Concentrated xanthan gum solutions

Claim 2

A process for clarifying and concentrating raw Xanthomonas heteropolysaccharide fermentation broth which comprises (1) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution containing between about 0.1-3 weight percent of xanthan gum; and (2) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises.

Claim 3

A process in accordance with claim 1 wherein the step (1) filtration medium is diatomaceous earth.

Claim 4

A process in accordance with claim 1 wherein the insoluble fermentation solids constitute up to about 20 weight percent of the total solids content of the fermentation broth.

Claim 5

A process in accordance with claim 1 wherein the clarified and concentrated xanthan gum solution in step (2) contains between about 10-12 weight percent of xanthan gum, and the solution viscosity is between about 15,000-17,000 centipoises.

Claim 6

A process for clarifying and concentrating raw Xanthomonas heteropolysaccharide fermentation broth which comprises (1) heating the fermentation broth at a temperature between about 60°-150° C. for a period of time between about 0.3-3 hours; (2) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution containing between about 0.1-3 weight percent of xanthan gum; and (3) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises.

Claim 7

A process for clarifying and concentrating raw Xanthomonas heteropolysaccharide fermentation broth which comprises (1) heating the fermentation broth at a temperature between about 60°-150° C. for a period of time between about 0.3-3 hours; (2) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution containing between about 0.1-3 weight percent of xanthan gum; and (3) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises.

Claim 8

A process in accordance with claim 5 wherein the step (2) filtration medium is diatomaceous earth.

Claim 9

A process in accordance with claim 5 wherein the clarified and concentrated xanthan gum solution in step(3) contains between about 10-12 weight percent of xanthan gum, and the solution viscosity is between about 15,000-17,000 centipoises.

Claim 10

A process for clarifying and concentrating Xanthomonas hydrophilic colloid fermentation broth which comprises (1) adjusting the volume of the fermentation broth to provide a broth which contains between about 0.1-1 weight percent of xanthan gum; (2) heating the broth at a temperature between about 70°-110° C. for a period of time between about 0.5-2 hours; (3) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution of xanthan gum; and (4) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises.

Claim 11

A process for clarifying and concentrating Xanthomonas hydrophilic colloid fermentation broth which comprises (1) adjusting the volume of the fermentation broth to provide a broth which contains between about 0.1-1 weight percent of xanthan gum; (2) heating the broth at a temperature between about 70°-110° C. for a period of time between about 0.5-2 hours; (3) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution of xanthan gum; and (4) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises.

Claim 12

A process in accordance with claim 8 wherein the broth in step(2) is subjected to high shear stirring during the heating period.

Claim 13

A process in accordance with claim 8 wherein the step(3) filtration medium is diatomaceous earth.

Claim 14

A process in accordance with claim 8 wherein the temperature of the fermentation broth is about 40°-100° C. during the step(3) filtration procedure.

Claim 15

A xanthan gum solution containing between about 8-15 weight percent of xanthan gum, which solution exhibits a viscosity between about 10,000-20,000 centipoises, and is characterized by the following viscosity/concentration profile: ______________________________________ Weight % Viscosity, centipoises ______________________________________ 15 10,000-20,000 12 9000-17,000 10 7000-15,000 8 6000-10,000 6 5000-8000 4 3500- 6000 2 2000-3000 1 1300-1800 0.8 1000-1400 0.6 800-1100 0.4 600-740 0.2 370-430 0.1 280-180 0.05 50-200 ______________________________________

Claim 16

A xanthan gum solution containing between about 8-15 weight percent of xanthan gum, which solution exhibits a viscosity between about 10,000-20,000 centipoises, and is characterized by the following viscosity/concentration profile: ______________________________________ Weight % Viscosity, centipoises ______________________________________ 15 10,000-20,000 12 9000-17,000 10 7000-15,000 8 6000-10,000 6 5000-8000 4 3500- 6000 2 2000-3000 1 1300-1800 0.8 1000-1400 0.6 800-1100 0.4 600-740 0.2 370-430 0.1 280-180 0.05 50-200 ______________________________________

Claim 17

A xanthan gum solution in accordance with claim 12 which exhibits a light transmittance of greater than about 5 percent as measured by colorimetry.

Claim 18

A xanthan gum solution in accordance with claim 12 which exhibits a particle count of not greater than about 10 9 particles per cubic centimeter under an optical microscope.

Claim 19

A process for recovering high purity xanthan gum solids from raw Xanthomonas heteropolysaccharide fermentation broth which comprises (1) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution containing between about 0.1-3 weight percent of xanthan gum; (2) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises; (3) diluting the clarified and concentrated xanthan gum solution with a water-soluble solvent medium to precipitate xanthan gum solids from the said solution; and (4) separating and recovering the precipitated xanthan gum solids.

Claim 20

A process for recovering high purity xanthan gum solids from raw Xanthomonas heteropolysaccharide fermentation broth which comprises (1) filtering the broth to remove substantially all of the insoluble fermentation solids and provide a clarified solution containing between about 0.1-3 weight percent of xanthan gum; (2) subjecting the clarified xanthan gum solution to ultrafiltration to yield a clarified and concentrated xanthan gum solution which contains between about 8-15 weight percent of xanthan gum, and which exhibits a solution viscosity between about 10,000-20,000 centipoises; (3) diluting the clarified and concentrated xanthan gum solution with a water-soluble solvent medium to precipitate xanthan gum solids from the said solution; and (4) separating and recovering the precipitated xanthan gum solids.

Claim 21

A process in accordance with claim 15 wherein the water-soluble solvent medium in step(3) is a water-soluble alcohol.