Development and characterization of Caesalpinia pulcherrima seed gum‑based flms to determine their applicability in food packaging

Abstract

Investigation of potential biopolymers for developing edible flms as alternatives for plastic packaging is a recent trend. Among the biopolymers used in edible flm making, galactomannan is a good flm-forming agent. Caesalpinia pulcherrima seed gum is a rich source of galactomannan and could be used as an edible flm making material. The main objective of this study was to identify the ability of Caesalpinia pulcherrima seed gum in making a food packaging flm and assessing its performance. In this study, the gum was extracted from Caesalpinia pulcherrima seeds and dissolved in distilled water along with the plasticizer glycerol. In preparing flm-forming solutions, a previously selected range of glycerol concentrations (0.0, 0.5, 1.0 and 1.5%) was used. After casting and drying, the resultant flms were analyzed for their physical and mechanical properties. In the present study, the flm prior to incorporating glycerol was brittle, less fexible and had a strong flm matrix. With the increase of glycerol content, the flm became more fexible, sticky and weak. Further, the physical properties namely thickness, moisture content, swelling index, water solubility of Caesalpinia pulcherrima seed gum-based flms were increased from 0.039±0.001 to 0.076±0.001 mm, from 62.92±0.51 to 69.40±0.15%, from 5.39±0.17 to 8.45±0.17, from 55.69±0.51 to 66.66±0.45%, respectively, with the increase of glycerol content from 0.0 to 1.5%. Concerning the mechanical properties, the tensile strength and Young’s module were decreased from 10.90±0.08 to 2.11±0.05 MPa and from 48.46±0.24 to 3.47±0.09 MPa, respectively, and the elongation was increased from 22.50±0.05 to 60.84±0.04% with increasing the glycerol content from 0.0 to 1.5%. Due to its physical and mechanical properties, Caesalpinia pulcherrima seed gum is a potential source for edible packaging flm manufacture.