β-Cyclodextrin/Thymol Microcapsule-Embedded Starch Coatings for Synchronized Antimicrobial Release and Shelf-Life Extension in Blueberries

An eco-friendly composite coating was developed for blueberry preservation through the incorporation of thymol-loaded β-cyclodextrin microcapsules (THY@β-CD) into a potato starch (PO) matrix. Microencapsulation at an optimal wall-to-core ratio of 13:1 achieved a THY encapsulation efficiency of 73.24%. Structural analyses confirmed the successful formation of an inclusion complex, which enhanced thermal stability and provided a controlled release profile governed by Fickian diffusion mechanisms. When applied to blueberries, the coating significantly reduced weight loss by 22%, delayed softening, and more effectively preserved anthocyanin content compared to uncoated fruit during 10-day storage. Furthermore, it well-maintained the sensory quality and visual appeal of the fruit. These results demonstrate that the THY@β-CD/PO coating synergistically integrates sustained antimicrobial delivery with matrix compatibility, offering a promising natural alternative to synthetic preservatives for extending the shelf life of blueberries.