Continuous aqueous two-phase extraction of α-lactalbumin from whey in conventional rotating disc contactor

ABSTRACT

The differential partitioning of α-La to the PEG-rich phase and β-Lg to the salt-rich phase was studied in the continuous extractor, rotating disc contactor (RDC), using polyethylene glycol (PEG) 1000–trisodium citrate system. The performance of the extractor was evaluated in terms of holdup, mass transfer coefficient, extraction efficiency, and recovery by studying the operating variables such as phase velocities and rotor speed. The process conditions for the maximum dispersed phase mass transfer coefficient and recovery of α-La was also obtained and reported.

KEYWORDS:

• Aqueous two-phase extraction
• mass transfer coefficient
• rotating disc contactor
• whey proteins
• α-lactalbumin

Conclusions

The present investigation confirms the suitability of conventional rotating disc columns for ATPE of proteins. A maximum α-La recovery of 86% with a purity of 85.58% was obtained at the operating conditions: rotor speed of 5 s⁻¹, phase velocities of U_d 9.86 × 10⁻⁵ m/s and U_c 1.34 × 10⁻⁵ m/s. From the preceding discussion, it is evident that lesser height of transfer units can be achieved for the maximum throughputs by operating the reactor at highest permissible rotor speed and dispersed phase superficial velocity and at the lowest continuous phase velocity. The obtained range of HTU (0.07–0.3 m) at low continuous phase velocity (1.65 × 10⁻⁵ m/s) and at high dispersed phase velocity and rotor speed (above 5 s⁻¹) is highly encouraging for the commercial implementation of the continuous ATPE of valuable individual whey proteins in RDC.

Funding

This research was financially supported by the Department of Biotechnology, New Delhi, India (scheme number BT/PR11935/PID/06/456/2009).

Additional information

Funding

This research was financially supported by the Department of Biotechnology, New Delhi, India (scheme number BT/PR11935/PID/06/456/2009).