What question did this study set out to answer?

The main goal is to enhance the mechanical and barrier properties of gelatin films through crosslinking with fatty aldehydes for improved food packaging applications.

April 22, 2026Open Access

Green fabrication of gelatin coating film via fatty aldehyde crosslinking for synergistically enhanced barrier-mechanical properties and strawberry preservation

Key Points

The main goal is to enhance the mechanical and barrier properties of gelatin films through crosslinking with fatty aldehydes for improved food packaging applications.
Covalent crosslinking of gelatin using fatty aldehydes via Schiff base reaction.
Optimization of modification process by monitoring water contact angles and interfacial tension under varying pH and temperatures.
Structural analyses conducted using FT-IR, 1H NMR, and XPS to confirm successful modifications.
Hexadecanal-modified gelatin films showed a 2.65-fold increase in tensile strength, reaching 75.73 MPa.
Modified films exhibited enhanced barrier properties against water vapor, oxygen, and ultraviolet light.
The films maintained biodegradability and demonstrated effective preservation of strawberries, reducing weight and rotting rates.

Abstract

• Aroma fatty aldehydes covalently crosslinked gelatin via Schiff base reaction. • Hexadecanal modification boosted gelatin film tensile strength 2.65-fold vs control. • Modified films exhibited enhanced barrier to vapor, oxygen, and ultraviolet light. • Modified films retained full biodegradability and good HaCaT cell biocompatibility. • Modified gelatin coating enhanced strawberry preservation performance. Poor mechanical strength and high hydrophilicity of gelatin films significantly limit their applications in food packaging. This study proposed a green and sustainable strategy to concurrently enhance the hydrophobicity and mechanical properties of gelatin films by crosslinking them with fatty aldehydes (butanal, octanal, dodecanal, and hexadecanal). The modification process was systematically optimized by monitoring water contact angle and interfacial tension, identifying pH 7 as the universal optimal pH, with the best reaction temperatures being chain-length-dependent (60-80°C). Under optimal conditions, the tensile strength of the modified films increased with the aldehyde chain length, reaching a maximum of 75.73 MPa for the hexadecanal-modified film, which was 2.65 times that of the pure gelatin film. Comprehensive structural analyses (FT-IR, 1 H NMR, XPS, free amino content) confirmed the successful formation of covalent imine bonds (C=N) via Schiff base reaction, which increased the carbon content (up to 79.50% for octanal) and crosslinking degree (38.28% for hexadecanal). Furthermore, the modification significantly improved the water resistance and barrier properties against UV light, water vapor, and oxygen, while preserving excellent degradability in soil (4-5 days, via combined abiotic and microbial processes) and cytocompatibility (HaCaT cell viability > 80%). In practical applications, octanal and dodecanal modified film significantly reduced the fruit weight loss rate and rotting rate, while better maintaining the strawberry color and visual appearance. In summary, this work demonstrated that fatty aldehyde crosslinking was an effective and eco-friendly approach for fabricating high-performance gelatin-based films with great potential for sustainable food packaging.

Green fabrication of gelatin coating film via fatty aldehyde crosslinking for synergistically enhanced barrier-mechanical properties and strawberry preservation

Key Points

Abstract

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