Mechanical, sensory, and consumer evaluation of ketogenic, gluten-free breads

Ketogenic, gluten-free breads comprised of almond flour, oat bran fiber, or combinations of both were compared. The textural properties, sensory attributes, and consumer acceptance were analyzed on each bread containing 100% almond flour (AF), 66.7% almond flour with 33.3% oat bran fiber (AOB), 66.7% oat bran fiber with 33.3% almond flour (OBA), and 100% oat bran fiber (OB). AF and AOB breads had a more open crumb structure composed of cells between 1-4 mm². OBA and OB had a significantly dense crumb pattern made up of more cells less than one millimeter squared. Quantitative-descriptive analysis (QDA) and consumer acceptance testing was conducted 24 hr after baking and mechanical endpoints were evaluated 24, 72, and 120 hr after baking. AF and AOB breads were preferred over OBA and OB breads in QDA evaluation and consumer acceptance scores. Greater percentages of oat bran fiber resulted in a bread that was less moist, firmer in texture, and chewier with trained panelists. In both sensory evaluations, higher amounts of almond flour resulted in higher values in eggy flavor while increased amounts of oat bran fiber correlated with higher values in earthy flavor. Mechanical testing identified higher percentages of almond flour resulted in bread that was less firm and less chewy. Over time, all variations with almond flour became softer and less chewy, while the OB bread increased in firmness. Sensory cohesiveness did not correlate with the mechanical equivalent, identifying a need to re-evaluate the parameters used to calculate this objective endpoint.