In the food industry, manufacturers and customers have been paying more attention to natural pigments due to their excellent coloring abilities and health properties.
Microalgae have proven to be one of the main sources of pigments, especially chlorophylls, carotenoids, and phycobiliproteins.
Researchers from Shenzhen University, the Ocean University of China, and Fujian Normal University published an updated review on the characteristics, fields of application, production stability, and extraction processes of chlorophylls, carotenoids, and phycobiliproteins to standardize and analyze production and microalgae trade.
Potential Application of Microalgae Pigments
Pigments from microalgae have been considered promising eco-friendly dyes, nutraceuticals, and antioxidants with high commercial value in food and dairy, alternative foods, dietary supplements, pharmaceuticals, cosmetics, aquaculture, textiles, and other product manufacturing fields.
Chlorophylls have numerous functions in the food additives industry, the largest application being as colorants.
Currently, microalgae have been identified as a sustainable source to produce natural dyes to be used in food, with low allergenicity, toxicity, and carcinogenicity.
Chlorophylls, the most abundant natural pigment, are currently gaining immense attention as food, feed, cosmetic and pharmaceutical colorants, and functional food supplements.
The addition of dyes, such as microalgae pigments, can present auxiliary effects of preservation and antisepsis in food storage, as a consequence of their physiological activities.
Natural carotenoids are the best color choice for food manufacturers, particularly for cooked sausage, soft drinks, and baked goods. Apart from that, its excellent antioxidant and preservative attributes help foods retain their original color and flavor during storage, and prevent fatty acids and other substances from oxidizing and spoiling.
Furthermore, carotenoids also have antioxidant, anti-inflammatory, and neuroprotective effects, which may also ameliorate age-related macular degeneration and cardiac dysfunction.
β-Carotene represents the red pigment, which is currently the most popular and has been widely applied to many food products (for example, cakes, margarine, butter, cheese, canned food, baked goods, healthy condiments, candy, dairy products, and soft drinks) and pet food.
Astaxanthin is also a carotenoid with important commercial value since it is a natural colorant. Astaxanthin extracted from H. pluvialis is approved in Japan, the US, and some European countries for use in human dietary supplements and salmonid feed.
Lutein has been considered an important nutraceutical, which can be applied in food coloring, cosmetics, and medicines. It is now added commercially to flavorings, tobacco, cakes, confectionery, infant formula, and a variety of food products to provide them with a distinctive and attractive color.
The production of fucoxanthin microalgae has not been industrialized on a large scale, and its application as a food colorant is limited. It can be applied to egg yolk, butter, cake, green tea cakes, baked goods, and dairy products for better color and functional function.
Phycobiliproteins are widely used as a food color in food products, including candies, syrups, dairy products, baked foods, gelatin desserts, dry foods, fermented milk products, ice cream, and milkshakes.
According to the study, phycobiliproteins have antioxidant, anti-inflammatory, and liver-protective effects, giving them significant potential in human health.
Due to their bioactive properties, phycobiliproteins are also widely used in immunological laboratories. In general, they have been used as fluorescent markers in molecular biology and as fluorescent dyes in microscopy and immunoassays.
Factors Affecting Pigment Production in Microalgae
At present, microalgae fermentation has become one of the effective strategies for the production of natural pigments.
Compared to those from aquatic plants and animals, pigments obtained from the industrial production of microalgae have a multitude of advantages, including controllable production, easy extraction, high yields, availability of raw materials, and no seasonal variations.
During the cultivation of microalgae, any slight change in environmental conditions can cause an alteration in pigment productivity and molecular structure, ultimately affecting the market acceptance and bioaccessibility of the final products.
The study describes variables such as light, temperature, and the culture medium.
It is promising to use microalgae as strong candidates to obtain value-added compounds, such as pigments.
“After decades of research and exploration, microalgae pigments have been shown to have excellent colorability and beneficial properties, when used in the food industry,” they conclude.
The study was funded by the Shenzhen Science and Technology R & D Fund, Key Realm R&D Program of Guangdong Province, Guangdong Province Zhujiang Talent Program, Science and Technology Innovation Commission of Shenzhen, and the Open-ended Project of Carbon Neutral Research Institute, Fujian Normal University.
Reference (free access)
Sun, Han, Yuxin Wang, Yongjin He, Bin Liu, Haijin Mou, Feng Chen, and Shufang Yang. 2023. “Microalgae-Derived Pigments for the Food Industry” Marine Drugs 21, no. 2: 82. https://doi.org/10.3390/md21020082