Common Synthetic Blue Food Dyes
The vast majority of intensely colored blue foods on the market use synthetic, petroleum-based dyes for their stability, low cost, and vibrant pigmentation. In the United States, these are regulated by the FDA and labeled with "FD&C" numbers, while in Europe they are designated with "E" numbers. The most common synthetic blue colorants are:
- Brilliant Blue FCF (FD&C Blue No. 1 / E133): This is one of the most widely used blue dyes in processed foods. It is a triarylmethane dye that creates a vibrant, bright blue shade. You can find it in items such as baked goods, frostings, cereals, ice creams, and sodas. It is known for its excellent stability against heat and light, which makes it ideal for many manufacturing processes.
- Indigo Carmine (FD&C Blue No. 2 / E132): This indigoid dye produces a darker, richer royal blue color compared to Brilliant Blue FCF. Unlike Blue 1, it is a synthetic version of a dye naturally found in plants and is not petroleum-based. Indigo Carmine is often used in candies, pet foods, baked goods, and some beverages. It is known to have poorer stability in the presence of light and varying pH levels compared to Blue 1.
- Patent Blue V (E131): This sky-blue synthetic dye is primarily used in Europe and is known as Food Blue 5. It is a triarylmethane dye like Brilliant Blue FCF, but it is banned in some countries, including the U.S. and Australia.
The Rise of Natural Blue Alternatives
With growing consumer demand for natural and healthier ingredients, the food industry has sought alternatives to synthetic blue dyes. While natural blue pigments can be challenging to source and stabilize, several options are becoming more prevalent.
Key Natural Blue Colorants
- Phycocyanin (from Spirulina): This pigment is derived from the cyanobacterium Arthrospira platensis, commonly known as spirulina. It is a bright blue protein that is water-soluble. Phycocyanin has gained regulatory approval in many regions, including the U.S., but it is more sensitive to heat and pH changes than its synthetic counterparts.
- Anthocyanins: These pigments are responsible for the red, purple, and blue colors in many fruits and vegetables, such as red cabbage, purple sweet potatoes, and butterfly pea flowers. Anthocyanins extracted from butterfly pea flowers, specifically, can create a vibrant blue and are gaining approval as a natural food colorant. Their color is highly dependent on pH, shifting from red in acidic conditions to blue in alkaline ones.
- Gardenia Blue: Extracted from the fruit of the Gardenia jasminoides flower, this is a naturally derived blue pigment. The color is formed by a reaction between genipin (from the fruit) and amino acids. It has been used for years in East Asia and has been approved for certain uses in the U.S..
Synthetic vs. Natural Blue Food Dyes
| Feature | Synthetic Blue Dyes (FD&C Blue 1/2) | Natural Blue Dyes (Spirulina/Anthocyanins) |
|---|---|---|
| Cost | Generally more affordable | Often more expensive |
| Color Intensity | Highly vivid and consistent | Less vibrant and can be less stable |
| pH Sensitivity | Highly stable across pH ranges | Color can change significantly with pH variations |
| Heat Stability | Generally very stable | Can be sensitive to high temperatures |
| Light Stability | Excellent stability | Often susceptible to degradation from light |
| Consumer Perception | Viewed with caution; seen as artificial | Preferred by consumers; perceived as healthier |
| Ingredient Source | Derived from petroleum (petrochemicals) | Extracted from plant or algal sources |
| Nutritional Value | Provides no nutritional benefit | May offer additional functional properties like antioxidants |
Understanding the Label
Because of the variety of blue dyes, reading ingredient labels is the best way to know which colorant is used. Synthetic dyes will be listed as “FD&C Blue No. 1,” “FD&C Blue No. 2,” or by their E numbers (E133, E132). Natural alternatives are more likely to be listed by their source, such as “Spirulina Extract” or “Butterfly Pea Flower Extract”. This transparency allows consumers to make informed choices based on their preference for synthetic or natural ingredients.
The Quest for the Perfect Natural Blue
Food scientists continue to search for natural blue colorants that can compete with the stability and cost-effectiveness of synthetic options. While progress has been made with pigments like phycocyanin and certain anthocyanins, challenges remain regarding thermal and pH stability, particularly in a wide range of acidic and heat-processed foods. New methods of extraction and stabilization, as well as novel sources like certain algae and bacteria, are constantly being explored to meet the demands of a health-conscious market without sacrificing visual appeal. The development of new FDA-approved natural dyes, like gardenia blue and butterfly pea flower extract in 2025, shows that this trend is continuing to evolve. For more in-depth information on the properties of food colorants, the National Institutes of Health provides an extensive resource on the topic.
Conclusion
Ultimately, the question of "what is blue food dye called" has multiple answers, ranging from the well-established synthetic dyes FD&C Blue 1 and Blue 2 to a new generation of natural colorants derived from sources like spirulina algae and butterfly pea flowers. While synthetic dyes offer stability and cost efficiency, natural alternatives align with modern consumer preferences for cleaner labels and healthier ingredients. The choice between them often comes down to a balance of visual appeal, processing requirements, and consumer demand.
