Change in conformational, digestive and immunological characteristics of bovine allergen β-lactoglobulin induced by metal ions in combination with heating

Aggregation of bovine beta-lactoglobulin is affected easily by external factors. In this study, effects of metal ions combining with temperature on aggregation of beta-lactoglobulin were explored. The conformational characteristics of aggregates were detected by environment scanning electron microscope, CD spectrum and free sulfhydryl group, respectively. Digestive and immunological characteristics were assessed by simulated digestion in vitro and ELISA respectively. The results showed that the morphology of beta Psi-lactoglobulin aggregates became more amorphous in Cu2+ and Mg2+ treated samples and more constricted in Zu(2+)-induced protein. Among them, Cu2+ altered the secondary structure of beta-lactoglobulin aggregates and free sulfhydryl content most as well as that in gastric digestion. However, all ion-treated groups had similar digestive stability in intestinal digestion. Specially, Ca2+ and Mg2+ made the antigenicity and potential allergenicity of beta-lactoglobulin aggregates decrease, which helps us understand the role of metal ions in immunological characteristics.

Automated summary

This study investigated the effects of metal ions and temperature on the aggregation of bovine beta-lactoglobulin. It was found that Cu2+ and Mg2+ treatments led to more amorphous aggregates, while Ca2+ and Mg2+ decreased the antigenicity and potential allergenicity of the aggregates. All ion-treated groups showed similar digestive stability in intestinal digestion.