THE QUALITY AND GRADING OF FROSTED WHEAT: ANNUAL SURVEYS OF THE 1930 TO 1935 WESTERN CANADIAN CROPS

Abstract

Fifteen officially graded samples of frosted wheat were collected from each of grades No. 3 Northern to No. 6, for 1930, 1931, 1932 and 1933, and 20 samples from each of these grades in 1934 and 1935. Physical classification of the kernels in each sample showed that the present system of grading is efficiently applied. While this system usually gives grades of frosted wheat, the averages of which fall in the right order with respect to combined milling and baking quality, it fails to give close indication of the baking quality, particularly of individual samples.A statistical examination of the relation between quality characteristics and grading factors showed that milling quality is closely related to the percentages of immature and heavily frosted kernels and also to the weight per measured bushel. Baking quality is not closely related to any of the grading factors now in use. Protein content is the best single index of baking quality, and the relation is improved if the percentages of immature and heavily frosted kernels are taken into account. The quality decreases more or less uniformly over the entire protein range with increasing percentages of immature kernels, but the presence of heavily frosted kernels is related to greater quality decreases in low protein samples than in high protein samples. The correlation between yield of straight flour and loaf volume facilitates simultaneous evaluation of milling and baking quality in grading. The application of these findings to practical grading is discussed.