| 摘要 |
PURPOSE:To obtain the title red pigment having excellent color tone, tinting power, stability, etc. and suitable for use as a pigment for food, cosmetics, etc., by cultivating specified red pigment-producing algae or a nutrient medium, recovering algae in the latter stage of a linear growth period and extracting the algae with a weakly acidic salt soln. CONSTITUTION:Red pigment-producing algae (e.g., Calothrix brevissima M-7 strain) belonging to Rodophyceae, Cyanophyceae or Cryptophyceae are cultivated on a nutrient medium. Algae in the latter stage of a linear growth period are collected and extracted with a salt soln. having a pH of 5-6.5 (e.g., potassium phosphate buffer soln.) to obtain a red pigment. In this way, the title natural red pigment can be obtd. which has the max. absorption bands in the visible light region of 560-570nm in a salt soln. having a pH of 6, gives the max. luminescence at 550-600nm by exciting rays at 480-565nm and has a mol.wt. of 20,000-60,000 Dalton as measured by a gel permeation method and in which at least 95% of absorbance of 565nm remains when treated at a pH of 6 and at 0-40 deg.C for 30min or treated at a Ph of 5-6.5 and at 25 deg.C for 30min. |
