Structure-activity relationships and activity enhancement techniques of marine bioactive peptides (MBPs)

Marine bioactive peptides (MBPs) are a type of natural compound with a variety of bioactivities, such as anticancer, antimicrobial, antioxidant, and antihypertensive. Due to a wide range of sources, low toxicity, and high specificity, MBPs have now received extensive attention in the fields of food, medicine, and cosmetics. The structure of MBPs determines their biological activities. Therefore, it is essential to analyze the relationship between the structure and bioactivity of MBPs. Because of the advantages of mild conditions, high specificity, safety, and environmental friendliness, enzymatic hydrolysis has become the most commonly used method to produce MBPs. However, the high cost and low yield of enzymatic methods have motivated researchers to search for alternative technologies. Novel pretreatments like ultrasound, microwave, high hydrostatic pressure, and pulsed electric fields have been employed in the production of MBPs. By inducing protein unfolding and increasing enzymatic cleavage sites, these techniques have been demonstrated to accelerate protein hydrolysis and enhance the biological activity of MBPs. This article reviews recent research advances on marine-derived protein hydrolysates and peptides, discusses the relationship between their biological activity and structure, and compares the mechanisms of action of different novel technologies used to promote protein hydrolysis and enhance the biological activity of MBPs. In addition, the current challenges facing the development and application of MBPs are outlined and possible future work in tackling these challenges is also suggested in the current review. It is hoped that this review can promote further development and application of marine active substances.