Impact of Incorporating Dried Chaga Mushroom (Inonotus obliquus) into Gluten-Free Bread on Its Antioxidant and Sensory Characteristics

Gluten-free bread is increasingly popular among individuals with celiac disease, and The incorporation of mushroom flour offers a novel method to enhance its nutritional profile, antioxidant content, and sensory properties. This study aimed to evaluate the antioxidant and sensory characteristics of gluten-free bread with varying amounts of chaga mushroom flour (5%, 10%, 15%, 20%). The total contents of polyphenols and flavonoids were measured using a spectrophotometric method. Antioxidant activity was assessed through DPPH and FRAP methods, while textural properties were evaluated using the TPA test. Bread colour was analysed using the CIELab system, and sensory evaluation was performed by a panel of trained consumers. The results showed that gluten-free bread enriched with chaga flour had increased polyphenol and flavonoid content and enhanced antioxidant activity. The highest levels of polyphenols, flavonoids, DPPH, and FRAP activity were found in bread with 20% chaga. The addition of chaga mushroom significantly affected the bread's hardness, cohesiveness, and chewiness. Specifically, 20% chaga flour had the most pronounced effect on hardness and elasticity, while 15% chaga flour had the greatest impact on chewiness and cohesiveness. The bread's colour darkened with higher chaga concentrations. The results of sensory evaluation showed a negative correlation between consumer preferences and bread fortified with chaga mushroom flour. The overall consumer acceptability score indicates that only a small addition of mushroom flour (up to 10%) can be used to bake gluten-free bread.