Abstract:
A study was conducted on the application of anchote (Coccinia Abyssinica) starch for the manufacture of plastic films by using glycerol as plasticizer. The aim was to study some selected properties of the starch and develop a plastic film. The experiment was planned with two factors: glycerol concentration and starch concentrations, and consisted of nine combinations of treatments executed using factorial experiment. The glycerol concentrations were 20, 25 and 30% while those of the starch were 3, 5 and 7 g/100mL. The physical, mechanical and optical properties of the plastic films were evaluated. The results indicated that the anchote starch exhibited moisture of 13.60% (wb), bulk density of 0.49 g/mL, tapped density of 0.57 g/ml, carry’s index of 14.04%, hausner ratio of 1.16 and 34.00° angle of repose. The functional properties such as water absorption capacity, swelling power, solubility and dispersibility of anchote starch were recorded to be 1.80 g/g, 6.36 g/g, 15.81% and 87.00%, respectively. The pasting properties of the same were 72.72°C pasting temperature, 4984.25 cP peak viscosity, 1929.15 cP trough viscosity, 5132.20 cP final viscosity, 3055.28 cP breakdown viscosity, 3205.50 cP setback viscosity, 0.87 stability ratio, and 2.66 setback ratio. The properties of anchote starch plastic film included the moisture content of 9.39 to 11.89%, water solubility of 71.31 to 74.56%, water absorption of 23.43 to 33.58%, tensile strength of 35.55 to 42.25 Mpa, elongation at break of 95.08 to 110.44%, Young’s modulus of 163.82 to 171.51 Mpa, thickness of 0.41 to 0.49 mm, transparency values of 79.39 to 87.41%, and lightness of 81.48 to 83.78 all showing significant (P<0.05) differences among each other due to glycerol concentration and starch concentration treatments. On the other hand density (0.97 to 1.05g/cm3), color values {a*(- 0.33 to -0.37), b*(3.10 to 3.22) and E (13.83 to 15.46)}, and white index (82.33 to 83.99)}, were significantly (P<0.05) affected due to the glycerol concentration only. Thus it can be concluded that the properties of the plastic films were affected both by the glycerol concentration and starch concentrations. The mechanical and optical properties of the same showed that the film was suitable for food packing.
