Most of the food natural colorants are taken from plants (such as various anthocyanins, carotenoids), some are taken from animals (cochineal red), minerals (such as titanium dioxide) and microorganisms (red yeast red). Food natural colorants can be divided into 6 categories according to their chemical structure:
1. Polyphenol derivative. Anthocyanin polyphenol derivatives are a class of water-soluble colorants.
It is widely distributed in plants. Anthocyanin colorants are the main colorants in the food industry, such as cranberry red, radish red, red rice red, black bean red, roselle red and mulberry red. Anthocyanins are composed of sugar and anthocyanins.
Flavonoid colorants are another class of water-soluble colorants in polyphenolic derivatives, which are also widely distributed in the plant kingdom in the form of glycosides. Its basic chemical structure is α-phenylbenzopyrone. The colorants of this type have good stability, but are also affected by the number of phenolic hydroxyl groups in the molecule and the binding position. In addition, light, heat and metal ions have a definite effect on it.
2. Isoprene derivative. Such as β-carotene, gardenia yellow, capsicum red, etc., carotenoids are isoprene derivatives, belonging to polyene colorants. They are widely distributed in the biological world, and their colors range from yellow, orange, red and purple. They do not fall into water and are soluble in fat solvents. They are fat-soluble colorants. Carotenoid colorants are more stable to pH and more stable to heat, but light and oxygen have a destructive effect on it.
3. Tetrapyrrole derivatives (porphyrin derivatives) such as chlorophyll, heme, and the like.
4. Ketone derivatives, such as red yeast red, curcumin and the like.
5. Steroid derivatives, such as shellac red, cochineal red and so on.
6. Other pigments, such as beet red, caramel and so on. According to the structure, it can also be divided into: pyrrole pigment (chlorophyll, heme, polyene pigment (chili red, β-carotene), ketone oxime pigment (red koji red, shellac red), pyridine pigment (beet red), etc. It may also include certain inorganic pigments.
Natural food colorants are derived from nature, have a wide variety, and most have no toxic side effects, and have outstanding characteristics compared to synthetic colorants. The characteristics of natural food colorants are as follows:
1. Most natural colorants are derived from edible animals and plants, with high safety, low toxicity and side effects, and toxicological experiments are not high;
2. Many natural colorants contain nutrients needed by the human body or are vitamins or vitamins themselves; some natural colorants have pharmacological effects and have preventive effects on certain diseases, such as flavonoid pigments, which have positive effects on the prevention and treatment of cardiovascular diseases: There are also some pigments that have antioxidant, analgesic, and antihypertensive effects.
3. Natural colorants are natural in color, easy to be accepted by consumers, and have certain use value and economic value.
4. Some varieties have a special aroma to increase the flavor of the food.