Optimization of extraction process parameters of caffeic acid from microalgae by supercritical carbon dioxide green technology

Abstract

Abstract Purpose In this study, the optimization of extraction process parameters of caffeic acid content from Spirulina platensis is performed by supercritical green technology. Methods Especially, the optimization of supercritical carbon dioxide (SC-CO2) extraction parameters was carried out employing Box-Behnken design (BBD) and response surface methodology (RSM). Alongside, the three levels of extraction parameters i.e. extraction pressure, extraction time and temperature have been fixed. As a response, the caffeic acid content of the extracts was determined by HPLC. The statistical analysis (ANOVA) of developed mathematical models was used in the process. Results The extract exhibited the highest content of caffeic acid as 72.11 µg/g of dw at the optimized extraction conditions of 360.08 bar pressure for 57.13 min extraction time at 38.31 °C temperature. Simultaneously this extract exhibited the highest content of total phenolic content (76.87 µg GAE/g dw), reducing power (2278 µg BHT/g dw), FRAP value (4.19 mM FeSO4 equivalent/g dw) and IC50 for DPPH activity (89.28 µg/mL). Conclusion It has been also noted that supercritical fluid extract can significantly retard the growth of microorganisms in litchi beverage. Consequently, we can also predict that isolated SC-CO2 antioxidant containing fraction would have hopeful for foodstuff preservative.

Keywords

• Microalgae
• SC-CO2 extraction
• Antioxidant
• Caffeic acid
• Preservative