Author:

Keywords:

stability, microalgae, lipids, free fatty acids, lipolysis, lipase, Science & Technology, Life Sciences & Biomedicine, Biotechnology & Applied Microbiology, Stability, Microalgae, Lipids, Free fatty acids, Lipolysis, Lipase, FREE FATTY-ACIDS, PHAEODACTYLUM-TRICORNUTUM, BIODIESEL PRODUCTION, LIPID-CONTENT, MICROALGAE, GALBANA, DIATOM, PRODUCTS, BIOMASS, PLASMA, 0607 Plant Biology, 0904 Chemical Engineering, 1003 Industrial Biotechnology, 3108 Plant biology, 4004 Chemical engineering

Abstract:

Previously, it has been observed that lipolysis occurring during (even short term) wet storage of microalgal biomass causes high free fatty acid (FFA) concentrations in the biomass. These FFA have a negative impact for different applications of microalgal lipids, e.g. downstream processing problems in biodiesel production, off-flavors and loss of nutritional value for food applications. However, it is not clear which factors influence lipolysis in microalgal biomass and which lipid class are more susceptible to lipolysis. In this study, wet biomass of T-Isochrysis lutea was stored at 20°C, 4°C and -20°C during 3 weeks. The extent of lipolysis was followed by analyzing the lipid classes distribution by ultrahigh-performance liquid chromatography−accurate mass mass spectrometry (UHPLC-amMS) and the FFA content. It was observed that FFA were formed very rapidly during post-harvest storage of wet biomass at 20°C and 4°C, the rate of this process being faster at 20°C than at 4°C, while almost no lipolysis was observed at -20°C. However, the FFA content levelled off after several days of storage because FFA reacted with alcohols to form fatty acyl esters.