Location: Grain Quality and Structure ResearchTitle: Improvement of whole wheat dough and bread qualities with hydrocolloids
|TEBBEN, LAUREN - Kansas State University|
|Tilley, Michael - Mike|
|LI, YONGHUI - Kansas State University|
Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2021
Publication Date: 8/22/2021
Citation: Tebben, L., Tilley, M., Li, Y. 2021. Improvement of whole wheat dough and bread qualities with hydrocolloids. Food Hydrocolloids. 3:116-128. https://doi.org/10.23789/1869-2303-2021-03-116.
Interpretive Summary: Hydrocolloids are high molecular weight polymers that are hydrophilic and form gels or highly-viscous suspensions in water-based systems. In foods, hydrocolloids are used to modify texture and viscosity, and can be broadly classified as thickeners. Hydrocolloids come from several sources, including seeds, plant exudates or cell wall material, seaweed, cellulose derivatives, microbial fermentation products, and modified starches. Hydrocolloids are used extensively in gluten-free bakery products to provide strength, stability, and viscoelasticity in the absence of a gluten network. In wheat-based bakery applications, hydrocolloids increase water absorption and modify dough properties, provide stability to frozen dough and par-baked bread, and, increase loaf volume, improve crumb texture, increase moisture retention, and retard staling. Whole wheat bread in particular can benefit from the strengthening effects of hydrocolloids, since the bran and germ in whole wheat flour lead to a weaker gluten network and smaller loaf volume compared to white bread. Five hydrocolloids were chosen to represent a range of structures and sources: CMC (carboxymethyl cellulose) and HPMC (hydroxypropyl methylcellulose) (cellulose derivatives), guar gum (galacto-mannan, from guar beans), sodium alginate (seaweed extract), and xanthan gum (product of bacterial fermentation). The hydrocolloids were evaluated individually at three levels on the physical properties of dough and bread made with whole wheat flour, with the aim of increasing loaf volume and decreasing staling. All hydrocolloids except for CMC increased specific loaf volume for at least one of the levels tested (P < 0.01), with minimal change to crumb structure. HPMC was the most favorable hydrocolloid to increase loaf volume and delay staling of whole wheat bread.
Technical Abstract: Hydrocolloids are used to improve dough handling and bread quality and retard staling. The strengthening effect is particularly beneficial to bread from whole wheat flour and other flours of low gluten quality. Hydrocolloids carboxymethyl cellulose (CMC), guar gum, hydroxypropyl methylcellulose (HPMC), sodium alginate, and xanthan gum were evaluated individually at 0.25, 0.5, and 1.0% fwb in whole wheat dough and bread to improve loaf volume and reduce staling. Dough properties were determined by farinograph, mixograph, Chen-Hoseney stickiness test, and Kieffer rig uniaxial extensibility. Effect on starch retrogradation in bread crumb was quantified by differential scanning calorimetry (DSC) after the 7 days. Hydrocolloids increased water absorption and mixing time for whole wheat dough. All hydrocolloids except for CMC increased specific loaf volume for at least one of the levels tested (P < 0.01), with minimal change to crumb structure. HPMC (all levels) and xanthan gum (medium level) produced the greatest increases in specific loaf volume. The high level of guar gum and medium level of HPMC reduced crumb hardness on Day 1 (P < 0.01). On Day 7, only HPMC and xanthan gum at the medium level decreased crumb hardness compared to the control. HPMC, sodium alginate, and xanthan gum decreased the rate of crumb firming during storage. No significant changes in amylopectin retrogradation or amylose-lipid complexation were observed, although xanthan gum showed a trend toward decreasing formation of the complex. HPMC is recommended as the most favorable hydrocolloid to increase loaf volume and delay staling of whole wheat bread.