Effect of banana flour composition and glycerol content on properties of compression-molded banana sheet.

摘要

Banana is an abundant fruit in Asian countries including Thailand; however, the utilization as commercial banana products is not as widespread as fresh consumption. Recently, banana flour has been shown to form edible films through solution casting with moderate mechanical properties and good oxygen barrier. Therefore, banana flour has a potential to be a natural packaging material for fresh fruits and vegetables and other food products. The objective of this study was to determine the effect of banana flour type and glycerol (G) content on the physical and mechanical properties of compression-molded banana sheet. It was found that different chemical compositions of banana flour caused different banana sheet properties and the compression molding process affected sheet appearance. The compression molding conditions for banana sheet were 105 degrees C, 5 MPa for 4 min. At least 60% water (W) and 30% G content or 40% W and 40% G as plasticizers were required together with the banana flour to produce banana sheets. Whole banana flour prepared with pulp and peel affected the color of the banana sheet. Banana flour without peel showed a significantly higher elastic modulus, stretch and tensile strength than whole banana flour. Banana sheet plasticized with 60% W and 30% G showed the highest modulus and tensile strength, but the lowest stretch. This indicated that plasticized-banana flour shows flowability and a thermoplastic character. Compression molding, which is a rapid process for film formation, is hence a good alternative to the time-consuming solution casting technique. Banana sheets can be used to form biodegradable packaging, such as trays, and are an environmental friendly packaging material.