The environmental concerns associated with synthetic polymers have intensified the search for sustainable and biodegradable alternatives, particularly for food packaging applications. Natural biopolymers offer promising solutions due to their biodegradability, reduced environmental impact, and reliance on renewable resources. Among these, agri-food waste and by-products have gained significant attention as valuable feedstocks for polymer production, supporting a circular economy approach. This review critically examines the current status of biopolymers derived from plant, animal, and microbial sources, focusing on their physical and chemical properties and their application in food packaging. The findings underscore that the properties of plant- and animal-based biopolymers are heavily influenced by the source material and extraction techniques, with successful examples in biodegradable films, coatings, and composite materials. However, a critical gap remains in the characterization of microbial biopolymers, as research in this area predominantly focuses on optimizing production processes rather than evaluating their material properties. Despite this limitation, microbial biopolymers have demonstrated considerable potential in composite films and fillers. By addressing these gaps and evaluating the key factors that influence the success of biopolymer-based packaging, we contribute to the ongoing efforts to develop sustainable food packaging solutions and reduce the environmental impact of plastic waste.

The aim of this work was to develop active packaging based on polypropylene (PP) and polylactic acid (PLA) matrices using a high value by-product extracted from orange peel as an active compound for food packaging applications. Different films with and without orange peel extract (OPE) based on PP and PLA were obtained via cast extrusion and characterized in terms of their mechanical, thermal, optical, and sealing properties. The films obtained were transparent, but when OPE was incorporated, the transmittance spectrum decreased, causing slight coloration. Mechanical properties were affected by the incorporation of OPE, as elongation at break and tensile strength increased in the cross-direction of the PP film, although the main differences found were related to the polymer itself. In addition, sealing strength also increased via the incorporation of OPE in the PP matrix. However, thermal properties were not affected by OPE in the PP matrix but slightly decreased stability in PLA. Regarding antimicrobial activity in in vitro studies, no inhibition of the growth of Listeria innocua, Saccharomyces cerevisiae, Aspergillus niger, or Escherichia coli was observed. Finally, antioxidant activity was observed in in vitro studies with 2,2-Diphenyl-1picrylhydrazyl (DPPH) radical. The results of this study showed that the obtention of materials with OPE incorporated into the PLA and PP matrix is feasible. The new materials obtained can be used for applications of oxidation-sensitive fresh products.

This research aimed to develop new hazelnut and pumpkin seed oil-based creams and to assess the effect of different fat and sugar phases on the structure and physical properties of those creams at different refining degrees. In this study, three novel spreadable creams were prepared in a stirred ball-mill: CBS with cocoa butter, pumpkin seed oil and saccharose; OS with pumpkin seed oil and carnauba wax-basedoleogel and saccharose; OLS with oleogel, saccharose and Lucuma powder. OS and CBS creams reached a D90 value lower than 30 µm at 150 min of refining, the OLS cream showed the highest D90 value, with a particle size distribution and a rheological behaviour little affected by the refining time. The OS and CBS creams differed in yield stress, indicating that the attractive particle–particle interactions are affected not only by the particle size, but also by fat composition. Moreover, all the creams showed solid-like behaviour and a good tolerance to deformation rate, a high oil-binding capacity and a good physical stability. Thus, it is possible to reformulate spreadable creams with healthier nutritional profiles.

Natural and biodegradable polymers have gained significant attention as environmentally friendly alternatives to traditional synthetic materials, especially in food packaging. These materials offer several benefits, such as reduced environmental impact, biodegradability, and the use of renewable resources. In this context, agri-food waste and by-products have attracted huge attention as an effective strategy to valorize biomasses as renewable sources for the generation of polymeric materials. This review examines biopolymers from plant, animal, and microbial sources, focusing on their physical and chemical properties and application in food packaging. Results highlighted how the characteristics of the biopolymers extracted from plant and animal waste and by-products depend on source material and extraction techniques. In addition, a significant lack in the literature has been observed on microbial biopolymers' physical and chemical characteristics, for which the research is still focused on optimizing the production process. Despite this gap, microbial biopolymers have been successfully used in composite films and fillers. By comprehensively examining the properties of the biopolymer extracted from agri-food waste and by-products that play a crucial role in defining their success in producing food packaging material, we contribute to the ongoing efforts to create a circular economy and reduce the environmental impact of waste disposal.