Food-Grade Delivery Systems for Hepatoprotective Functional Foods: From Rational Design and Delivery Mechanisms to Industrial Processing and Nutritional Intervention

The liver is a crucial metabolic organ in humans and is susceptible to oxidative stress, which can have an adverse impact on human health. Nutritional intervention with food-derived bioactive substances has the potential to improve liver health. However, their application in functional foods is limited by low oral stability and bioavailability. Therefore, a food-grade oral delivery system is required to enhance their stability and utilization efficiency. This review summarizes the research progress on the use of foodborne bioactive substances through food-grade oral delivery systems for nutritional intervention in liver oxidative stress. Firstly, this review introduces the physiological basis of liver-enriched active substances in food and the design principles of food-grade carriers. Furthermore, we summarize the types of delivery systems, including protein-based systems, polysaccharide and protein-polysaccharide composite systems, and lipid and emulsion systems, as well as emerging food-derived structural carriers. Additionally, we outline the methods for evaluating liver exposure, such as simulated digestion, intestinal transport, and hepatocyte uptake. Finally, we discuss the potential applications of machine learning in carrier design and process optimization, and analyze challenges, including large-scale production, sensory quality, and food regulations. This review provides a comprehensive theoretical and technical foundation for the development of food-grade oral delivery systems, aiming to bridge the gap between advanced delivery technologies and practical industrial applications in the functional food sector. The insights presented are expected to accelerate the development of next-generation liver health-promoting foods with high bioavailability and stable nutritional effects.