Overview of Agro-Food Waste and By-Products Valorization for Polymer Synthesis and Modification for Bio-Composite Production

Abstract

The increase in the world’s economic growth and global population requires a more efficient management of the Earth’s natural resources. The combined plastic and food sector forms an important part of the EU economy, accounting for 15 million jobs. Unlocking the innovation potential in the field of packaging and cosmetics will significantly contribute to job creation and competitiveness. Sustainable synthesis of polyhydroxyalkanaotes from agro-food by-products as well as synthesis of lactic acid co-polymers constitute a pathway to achieving sustainable polymeric matrices. Natural fibers, as well as polysaccharides (starch, cellulose, chitin, chitosan), cutin, and protein rich by-products, are abundantly available from the agro-food industry. Natural fibers may be modified chemically with enzymes or by treating their surface with natural waxes, with a significant improvement in adhesion and impact resistance. An overview on the availability, collection, treatment, and approach of valorization of largely available agro-food waste biomass for both polymer and biocomposite production is hereby reported, with examples of case studies and product developed in our research units, such as sustainable pots, rigid containers, active films, and non-woven tissue.

By-Products from Food Industry as a Promising Alternative for the Conventional Fillers for Wood–Polymer Composites

“…Such an effect can also signifi-cantly affect the mechanical performance of polymer composites, which was repeatedly proven by other researchers [41,42]. Differences in the microstructures between wood and food-industry by-products (pea, bran, and potato fibers) were also noted by Cinelli et al [10]. They reported fibrous structure of wood flour and flaked, platelet-like particles of other materials.…”

“…The complete replacement of wood flour with waste materials caused 36% and 42% drop of modulus to 487 and 438 MPa, respectively, for ŁK and BSG. Cinelli et al [10] also noted the deterioration in the tensile performance of composites when potato, pea, or bran fibers were incorporated into composites instead of wood particles. They attributed this effect to the insufficient interfacial adhesion and improper stress transfer when external force is applied.…”

A Review on the Challenges and Choices for Food Waste Valorization: Environmental and Economic Impacts

“…53 potato fiber, and pea fiber were also used with polymeric matrixes producing a biocomposite for sustainable pots, containers, nonwoven tissues, and films. 78 Fritsch et al have summarized various extraction methods that have been used at optimal conditions for maximum phenolic compound yields from different potato peels, which varied 10.3−593.3 mg/100 g (dry basis) depending on the potato cultivars and the methods of extractions. 79 The yield of value-added products from FW was also observed to widely vary depending on the type of FW and conversion technologies (Table 2).…”

Liquid and Solid Functional Bio-Based Coatings

“…Indeed, to develop sustainable coatings for cellulose or bioplastic substrates is a technological goal of huge importance and it has become mandatory in the bioeconomy and circular economy context, aimed at imparting proper functional characteristics, based on biopolymer and functional materials coming from agro-food waste streams [11].…”