*2.1. Materials*

Cellulosic tissues were provided by Lucense SCaRL (Lucca, Italy) (thickness = 200 μm, 19.5 × 20.5 cm).

Polyphenols powder was extracted by the University of Alicante (Alicante, Spain) from tomato seeds obtained from agri-food wastes. Dried seeds were ground with a highspeed rotor mill at 12,000 rpm (Ultra Centrifugal Mill ZM 200, RETSCH, Haan, Germany), and particles passing through a 1 mm sieve were used. Then, microwave-assisted extraction (MAE) was applied by using a FLEXIWAVETM microwave oven (Milestone srl, Bergamo, Italy), as reported in the literature [72]. One gram of sample was introduced and mixed with 80 mL of 65% (*v*/*v*) ethanol at 400 rpm for 15 min at 80 ◦C. The obtained extract was cooled to room temperature and centrifuged at 5300 rpm for 10 min. The solid residue was washed twice with the extraction solvent and then discarded. Then, the supernatant was pooled with the washing solvent and stored overnight at −20 ◦C in order to remove possible interferences by precipitation. After that, the precipitate was removed by centrifugation at 5300 rpm and 4 ◦C for 10 min. The supernatant was collected and the ethanol was subsequently evaporated under reduced pressure. Afterward, the extract was frozen at −80 ◦C and freeze-dried until complete dryness. Finally, tomato seed extract was stored in vacuum-sealed packs at −20 ◦C in darkness.

A partially deacetylated chitin nanofibrils (ChNFs) suspension was supplied by Celabor (Chaineux, Belgium). The suspension was obtained through a chemical pre-treatment followed by a mechanical defibrillation process using an ultra-fine friction grinder Super masscolloider (Masuko® Sangyo Co. Ltd., Kawaguchi, Japan) equipped with two ceramic nonporous grinders adjustable at any clearance between the upper and lower grinder. Chemical pre-treatment was performed by a partial deacetylation of commercial chitin from shrimp shells (Sigma-Aldrich, St. Louis, MO, USA) using concentrated sodium hydroxide. The reaction was stopped when a degree of deacetylation (DDA) of 16% was reached. The product was then purified until the pH value reached 6.5~7. After the partial deacetylation, the resultant chitin suspensions were then prepared for mechanical defibrillation by dispersing them in acidified water at a concentration of 1.5 wt%. The solution was then manually poured into the grinder and the partially deacetylated chitin suspensions fed into the hopper were dispersed by centrifugal force into the clearance between the grinding stones, where they were ground into ultra-fine particles, after being subjected to massive compression, shearing, and rolling friction forces. ChNFs were thus obtained and stored at 4 ◦C until further use.
