Covalent or non-covalent binding of polyphenols, polysaccharides, metal ions and nanoparticles to beta-lactoglobulin and advanced processing techniques: Reduce allergenicity and regulate digestion of beta-lactoglobulin

Milk allergy is a global health issue, which affects the quality of life and can even be life threatening. According to epidemiological investigation, 2%–6% of infants are sensitive to beta-lactoglobulin (β-LG) in milk. Avoiding allergens is still the first-rank option for vulnerable group because immunization therapy is hardly available. Therefore, exploring the allergic mechanism of β-LG and applying appropriate antiallergic treatments are the key to solving the problem of milk allergy. This review describes the occurrence of β-LG, including the type, structure, epitopes of β-LG, the performance of gastrointestinal digestion, the mechanism and allergy consequence of β-LG allergic responses. Then, various methods to reduce the sensitization of β-LG were summarized, including covalent and non-covalent interactions, non-thermal processing technologies (fermentation, irradiation, pulsed electric field, ultrasound), thermal processing technology (microwave), and combination therapies. Key findings and conclusions: β-LG allergy is an immediate type I hypersensitivity reaction involving immunoglobulin (IgE) dependent antibody responses that cause a variety of clinical symptoms, such as asthma, eczema, gastrointestinal disorders, and anaphylactic shock in severe cases. To reduce the allergenicity of the β-LG, it is necessary to adopt novel processing strategies with higher efficiency. This review covers the covalent or non-covalent binding of polyphenols, polysaccharides, metal ions and nanoparticles to β-LG, as well as emerging technologies, and finds that structural modifications and conformational epitope changes of β-LG are associated with immunomodulatory properties. The combination of various approaches is a potential new way to reduce β-LG hypersensitivity.