Ultrasonic-assisted food-grade solvent extraction of high-value added compounds from microalgae Spirulina platensis and evaluation of their antioxidant and antibacterial properties

Spirulina platensis has been referred as a potential source of high-value added compounds. The objective of this work was to investigate ultrasound-assisted food-grade solvent extraction of valuable compounds from microalgae Spirulina platensis. Besides the ultrasound-assisted solvent extraction, conventional extraction methods such as pre-soaking and homogenization were implemented for effective disruption of cells. Individual food-grade solvents (water (W), ethanol (E)) and their mixture (70% water +30% ethanol (WE30), 50% water +50% ethanol (WE50), 30% water +70% ethanol (WE70)) were used for the extraction procedures. The optimum Cphycocyanin concentration was obtained for the W extraction with 20 min of sonication. The optimal extraction condition for chlorophyll a was found at 10 min of sonication when ethanol was used as the solvent. Moreover, the optimal extraction condition for chlorophyll b was obtained at 30 min of sonication and the highest yield of carotenoids extraction was found at 20 min of sonication when ethanol was used as the solvent. In case of polyphenols, the highest yield was found at 30 min of sonication when WE70 was used as the solvent. The use of ultrasound-assisted food-grade solvent extraction increased the extraction of the high-value added compounds and therefore resulted in higher antioxidant and antibacterial activities.

Automated summary

Ultrasound-assisted food-grade solvent extraction of Spirulina platensis can enhance the extraction of high-value added compounds, with different food-grade solvents and extraction times affecting the extraction of pigments and polyphenols in Spirulina.