting of wheat kernels. Artificially sprouted, midge-damaged, and healthy wheat kernels were scanned using NIR hyperspectral imaging system in the range of 1000-1600 nm at 60 evenly distributed wavelengths. Multivariate image analysis (MVI) technique based on principal components analysis (PCA) was applied to reduce the dimensionality of the hyperspectral data. Three wavelengths 1101.7, 1132.2, and 1305.1 nm were identified as significant and used in analysis. Statistical discriminant classifiers (linear, quadratic, and Mahalanobis) were used to classify sprouted, midge-damaged, and healthy wheat kernels. The discriminant classifiers gave maximum accuracy of 98.3 and 100% for classifying healthy and damaged kernels, respectively.
Cereal Chem. 86(3):256-260
Canada is the sixth largest producer of wheat and ranks among the top exporters in the world with 27 Mt average annual production and 15 Mt annual export (FAOSTAT 2007). Canada has a reputation of producing and supplying very high quality wheat in the world grain market. Sprouting is considered one of the important grading factors of wheat in Canada and all classes of Western Canadian wheat are tested for sprout damage. Sprouting occurs as a result of germination of wheat kernels by absorbing water mosdy due to rain before the harvest. Enzymatic activity in the germinated kernels results in decrease in starch, increase in sugar, increase in total protein, change in amino acid composition, and dry matter loss (Lorenz and Valvano 1981). α-Amylase, a common enzyme produced in sprouted wheat kernels affects the baking quality of bread, and mus lowers the premium paid for wheat. a-Amylase is present in very high concentration in sprouted kernels (Kruger 1999). The quality of wheat flour for breadmaking is defined by several parameters such as water absorption capacity, dough mixing, loaf volume, crumb strength, and slicing characteristics of baked bread. These parameters are adversely affected due to starch damage in sprouted kernels (Finney et al 1988). Sprouted kernels are at a high risk of being contaminated with pathogens and ideal for the growth of bacteria (Health Canada 2006). These padiogens are trapped in cracks and crevices that develop...