Clean Label in Bread

Bread is considered a staple food worldwide, and therefore there is much interest in research around the topic. The bread industry is usually looking for ways to improve its formulations. Therefore, other ingredients such as dough conditioners, crumb softeners, emulsifiers, and surfactants can be added to enhance bread quality. These ingredients perform functions such as helping standardize processes in the industry, reducing dough-mixing time, increasing water absorption, improving bread quality, and extending its shelf life. Consumers are concerned about the effect of these ingredients on their health, and this has increased the popularity of clean-label bread formulations. A clean label generally indicates that a product is free of chemical additives, has an ingredient list that is easy to understand, has undergone natural or limited processing, and/or is organic and free of additives or preservatives. However, there is no scientific definition of the term “clean label.” Researchers have focused on these clean-label initiatives to replace dough strengtheners and preservatives in bread formulations and give consumers what they perceive as a healthier product.

Changes in Hydrophobic Interactions among Gluten Proteins during Dough Formation

In this study, changes in hydrophobic interactions among gluten proteins were analyzed during dough mixing. Size-exclusion high-performance chromatography and two-dimensional fluorescence difference gel electrophoresis were performed on proteins extracted with 1-propanol by weakening the hydrophobic interaction. The amount of proteins extracted with 30% 1-propanol increased from the start of mixing to peak consistency, suggesting that the hydrophobic interactions among the strongly aggregated proteins weakened and resulted in disaggregation. The amount of proteins extracted with 10% 1-propanol decreased during hydration, indicating that these proteins aggregated through relatively weak hydrophobic interactions. The proteins that extractability decreased were mainly low molecular weight glutenin, α-gliadin, and γ-gliadin. The amount of monomeric proteins extracted with 30% 1-propanol decreased after peak consistency. The decreased protein was mainly ω-gliadin, indicating that ω-gliadin aggregated with other proteins through hydrophobic interactions. A front-face fluorescence analysis was performed on the dough with the addition of 8-anilino-1-naphthalenesulfonic acid or thioflavin T. The fluorescence intensity increased as a result of exposure to the hydrophobic groups of the gluten proteins and the formation of protein aggregates during dough mixing. These results indicate the importance of hydrophobic interactions in dough formation.

Effect of Purple-Colored Wheat Bran Addition on Quality and Antioxidant Property of Bread and Optimization of Bread-Making Conditions

Purple-colored wheat bran was blended with flour at different ratios. The dough mixing characteristics of the flour–bran blends and quality characteristics and antioxidant activity of the bread prepared with the blends were investigated. Additionally, response surface methodology (RSM) was used to optimize the formula and processing conditions for the bread prepared with the blend at 30% bran. Solvent retention capacity (SRC), as a quality characteristic of the blends, showed that water absorption and damaged starch contribution increased proportionally as the bran blending ratio increased. Dough mixing patterns of blends determined by a mixograph exhibited deteriorated gluten strength by increasing the bran blending ratio. The total phenolic and anthocyanin contents and antioxidant activity (ABTS and DPPH radical scavenging activity) of the bread increased proportionally as the bran blending ratio increased. RSM analysis revealed that the best-fitted model for the results was a quadratic polynomial model with regression coefficient values close to or more than 0.900 for all responses. Optimized conditions were 68.1 g water, 4.0 min mixing time, and 67.3 min fermentation time. Overall, purple-colored wheat bran was successfully applied to produce bread with healthy functional properties by controlling water and mixing time.