Microencapsulation in spices for protecting the bioactive compounds: A review

India, a leading producer of spices, has witnessed a growing interest in the application of spices in the food, pharmaceutical and nutraceutical industries. This is primarily due to the antibacterial and antioxidant properties of many spice essential oils, oleoresins and their bioactive components. These characteristics emphasised the therapeutic and preservative properties of spices. However, the high volatility and sensitivity of essential oils, oleoresins, and bioactive components to external factors present challenges in their direct use as food ingredients and nutraceuticals. Microencapsulation has emerged as an advanced technology to enhance the stability, taste and functionality of spice-derived products in these industries. It is considered one of the most effective preservation techniques for the spice industry, as it helps maintain the quality and efficacy of spice compounds. Microencapsulation involves coating active compounds, such as essential oils, oleoresins, and bioactive ingredients, with protective materials to form microcapsules. Common wall materials used for encapsulation include maltodextrins, starch, gum acacia, and sodium alginate. Several techniques are employed for microencapsulation, including spray drying, fluidized bed coating, coacervation, extrusion, emulsification and freeze-drying. These methods significantly enhance the stability, shelf life and controlled release of encapsulated compounds, making them more suitable for food products and nutraceuticals. This review presents an overview of the major microencapsulation techniques applied to spice products, highlighting the principles and processes involved.