What is Phycocyanin? A Guide to Its Colour, Properties & Benefits

You may have seen a stunning, vibrant blue in foods and drinks and wondered, “what is phycocyanin?” Phycocyanin is a brilliant blue, natural pigment-protein complex derived from Spirulina. But it’s more than just a beautiful phycocyanin colour; it’s also a powerhouse of health benefits. This guide will break down everything you need to know.

What is Phycocyanin? A Simple Definition

Phycocyanin is a natural blue pigment that is carefully extracted from blue-green algae, most commonly Spirulina. It is unique because it is a pigment-protein complex, meaning it’s a color that is also a protein, rich in amino acids.

In the Spirulina organism, its job is to help with photosynthesis, capturing light energy for the algae to grow. It is one of the very few truly natural and stable blue colorants approved for use in food, making it a highly sought-after, clean-label ingredient. Spirulina is a microalgae species currently cultivated on a large scale in China, and phycocyanin is a unique photosynthetic pigment of Spirulina, with a content of over 20% of its dry mass. Therefore, Spirulina is an economical and effective preferred raw material for producing phycocyanin.

The Brilliant Phycocyanin Colour

Phycocyanin is famous for its vibrant, pure, sky-blue to electric-blue hue. Unlike other natural sources that can be muted, phycocyanin provides a brilliant color that is perfect for eye-catching foods and beverages. Its main application is as a natural blue food coloring in products like smoothies, ice cream, confectionery, and drinks. The intensity and stability of this color can be affected by factors like pH and temperature, which we will explore below.

• Key Properties: Understanding How Phycocyanin Behaves
• Solubility: How It Mixes

Soluble in polar solvents such as water and ethanol.

Insoluble in non-polar solvents such as ether and chloroform.

Simple Takeaway: Perfect for beverages, gummies, and water-based products.

Stability in Different Conditions

• pH: Most stable blue color between pH 6-9.
• Temperature: Very stable below 40 ℃ (104 °F). The stability decreases significantly when the temperature exceeds 60 ℃ (140 °F).
• Light: Its photostability is poor. The color fades significantly after 18 hours under natural light indoors, and fades to near colorless after 1 hour of strong sunlight exposure.
• Oxidation: Phycocyanin has a certain degree of oxidation resistance. The blue-green color of the solutions remained unchanged after 3 hours of being exposed to different H₂O₂ contents.
• Simple Takeaway: Best used in products that are not subjected to high heat and are stored in protective packaging.

The Influence of Metal Ions

Among all metal ions, calcium and potassium ions have no effect on pigments, while in the presence of zinc and iron ions, pigments slowly precipitate. As the amount of zinc and iron ions increases, the phycocyanin colour changes from blue to green and then to yellow.

The Science-Backed Health Benefits of Phycocyanin

Among all metal ions, calcium and potassium ions have no effect on pigments, while in the presence of zinc and iron ions, pigments slowly precipitate. As the amount of zinc and iron ions increases, the phycocyanin colour changes from blue to green and then to yellow.

Rich in Amino Acids

As a protein, phycocyanin provides essential amino acids the body needs. Domestic and foreign studies have shown that phycocyanin belongs to protein binding pigments, and its amino acid composition ratio is very reasonable. The content of eight essential amino acids is close to or exceeds the standards recommended by FAO.

Enhances Iron Absorption

It helps the body absorb iron from plant-based foods more effectively. Under similar digestive conditions, Japanese researchers have found that phycocyanin, similar to heme, can form soluble compounds with iron, greatly enhancing the body’s absorption of iron.

Boosts Immune Function

Studies suggest it can stimulate the immune system to help the body fight off illness. Animal experiments have shown that after oral administration of phycocyanin to experimental mice injected with liver tumor cells, the survival rate of the experimental group mice is significantly higher than that of the control group mice.

Promote the Regeneration of Animal Blood Cells

In 1988, Morcos et al. treated mouse myeloma cells with phycocyanin containing 0.25mg/mL, and compared with laser irradiation control cells, the cell survival rate increased from 15% to 71%. The study also showed that phycocyanin has a stimulating effect on bone marrow hematopoiesis and can be used as a clinical adjuvant therapy for various blood diseases. It also has therapeutic effects on blood cancer.

Antioxidation

Peroxidized lipids are formed by the oxidation of polyunsaturated fatty acids on the cell membrane by superoxide anions (LPO), which are important factors leading to tissue damage, cellular dysfunction, and muscle aging. Experiments have shown that phycocyanin can generate free radicals under light and eliminate them in the dark. Therefore, phycocyanin has a dual function of generating and scavenging free radicals.