Carrageenans obtained from seaweeds can be processed into films for a range of applications including food packaging. The level of carrageenan refinement during extraction can influence the key properties, with semi-refined carrageenan (SRC) containing more impurities than the more refined carrageenan (RC). Further refinement steps, however, result in higher costs associated with the production of RC. In order to obtain a lower cost and more ecofriendly, bio-based material for food packaging applications, SRC was used in this investigation to produce a thin film reinforced with nanocellulose fibrils (NCF). Films derived from RC containing NCF were also investigated with water sensitivity and physico-mechanical and thermal properties among the properties tested. Levels of NCF were varied from 1% to 7% (w/w), and in general, the NCF reinforcement improved the overall properties of both the SRC and RC films, including the water sensitivity and moisture barrier. However, NCF inclusion in SRC film was less effective with regard to the mechanical and thermal properties compared with NCF inclusion in RC film. The enhancement in properties was attributed to the greater cohesiveness of the reinforced polymer structure and the crystalline regions formed in the structures of SRC and RC films by NCF incorporation.

This study aimed to develop and characterize biodegradable packaging film from blends of two natural polysaccharides, i.e., agar and glucomannan. The glucomannan used was derived from the specific tuber plant Amorphophallus oncophyllus (locally known as “porang”), which grows abundantly in Indonesian forests and remains underutilized. Various ratios of agar and porang-glucomannan (PG) proportions were formulated to produce a food packaging film, which was subsequently tested for its mechanical, physical, chemical, and thermal properties. The results showed that the inclusion of PG to the film formulations notably enhanced the stretchability of agar films, achieving maximum a twofold increase, while concurrently reducing their water resistance such as increased water solubility and water swelling for up to 125% and 105%, respectively. The mechanical and thermal properties, as well as the water vapor permeability of the resulting film, were significantly affected by the polymer matrix structure formed by the varying proportions of the two biopolymers. The enhancement of these properties was associated with a more solid/compact film structure, as corroborated by cross-sectional images obtained through SEM analysis. The study’s findings suggest that utilizing agar and porang biomass has significant potential for further development as an environmentally friendly food packaging material.

In the current investigation, to develop a carrageenan/cornstarch bioplastic production technique suitable for commercial-scale production, an alternative method to the commonly used solvent-casting technique was implemented through a hot-melt extrusion process. Moreover, to enhance the water resistance of the bioplastic and reduce production costs, waste cooking oil (WCO) was used as a substitute for glycerol plasticizer. Various weight ratios of WCO to glycerol (w/w) were used in formulations. All the material ingredients were compounded using a double-screw extruder at 115°C. Subsequently, the resulting extrudate was then cut into resin pellets, followed by hot compression to produce bioplastic film samples. The film samples underwent testing for mechanical properties, water resistance, biodegradability, chemical structure and morphology. The overall results showed that the addition of WCO improved the tensile properties and water resistance and accelerated biodegradation. These findings were attributed to the presence of ester groups in the polymer structure, the intrinsic hydrophobic nature of WCO and the formation of voids within the film structure, as revealed by Fourier transform infrared spectroscopy and scanning electron microscopy analyses. Based on the findings, the utilization of WCO in carrageenan/cornstarch-based bioplastic production offers potential advantages for commercial applications.