Starch-based gel delivery systems for functional ingredients: insights into design, controlled release and applications.

Functional ingredients, which are components capable of exerting specific biological activities such as polyphenols, vitamins, bioactive peptides, and probiotics, play a vital role in promoting human health and preventing chronic diseases. However, their bioactivity is easily compromised by external conditions, limiting their functional efficacy. Delivery systems are commonly used strategies for embedding, protecting and delivering bioactive components. Selecting an appropriate delivery system is crucial for enhancing the stability and bioavailability of functional ingredients. Starch, as a natural polymer, has excellent safety and biocompatibility. As a delivery carrier, it has great potential in encapsulation and controlled release. This review summarizes the latest progress in delivering functional ingredients by starch-based gels. Firstly, the major categories of functional ingredients and their current limitations are discussed. The structural and functional properties of starch that enable it to serve as a carrier are then outlined. Recent progress on 3D-printed starch-based gels, hydrogels, emulsion gels, aerogels, and microgels is systematically summarized, with emphasis on their impacts on encapsulation efficiency and release behavior. Finally, the current applications, challenges, and future research directions of starch-based delivery systems are examined. It aims to provide a theoretical basis and new insights into the construction and exploration of the delivery system for functional ingredients encapsulated in starch-based gels.