What if a small sticker inside a food package could help prevent mold growth without adding preservatives directly to the product? This innovative technology introduces an active sticker made from bio-based materials and clove essential oil. Designed to slowly release natural antifungal compounds into the package headspace, the sticker helps suppress mold development in bakery products while avoiding direct contact with the food.

The results demonstrated strong antifungal performance against major spoilage molds commonly found in baked goods. When applied inside butter cake packaging, the active sticker extended the mold-free period from approximately 4 days to 6 days while maintaining the cake’s texture and quality. Beyond preserving food, this innovation has the potential to reduce food waste caused by spoilage, support more sustainable packaging systems, and decrease reliance on synthetic preservatives. By combining natural ingredients with smart packaging design, the technology represents a promising step toward safer, cleaner-label, and more environmentally responsible food systems for the future. 

Topic: Antifungal effect of active sticker coated with hydroxypropyl methylcellulose combining waxes and essential oil and its application on butter cake

Authors: Thanakornmetee, Y.| Thongchai, P.| Sangsuwan, J.

Abstract: 

This study developed an active sticker to inhibit mold growth on butter cake using coatings of hydroxypropyl methylcellulose (HPMC), carnauba wax (CW) or beeswax (BW), and clove essential oil (CEO). Single layer (HPMC+BW, HPMC+CW, HPMC+BW+CEO, HPMC+CW+CEO) and double layer coatings (HPMC+CEO/BW, HPMC+CEO/CW, HPMC/BW+CEO, HPMC/CW+CEO) were applied on sticker papers and evaluated for their properties, including structural and thermal characterization, surface morphology, physical properties, water resistance, and antifungal efficacy. Double layer with beeswax coatings exhibited better adhesion to the paper, without cracking. All CEO-containing coating formulations effectively inhibited Rhizopus stolonifera and Aspergillus flavus. Based on this, large (4.5 × 6.0 cm) and small (4.5 × 3.0 cm) sizes of papers coated with HPMC+BW+CEO and HPMC/BW+CEO were selected for in-package testing with butter cake by adhering the coated sticker paper inside PET containers. The large piece of double layer HPMC/BW+CEO coating provided the best mold suppression on butter cake, a result directly correlated with its greater CEO release profile. The active sticker did not alter cake texture, however, it led to a noticeable reduction in sensory scores for odor, taste, and overall acceptance compared to the control. Analysis of water resistance properties (water vapor transmission rate, water absorption, and contact angle) confirmed that double layer coatings provided significantly better water resistance than single layer coatings and uncoated paper. The HPMC/BW+CEO coated paper is identified as a promising candidate for extending the shelf life of the butter cake industry. This active sticker acts as a biocontrol for reduction in food waste, supporting a better environment and health.

Source: Applied Food Research Volume 6(1) (June 2026)

Keywords: Clove essential oil; Beeswax; Carnauba wax; HPMC; Active sticker coated paper

View at publisher: https://www.sciencedirect.com/science/article/pii/S2772502226003926