ASSESSING MECHANICAL PROPERTIES AND ANTIMICROBIAL ACTIVITY OF ZINC OXIDE-STARCH BIOFILM

Abstract

Tapioca starch is able to form flexible transparent film eventhough the film was made without the use of additional chemicals. However, films made from tapioca starch still have various disadvantages in terms of functional properties. It is therefore an effort have to be done by adding chemical additif such as nanopartikel. The main objective of this study was to improve the functional properties of tapioca starch packaging by using ZnO nanoparticle as repair agents and glycerol as plasticizers. Some properties of the biofilm were analyzed including thickness, tensile strength, elongation, and water vapor permeability as well as antibacterial properties. The addition of nanoparticles was carried out in the amount of 0%, 1%, and 2% by weight of starch (w/w). While glycerol was used at 20% by weight of starch (v/w). The result of biofilm thickness can be determined the best treatment that was at 2% of ZnO where as the film had thickness value approaching JIS (Japanesse Industrial Standart) with 0,1087 mm. The highest tensile strength was reached at value of 2%, while the highest elongation was at 0% concentration Water vapor permeability (WVP) allowed the best results at 2% concentration of ZnO with a value of 1.0146 × 10−9gs−1m−1Pa−1. The results of this study indicated that tapioca starch film containing ZnO nanoparticle could be used as food packaging material with antibacterial properties. The inhibition index of the film was 7,67 mm from the film with 2% ZnO to bacteri of E. coligreater than film witl 1% ZnOat about 5,40 mm. Meanwhile, for Salmonella sp., after 24 h incubation, the film either 1% and 2% ZnO nanoparticle exhibited 6, 97 mm of clear zone of diameter.