Improvers and functional ingredients in whole wheat bread: A review of their effects on dough properties and bread quality

Background: Despite the associated health benefits of whole grains, consumption of whole grain products remains far below recommended levels. Whole wheat bread is often associated with many distinctive attributes such as low loaf volume, firm and gritty texture, dark and rough crust and crumb appearance, bitter flavor, and reduced shelf-life. There is a need to improve its quality and sensory characteristics so as to increase consumer appeal and, ultimately, increase the intake of whole wheat bread. The inclusion of various ingredients improves dough and bread properties. Scope and approach: This review examines the effects of enzymes, emulsifiers, hydrocolloids, and oxidants on the properties of whole wheat bread and dough, with particular attention to effects on loaf volume and hardness. Wheat gluten and other plant materials are also discussed. Gaps in the research into whole wheat bread are identified, and future research needs are recommended. Key findings and conclusions: Xylanase reduces the water absorption of whole wheat flour and increases loaf volume and crumb softness by hydrolyzing ararbinoxylans. a-amylase can be beneficial under certain conditions. Phytase may activate endogenous a-amylase. G4-amylase is promising but needs validation by further research on its effect on loaf volume, crumb hardness, and staling. Vital wheat gluten overcomes many of the challenges of whole wheat bread production and is found in the majority of commercial whole wheat breads. Emulsifiers DATEM and SSL can improve the volume, texture and staling profile of whole wheat bread. Several types of improvers are generally needed in combination to provide the greatest improvement to whole wheat dough and bread.