Process for producing of citric acid and monovalent citrate salts
First Claim
1. A process for preparing citric acid that comprises the steps of:
- (a) culturing Aspergillus Niger conidia at a concentration of about 1×
105 to about 1×
106 conidia/mL in an aqueous solution of decationized glucose syrup to form a fermentation medium, said fermentation medium (i) containing salts suitable for germinating said conidia and forming mycelia pellets in a submerged culture, (ii) containing about 2.5 to less than 20 parts per billion Mn+2 ions and (iii) having a pH value of about 1.5 to about 3.0;
(b) maintaining said fermentation medium at said pH value and at a temperature of about 25°
to about 35°
C. under aerobic conditions for a time period of about 4 to about 7 days to form mycelia pellets in an aqueous product broth;
(c) filtering said product broth to remove said mycelia pellets and form a clear, citric acid-containing aqueous broth;
(d) electrodialyzing said citric acid-containing aqueous broth to form a citric acid-containing aqueous concentrate; and
(e) decolorizing and ion-exchanging said citric acid-containing aqueous concentrate to remove color and inorganic ions therefrom and form an aqueous citric acid solution in which citric acid constitutes at least 98 percent of the organic acid present.
1 Assignment
0 Petitions
Accused Products
Abstract
A short process is disclosed for the production of citric acid in high yield and purity. Conidia of Aspergillus niger are cultured in an aqueous solution of decationized glucose syrup in a fermentation medium whose manganese(II) concentration is 2.5 to less than 20 parts per billion and whose pH value is about 1.5 to about 3.0. The fermentation medium is maintained for about 4-7 days to form citric acid and mycelia pellets in an aqueous product broth. That broth is filtered and then electrodialyzed to form a citric acid-containing aqueous broth. That broth is decolorized and ion-exchanged to remove color and inorganic ions and form an aqueous citric acid solution in which citric acid constitutes at least 98 percent of the organic acid present.
25 Citations
11 Claims
-
1. A process for preparing citric acid that comprises the steps of:
-
(a) culturing Aspergillus Niger conidia at a concentration of about 1×
105 to about 1×
106 conidia/mL in an aqueous solution of decationized glucose syrup to form a fermentation medium, said fermentation medium (i) containing salts suitable for germinating said conidia and forming mycelia pellets in a submerged culture, (ii) containing about 2.5 to less than 20 parts per billion Mn+2 ions and (iii) having a pH value of about 1.5 to about 3.0;(b) maintaining said fermentation medium at said pH value and at a temperature of about 25°
to about 35°
C. under aerobic conditions for a time period of about 4 to about 7 days to form mycelia pellets in an aqueous product broth;(c) filtering said product broth to remove said mycelia pellets and form a clear, citric acid-containing aqueous broth; (d) electrodialyzing said citric acid-containing aqueous broth to form a citric acid-containing aqueous concentrate; and (e) decolorizing and ion-exchanging said citric acid-containing aqueous concentrate to remove color and inorganic ions therefrom and form an aqueous citric acid solution in which citric acid constitutes at least 98 percent of the organic acid present. - View Dependent Claims (2, 3, 4)
-
-
5. A process for preparing citric acid that comprises the steps of:
-
(a) culturing Aspergillus Niger conidia at a concentration of about 1×
105 to about 1×
106 spores/mL in an aqueous solution of decationized glucose syrup present at about 100 to about 200 g/L to form a fermentation medium, said fermentation medium (i) containing salts suitable for the transforming said conidia into mycelia pellets in a submerged culture, (ii) containing about 3 to about 10 parts per billion Mn+2 ions and (iii) having a pH value of about 1.5 to about 3.0;(b) maintaining said fermentation medium at said pH value and at a temperature of about 25°
to about 35°
C., under aerobic conditions for a time period of about 5 to about 6 days to form mycelia pellets in an aqueous product broth;(c) filtering said product broth to remove said mycelia pellets and form a clear, citric acid-containing aqueous broth; (d) electrodialyzing said citric-acid-containing aqueous broth to form a citric acid-containing aqueous concentrate; and (e) decolorizing and ion-exchanging said citric acid-containing aqueous concentrate to remove color and inorganic ions and form an aqueous citric acid solution in which citric acid constitutes at least 98 percent of the organic acids present. - View Dependent Claims (6, 7, 8, 9, 10, 11)
-
Specification