Chlorophyll Extraction from Microalgae: A Review on the Process Engineering Aspects

Abstract

Chlorophyll is an essential compound in many everyday products. It is used not only as an additive in pharmaceutical and cosmetic products but also as a natural food colouring agent. Additionally, it has antioxidant and antimutagenic properties. This review discusses the process engineering of chlorophyll extraction from microalgae. Different chlorophyll extraction methods and chlorophyll purification techniques are evaluated. Our preliminary analysis suggests supercritical fluid extraction to be superior to organic solvent extraction. When compared to spectroscopic technique, high performance liquid chromatography was shown to be more accurate and sensitive for chlorophyll analysis. Finally, through CO 2 capture and wastewater treatment, microalgae cultivation process was shown to have strong potential for mitigation of environmental impacts.

Cyanotoxins in inland lakes of the United States: Occurrence and potential recreational health risks in the EPA National Lakes Assessment 2007

“…Interestingly, of all samples that exceeded 100,000 cells/mL for cyanobacteria abundance (n = 85) only 65% had detectable levels of microcystin (>0.10 mg/L). When cyanobacteria were dominant, chlorophyll can be a good predictor of cyanobacteria (Forget et al, 2009;Ha et al, 2009;Hosikian et al, 2010), but not necessarily toxin occurrence. Some studies have noted strong correlations between microcystin and chlorophyll (Fastner et al, 1999), but this relation is dependent on dominance by microcystin-producing cyanobacteria.…”

Revisiting chlorophyll extraction methods in biological soil crusts – methodology for determination of chlorophyll a and chlorophyll a + b as compared to previous methods

“…Using the DMSO method, the duration of the chlorophyll extraction procedure is fairy uncritical, as after extraction the samples can even be stored in the fridge overnight and spectrometrically analyzed on the next day (Barnes et al, 1992). During chlorophyll extraction with DMSO, CaCO 3 is added to prevent acidification and minimize the phaeophytinization of Chl a+b 10 (Barnes et al, 1992), which otherwise happens easily, as chlorophyll is sensitive to extreme light exposure, pH values and temperature (Molnár et al, 2013;Hosikian et al, 2010). In studies, where acidification has not been prevented, unnaturally high absorption values were observed for lichen samples around 665 nm (Lan et al, 2011), where also phaeophytin is absorbing (Ritchie, 2008), thus suggesting phaeophytinisation of Chl a by lichen acids.…”

“…The photosynthetic apparatus undergoes disassembly during desiccation, so rehydration is required to repair the photosynthetic apparatus (Harel et al, 2004). During the entire chlorophyll extraction procedure, the samples were 25 kept in the dark or at minimum light to prevent degradation of chlorophyll (Molnár et al, 2013;Hosikian et al, 2010).…”

Cultivation of Oleaginous Microalgae Scenedesmus obliquus on Secondary Treated Municipal Wastewater as Growth Medium for Biodiesel Production

“…The chlorophyll a content was determined according to Richmond (2008) and Hosikian et al (2010) with some modifications: 1 mL of algal culture was centrifuged at 10000 rpm for 10 min, the supernatant was discarded and the cells were re-suspended in 1 mL of 90% methanol and sonicated in an ultrasonic water bath at maximum power for 15 min. The mixture was vortexed for 5 min, centrifuged and the supernatant (contains chlorophyll) was transferred into a new tube.…”