Pingping Zhang1, Tom O Jondiko, Michael Tilley, Joseph M Awika. 1. Cereal Quality Lab, Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA; Provincial Key Lab for Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China.
Abstract
BACKGROUND: Steamed bread is a popular staple food in Asia with different flour quality requirements from pan bread. Little is known about how glutenin characteristics affect steamed bread quality. This work investigated how deletions of high-molecular-weight glutenin subunits (HMW-GS) influence gluten properties and Chinese steamed bread quality using 16 wheat lines grown in Texas. RESULTS: Although similar in protein content (134-140 mg g⁻¹), gluten composition and dough properties differed widely among the lines. Compared with non-deletion lines, deletion lines had lower (P < 0.05) unextractable polymeric protein (294 vs 470 mg g⁻¹), HMW-GS/low-molecular-weight glutenin subunit ratio (0.25 vs 0.41), dough force to extend (0.16 vs 0.44 N) and mixing peak time (2.03 vs 4.52 min). Deletion lines with HMW-GS composition of 2*/17+_/5+_ and 2*/17+_/2+12 showed moderate gluten strength (mixing peak time, 1.96-2.94 min; force to extend, 0.18-0.23 N) and high dough extensibility (106-129 mm). These lines also produced good steamed bread quality (score, 60.8-65.0) with good elasticity and crumb structure. CONCLUSION: Deletion at Glu-B1y and/or Glu-D1y loci in high-strength hard wheat produced good dough properties for steamed bread. This suggests that wheat functionality for steamed bread can be improved by manipulating HMW-GS composition.
BACKGROUND: Steamed bread is a popular staple food in Asia with different flour quality requirements from pan bread. Little is known about how glutenin characteristics affect steamed bread quality. This work investigated how deletions of high-molecular-weight glutenin subunits (HMW-GS) influence gluten properties and Chinese steamed bread quality using 16 wheat lines grown in Texas. RESULTS: Although similar in protein content (134-140 mg g⁻¹), gluten composition and dough properties differed widely among the lines. Compared with non-deletion lines, deletion lines had lower (P < 0.05) unextractable polymeric protein (294 vs 470 mg g⁻¹), HMW-GS/low-molecular-weight glutenin subunit ratio (0.25 vs 0.41), dough force to extend (0.16 vs 0.44 N) and mixing peak time (2.03 vs 4.52 min). Deletion lines with HMW-GS composition of 2*/17+_/5+_ and 2*/17+_/2+12 showed moderate gluten strength (mixing peak time, 1.96-2.94 min; force to extend, 0.18-0.23 N) and high dough extensibility (106-129 mm). These lines also produced good steamed bread quality (score, 60.8-65.0) with good elasticity and crumb structure. CONCLUSION: Deletion at Glu-B1y and/or Glu-D1y loci in high-strength hard wheat produced good dough properties for steamed bread. This suggests that wheat functionality for steamed bread can be improved by manipulating HMW-GS composition.