Studies on some engineering properties of breadfruit (Artocarpus altilis) starch flour

This research work evaluated some engineering properties of breadfruit starch flour following standard procedures with the aim of providing engineering data that would help its usage in food processed industries. Starch was extracted from matured breadfruit fruits, modified using acid and engineering properties were examined following standard procedures. Results of moisture contents, loose and packed bulk densities, density ratio and porosity were ranged from 8.23-9.13% dry basis (DB); 0.44-0.51 g.mL-1; 0.60-0.66 g.mL-1; 70.01-80.14% and 19.87-29.99%, respectively. Similarly, Carr index values ranged from 19.44-30.61% and Hausner ratio values ranged from 1.25-1.43, indicating that the flour samples investigated had poor (native), fair (modified) and good (potato) flow properties, using Carr index standard. Amylose, amylopectin and amylose-amylopectin ratio contents values ranged from 21.52-29.77%; 70.23-78.48% and 0.28-0.42%, respectively. Also, the flour samples thermal properties values using Differential Scanning Calorimeter (DSC) ranged from 106.4-129.09 °C; 31.93-78.36 °C; 106.2-175.75 °C; 214.90-278.6 J.g-1; 35.5-148.82 °C; 2.26-10.95 J.g-1.K-1; 0.305-3.0 (×10-6) W.m-1. °C-1, and 0.095-1.32 (×10-6) m2.s-1 for peak temperature, onset temperature, end temperature, enthalpy, temperature range, specific heat capacity, thermal conductivity and thermal diffusivity, respectively. Viscosity values as influenced by concentration and temperature ranged from 25.8-149 mPas for native starch and 41.9-109.6 mPas for modified starches. Hence, this research work provides engineering data that would help in process control, process design and bulk handling of breadfruit starch flour so as to promote its usage in food process industries.