ACTIVE PACKAGING FILM OF POLY(LACTIC ACID) INCORPORATED WITH PLANT-BASED ESSENTIAL OILS OF TRACHYSPERMUM AMMI AS AN ANTIMICROBIAL AGENT AND VANILLA AS AN AROMA CORRECTOR FOR WAFFLES

Abstract

This study developed active packaging films of Polylactic acid (PLA) incorporated with the plant-based essential oils of Trachyspermum ammi (T. ammi, T) and Vanilla (V) to package waffles, where the antimicrobial property was provided by T. ammi essential oil and its odor was masked by vanilla essential oil. Compared to conventional solvent-cast films of smaller sizes requiring a huge amount of solvents, bigger-size PLA-oil films with lower solvent demand were prepared by a unique tape casting technique with 10, 30, and 50 wt.% essential oil blends. Films were studied for their morphological, chemical, mechanical, barrier, and antimicrobial properties. The presence of essential oils in PLA films was confirmed by infrared spectroscopy. In parallel, the time-bound release of volatile oils from the films was also determined, with a continuous release/decrease of oils from the films till day 30. The plasticizing effect of oils in films was evidenced by decreased tensile strength and crystallinity. In contrast, an increase in elongation at break and water vapor permeability of oil films were also measured. Finally, the antimicrobial activity of PLA-oil films was checked against fungus grown previously on waffles. When packed in PLA films containing 50 wt.% blend of both oils, waffles shelf-life extended up to 30 days compared to 2 days for the neat PLA film.