The effects of green tea extract (GTE) concentrations (0, 1, 2, 3, 4, and 5%) on the thicknesses, mechanical strengths, storage/loss moduli, glass transition temperatures (Tg), chemical structures, morphologies, antioxidant activities, moisture contents, and gas permeabilities of low methoxyl pectin films were investigated in this study. Dynamical mechanical analysis and tensile testing were used to measure changes to the mechanical properties of the films, while the permeabilities to oxygen and moisture with increasing GTE concentrations were monitored. To understand how GTE interacted with the polymeric structure of the pectin, Fourier Transform Infrared Spectroscopy was used to investigate changes to the chemical structure, with changing GTE concentrations. Decreases in the percent elongation (46.3%) and moisture content (16%) accompanied by increases of 26% tensile strength, 55.39% elastic, and more storage moduli were observed with increasing GTE concentrations. Changes in the Tg from -46.6 to -37.5°C also occurred with increasing GTE contents in the films. The thicknesses of the pectin films were not significantly affected by the concentrations of GTE. Both oxygen and water vapor permeabilities decreased by 35% when the GTE contents increased from 0 to 5% in the films. The FTIR results showed increasing ester (at 1737 cm-1) and hydrogen bonding formations (at 3350 cm-1) with increasing concentrations of GTE from 0 to 2% in the pectin polymer. When the GTE concentrations increased from 2 to 5%, there was an increase in ester, but a decrease in the H-bonding. The XRD results showed that the crystallinity of the films increased as a result of increasing GTE contents. The antioxidant activities plus oxygen and water vapor barrier properties showed enhancements due to the higher concentrations of GTE. Therefore, GTE can be incorporated into low methoxyl citrus pectin to make films with the desired mechanical strength, gas barrier, and antioxidant properties. Speakers: Huan Wei, MS, Melvin Pascall, PhD