One-step method for the isolation of α-lactalbumin and β-lactoglobulin from cow’s milk while preserving their antigenicity

ABSTRACT

Milk is a highly nutritional food, and separation of major allergens from milk has become important to people who are allergic. The aim of this study was to establish a simple and repeatable method for the isolation of α-lactalbumin and β-lactoglobulin from cow’s milk while preserving their antigenicity. Fractions of α-lactalbumin and β-lactoglobulin were salted-out using 50% ammonium sulfate from whey that was collected from cow’s milk after pH adjustment and then purified by anion-exchange chromatography with diethylaminoethyl-Sepharose Fast Flow. The antigenicity of the purified proteins was evaluated by indirect competitive enzyme-linked immunosorbent assay. The results showed that the purities of the α-lactalbumin and β-lactoglobulin collected were 84.85 and 94.91% and the cross-reactivities of the purified proteins were 93.2 and 95.4%, respectively. Therefore, this simple and efficient strategy consisting of a one-step process for α-lactalbumin and β-lactoglobulin is suitable for purifying the major allergens in cow’s milk. In addition, a scientific experimental basis for the preparation of non-allergenic milk was also offered in this study.

KEYWORDS:

• Milk
• α-lactalbumin
• β-lactoglobulin
• Purification, Antigenicity

Funding

This study was supported by the National Natural Science Foundation of China (Grant No. 31301519) and the Natural Science Foundation of Heilongjiang Province of China (C201134) and Heilongjiang Postdoctoral Grant (LBH-Q13029).