| Beet red pigment as a natural food coloring with good color and tinting strength is safe and non-toxic. It is widely used in the area of medicine and health, cosmetics, and other areas of research. The development space is large and application prospects is broad. Although people has researched the extraction, stability and other aspects of beet red pigment, the pigment extraction and purification technology areas need further study.This paper puts red beet as raw material and optimizes pigment extraction process through ultrasound-assisted extraction. In addition, this paper uses yeast for fermentation of sugar and studies the fermentation conditions. The product color value is effectively improved through the use of fining agents.The following conclusions are drawn. Firstly, the extraction method of beet red pigment has been optimized. The author puts 0.5% citric acid solution as extract and with the power of 540 w ultrasonic and assists the extraction for 30 minutes at the extraction temperature of 25 ℃. Secondly,Extraction time of 10 minutes were shortened by ultrasonic assisted extraction,The absorbance values was increased by 0.06, and the extraction rate of pigment was improved. Thirdly, this paper determines the optimal conditions for fermentation of sugar is the fermentation temperature of 25 ℃, 2 hours as fermentation time, yeast concentration of 4% and 250 rpm as shaker speed. Fourthly, the use of 0.03%pectinase absorbance values than the control group improved 0.42. Fifth, The experiment uses a solution of tannin 50 mg / L which effectively promotes pigment purification by the light transmittance is 69.4%. Sixth, under the condition of the vacuum 0.04 MP, concentrate the broth from 200 ml to 10 ml, with the required temperature 55 ℃ and time-consuming28 minutes. Then directly concentrate and dry with the pigment extraction rate of 18.2%. |
