Optimization of microalgae protein extraction from Scenedesmus obliquus and investigating its functional properties

Abstract

The objective of this work was to evaluate alkaline treatment with enzymatic approaches for the optimal extraction of proteins from Scenedesmus obliquus microalgae. The experiments were designed with an emphasis on the alkaline treatment period and the enzyme-to-substrate ratio utilizing response surface methodology (RSM) with central composite design (CCD). Higher enzyme concentrations led to better extraction rates and efficiency, according to the findings. Cellulase demonstrated extraction efficiencies between 16.88% and 21.42%, but the multi-enzyme complex had efficiencies ranging from 15.28% to 27.87%. With an extraction rate of 19.13%, alkaline treatment was less advantageous than enzymatic treatment due to its longer procedure. Microalgal proteins' functional characteristics were also looked at. These proteins demonstrated foaming capacity, oil absorption, and emulsification ability, making them suitable alternatives to animal proteins in food systems such as egg white and soybean. Although microalgal protein powder had lower foam capacity (20%), stability (25%), fat absorption capacity (124%), and emulsification ability compared to egg white powder, it still exhibited favorable functional properties, highlighting its potential for various food applications. Further enhancement of the functional properties can be achieved by optimizing the environmental conditions during extraction.