Monascus red pigment is one of the most commonly used natural colorants in food processing. It is a kind of secondary metabolite pigment of Monascus, and it is the only natural pigment prepared by microbial fermentation. Monascus red pigment is widely used in meat, seafood, beverages, condiments, confectionery, medicine and cosmetics industries.

However, in practical applications, some producers have found that products colored with red yeast red pigment will often fade. Today, we explain the reasons for the fading of red yeast red pigment and provide several countermeasures.

Causes the discoloration of red yeast red pigment:

1, temperature

The red yeast red pigment is relatively stable below 130 ° C. When the temperature is higher than 150 ° C, the red yeast red pigment begins to decompose rapidly, resulting in rapid color loss.

2, light

Studies have found that continuous illumination significantly reduces the stability of erythropoietin. Monascus red pigment is relatively sensitive to sunlight, and it will fade significantly under the illumination of sunlight. At the same light intensity, as the wavelength decreases, the degree of degradation of monascus red pigment increases, especially sensitive to ultraviolet light.

3, metal ions

Studies have found that a small amount of sodium ions and calcium ions have little effect on monascus red pigment, while zinc ions and copper ions have a significant effect on monascus red pigment. Among them, Cu2+ and Fe3+ cause the red yeast red pigment to turn red and turn brown, and precipitate.

4. Additives or other pharmaceutical agents

The experiment found that red yeast red pigment has an effect on additives and reagents such as sodium nitrite, ascorbic acid and hydrogen peroxide, but in the presence of sodium hypochlorite, red yeast red pigment is highly discolored.

5, oxygen

Monascus red pigment has a strong ability to scavenge free radicals and has remarkable antioxidant properties. Oxidation changes the color of red yeast red pigment.

6, pH

Monascus red pigment is relatively stable in the range of pH 3~10, higher or lower than this range, and the stability of monascus red pigment is significantly decreased.

Prevention of red yeast red pigment fading measures:

1. Control the hot processing temperature. For the frying process, you can use low temperature frying.

2, to avoid light, using light-shielding measures.

3. Add a metal chelating agent such as disodium EDTA.

4. Add antioxidants such as ascorbic acid and citric acid.

5, replace the packaging materials, the use of light barrier oxygen barrier properties of better packaging materials.

6, pay attention to the amount of disinfection reagents and residues in the production environment