Can Protein Quantity and Quality Predict the Breadmaking Quality of South African Wheat?

Abstract

The breadmaking quality of South African wheat to a large extent is a reflection of the diverse production regions and environments in which the wheat is grown. Bread loaf volumes from wheat produced in the cooler irrigated regions of the Northern Cape and dryland production regions of the Western Cape suggest that grain protein content was not the primary factor determining loaf volume. The milling and baking industrial standard for loaf volume was achieved with 11–12% (grade 2) and 10–11% (grade 3) grain protein content. The primary factor responsible for variation in grain and flour protein contents and loaf volume for irrigated wheat and dryland wheats from both the summer and winter rainfall regions was environment, which complicates the selection of wheat for breadmaking quality. Although glutenin, gliadin, and albumin/globulin concentrations, which define protein quality, correlated significantly with grain protein content and loaf volume for wheat grown in all three production regions, trends were...