Combination of Alcalase 2.4 L and CaCl_2 for aqueous extraction of peanut oil

摘要

The combined application of CaCl_2 and Alcalase 2.4 L to the aqueous extraction process of peanuts was evaluated as a method to destabilize the oil body (OB) emulsion and improve the oil yield. After adding 5 mM CaCl_2, the oil yield was reached to 92.0% which was similar with that obtained using Alcalase 2.4 L alone, and the required enzyme loading was decreased by approximately 60 times. In addition, the demulsification mechanism during aqueous extraction process was also investigated. Particle size and zeta-potential measurements indicated that the stability of the peanut OB emulsion dramatically decreased when CaCl_2 was added. Under these conditions, the demulsification of Alcalase 2.4 L performed was more efficiently. SDS-PAGE results showed that adding CaCl_2 changed the subunit structure of the peanut OB interface proteins and promoted the cross-linking among the arachin Ara h3 isoforms, resulting in unstable emulsions.