Soft wheat quality characteristics required for making baking powder biscuits

Authors: MA, FENGYUN - The Ohio State University; Baik, Byung-Kee

Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2017
Publication Date: 1/1/2018
Citation: Ma, F., Baik, B-K. 2018. Soft wheat quality characteristics required for making baking powder biscuits. Journal of Cereal Science. 79:127-133.

Interpretive Summary: Baking powder biscuits, popularly consumed as a breakfast food, are prepared from the basic ingredients of wheat flour, shortening, salt and milk leavened with baking powder or baking soda. Desirable biscuits have a high height, flat top, and tender and flaky crumb structure. Currently little information exists for selecting wheats that mill into flour to produce biscuits according to the consumer’s preference for shape and texture. Our study focused on defining appropriate guidelines for the identification of wheat grain and the selection of breeding lines to develop wheat varieties specifically suited for making biscuits. We tested 15 soft wheat varieties for physical and compositional grain characteristics along with flour water absorption values, relating these to size, shape, volume and crumb texture of baked biscuits. We identified the useful wheat grain characteristics for predicting biscuit quality, and found that flour protein content and strength largely determine the height and shape of biscuits, while the degree of starch damage during milling as well as the flour’s water retention capacity predict biscuit volume. Accordingly, tests for protein content and strength, along with flour yield and damaged starch appear to be effective for identifying soft wheat varieties suitable for making biscuits. Soft wheat flour with high protein content, weak-to-medium gluten strength and low damaged starch content were found to produce biscuits with high height, a flat top, sizeable specific volume and soft crumb texture. These findings define the specific wheat grain profile suited for making biscuits of desirable quality. The profile for biscuit flour benefits wheat breeding programs by providing set soft wheat quality targets for variety improvement, and the soft wheat milling and baking industries by establishing a quality control guideline for wheat grain.

Technical Abstract: Fifteen soft wheat varieties were evaluated for their grain, milling, flour and dough mixing characteristics, as well as their solvent retention capacities (SRCs), pasting properties and suitability for making baking powder biscuits, to identify wheat quality characteristics required for making biscuits. Protein contents of grain and flour, and sodium dodecyl sulfate sedimentation (SDSS) volume, showed positive relationships with biscuit height and shape factor. Kernel hardness, damaged starch content (DSC) and water SRC exhibited negative correlations with biscuit specific volume, while peak and breakdown viscosities, and grain protein content, were positively associated with biscuit specific volume. Stepwise multiple regression analysis indicated that biscuit height and specific volume can be predicted from flour protein content (R2=0.65) and DSC (R2=0.69), respectively; while SDSS volume and flour yield together predict biscuit shape factor (R2=0.83). Cluster analysis based on biscuit height and shape factor indicated that seven soft wheat varieties with flour protein contents greater than 7.9% and SDSS volumes lower than 32.0 mL produce good-quality biscuits with high height, intermediate shape factor, great specific volume and soft crumb. The results of this study suggest that soft wheat flours with high protein contents, weak-to-medium gluten strength and low DSCs are suitable for making desirable-quality biscuits.