In this study, avocado seed (AS) waste was used as a feedstock for bacterial cellulose (BC) production. Global avocado consumption continues to rise due to its recognised health benefits, resulting in substantial amounts of waste generated by the avocado processing industry. This work proposes the efficient utilisation of avocado seed residues—rich in fermentable sugars—to enhance the economic viability of BC production while supporting responsible agro-industrial waste management. Hydrolysed avocado seeds were incorporated into a modified Hestrin–Schramm (MHS) medium for BC production using Komagataeibacter xylinus as the bacterial strain. The BC membranes obtained from the modified medium (BC-MHS) exhibited higher production (1.93 g/L) and productivity (0.19 g/L·day) compared with those produced in the standard HS medium (BC-HS). The morphology and nanofibre diameter (11–85 nm) of the resulting BC were not significantly affected; however, BC-MHS showed higher crystallinity (~78%) and a higher degradation temperature (~357 °C) than BC-HS. Conversely, the modified medium slightly reduced the mechanical performance of the BC in terms of elongation at break, tensile strength, and Young’s modulus. Overall, avocado seed waste was successfully transformed into a value-added material, demonstrating its potential for agro-industrial waste valorisation through scalable and sustainable biorefinery processes.

Intelligent packaging represents a sustainable solution for food preservation by enabling the monitoring of freshness through chromatic changes. In this study, a biofilm based on polyvinyl alcohol (PVA), nanocellulose (NC) extracted from rice straw and blueberry extract was developed and evaluated for its performance as a visual freshness indicator in tilapia fillets. Nanocellulose, obtained by TEMPO oxidation, exhibited proper integration into the polymeric matrix according to transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray diffraction analysis. The biofilms improved their mechanical properties with the addition of NC, by increasing tensile strength and reducing water solubility. However, the incorporation of anthocyanins increased solubility and water vapor permeability due to their hydrophilic character. Despite this, their high chromatic sensitivity to pH allowed for color changes: red in acidic media (pH 2-4) and green/brown in alkaline media (pH > 9). These visual changes validate the potential of anthocyanins as freshness indicators, positioning biofilms as a functional and sustainable alternative to conventional packaging. In addition to enabling real-time monitoring, these biofilms can contribute to reducing food waste and fostering more sustainable solutions in the packaging industry, with significant potential for innovative commercial applications.

Biodegradable trays were developed from starches of arracacha (Arracacia xanthorrhiza), potato (Solanum tuberosum), and lucuma seed (Pouteria lucuma) using a simplex lattice mixture design. The optimal formulation, with 90.2% lucuma starch and 9.8% potato starch, achieved a desirability of 0.880, with 18% solubility, 1.49% elongation at break, 1.14 MPa tensile strength, and 113.00 MPa Young’s modulus. X-ray diffraction revealed a type B crystalline pattern in all native starches, while FT-IR confirmed the preservation of hydroxyl, glycosidic, and C–O–C functional groups after thermoforming. The optimized tray exhibited a water activity of 0.67, an opacity of 0.88 Abs/mm, a DPPH radical-scavenging activity of 24.54%, and a total phenolic content of 23.93 mg GAE/g, all of which were attributed to residual polyphenols from lucuma starch. Thermogravimetric analysis identified four degradation stages, with a maximum degradation rate at 316 °C, indicating good thermal stability. Microwave heating induced color changes associated with non-enzymatic browning and moisture loss, corroborated by SEM observations. Overall migration remained below the 10 mg/dm² limit established by Regulation (EU) N°. 10/2011. Composting assays showed 88–100% mass loss after 140 days. These findings demonstrate the potential of the optimized formulation as a biodegradable packaging material for food applications.