Increased environmental and health concerns over the use of plastic packaging or fluorine-containing coatings, in combination with increased market demand for products with a longer shelf life, make bio-based materials one of the most important research candidates for alternative paper packaging materials for oil resistance. These bio-based materials have excellent oxygen and oil barriers, which are critical for food packaging. Moreover, they are biodegradable, naturally renewable, and safe. In this artical, two main groups of bio-based oil repellents for paper food packaging, including polysaccharide-based biopolymers and protein-based biopolymers, are enumerated, and the advantages and weaknesses of bio-based oil repellents are discussed, and effective solutions are proposed. Finally, research status and prospects on the development of bio-based oil-resistant coatings for the food packaging industry are presented.

Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process. Bleached softwood pulp fibers with a concentration of 30% were dispersed at a high speed under the action of a dispersant. The effects of the dispersant dosage of the fibers on the porosity, foam density, and static compression characteristics were discussed. Furthermore, the effects of the reinforcing adhesive including polyvinyl alcohol (PVA), and cassava starch on the physical and mechanical properties of the foam trays were studied, as well as the relationship between these properties and the microstructure of the foam trays. The dispersant enhanced the rheological and blistering properties of the fiber dispersion. As the dispersant dosage increased from 2% to 4%, the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased. Under the condition of constant dosage of dispersant, increasing the fiber proportion from 67% to 77% improved the porosity and foam density and slightly reduced the static compression performance. In additioton, the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.

In this study, we investigated the barrier properties of different kinds of microfibrillated cellulose (MFC) coating layers. The air, oxygen, and water vapor permeability, as well as the water contact angles (WCA), were measured to quantify the barrier efficacy of the applied coatings. The WCA data showed that the surfaces of MFC-coated cardboards are more hydrophilic than those of uncoated cardboards. However, different MFC coatings realize different oxygen transmission rates (OTRs) and water vapor transmission rates (WVTRs). The MFC coating derived from bleached bamboo pulp subjected to carboxyethylation pretreatment (MFC_CBP) gave the best oxygen and water vapor barrier performances. The OTR of the virgin cardboard (> 16500 cm³/(m²·24 h)) decreased to 4638 cm³/(m²·24 h) after coating with the MFC_CBP. The WVTR similarly decreased from 1016.7 g/(m²·24 h) to 603.2 g/(m²·24 h).