FUNCTIONAL PROPERTIES AND ANTIMICROBIAL EFFICIENCY OF PACKAGINGS PLASTICIZED AND INCORPORATED WITH CINNAMON ESSENTIAL OIL (CINNAMOMUM CASSIA)

The use of essential oils for preparation of antimicrobial food packaging has attracted increasing attention. Cinnamon essential oil (CEO) has phenolic compounds with proven antimicrobial action. In addition, plasticizer compounds, such as glycerol, are incorporated into the polymer matrix to suitability packaging desirable characteristics, such as malleability improvement. In this study, by casting method, cellulose acetate (CA) films were elaborated with the incorporation of CEO (50% w/w) and different concentrations of glycerol (5, 10, 20 and 30% w/w). The films were characterized for thickness, visual aspects (Minouta CM-5-ID), chemical structure (FT/IR-4700, Jasco Corporation), surface (Carl Zeiss, model EVO MA 10), mechanical strength (TA.XTplus Texturometer), water vapor transmission rate (WVTR) and antimicrobial activity in vitro. The incorporation of glycerol caused a decrease in tensile strength (TS) and Young's modulus (YM), increase in elongation at break (EB), thickness, opacity, luminosity and yellow color (b*). In addition, the presence of 10, 20 and 30% of glycerol became the films reddish (a*). WVTR was not affected by the incorporation of glycerol. In the scanning electron microscopy (SEM) images, the presence of 5, 10 and 30% of glycerol caused changes in the surface and fracture region of the films. Regarding antimicrobial efficiency, film with 30% glycerol presented increased efficiency for Staphylococcus aureus, while 5 and 30% glycerol caused increase of the efficiency for Escherichia coli. Specific bands modification were observed in infrared (FTIR-ATR) analysis after the addition of glycerol, which suggests possible chemical interaction between the polymer matrix and additives. It is noticed that glycerol caused minimal and acceptable changes in the functional properties of the film, besides potentialize the antimicrobial action, which makes it suitable to pack a greater variety of foods.