Determinación de contenido proteico de microalgas como fuentes alimentarias alternativas

Abstract

Uncontrolled population growth, environmental impacts, climate change and agricultural intensification have increased global food demand. This has created the need to look for food alternatives such as microalgae, which are protein sources that could improve the nutritional value of conventional foods. However, due to their complex morphological structure, it is necessary to explore methods that facilitate the rupture of their cell wall and membrane for the extraction of intracellular proteins. In the present study, two types of sample treatments were evaluated; with and without hydrolysis to achieve a destruction of the microalgal cells that allows the release of the proteins. Subsequently, the proteins were quantified by Bradford’s method and the amino acid profile was described by HPLC. The hydrolysis process significantly improved the protein extraction and the determination of the amino acid profile, since it reduced matrix interferences in the chromatograms and allowed a better quantification of each amino acid. The protein content determined was 0.89 mg/g in Chlorella vulgaris, 7.50 mg/g in Nannochloropsis sp., 50.10 mg/g in Spirulina platensis, 1.69 mg/g in a possible Hapalosiphon species. In addition, two unidentified species were analyzed and coded as MAAL 29 (1.14 mg/g) and MAAL 32 (9.49 mg/g). Spirulina platensis and MAAL 32 were the microalgae with the best protein potential to be scaled up. These results can be used to evaluate the possibility of microalgae as source of food, additives or nutritional supplements.