Development of functional bread enriched with coffee husk flour: Physicochemical, fiber, and antioxidant characteristics

Abstract:

The increasing global production of coffee generates substantial amounts of agro-industrial by-products, including coffee husk (CH), which is rich in dietary fiber and antioxidant compounds. This study investigated the effects of partial substitution of wheat flour with CH flour on the physicochemical and functional properties of bread. Bread samples were prepared by substituting CH flour for wheat flour at levels of 0%, 1.5%, 3.0%, 4.5%, 6.0%, and 7.5% (w/w). The bread samples were analyzed for color, loaf expansion, texture, moisture content, ash content, dietary fiber, and antioxidant activity. The incorporation of CH flour significantly affected bread characteristics. Increasing levels of CH flour reduced the lightness (L*) value and loaf expansion while increasing bread hardness. Moisture and ash contents also increased due to the CH flour's high water-binding capacity and mineral content. Moreover, bread enriched with CH flour exhibited markedly higher total dietary fiber and antioxidant activity than the control bread. Total dietary fiber increased from 2.72% in the control bread to 9.47% in bread containing CH flour, while antioxidant activity increased from 6.09% to 26.53%. These findings demonstrate that CH flour has strong potential as a functional ingredient for improving the nutritional and functional properties of bread. The utilization of CH flour also represents a promising strategy for valorizing coffee-processing byproducts and developing sustainable functional bakery products with potential health benefits.