Biopolymer films from glucomannan: the effects of citric acid crosslinking on barrier properties

Abstract

Glucomannan extracted from konjac root is used to form biodegradable films with gas and grease barrier properties for food packaging application. Nano-fibrillated cellulose (NFC) and plasticizers were used to improve the strength properties of the films. Citric acid and sodium hypophosphite (SHP) were used as crosslinking agent and catalyst, respectively, to improve the barrier property of the films against moisture. The film samples were prepared from glucomannan and NFC using a dispersion-casting method. The moisture barrier properties were characterized by the moisture vapor transmission rates (MVTR) and showed a significant decrease of 49.7 % (with 0.35 g citric acid in formulation, cured; marked as CA35-C). The crosslinked glucomannan films were calibrated with increasing mean tensile strength, modulus and elongation.