Federation of Engineering Institutions of Islamic Countries
Abstract
Microalgae are being consumed as supplements because they are rich in protein, vitamins, carbohydrates and
lipids. Hence, extraction processes to obtain the bioactive compounds are being extensively studied and
developed. Sub-critical water extraction (SWE) technology has been used in extracting active compounds from
different biomass materials with low process cost, mild operating conditions, short process times, and
environmental sustainability. Therefore, this study utilizes SWE for extracting biochemical compounds such as
lipids, carbohydrates and protein from Nannochloropsis gaditana. Different parameters were applied include
temperature (156°C-274°C), biomass loading (33 g/L-117 g/L) and retention time (6.6 min-23.4 min) for
maximum production of those compounds. It was found that higher crude oil yield of 17.86 wt% was achieved
under SWE (215oC, 15 min, 75 g/L) compared to conventional method (10.2 wt%). The similar pattern was also
observed for carbohydrates and protein yields as shown by Fourier transform infrared spectroscopy (FT-IR)
result. Overall, the findings of this study will benefit food and pharmaceutical industries as well as enhancing
the usage of this abundant biomass for commercial purposes
