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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » Grain Quality and Structure Research » Research » Publications at this Location » Publication #302975

Title: Effect of sorghum flour composition and particle size on quality properties of gluten-free bread

item FREDERICK TRAPPEY, EMILY - Kansas State University
item KHOURYIEH, HANNA (JOHN) - Kansas State University
item ARAMOUNI, FADI - Kansas State University
item Herald, Thomas

Submitted to: Food Science and Technology International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2014
Publication Date: 2/11/2014
Citation: Frederick Trappey, E., Khouryieh, H., Aramouni, F., Herald, T.J. 2014. Effect of sorghum flour composition and particle size on quality properties of gluten-free bread. Food Science and Technology International. 21(3):188-202. DOI: 10.1177/1082013214523632.

Interpretive Summary: The increased awareness and better diagnosis for celiac disease has caused a higher demand for gluten-free products. Sorghum is the fifth most important cereal crop grown in the world. Sorghum does not contain gluten and maybe a viable grain for the gluten-free food market. This research evaluated the effect of white food-grade sorghum flour particle size on bread quality. A range of different tests were conducted on the sorghum flour produced from the milling process and subsequently evaluated in bread making. The research concluded that smaller sorghum flour particle size resulted in better quality gluten-free bread compared to those made with larger flour particle size.

Technical Abstract: White, food-grade sorghum was milled to flour of varying extraction rates (60%, 80%, 100%) and pin-milled at different speeds (no pin-milling, low-speed, and high-speed) to create flours of both variable composition and particle size. Flours were characterized for flour composition, total starch content, particle size distribution, color, damaged starch, and water absorption. Bread was characterized for specific volume, crumb structure properties, and crumb firmness. Significant differences were found (p<0.05) in the composition of sorghum flours of varying extraction rate, most notably for fiber and total starch contents. Flour particle size and starch damage were significantly impacted by extraction rate and speed of pin milling. Water absorption increased significantly with increasing extraction rate and pin-milling speed. Breads produced from 60% extraction flour had significantly higher specific volumes, better crumb properties, and lower crumb firmness when compared to all other extractions and flour types. The specific volume of bread slices was ranged from 2.01 mL/g (100% extraction, no pin-milling) to 2.54 mL/g (60% extraction, low-speed pin-milling), while the firmness was ranged from 553.28 g (60% extraction, high-speed pin-milling) to 1096.26 g (commercial flour, no pin-milling). The bread characteristics were significantly impacted by flour properties, specifically particle size, starch damage, and fiber content (p<0.05).