Incorporation of oyster mushroom powder and pearl millet flour improves the nutritional quality and glycemic response of Indian flatbread

Abstract The purpose of present study is to develop a nutritionally enriched and low GI (glycemic index) Indian flatbread using nutritionally balanced crops. To achieve this goal, whole wheat flour was supplemented with different levels of oyster mushroom powder (OMP) – 5 %, 10 %, 15 %, and 20 %, along with pearl millet flour (PMF) – 10 %, 20 %, 30 %, and 40 %, resulting in a range of formulations for the study. The prepared formulations were evaluated for their chemical, physical, pasting, texture, predicted GI, resistant starch and sensory properties along with color analysis. The protein and fiber content in formulated flatbread increased with increase in percentage of OMP and PMF from 5–20 % and 10–40 % respectively. The pasting properties showed a significant (p < 0.05) reduction in peak, breakdown, trough, final and setback viscosities of composite flour. However, no significant effect on dough handling was observed due to change in pasting behaviour. Furthermore, in vitro protein digestion studies (IVPD%) indicated improved protein quality in formulated flatbread. The whole wheat flour supplementation has also reduced starch hydrolysis rate by decreasing composite flatbread’s predicted glycemic response (pGI) from 82 in control wheat bread to 61–50 in formulated flatbread. Colour attributes of enriched flatbread showed a darker colour than control, however, it was preferred by the panellists at OMP (15 %) and PMF (30 %) substitution by obtaining an overall acceptability score of 7.3 out of 9.0. Practical application: The present study will be very helpful for a diabetic patient to take the best composition of flatbread in their diet to effectively manage their rise in blood glucose level.