Impact of bran components on the quality of whole wheat bread

Authors: KHALID, KHAIRUNIZAH - North Dakota State University; Ohm, Jae-Bom; SIMSEK, SENAY - North Dakota State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2016
Publication Date: 4/18/2016
Citation: Khalid, K.H., Ohm, J.-B., Simsek, S. 2016. Impact of bran components on the quality of whole wheat bread [abstract]. 15th International Cereal and Bread Congress, April 18-21, 2016, Istanbul, Turkey. p. 325.

Interpretive Summary:

Technical Abstract: Whole grains contain components, such as dietary fiber, starch, fat, antioxidant nutrients, minerals, vitamin, lignans, and phenolic compounds, which are beneficial to human health. Most of the beneficial components are found in the germ and bran as part of a wheat kernel, which are reduced in the grain-refining process. Despite the health benefits of bran and whole-wheat products, bran tends to negatively impact dough viscoelastic properties, loaf volume and end product quality in general. Therefore, effects of different major bran components including lipids, phenolics (extractable and hydrolysable), and fiber fractions on the whole wheat bread-making quality were investigated by following up a reconstitution approach using the 24 factorial experimental design. All analysis of variance (ANOVA) models were significant (P<0.0001) showing coefficients of determination greater than 0.8 for quality traits such as farinograph parameters (stability, water absorption, mixing tolerance index), gluten index, gassing power, and baking parameters (specific loaf volume, and proof height). The factorial model derived from a coded equation was used to visualize and identify the trend that individual bran components impacted the quality traits. Interestingly, bran fiber was identified as a single main factor that had highly significant impact on all flour, dough, and baking parameters measured in this experiment. Specifically, presence of fiber in dough system increased water absorption and decreased stability. Fiber and hydrolysable phenolics synergistically had negative impact on gluten index and dough quality. Gassing power of whole wheat dough showed a positive association with the presence of fiber in the system but a negative association with the presence of hydrolysable phenolics. Also, fiber and hydrolysable phenolics were the main factors that significantly impacted bread loaf volume. Reconstituted breads prepared without fiber or hydrolysable phenolics had higher loaf volume than white bread. Overall, influence of bran components on bread-making quality seemed very complex since analysis of variance showed that interaction of all four bran components (lipid, extractable and hydrolysable phenolics, and fiber) was highly significant (P<0.05) to cause changes in farinograph parameters, gluten index, baking parameters, and gassing power. The study of how each of these components effects on bread quality may lead to further investigation about pre-treatments that could be performed to bran in an effort to improve whole wheat bread quality.