Cyclodextrin–phytochemical inclusion complexes: Promising food materials with targeted nutrition and functionality

Natural phytochemicals suffer from poor aqueous solubility and storage stability as well as demonstrate limited bioaccessibility; thus, their effectiveness as food ingredients is severely restricted. The construction of cyclodextrin inclusion complexes (CICs) allows naturally derived phytochemicals with enhanced solubility and stability in various environmental situations to maintain their biological activity during food processing and storage. With the use of computational techniques, including molecular modelling and molecular dynamics simulation, the inclusion behavior of cyclodextrins and phytochemical molecules could be well elucidated. In the most recent studies, novel CIC materials, including nanofibers, nanosponges, and metal–organic frameworks, have been developed. The feasibility of these materials as functional additives in different food matrixes or in active packaging has been increasingly demonstrated, suggesting that the designable property of CICs render them as promising novel food materials. The improved bioaccessibility of phytochemicals in CICs could be demonstrated with the use of in vitro/vivo digestion models. However, additional safety and digestion assessments for these newly developed CICs are required for their practical application in the food industry. The involvement of advanced digestion models would help illustrate the potential application of innovative CIC materials in food industries. In this review, the most recent investigations on phytochemical–CICs were analyzed, and key points for the development of phytochemical–CICs to be used in the food industry are presented. This review is expected to provide valuable guidance for future research on food-targeted phytochemical–CICs.