Red pigment is a red natural pigment produced by Aspergillus erythropolis during its growth and metabolism. Aspergillus erythropolis is currently the only microorganism in the world that produces food coloring. Aspergillus erythropolis can be cultivated by both solid and liquid fermentation methods. Compared with other natural pigments, erythrulose pigment has good thermal stability, strong protein action, soft hue, stable to acid and alkali, and can also improve the stability of processed products to light, heat and oxygen, and erythrulose pigment is non-toxic, non-mutagenic, and high security.
Operation method
solid state fermentation
Principle
Red pigment is a red natural pigment produced by Aspergillus erythropolis during its growth and metabolism. Aspergillus erythropolis is currently the only microorganism in the world that produces food coloring. Aspergillus erythropolis can be cultivated by both solid and liquid fermentation methods. Compared with other natural pigments, erythrulose pigment has good thermal stability, strong protein action, soft hue, stable to acid and alkali, and can also improve the stability of processed products to light, heat and oxygen, and erythrulose pigment is non-toxic, non-mutagenic, and high safety. There are water-soluble pigments and fat-soluble pigments. Water-soluble pigments are partly soluble in organic solvents, while fat-soluble pigments are not easily soluble in water. The solubility of red pigment in ethanol and acetic acid is better. At present, there are roughly two types of domestic: red yeast rice and red yeast rice extract or deep fermentation of red yeast extract . The pigments produced by Aspergillus erythropolis have been identified six chemical structures, which can be divided into three categories, namely, the red pigments Monascorubramine and Rubropunctamine, the orange pigments Monascorubin and Rubropunc2tatin and the yellow pigments Ankaflavin and Monascin.
Materials and Instruments
Aspergillus erythropolis Move I. Process flow For more product details, please visit Aladdin Scientific website.
Rice Sterile water Alcohol
Triangular vials Spectrophotometer Porcelain plates Gauze Sterile pipettes
Rice → washing → soaking rice (8 h-10 h, drain the water) → portioning (40 g/250 ml triangular bottles) → steaming rice (121 ℃, 20 min) → shaking the rice while it is still hot → spraying water to cool it down (34 ℃) → access to Aspergillus erythrorhizonticus strains (take one piece of the preserved slant in the aseptic operating table, add 15 ml of sterile water, shake well to prepare A. erythrorhizonticus suspensions, and Each bottle was inoculated with 5 ml of Aspergillus erythropolis suspension) → constant temperature culture (32 ℃ -34 ℃, 7 d), knocking the bottle (1 time / d), add sterile water to moisturize → detection (maturity detection; color value determination) → drying (40 ℃ -45 ℃, 12 h) → finished products
II. Determination of maturity of red yeast rice
Mainly for visual inspection, the maturity of red yeast rice is observed every day, and the redness of the red yeast rice is judged from the redness of the red yeast rice to determine whether it is mature and whether it is contaminated. In addition, a small amount of red yeast rice should be taken regularly on the aseptic operating table, crushed, and observed to see if there is still whiteness inside the red yeast rice, so as to judge the maturity of the red yeast rice.
III. Methods of color value determination
When the red yeast rice is red through, take a little red yeast rice on the aseptic operating table, put it in a flat dish, and put it in the drying oven at 40℃-45℃ for 12 h-14 h to make it completely dry. Take 0.1 g of dried red yeast rice, grind it until crushed, transfer it to a test tube, then add 9 ml of 70% alcohol, macerate it in a water bath at 60℃ for 2 h, remove it and filter it, then dilute it 500 times with 70% alcohol, and then measure its absorbance at 505 nm using a 7200-type visible spectrophotometer. Calculate the color value.
Color value = absorbance A × dilution / weight = absorbance A × 5000