THE STUDY OF SOME ENGINEERING PROPERTIES OF ENSET (Ensete Ventricosum) STARCH FROM BULLA AND ITS UTILIZATION FOR THE MANUFACTURE OF FLEXIBLE FILMS

Abstract

A study was conducted on the study of some engineering properties of enset starch from bulla and its utilization for the manufacture of flexible film using glycerol as plasticizer. The experiment was planned with two factors: glycerol concentration and drying temperatures. It consisted of nine combinations of treatments executed using factorial experiment. The glycerol concentrations were 15, 20, and 25% while the drying temperatures were 35, 45, and 55 oC. The physical properties of enset starch were recorded 13.90% wb moisture, 0.38 g/ml bulk density, 0.45 g/ml tapped density, 15.56% carry’s index, 1.17, hausner ratio and 35.00° angle of repose showed significance (P<0.05) difference from values 14.63% wb, 0.45 g/ml, 0.54 g/ml, 16.7%, 1.32, and 37.67° of the respective attributes of bulla flour. The functional properties such as water absorption capacity, swelling power, and solubility of enset starch were 1.63 g/g, 4.03 g/g, and 18.33%, while those of bulla were 1.40 g/g, 3.67 g/g, and 15.33% respectively. The pasting properties of enset were pasting temperature (72 oC), peak viscosity (4800.67 cP), trough viscosity (1850.13cP), final viscosity (2100 cP), breakdown viscosity (2950.54 cP), setback viscosity (249.87 cP), stability ratio (0.39), and setback ratio (1.14) recorded. The properties of enset starch flexible film such as the moisture content (9.18 to 11.50%), water solubility (61.33 to 65.60%), water absorption (26.53 to 33.11%), water vapor permeability (3.65 x 10-10 to 5.92 x 10-10 g.m-1.s-1.Pa-1), elongation at break(33.34 to 39.56 %,), transparency (78.46 to 85.08%) showed significant(P<0.05) differences due to the treatments of glycerol concentrations, and temperatures. while density (0.94 to 1.02 g/cm3), thickness (0.37 to 0.42 mm), tensile strength (4.03 to 4.84 MPa), L*(80.77 to 84.22), a*(4.04 to 4.94), b*(1.81 to 2.07), E (11.13 to 14.07), WI (80.82 to 83.76), significantly (P<0.05) affected due to the glycerol concentration only. The properties of the flexible films were affected both by the glycerol concentration and drying temperature.