Nutrient composition, bioactive components, functional, thermal and pasting properties of sweet potato flour-incorporated protein-enriched and low glycemic composite flour

Abstract

The composite flour was produced with wheat flour, sweet potato flour, chick pea flour, and soybean flour (WF:SPF:CPF:SF) in the proportions of 100:0:0:0 (control), 0:100:0:0 (100% SPF), 70:10:10:10 (10% SPF), 60:20:10:10 (20% SPF), 50:30:10:10 (30% SPF), 40:40:10:10 (40% SPF), 30:50:10:10 (50% SPF), 20:60:10:10 (60% SPF), and 10:70:10:10 (70% SPF). The addition of SPF in blends leads to elevation in fiber, ash, minerals, and bioactive components. Protein content of flour blends was increased from 12.53% (Control) to 28.01% (10% SPF) due to addition of CPF and SF. The low glycemic functional properties of SPF reduced the estimated glycemic index of flour blends from 73.87 (Control) to 50.54 (70% SPF). The pasting temperature of flour blends was higher, whereas peak viscosity, break down viscosity, final viscosity, set back viscosity, and peak time were lower than control sample. The thermal properties were significantly higher in composite flours containing SPF than control. The prepared composite flour with 70% SPF, 10% WF, 10% CPF, and 10% SF was suitable for the development of protein enriched and low glycemic functional food. Novelty impact statement: The present study investigates the use of under exploited sweet potato tubers for the development of composite flour having low glycemic index and enriched in protein content with the addition of chick pea and soy flour. The protein content was increased from 12.53% to 28.01%, and glycemic index was reduced from of 73.87 to 50.54 for sweet potato-based composite flour in comparison with the control. Composite flour also found rich in fiber, ash, microelements, bioactive compounds, and antioxidant activity. The composite flour enriched in protein content, bioactive compounds with reduced glycemic index could be used to develop functional food products for the management of the life style diseases.