Film Properties of Pectin Obtained from Various Fruits’ (Lemon, Pomelo, Pitaya) Peels

Abstract

Food by-products, as sources of high-value compounds, have shown great promise for formulating novel food packaging and edible films for food preservation. This work focused on extracting pectin from lemon, pomelo, and pitaya peels using an ethanol precipitation method. The degree of esterification and the monosaccharide composition of the extracted pectin were determined, and the antioxidant activity of the pectin was assessed. Subsequently, pectin-based films were prepared using the casting method, employing pectin from various sources. These films’ physical and mechanical properties (tensile strength and elongation at break) were assessed, and their microstructure and intermolecular interactions were examined using scanning electron microscopy and Fourier transform infrared spectroscopy analysis. The results of this study demonstrate variations in the degree of esterification among the three pectin samples, with pomelo peel and lemon peel pectins exhibiting higher degrees of methylation compared to pectin from pitaya peel, which had a lower degree of methylation. However, no significant differences were observed regarding the films’ moisture content and water vapor permeability. Notably, the films made from pitaya peel pectin exhibited superior tensile strength and elongation at break to those derived from pomelo peel and lemon peel pectins. The pectin recovered from these fruit peels had great film properties and thus could be utilized for food packaging and edible films.