Functional Characterisation of Rosemary-Enhanced Alginate Films for Strawberry Preservation.

Area of Science:

• Food Science
• Materials Science
• Agricultural Science

Background:

• Alginate-based edible films are promising for food preservation.
• Rosemary extract (RE) possesses antimicrobial and antioxidant properties.
• Utilizing distillation by-products offers a sustainable source for food additives.

Purpose of the Study:

• To develop and evaluate alginate-based edible films enriched with rosemary extract (RE).
• To assess the physicochemical, functional, and preservation performance of these films on strawberries.
• To investigate the potential of using rosemary distillation by-products as a natural preservative.

Main Methods:

• Incorporation of 9% (v/v) RE into 2% (w/v) sodium alginate solutions.
• Application of films as coatings and standalone films on fresh strawberries.
• Evaluation of film properties (thickness, density, moisture, UV-Vis protection, water vapor permeability) and microbial inhibition in strawberries stored at 5°C.

Main Results:

• RE incorporation increased film thickness, density, and viscosity, while reducing moisture content.
• Enhanced UV-Vis light protection and a slight increase in water vapor permeability were observed.
• RE-enriched coatings significantly inhibited bacterial, yeast, and mould growth on strawberries over 14 days.

Conclusions:

• Alginate films enriched with rosemary extract show significant potential for preserving fresh strawberries.
• Rosemary distillation by-products serve as an effective and sustainable source for natural food preservatives.
• These edible films contribute to extending the shelf life of fresh produce under refrigerated conditions.