Research progress and prospects of nutrient delivery systems in food design for the elderly.

The global aging population has led to age-related digestive dysfunction, which has become a key driver of malnutrition and declining health. Physiological degeneration in older adults severely reduces nutrient bioavailability, making conventional single nutrient supplementation ineffective. Nutrient delivery systems tailored to the physiological constraints of the elderly show great value in alleviating geriatric malnutrition. Micro/nanoencapsulation, emulsions, and gels are particularly promising platforms for elderly-targeted food innovation due to their tunable structure, controlled targeted release, and good biocompatibility. Moreover, combining delivery systems with 3D printing for personalized nutrition and dysphagia-friendly texture design has emerged as an important trend in age-appropriate food development. This review outlines the digestive physiological constraints of the elderly and the design principles of nutrient delivery systems, highlights the adaptive optimization and recent applications of major delivery technologies in geriatric foods, and discusses intervention strategies, current challenges, and future directions. It aims to provide theoretical support for the research and innovation of functional foods tailored for older adults.