PREPARATION AND CHARACTERISATION OF BIOPLASTIC FILMS FROM SWEET POTATO (Ipomoea batatas L.) PEEL STARCH BLENDED WITH BANANA (Musa acuminata C.) PSEUDOSTEM CELLULOSE FOR PACKAGING

Abstract

Environmental pollution caused by petroleum derived plastics used for packaging has increased the need for environmentally friendly packaging materials. This study focused on development of biofilms from potato peel starch incorporated with banana seudostem cellulose (BPC) powder of 0.2 mm for packaging purposes. The cellulose was obtained from dried banana pseudostem by alkali delignification and bleaching. The bioplastic films were produced by casting and oven drying the gelatinized blends of potato peel starch and banana pseudostem cellulose (BPC) at 0, 5, 10, 20 and 30 wt % of BPC to give films of sample A, B, C, D and E respectively with constant weight of glycerol (plasticizer) in all the films. Physical properties such as moisture content, opacity, water solubility, thickness and density of the films were evaluated. The films were also characterised using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Universal Testing Machine, Thermo-gravimetric/Differential Thermal Analysis (TG/DTA) and soil burial method for films biodegradation. The starch exhibited good pasting properties due to high amylose content of 23.65 % and amylopectin 76.35 %. As the concentration of BPC increases in the biofilms produced, moisture content decreases from 30.20 to 18.30 %, water solubility from 54.05 to 25.00 %, density from 0.25 to 0.10 g/cm3, whereas thickness and opacity increases from 0.26 to 0.34 mm and 0.35 to 1.09 % respectively. Improvement was also observed in tensile strength from 5.20 to 12.80 MPa, young modulus from 28.44 to 188.98 MPa and decrease in elongation at break from 14.42 to 8.62, all from control sample 0 % BPC to 30% BPC. Surface morphology revealed smoother surface of the films with less pores as the concentration of BPC increases. Functional groups identified showed good interaction between the components of the films. Thermal stability was at maximum in Samples C and E with both samples having highest TGA and DTA value of 377 oC. All the samples were completely biodegraded within 12 days by soil burial method. This study has shown that incorporation of cellulose powder in starch-based bioplastic gives better bioplastic films as a substitute to petroleum-based plastics.