Recent advances in the effects of food microstructure and matrix components on the bioaccessibility of carotenoids

Carotenoids have gained considerable attention due to their potential positive impact on health, which heavily depends on their bioavailability (including bioaccessibility, uptake by intestinal cells and further metabolism in the body). Food microstructure and the interaction of carotenoids with other components in the human diet matrix are key factors influencing bioaccessibility. This review mainly focused on the findings of recent studies on the effects of various food processing technologies-mediated alterations in food microstructure and matrix components (mainly lipids, dietary fiber, proteins, minerals, and flavonoids), as well as the influence of co-ingestion of carotenoids with these food components on carotenoid bioaccessibility. Studies have suggested that food microstructure (cell wall and chromoplasts) acting as physical boundary of carotenoids release may adversely affect the bioaccessibility of carotenoids, while some food processing techniques applying to food microstructure have shown a positive effect. However, the effects of interaction between carotenoids and various food matrix components on carotenoid bioaccessibility are much more complicated. Lipids and flavonoids may enhance while minerals may decrease carotenoid bioaccessibility. Dietary fibers and proteins are likely to affect bioaccessibility through encapsulation and interaction with bile salts and lipases in the digestive environment. Their presence has been shown to either increase or decrease bioaccessibility, which is specifically related to various factors such as their structural properties, concentrations and carotenoid type. It is important that these effects be further explored in order to achieve target regulating of carotenoid bioaccessibility to realize the optimum positive health impact.