EFFECT OF HEAT PROCESSING TREATMENTS ON THE CHEMICAL COMPOSITION AND FUNCTIONAL PROPERTIES OF LIMA BEAN (Phaseolus lunatus) FLOUR

Abstract

Purpose: The effect of heat treatment methods on the nutrient composition and functional properties of lima bean (Phaseolus lunatus) flour were investigated.Methodology: The lima bean seeds were sorted, cleaned and processed into boiled, roasted and autoclaved lima bean flours. The flours obtained were analyzed for proximate composition, mineral content and functional properties using standard methods.Results: The proximate composition of the samples revealed that the flours had a range of moisture, 8.25±0.01 - 10.21±0.06%, crude protein, and 18.24 ±0.02 - 22.72±0.00%, ash, 3.94±0.13 - 4.82±0.02%, fat, 1.47±0.03 - 1.68±0.00%, crude fiber, 3.62±0.00 - 4.27±0.02%, carbohydrate, 57.31±0.13 - 62.89±0.01%, and energy 334.11±0.30 - 339.91±0.18kJ/100g, respectively. The mineral composition showed that the flours contained 176.89±0.002 - 234.72±0.17mg/100g calcium, 2.38±0.03 - 3.24±0.00mg/100g iron, 68.36±0.00 - 73.62±0.26mg/100g sodium, 163.73±0.11 - 195.33±0.01mg/100g magnesium, and 125.86±0.00 - 136.76±0.06mg/100g potassium, and 158.78±0.03 - 184.29±0.01mg/100g phosphorus, respectively. The result of the functional properties of the flours equally revealed that the water absorption, solubility index, foam capacity, oil absorption and swelling capacities and bulk density of the samples were significantly (p<0.05) increased by roasting than the boiling and autoclaving treatments. However, the nutrient composition and the functional properties of the flours observed suggested that the processed flours have the potentials to be used as nutritional supplements and functional ingredients in the preparation of a wide range of food products than the raw sample.