Quality and Functional Characteristics of Morning Bread Supplemented with Brewer's Spent Grain Powder

This study evaluated the physicochemical properties and antioxidant activity of morning bread prepared by substituting 10%－30% wheat flour with brewer's spent grain (BSG) powder. The effects of BSG on the baking characteristics were assessed. Bread weight increased from 34.83 to 36.03 g with elevating BSG levels, whereas height and volume decreased; specifically, the height of bread with 30% BSG reduced by 16.66%, restuling in the lowest specific volume. Baking loss declined from 12.92% to 9.92% as the BSG content increased. Texture profile analysis revealed that bread hardness increased with BSG addition, reaching 861.00 g at the 30% level Cohesiveness decreased, while chewiness peaked in the 30% BSG bread. Color examination indicated that crust and crumb lightness declined, whereas redness and yellowness increased, resulting in a dark-red appearance. Soluble solids increased from 4.30 to 4.95 °Brix, pH reduced from 5.85 to 5.75, and total titratable acidity rose from 0.11 to 0.12－0.15 with higher BSG levels. Moisture and crude protein contents increased from 30.35% to 33.39% and 8.60% to 12.18%, respectively. Ash and total dietary fiber were also elevated, while crude fat remained unchanged. Total polyphenol and flavonoid contents significantly improved from 49.06 to 142.02 µg gallic acid equivalent/g and 43.87 to 75.47 µg catechin equivalent/g, respectively. Antioxidant activity also markedly improved with BSG addition. Overall, substituting 10% of wheat flour with BSG is recommended to optimize baking quality, physicochemical properties, and functional value, demonstrating BSG's potential as a functional ingredient.