Bioactive Ingredients from Microalgae: Food and Feed Applications

Abstract

Microalgae (green or blue-green ones) are among the most important organisms on the world, with a versatile and adaptive metabolism. They are able to synthesize bioactive molecules (mainly secondary metabolites such as unsaturated fatty acids, pigments, amino acids) with biomedical applications, enhancement of the nutritional value of food, animal feed/aquaculture, as well with impact on the environmental protection ( as raw materials for biofuels). Last decade, by a targeted selection of wild microalgae strains, their cultivation in farms developed in parallel with the bioreactors’products. There are nowadays cultivated at industrial scale especially Dunaliella salina p., Spirulina platensis, Hematococcus pluvialis or Chlorella vulgaris as valuable resources of polyunsaturated lipids and sterols, proteins, polysaccharides, carotenoid pigments, vitamins, minerals with antioxidant, antibacterial or antiviral effects. This review presents a systematic approach on the recent literature data collected the last years, underlying their morphologic and biochemical potential, the advanced technologies to use the bioactive components of different microalgae, new formulations which incorporate, stabilize and store their bioactivity and increase the bioavailability of their components in food and feed. Although their morphologic and biochemical potential is well described, there are presented new data on their bioactive components and formulations using emerging technologies for new application approaches which aims their use as ingredients in added value products for food, cosmetics and feed industry, to be exploited for commercial use. This review updated the last findings in these areas, underlined the reason for the scientific and technological advances, due to their huge potential, not only in environment, energy, but more and more as ingredients for food and feed/ aquaculture products, in the future.

Microalgae n-3 PUFAs Production and Use in Food and Feed Industries

“…The term “algae” describes a diversity of micro and macro aquatic organisms able to survive and proliferate by photosynthesis [ 1 ]. Macroalgae (multicellular) and microalgae (unicellular) develop in both freshwater and marine environments [ 1 ]. Microalgae are planktonic or benthic algae floating in the water, while macroalgae are benthic and sedentary [ 2 , 3 ].…”

“…Microalgae are planktonic or benthic algae floating in the water, while macroalgae are benthic and sedentary [ 2 , 3 ]. They include either eukaryotic species or prokaryotic cyanobacteria that are devoid of a membrane-bound nucleus and are classified between bacteria and plants [ 1 ]. The most abundant microalgal phyla are blue-green algae ( Cyanophyceae ), green algae ( Chlorophyceae ), Bacillariophyceae (including diatoms), and Chrysophyceae (including golden algae) [ 1 , 4 ].…”

“…The ease with which they can be cultured explains in part why they have been receiving increasing interest in recent years. Microalgae chemical composition has been widely studied in the literature, with proportions varying widely between the different species and culture conditions used [ 1 , 12 ]. They have been recognized as a reliable source of bioactive compounds such as proteins, lipids, carotenoids, hydrocarbons and vitamins [ 3 , 6 ].…”

“…Indeed, they can represent up to 74% of microalgae’s total biochemical content according to species [ 12 ]. These molecules are built with fatty acids with 12 to 24 atoms of carbon and include the polyunsaturated fatty acids of the n-3 or n-6 families (n-3 PUFAs and n-6 PUFAs, respectively) [ 1 ]. N-3 PUFAs, also called omega-3 fatty acids, are characterized by their health benefits for both animals and humans.…”

“…Microalgae are also used for feed, especially in aquaculture, since they represent the conventional diet of marine and freshwater consumers in natural ecosystems [ 179 , 198 ]. Species like Dunaliella , Chlorella , Arthrospira , Nannochloropsis or Tetraselmis proved to have good application in aquaculture [ 1 ]. Indeed, species like Nannochloropsis sp.…”