Feasibility study on using hard resin of ‘Ton Jik’ Taengwood balau tree (Shorea Obtusa Wall) with multilayer plastic film as materials of ethanol vapor controlled release sachets in active packages

Abstract

The purpose of this research was to study feasibilities in using hard resin of Taengwood balau tree
(KC material) with multilayer plastic films as materials of ethanol vapor-controlled release sachet in active packaging. The resin and the tree are locally called KeeCee (or KC) and Ton Jik, respectively. This research developed a prototype of a multi-layer plastic film by applying a KC material solution on the surface of the ethylene vinyl acetate (EVA) film of which low density polyethylene (LDPE) plastic films subsequently were laminated on both sides using the heat-sealing technique. The active KC film prototype (LDPE/KC/EVA/LDPE) was developed further as an ethanol vapor-controlled release sachet, so-called KC sachet. The sachet comprises with an aluminium laminated film on one side and the KC film on the other and contains a filter paper pre-saturated with ethanol liquid. The present research studied ethanol vapor released from the KC sachet within the 250-ml aluminium laminated packages. Ethanol vapor concentrations were analyzed using the flame-ionized detector gas chromatogram (FID-GC) during 17 days at 25ºC and were compared to those released from sachets of which the material on one side was made of either LDPE (LDPE sachet) or multi-layer film having no KC layer (2LDEVA sachet). Experimental results show that ethanol vapor concentrations of all treatments rapidly and continuously increased during 7 days of the storage period. Changes of the concentrations thereafter became slower and apparently, had steady trends. The highest ethanol vapor concentration was found in the KC sachet treatment, whilst the lowest one was observed in the 2LDEVA sachet one. The first-order kinetic mathematical model could well predict concentration levels and their changes in all treatments (R² = 0.99). The highest rate of the concentration changes in the KC sachet treatment hypothetically was attributed to the plasticization phenomena occurred within the film structures caused by molecules of both ethanol and KC-based organic compounds, continuously permeating into the film layers. In addition, the volatiles which presumably were of the KC were released from the KC sachet, together with the ethanol vapor. These currently have been identified for types and their anti-microbial activities for further development of the KC sachets.