Influence of Dehulled African Breadfruit Substitution on Starch Digestibility, Dietary Fibre and Glycemic Index of High-Fibre Snack Bars from Maize and Coconut Flour Blends

Abstract

In this article, African breadfruit seeds were dehulled and made into flour alongside maize and coconut, and the flours were analyzed for their particle sizes and nutritive value. Snack bars were prepared by substituting different levels of dehulled African breadfruit (Treculia africana) seed flour with maize flour at a constant level of coconut grits viz., 0:95:5=T0, 20:75:5=T1, 25:70:5=T2, 30:65:5=T3, 35:60:5=T4, 95:0:5=T5. The snack bars were analyzed for their starch fractions, in vitro starch digestibility, glycemic index and dietary fibre fractions. Rapidly digestible starches (RDS) ranged from 26.32 – 34.62 %, slowly digestible starches (SDS) ranged from 34.46 – 38.71 %, and resistant starch (RS) content was from 3.15 to 9.24 %, while total starch content (TS) was 62.44 – 72.42 %. In vitro starch digestibility (IVSD) and glycemic index (IVGI) ranged from 34.29 – 57.48 % and 47.32 – 57.34 % respectively. Dietary fibre content showed 3.46 – 5.18%, 6.66 – 13.72% and 10.72 – 17.18 % for soluble dietary fibre (SDF), insoluble dietary fibre (IDF) and total dietary fibre (TDF) respectively. SDS and SDF increased, while IVSD and IVGI decreased significantly (p<0.05) with increase in dehulled African breadfruit flour substitution. The higher the TDF, the lower the glycemic index (GI) of the snack bars. All snack bars prepared showed high fibre content and low – medium GI, indicating that they could be useful for consumers interested in weight management or battling diabetes.