Mass transfer process of peanut protein extracted by bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles

Abstract

The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds, which have become increasingly popular in recent years. However, there are few studies on mass transfer processes and models, which are helpful to better control the extraction process of oils and proteins. In this paper, mass transfer process of peanut protein extracted by bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/isooctane reverse micelles was investigated. The effects of stirring speed (0, 70, 140, and 210 r/min), temperature of extraction (30, 35, 40, 45, and 50 °C), peanut flour particle size (0.355, 0.450, 0.600, and 0.900 mm) and solid-liquid ratio (0.010, 0.0125, 0.015, 0.0175, and 0.020 g/mL) on extraction rate were examined. The results showed that extraction rate increased with temperature rising, particle size reduction as well as solid-liquid ratio increase respectively, while little effect of stirring speed (P > 0.05) was observed. The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant (A) was 1.91 by Arrhenius equation. There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius (1/r₀²) (P < 0.05). This phenomenon and this shrinking core model were anastomosed. In brief, the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction. Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results. The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.