Potential of Pleurotus ostreatus as a novel protein source in rice-millet-based gluten-free muffins

The study used oyster mushroom powder (OMP) as a nutrient source to improve the nutritional value of gluten-free (GF) muffins. OMP was added at 5, 10, 15, and 20% in rice-pearl millet-based gluten-free formulation for preparing muffins. The addition of OMP significantly (p < 0.05) improved the nutritional value of muffins. The protein content of the control muffin was 7.12% which increased to 9.41% and 10.19%, with 10% and 15% addition of OMP, respectively. Further, adding mushroom powder at a 10% level or more almost doubled the amount of fibre content in the muffins. The addition of 10% and 15% OMP also increased the magnesium and potassium contents to 19.20% and 27.20%, which were 42.91% and 57.48% higher compared to the control muffin, respectively. Replacement of rice flour with OMP increased the hardness and chewiness of gluten-free muffins. At higher levels (15% and 20%), OMP had also significant changes in the colour attributes. Interestingly, these changes in textural and colour parameters as a result of OMP addition had no adverse effect on the sensory attributes of muffins. OMP-enriched muffins were in the highly acceptable range (>7.0), with the 15% OMP-enriched gluten-free muffins having the highest overall acceptability scores among the evaluated samples. Furthermore, the technology was demonstrated among gluten-intolerant persons and small-scale gluten-free product entrepreneurs. More than 90% of the respondents liked the OMP-enriched muffins compared to the control sample. Moreover, gluten-free processors also appreciated this simple food technology to enhance the nutritional value of existing gluten-free diets.