Effect of ultrasound treatment on protein content and functional properties of Spirulina powder grown in Algeria

Abstract

There is an important interest to research new protein sources. In this context, Microalgae, particularly Spirulina (Arthrospira platensis), seems to be a good alternative due to its wealthy nutritional composition. The aim of this study is to optimize Spirulina functional properties and to extract protein from whole biomass using (RSM). Ultrasound wad used as pre-treatment to optimize functional properties and to extract proteins from Spirulina powder by isoelectric precipitation. The effect of ultrasound and remaining parameters (pH, temperature, solid to liquid ratio and time) was evaluated by Box-Behnken design. The model was fitted by ANOVA analysis. ANOVA analysis showed a significant model (p < 0.05) for functional properties and protein extraction. The protein content of Spirulina powder was found to be 55% (w/w). There is a significant effect of ultrasound on functional properties and protein extraction from Spirulina. The optimum Water Holding Capacity (WHC) was 4.97 g H2O/g Spirulina powder, obtained at pH 4, 50 W power and 5 min sonication. The optimum Oil Holding Capacity (OHC) is 2.3 g H2O/g Spirulina powder, it was obtained at 50°C temperature, 70 w power and 10 min sonication. Ultrasound has a significant effect on functional properties and protein extraction from Spirulina. Arthrospira platensis grown in Algeria could be incorporated in foodstuff as natural supplement to improve nutritional value and consumer acceptability.