Comparison of the chemical composition and functional properties of Phaseolus lunatus prime and tailing starches

A physicochemical characterization was made of the tailing starch isolated from the legume Phaseolus lunatus L. Proximate composition was: 1.33% protein, 3.64% fibre, 0.18% fat, 1.10% ash and 93.8% carbohydrates as nitrogen-free extract. Total dietary fibre content was 22.0%, soluble fibre was 2.28%, and insoluble fibre was 19.7%, as determined using the Prosky AOAC 71, 1017 (1988) method. Amylose, as quantified by differential scanning calorimetry, (DSC) was 35.2%. Gelatinization temperature range, as determined by DSC, was from 67.9 to 89.1 °C, with 75.2 °C being the peak temperature. Transition enthalpy was 10.70 J/g. Swelling power ranged from 5 g water/g starch at 60 °C, to 13.89 g water/g starch at 90 °C. Solubility, analyzed within the same temperature range was from 3 to 14.82%. Syneresis, in a 6% gel stored at 4 °C for 24 h, was 20.6 ml water/50 ml gel. Clarity, expressed as transmittance, was 9.71%. Initial paste temperature was 82.5 °C, breakdown was 72 BU, consistency was 65 BU, and setback was −7 BU.