Development of Innovative Glazing Sprayable Solutions for Bakery Products

Aim: Glazing enhances bakery items’ characteristics improving glossy appearance and providing a protective layer able to maintain freshness, texture, and flavor. This work aimed to develop innovative plant-based glazing solutions for bakery products by implementing the aerosol-spray packaging technology (applied to food for its precise laying, waste reduction, and increased efficiency). The addition of ethanol as a preservative was investigated evaluating its ability to ensure glaze safety and quality during an extended shelf-life. Method: Sample microbial stability was tested under vacuum and non-vacuum at two storage temperatures (4°C, 25°C). Ethanol (5%, 7.5%, 10%, 15%, 20%) was added to the glaze and a challenge test was performed to determine its effectiveness in inhibiting bacteria (Escherichia coli, Latilactobacillus sakei, Staphylococcus xylosus, Bacillus subtilis), yeasts (Saccharomyces cerevisiae, Zygosaccharomyces bailii), and molds (Penicillium chrysogenum). Ethanol effect and suitability in spray packaging were monitored through comprehensive physical and rheological tests (pH, water activity, moisture, color, viscosity, viscoelasticity, flocculation, particle size). Three glazing techniques were investigated to undestand their usage and benefits: pastry brush, aerosol-spray can (mixture of N2 propellant and glaze), and bag-onvalve system (compressed air surrounding a welded bag containing the glaze). Frozen croissants were glazed using the different techniques, baked, and evaluated for color and texture (cutting test). Results: Ethanol was effective in preserving glaze quality and stability: 10% addition at 25°C resulted the best in microbiological and technological terms. Concerning the yield on croissants, ethanol did not affect the product crispiness; compared to pastry brush, 33% less glaze was sprayed obtaining equivalent color and texture together with a reduction in the erogation time. Bag-on-valve system was the most efficient providing continuous spraying. Conclusion: In conclusion, ethanol can be easily added to a plant-based glaze giving a longer stability and ensuring its microbiological safety. The application of the aerosol-spray packaging technology results in a product that is sustainable, anti-waste, easy- and ready-to-use, and also stable without the need of cold chain.