Innovative sprayable plant-based glazes for bakery products: Optimizing stability and application performance

Glazing enhances food by providing a glossy appearance and a protective layer that preserves freshness, texture, and flavour. This work aimed to develop innovative plant-based glazes using aerosol-spray packaging technology (guaranteeing precise laying, waste reduction, and increased efficiency). Microbial stability was tested under vacuum and non-vacuum conditions at 4◦C and 25◦C. Ethanol (5%, 7.5%, 10%, 15%, 20%) was evaluated as a preservative to ensure its ability to ensure safety and quality: a challenge test determined its effectiveness in inhibiting bacteria (Escherichia coli, Latilactobacillus sakei, Staphylococcus xylosus, Bacillus subtilis), yeasts (Saccharomyces cerevisiae, Zygosaccharomyces bailii), and moulds (Penicillium chrysogenum). Ethanol effect and suitability for spray packaging were monitored through physical and rheological tests (pH, Aw, moisture, colour, viscosity, viscoelasticity, flocculation, particle size). Three glazing application techniques were compared: pastry brush, aerosol-spray can (N2 propellant), and bag-on-valve system (compressed air surrounding a welded bag). Frozen croissants were glazed, baked, and evaluated for colour and texture (cutting test). Ethanol effectively preserved glaze quality and stability: 10% addition at 25◦C yielding optimal result. Concerning croissant yield, ethanol did not affect product crispiness; 33% less glaze was sprayed, obtaining equivalent colour and texture, together with a reduction in dispensing time. The bag-on-valve system provided the most efficient and continuous spraying. Ethanol did not remain in the final product, as it evaporated during baking. Overall, ethanolenhanced plant-based glaze combined with aerosol-spray technology offers a stable, safe, sustainable, readyto- use solution that reduces waste and eliminates cold-chain requirements.