Preparation of gardenia red pigment by hydrolysis of geniposidic acid with co-immobilized enzyme

摘要

Geniposidic acid is hydrolyzed to produce genipinic acid by the co-immobilized enzyme,and the type of amino acids which react with genipinic acid to produce gardenia red pigment and some reaction conditions are optimized,we also studied on the methods of purifying gardenia red pigment by macroporous resin. Optimized conditions are: pH of reaction solution of genipinic acid and amino acid is 4.0, the temperature is 40 °C, reaction time is 42 hr, glutamic acid is better for producing gardenia red pigment than other amino acids, molar ratio of glutamic acid and genipinic acid is 2:l,molar ratio of citric acid and genipinic acid is 6:1.Gardenia red pigment is adsorbed by HPD100 macroporous resin,then elute by ammonia water of pH 11, the eluent is dried under 50°C,the violet black powder is obtained,it's color value can reach 92.32 (E1% 1cm,528nm). To prepare gardenia red pigment from geniposidic acid by the co-immobilized enzyme has advantages of low cost, environmental friendly and easy to mass production.