Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2005
Publication Date: 7/1/2005
Citation: Schober, T., Messerschmidt, M., Bean, S., Park, S.H., Arendt, E.K. 2005. Gluten-free bread from sorghum: quality differences among hybrids. Cereal Chemistry. 82(4): 394-404.
Interpretive Summary: It is estimated that 1-2 million people in the U.S. may have celiac disease (CD), an intolerance wheat gluten proteins and similar proteins in barley and rye. There is no cure for CD, people afflicted with this disease must simply avoid all products containing wheat, barley, or rye, severally limiting their choice of cereal based food products. Sorghum is considered to be a safe food for persons with CD; thus the development of high quality baked products from sorghum would greatly benefit this group of people and provide new markets for U.S. sorghum. This study was designed to investigate to develop a system to evaluate the breadmaking potential of U.S. sorghum hybrids. Using the developed baking system, 10 sorghum flours were baked and significant differences in bread quality were observed. This suggests that sorghum hybrids with improved food functionality may be identified and that sorghum breeding programs may be able to breed sorghum specifically for improved human food production.
Technical Abstract: Gluten-free breadmaking quality of ten sorghum flours was evaluated and compared. A basic recipe was first developed consisting of (relative basis) decorticated sorghum flour (70), corn starch (30), water (105), salt (1.75), sugar (1), and dried yeast (2). To compare the different sorghum samples, batter consistency was standardized by varying water levels to achieve the same force during extrusion. Crumb properties were evaluated by digital image analysis and texture profile analysis (TPA). Significant differences (P<0.001) in crumb grain were found among the hybrids with mean cell area ranging from 1.3 to 3.3 mm2 and total number of cells ranging from 13.5 to 27.8/cm2. TPA hardness values of the crumb also varied significantly (P<0.001). Breads differed little in volume, height, bake loss, and water activity. Investigation of added ingredients on bread quality was conducted using response surface methodology (RSM) with two sorghum hybrids of opposite quality. Addition of xanthan gum (0.3 - 1.2 % flour weight basis [fwb]) and skim milk powder (1.2-4.8% fwb) and varying water levels (100-115% fwb) were tested using a central composite design. Increasing the water level increased loaf specific volume, while increasing xanthan gum levels decreased the volume. As skim milk powder levels increased, loaf height decreased. Quality differences between the hybrids were maintained throughout the RSM. This study showed that certain sorghum hybrids have higher intrinsic bread quality than others.