Osteopontin as an emerging multifunctional food ingredient: recent advancements, production, applications, and challenges

As protein supplement products continue to evolve toward premium offerings, enhancing their nutritional value based on protein characteristics has become increasingly crucial. As one of the bioactive proteins derived from milk, osteopontin (OPN) possesses outstanding multifunctionality and plays a vital role in vivo, making it a promising “golden ingredient” for protein supplement products. This review systematically summarizes the diverse sources of OPN, its structural characteristics enriched with functional domains, as well as efficient extraction and recombinant expression techniques. It further elaborates on the multifunctional roles and underlying mechanisms of action of OPN. The potential applications of OPN in the food industry are thoroughly explored, along with a discussion of current challenges and future prospects, offering valuable insights for OPN research in food and nutritional applications.