Chemical Characterization, Lipid Profile, and Volatile Compounds in Chlorella sp. and Spirulina platensis: A Promising Feedstock for Various Applications

Microalgae are among the most promising feedstocks for a wide range of applications due to their ease of cultivation, rapid growth rate, and ability to accumulate significant amounts of lipids and other valuable compounds. In the current study, two microalgae species, <i>Chlorella</i> sp. and <i>Spirulina platensis</i>, were studied regarding chemical composition, lipid extraction by ultrasound-assisted solvent extraction, and volatile compounds analysis. The optimization of the lipid extraction process was investigated with respect to the influence of different process parameters. The highest lipid content was found in <i>Chlorella</i> sp., which was more than twice as high compared to <i>Spirulina platensis.</i> Both microalgae contain saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). <i>Spirulina platensis</i> contains high palmitic acid (42.9%) and linolenic acid (22.5%), and is low in MUFA content (8.5%), whereas <i>Chlorella</i> sp. contains high oleic (21.9%), linoleic (25.3%), and α-Linolenic acid (10.2%). Based on the fatty acids profile, nutritional lipid indices were calculated. Regarding the volatile content, <i>Spirulina platensis</i> contains amines, aldehydes, alcohols, ketones, and hydrocarbons, whereas <i>Chlorella</i> sp. contains hydrocarbons, heterocycle, aldehydes, thiocyanates, and esters which give the odor profile.