Bioactive peptides (BPs) not only have nutritional value, but also have a wide range of biological activities, such as opioid activity, antibacterial activity, antioxidant properties and immunomodulatory which were associated with potential health benefits. Milk-derived BPs are the most researched, deepest and most widely used food-derived BPs. Milk-derived BPs perform an increasingly important role in regulating inflammatory balance in food allergy (FA) due to the immunomodulatory effect. This review outlines its immunomodulatory role in FA around cytokine level and gut regulation, and also emphasizes the production methods and current market applications of milk-derived BPs.

Silkworm pupa is a nourishing food with high nutritional value, but its consumption has been greatly limited given its allergenicity. Enzyme hydrolytic technique is recognized as an effective method to reduce the allergenicity of protein. In this study, we aimed to investigate the effect of enzymolysis on the allergenicity of silkworm pupa. Crude silkworm pupa protein was extracted through alkali extraction and acid precipitation, which included 5 proteins with the molecular weights ranging from 34 kDa to 76 kDa, and silkworm pupa were then hydrolyzed by alkaline protease. The allergenicity of silkworm pupa protein and its enzymatic hydrolysates was evaluated by establishing BALB/c mice model, and the mice were immunized via intragastric gavage and intraperitoneal injection, respectively. The results indicated that the intraperitoneal injection immunization route induced more by detecting with antibodies, histamine and Th2-related cytokines. Moreover, mice treated with silkworm pupa protein peptide displayed no obvious allergic symptoms, indicating that enzyme hydrolytic technique could significantly reduce the allergenicity of silkworm pupa.

Milk allergy is a common allergic reaction found in infants and young children, most of them appear tolerance after growing up. In this study, infant formula was digested by simulated in vitro digestion method. The potential non-allergenic peptides were further screened from undigested products by exclusion of the known epitopes from β-lactoglobulin (BLG) and α-lactalbumin (ALA). These potential non-allergenic peptides were synthesized and their transferability were determined by Caco-2 cell monolayer model. Finally, the potential allergenicity were evaluated by KU812 cell degranulation model. The results showed that 7 peptides were screened as non-allergenic sequences, among which were 3 from ALA and 4 from BLG. The Caco-2 cell model showed that all the synthetic peptides were absorbed and transported well. However, only peptide BLG_107-118 showed potential allegencity by KU812 model. In conclusion, six peptides, including ALA_29–51, ALA_80–90, ALA_94–103, BLG_1–20, BLG_24–50, and BLG_123–139 were evaluated as hypoallergenic peptides, which could be used for candidates of peptides inducing immune tolerance for persons with milk allergy.