Functional Characterisation of Rosemary‐Enhanced Alginate Films for Strawberry Preservation

This study developed alginate‐based edible films enriched with rosemary extract (RE), obtained from distillation by‐products and evaluated their physicochemical, functional and preservation performance in strawberries. RE (9% v / v ) was incorporated into 2% ( w / v ) sodium alginate film‐forming solutions, which were applied both as coatings and cast into standalone films. The incorporation of RE increased film thickness (from ~0.056 to ~0.068 mm), density (from ~1.05 to ~1.12 g/cm 3 ) and solution viscosity, while reducing moisture content (from ~12% to ~8.5%). RE also enhanced UV–Vis light protection and slightly increased water vapour permeability (from ~2.75 to ~3.0 × 10 −11 g · s −1 · m −1 · Pa −1 ). When applied to fresh strawberries stored at 5°C, RE‐enriched coatings significantly inhibited microbial growth. Total bacterial counts remained below 4.9 log10 CFU/g after 14 days compared with higher levels in uncoated controls, whereas total yeast and mould counts decreased from ~3.7 to ~3.1 log10 CFU/g. These results demonstrate that RE‐infused alginate films effectively slow microbial proliferation and help maintain fruit quality during refrigerated storage. The findings point out the efficacy of rosemary distillation by‐products as sustainable, natural additives for biodegradable edible coatings in fresh produce preservation.