Microalgae is one of the most important components in the aquatic ecosystem, and they are increasingly used in food and medicine production for human consumption due to their rapid growth cycle and survival ability in the harsh environment. Now, the exploration of microalgae has been gradually deepening, mainly focused on the field of nutrition, medicine, and cosmetics. A great deal of studies has shown that microalgae have a variety of functions in regulating the body health and preventing disease, such as nitrogen fixation, antitumor, antivirus, antioxidation, anti‐inflammatory, and antithrombotic. Furthermore, microalgae can synthesize various high‐valued bioactive substances, such as proteins, lipids, polysaccharides, and pigments. In this paper, we have briefly reviewed the research progress of main bioactive components in microalgae, proteins, lipids, polysaccharides, pigments, and other nutrients included, as well as their present application situation. This paper can provide the guidance for research and development of industrial production of microalgae.

Growth of ice crystals can cause serious problems, such as frozen products deterioration, road damage, energy losses, and safety risks of human beings. Antifreeze peptides (AFPs), a healthy and effective cryoprotectant, have great potential as ice crystal growth inhibitors for a variety of frozen products. In this review, methods and technologies for the production, purification, evaluation, and characterization of AFPs are comprehensively summarized. First, this review describes the preparation of AFPs, including the methods of enzymatic hydrolysis, chemical synthesis, and microbial fermentation. Next, this review introduces the major methods by which to evaluate AFPs’ antifreeze activity, including nanoliter osmometer, differential scanning calorimetry, splat‐cooling, the biovaluation model, and novel technology. Moreover, this review presents an overview of the molecular characteristics, structure–function relationships, and action mechanisms of AFPs. Furthermore, advances in the application of AFPs to frozen food, including frozen dough, meat products, fruits, vegetable products, and dairy, are summarized and holistically analyzed. Finally, challenges of AFPs and future perspectives on their use are also discussed. An understanding of the production, structure–function relationships, mechanisms and applications of AFPs provides inspiration for further research into the use of AFPs in food science and food nutrition applications.

The inhibition of α-glucosidase decreases postprandial blood glucose and therefore plays an important role in the treatment of type 2 diabetes mellitus. The present study investigated and characterized a peptide fraction of sericin hydrolysate, the kinetics of peptide-induced inhibition of α-glucosidase, and the interaction mechanism between the peptides and α-glucosidase. The fraction that eluted with 0.4 M NaCl (F5-SPs) on a DEAE-cellulose column exhibited significant inhibitory activity with an IC₅₀ of 41 ± 1.94 μg mL⁻¹. A kinetics analysis revealed that the F5-SP-induced inhibition was a reversible and parabolic mixed-type inhibition with a K_i value of 86.63 ± 0.014 μg mL⁻¹. F5-SPs can bind to α-glucosidase at multiple sites to alter the conformation of α-glucosidase. F5-SPs were found to be rich in Gly, Ser, Glu, Tyr, Arg, and Pro, and had a sericin-conserved sequence SEDSSEVDIDLGNLG, as analyzed by Nano LC-MS/MS. Fluorescence spectra analysis showed that F5-SPs quenched the intrinsic fluorescence of α-glucosidase by a static quenching mechanism, and circular dichroism analysis suggested that the binding of F5-SPs to α-glucosidase resulted in the alteration of the secondary structure of an enzyme. The results of this study support the dietary recommendation of F5-SPs for the treatment of type 2 diabetes.