Designing Protein Gels for Nutrient Delivery: From Formulation to Digestion
Xue Dong, Yong Wang, Xiao Chen, Cordelia Selomulya
Abstract
Protein gels have diverse applications in food industry, with plant proteins as potential alternatives to animal-derived products. The applications of protein gels mainly depend on gel properties while gel digestibility affects the delivery and release of nutrients. However, the relationship and synergistic influences among gelation mechanism, gel properties, and digestive characteristics, relevant to formulate gelation strategies of animal or plant proteins, have never been systematically discussed. This review provides insights into the relationship between molecular mechanism and gel properties, and effects on delayed or rapid digestibility and delivery of bioactive ingredients. Gel digestibility and delivery of bioactive ingredients can be controlled by altering gel properties and microstructure with various gel compositions and treatments. The encapsulation and delivery systems of bioactive ingredients based on protein gels were described. Finally, a comparison between in vitro static and dynamic digestion methods was conducted to evaluate suitability, limitations, and accuracy for assessing the digestibility and nutrient release of protein gels. Dynamic in vitro digestion systems mimic closely the physiological conditions of human digestion tract compared to that of in vitro static method. The comprehensive understanding of protein gel digestion with structural design and formulation strategies, offers practical insights for developing tailored protein-rich food systems with controlled digestive behavior relevant to satiety-enhancing foods and delivery systems with targeted outcomes such as elderly nutrition.