Introduction. Microalgae can be considered as one of the most reliable natural sources of nutrients and other valuable substances that could satisfy the growing needs in food and energy. In this review article, the global potential for the use of microalgae and the protein content of a number of microalgae is examined with a brief description of the microalgae species. Literature. Despite the high protein content and the presence of other valuable substances in microalgal biomass, microalgae mass production is still at its embryonic level. Microalgal proteins exhibit good nutritional, functional and technofunctional properties when compared to some conventional protein concentrates. Conclusions. There is therefore a need for the mass production of microalgae to be boosted by public and private institutions in order to avoid protein shortages.

The aim of this study was to evaluate the physicochemical properties of Spirulina colored soluble protein fractions extracted from spray-dried Spirulina powder. Three fractions, including the blue soluble Spirulina protein, the green soluble Spirulina protein, and the total soluble Spirulina protein fractions were obtained. Investigations on their behavior at air/water interface were carried out using dynamic methods of drop volume and bubble pressure surface tension measurements. Evaluation of their monolayer films' mechanical behavior was done via compression isotherms using Langmuir film balance. The protein contents of the fractions were 82.76, 82.29, and 74.53% for the blue, the green, and the total fractions, respectively. Surface tension decay increased with increasing concentration for all the fractions. No significant difference in surface tension decay was observed between the samples at 0.3% (w/w). Surface tension decay was less important at pH 3 for all the fractions. The total fraction and the blue fraction appeared to form more elastic films than the green fraction. The blue soluble fraction also presented the highest collapse pressure and initial expansion area.