Some microalgae fully qualify as superfoods-or superfeeds, in animal husbandry and aquaculture (e.g., Algatan)-due to the nutritional virtues and health benefits associated with their consumption.
Prominent among these is Chlorella, a traditional ingredient whose versatility offers interesting prospects for making different categories of functional foods. (1)
A recent study (Canelli et al., 2020), in Frontiers in Nutrition, considers the bioavailability of protein and lipids provided by this microalgae. And its possible applications for improving the nutritional and health properties of various foods. (4)
Microalgae, superfood?
Superfoods have been considered in recent years-in numerous market analyses, such as those carried out in Italy by the Immagino Observatory (GS1-Italy, Nielsen)-as foods variously presented as beneficial to health. Albeit in the absence of scientific consensus on their definition, as well as that of functional food, in the face of an extraordinary number of variables.
Microalgae can be framed here both for their high protein digestibility and ample supply of essential amino acids, Omega 3 fatty acids, dietary fiber, and for the variety of bioactive compounds(phytochemicals) that can prevent and counteract numerous diseases. (2) Renewability of sources and sustainability of production are moreover valuable for food security and nutrition security, particularly in #Veg (vegetarian, vegan) diets.
Chlorella
Chlorella
dominates the microalgae market-along with Spirulina (which is actually a cyanobacterium, as noted)-and is characterized in several ways.
A high protein content is complemented by an important concentration of betaglucans, prebiotic fibers effective in reducing so-called ‘bad cholesterol’ (LDL) in the blood, reducing free radicals and stimulating the immune system. (3)
Nutrients and bioavailability
The recent study by Canelli et al. (2020) examined the composition and bioavailability of nutrients in laboratory-grown Chlorella compared with a dozen commercially available products. The average values of protein and fatty acids are appreciable, 40% and 7% respectively.
The researchers gave a very favorable assessment of the ratios of Omega-6/Omega-3, polyunsaturated/saturated, hypocholesterolemic/hypercholesterolemic fatty acids. In addition to the atherogenic and thrombogenic indices, which express the virtues of microalgae in preventing atherosclerotic plaque formation and thrombosis.
Chlorella protein availability is significant and promising, while new strategies to increase lipid release in the body should be developed. (4)
Applications of Chlorella in various food categories
The addition of Chlorella in various food categories has shown the possibility of improving not only the nutritional but also the sensory properties of products. Some examples of applications:
– Innovative and color-attractive cookies (see Fig. 2), with a particularly welcome texture, (5)
– breadsticks. Reduction of browning due to cooking, enrichment in iron and selenium, (6)
– cheeses. Appreciable health impact, without changing product characteristics, (7)
– yogurt. Increased viability of probiotic microorganisms. (8)
Auxenochlorella prototeichodes
Auxenochlorella prototeichodes
, Chlorella‘s ‘cousin’, has been used in combination with soybeans to make a meat substitute product with interesting physical and nutritional characteristics. (9) The use of seaweed made the product more attractive because of the carotenoids. As well as improving its lipid profile and adding vitamins (B group, E). (10)
The use of microalgae makes it possible to produce products with a better nutritional level. (11) It lends itself well to combination with soy, which in turn exerts technological (even before nutritional) functions. With the idea of satisfying the nutritional and sensory needs of vegetarian and vegan as well as flexitarian consumers. (12)
Interim conclusions
Chlorella and Auxenochlorella are promising microalgae for human nutrition due to their richness in protein, Omega3 and phytocomplexes valuable for health. Their versatility of use allows their inclusion in the formulas (or recipes) of a wide variety of foods. Both within the production processes and also when consuming various foods.
The prospect of securing and improving human and animal nutrition through algae and microalgae finds further stimulation in a number of European research projects in the Horizon 2020 program, as noted. Chlorella is considered in the ProFuture(Proteins for the Future) project, among others.
For further discussion, we also recommend Chapter 3.10 of the book Nonvitamin and Nonmineral Nutritional Supplements (2019). (13)
Dario Dongo and Andrea Adelmo Della Penna
Notes
(1) Nicoletti (2016) Microalgae nutraceuticals . Foods 5:54, doi:10.3390/foods5030054
(2) Matos et al. (2017) Microalgae as healthy ingredients for functional food: a review. Food & Function 8(8):2672-2685, doi:10.1039/C7FO00409E
(3) Koyande et al. (2019) Microalgae: A potential alternative to health supplementation for humans. Food Science and Human Wellness 8:16-24, https://doi.org/10.1016/j.fshw.2019.03.001
(4) Canelli et al. (2020) Biochemical and nutritional evaluation of Chlorella and Auxenochlorella biomasses relevant for food application. Frontiers in Nutrition 7:565996, doi:10.3389/fnut.2020.565996
(5) Gouveia et al. (2007) Chlorella vulgaris biomass used as coloring source in traditional butter cookies. Innovative Food Science and Emerging Technologies 8:433-436, doi:10.1016/j.ifset.2007.03.026
(6) Uribe-Wandurraga et al. (2019) Effect of microalgae addition on mineral content, color and mechanical properties of breadsticks. Food & Function 10(8):4685-4692, doi:10.1039/c9fo00286c
(7) Jeon et al. (2006) Effect of Chlorella addition on the quality of processed cheese. J. Korean Soc. Food Sci. Nutr. 35:373-7, doi:10.3746/jkfn.2006.35.3.373
(8) Beheshtipour et al. (2013) Supplementation of Spirulina platensis and Chlorella vulgaris algae into probiotic fermented milks . Comprehensive Reviews in Food Science and Food Safety 12(2):144-154, https://doi.org/10.1111/1541-4337.12004
(9) Darienko et al. (2015) Genetic variability and taxonomic revision of the genus Auxenochlorella (Shihira et Krauss) Kalina et Puncocharova (Trebouxiophyceae, Chlorophyta) . Journal of Phycology 51(2):394-400, https://doi.org/10.1111/jpy.12279
(10) Caporgno et al. (2020) Extruded meat analogues based on yellow, heterotrophically cultivated Auxenochlorella protothecoides microalgae. Innovative Food Science and Emerging Technologies 59:102775, https://doi.org/10.1016/j.ifset.2019.102275(11) Caporgno et al. (2018) Trends in microalgae incorporation into innovative food products with potential health benefits. Frontiers in Nutrition 5:58, doi:10.3389/fnut.2018.00058
(12) Malav et al. (2015) Meat analog: A review. Critical Reviews in Food Science and Nutrition 55(9):1241-1245, https://doi.org/10.1080/10408398.2012.689381
(13) Seyed Mohammad Nabavi and Ana Sanches Silva (2019) Nonvitamin and Nonmineral Nutritional Supplements (Elsevier, ISBN 978-0-12-812491-8)
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
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