Student name: Diana C. Santos

RUN-EU institution: Politécnico de Leiria, Portugal

Abstract

Packaging is a vital aspect of food processing, offering numerous benefits for food preservation. Currently, fruits are predominantly packaged using petroleum-based materials such as polyethylene (PE) and polyethylene terephthalate (PET), due to their ease of production, storage, transport and safety. However, these materials are non-biodegradable, leading to significant environmental concerns. Their slow degradation results in accumulation in ecosystems, threatening marine life, freshwater habitats, and soil health. Consequently, the demand for sustainable food packaging alternatives has become increasingly urgent. Paper-based packaging, combined with biodegradable and bio-based coatings, offers a promising solution for sustainable packaging development. Properties such as printability, recyclability, and biodegradability make paper a widely used material in food packaging. However, its porosity and hydrophilic nature present challenges, particularly in achieving adequate barrier properties. Red fruits are especially perishable due to their high-water content and activity, making them susceptible to mechanical damage and microbial contamination. Therefore, packaging materials for red fruits must provide effective barrier properties against moisture, light, oxygen, carbon dioxide, and biological contamination while maintaining mechanical strength and food quality. Surface coatings applied to paper substrates are currently the most effective strategy to address these challenges. To develop such coatings from renewable sources, agro-industrial by-products and marine-derived resources are increasingly utilised. Agricultural waste, including pomace, peels and seeds, is a valuable source of polysaccharides, proteins, pigments, and phenolic compounds, contributing to circular economy strategies. Marine organisms, particularly seaweeds and microalgae, provide bioactive compounds such as sulphated polysaccharides, amino acids and others with antioxidant and antimicrobial properties. Thus, the combination of bioactive compounds from marine-derived and agro-industrial sources in the production of coatings to be applied to paper-based packaging will be tested to ensure physical, chemical, and biological protection for red fruits. This strategy not only addresses the functional requirements for food packaging but also aligns with environmental sustainability by reducing reliance on non-biodegradable alternatives.

Keywords: red fruits, microalgae, seaweeds, by-products.