Nutritional quality and starch digestibility of breadfruit-bambara groundnut composite flours for food formulations

Abstract

The focus of this study was to produce composite flour with nutritional and functional potentials from underutilized and inexpensive crops, which can be used in food formulations as a substitute to composite flours from commonly used and expensive crops. The proximate, mineral, and amino acid compositions, resistant starch content and in vitro starch digestibility of breadfruit-bambara groundnut (100:0, 90:10, 80:20, 70:30, and 60:40 respectively) composite flours were investigated using standard methods. Data generated were subjected to statistical analysis. Inclusion of bambara groundnut in the composite flours significantly (p≤0.05) increased protein (5.06-16.96%), ash (1.54-2.71%), fat (1.06-1.96%), potassium (727.82-797.73 mg/100g), phosphorus (143.36-177.32 mg/100g), magnesium (92.71-117.05 mg/100g) and resistant starch (11.45-21.98%) contents, while it significantly (p≤0.05) reduced fibre (4.65-5.39%), carbohydrate (65.33-79.69%), sodium (48. 64-71.25 mg/100g), and calcium (57.65-64.50 mg/100g) contents, as well as in vitro starch digestibility (40.41-58.75%). All the essential amino acids were present; they constituted 34.69 – 37.94% of the total amino acid. The predicted protein efficiency ratio ranged from 2.14 to 2.82. This study suggests that breadfruit-bambara groundnut composite flours may find usefulness in different food formulations and may exhibit lower postprandial hyperglycemia which is important for obese and diabetic patients.