US 4,618,579 AGranted

Raw starch saccharification

AssigneeGenencor, Inc.

InventorsBruce L. Dwiggins, Carl E. Pickens, Carl W. Niekamp

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Abstract

A multi-step process is provided for solubilizing and saccharifying granular starch slurries of between 20 and 60% d.s. starch. In a first step, an enzyme mixture exhibiting raw starch hydrolyzing activity is added to the slurry and maintained in contact therewith until at least a substantial portion but less than all of the starch is solubilized. The resulting syrup is separated from the remaining insoluble fraction. In a second step, the insoluble fraction is used to prepare a second slurry containing less than about 20% d.s. starch, and this second slurry is solubilized with a raw starch hydrolyzing enzyme preparation until substantially all (e.g., at least about 95% or more) of the starch is solubilized. The pooled syrup from the two steps is over about 20 weight percent saccharides, at least about 95% of which is glucose.

Claims24

Dependent claims

A method of preparing a syrup containing, on a dry substance weight basis, a high percentage of glucose, said method comprising:

(a) preparing a first aqueous slurry of granular starch containing between about 20 and about 60 weight percent starch, d.s.;
(b) adjusting the pH and the temperature of said first slurry to values suitable to promote activity of a raw starch hydrolyzing enzyme preparation which is produced by a fungal organism and which catalyzes the hydrolysis of granular starch directly to glucose, said raw starch hydrolyzing enzyme preparation being characterized in that it catalyzes the hydrolysis of granular starch suspended in water at a concentration of about 15 percent by weight starch solids substantially completely to soluble glucose syrup solids containing at least about 97 percent by weight glucose, d.s., when the hydrolysis is carried out at a pH of about 5.0 to about 7.0 and a temperature of about 55.degree. C. and without added alpha amylase or added debranching enzyme of the pullulanase, isoamylase or beta amylase type, said enzyme preparation being further characterized in that it is separable by carboxymethyl cellulose into a first adsorbing fraction and a second non-adsorbing proteinaceous fraction, said first adsorbing fraction containing a glucoamylase enzyme (EC 3.2.1.3) that has an isoelectric point of about 8.0 or higher and said second non-adsorbing fraction having glucoamylase-protentiating activity that catalyzes the hydrolysis of granular starch;
(c) adding to said first slurry the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify a substantial portion of the starch in said first slurry;
(d) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify a substantial portion, but less than all, of the starch in said first slurry to yield a first syrup of at least about 22 weight percent saccharides, d.s.;
(e) separating said first syrup from the insolubles which remain and which contain unsolubilized starch from said first slurry;
(f) preparing a second aqueous slurry from said insolubles, said second slurry containing less than about 20 weight percent, d.s., starch;
(g) adjusting the pH and the temperature of said second slurry to values suitable to promote raw starch hydrolyzing enzyme activity;
(h) contacting said second slurry with the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify substantially all of the starch contained in said second slurry;
(i) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify substantially all of the starch in said second slurry to provide a second syrup;
and
(j) separating said second syrup from insolubles contained therein.

8 more elements

A method of preparing a syrup containing, on a dry substance weight basis, a high percentage of glucose, said method comprising:

(a) preparing a first aqueous slurry of granular starch containing between about 20 and about 60 weight percent starch, d.s.;
(b) adjusting the pH and the temperature of said first slurry to values suitable to promote activity of a raw starch hydrolyzing enzyme preparation which is produced by a fungal organism that is a strain of the genus Humicola and which catalyzes the hydrolysis of granular starch directly to glucose, said raw starch hydrolyzing enzyme preparation being characterized in that it catalyzes the hydrolysis of granular starch suspended in water at a concentration of about 15 percent by weight starch solids substantially completely to soluble glucose syrup solids containing at least about 97 percent by weight glucose, d.s., when the hydrolysis is carried out at a pH of about 5.0 to about 7.0 and a temperature of about 55.degree. C. and without added alpha amylase or added debranching enzyme of the pullulanase, isoamylase or beta amylase type, said enzyme preparation being further characterized in that it is separable by carboxymethyl cellulose into a first adsorbing fraction and a second non-adsorbing proteinanceous fraction, said first adsorbing fraction containing a glucoamylase enzyme (EC 3.2.1.3) that has an isoelectric point of about 8.0 or higher and said second non-adsorbing fraction having glucoamylase-protentiating activity that catalyzes the hydrolysis of granular starch;
(c) adding to said first slurry the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify a substantial portion of the starch in said first slurry;
(d) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify a substantial portion, but less than all, of the starch in said first slurry to yield a first syrup of at least about 22 weight percent saccharides, d.s.;
(e) separating said first syrup from the insolubles which remain and which contain unsolubilized starch from said first slurry;
(f) preparing a second aqueous slurry from said insolubles, said second slurry containing less than about 20 weight percent, d.s., starch;
(g) adjusting the pH and the temperature of said second slurry to values suitable to promote raw starch hydrolyzing enzyme activity;
(h) contacting said second slurry with the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify substantially all of the starch contained in said second slurry;
(i) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify substantially all of the starch in said second slurry to provide a second syrup;
and
(j) separating said second syrup from insolubles contained therein.

8 more elements

A method of preparing a syrup contaning, on a dry substance weight basis, a high percentage of glucose, said method comprising:

(a) preparing a first aqueous slurry of granular starch containing between about 20 and about 60 weight percent starch, d.s.;
(b) adjusting the pH and the temperature of said first slurry to values suitable to promote activity of a raw starch hydrolyzing enzyme preparation which is produced by a fungal organism that is a strain of the species Humicola grisea and which catalyzes the hydrolysis of granular starch directly to glucose, said raw starch hydrolyzing enzyme preparation being characterized in that it catalyzes the hydrolysis of granular starch suspended in water at a concentration of about 15 percent by weight starch solids substantially completely to soluble glucose syrup solids containing at least about 97 percent by weight glucose, d.s., when the hydrolysis is carried out at a pH of about 5.0 to about 7.0 and a temperature of about 55.degree. C. and without added alpha amylase or added debranching enzyme of the pullulanase, isoamylase or beta amylase type, said enzyme preparation being further characterized in that it is separable by carboxymethyl cellulose into a first adsorbing fraction and a second non-adsorbing proteinaceous fraction, said first adsorbing fraction containing a glucoamylase enzyme (EC 3.2.1.3) that has an isoelectric point of about 8.0 or higher and said second non-adsorbing fraction having glucoamylase-protentiating activity that catalyzes the hydrolysis of granular starch;
(c) adding to said first slurry the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify a substantial portion of the starch in said first slurry;
(d) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify a substantial portion, but less than all, of the starch in said first slurry to yield a first syrup of at least about 22 weight percent saccharides, d.s.;
(e) separating said first syrup from the insolubles which remain and which contain unsolubilized starch from said first slurry;
(f) preparing a second aqueous slurry from said insolubles, said second slurry containing less than about 20 weight percent, d.s., starch;
(g) adjusting the pH and the temperature of said second slurry to values suitable to promote raw starch hydrolyzing enzyme activity;
(h) contacting said second slurry with the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify substantially all of the starch contained in said second slurry;
(i) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify substantially all of the starch in said second slurry to provide a second syrup;
and
(j) separating said syrup from insolubles contained therein.

8 more elements

A method of preparing a syrup containing, on a dry substance weight basis, a high percentage of glucose, said method comprising:

(a) preparing a first aqueous slurry of granular starch containing between about 20 and about 60 weight percent starch, d.s.;
(b) adjusting the pH and the temperature of said first slurry to values suitable to promote activity of a raw starch hydrolyzing enzyme preparation which is produced by a fungal organism that is a strain of the species Humicola grisea var. thermoidea and which catalyzes the hydrolysis of granular starch directly to glucose, said raw starch hydrolyzing enzyme preparation being characterized in that it catalyzes the hydrolysis of granular starch suspended in water at a concentration of about 15 percent by weight starch solids substantially completely to soluble glucose syrup solids containing at least about 97 percent by weight glucose, d.s., when the hydrolysis is carried out at a pH of about 5.0 to about 7.0 and a temperature to about 55.degree. C. and without added alpha amylase or added debranching enzyme of the pullulanase, isoamylase or beta amylase type, said enzyme preparation being further characterized in that it is separable by carboxymethyl cellulose into a first adsorbing fraction and a second non-adsorbing proteinaceous fraction, said first adsorbing fraction containing a glucoamylase enzyme (EC 3.2.1.3) that has an isoelectric point of about 8.0 or higher and said second non-adsorbing fraction having glucoamylase-protentiating activity that catalyzes the hydrolysis of granular starch;
(c) adding to said first slurry the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify a substantial portion of the starch in said first slurry;
(d) allowing said raw starch hydrolyzing enzyme preparation of solubilize and saccharify a substantial portion, but less than all, of the starch in said first slurry to yield a first syrup of at least about 22 weight percent saccharides, d.s.;
(e) separating said first syrup from the insolubles which remain and which contain unsolubilized starch from said first slurry;
(f) preparing a second aqueous slurry from said insolubles, said second slurry containing less than about 20 weight percent, d.s., starch;
(g) adjusting the pH and the temperature of said second slurry to values suitable to promote raw starch hydrolyzing enzyme activity;
(h) contacting said second slurry with the raw starch hydrolyzing enzyme preparation in an amount sufficient to solubilize and saccharify substantially all of the starch contained in said second slurry;
(i) allowing said raw starch hydrolyzing enzyme preparation to solubilize and saccharify substantially all of the starch in said second slurry to provide a second syrup;
and
(j) separating said second syrup from insolubles contained therein.

8 more elements

Dependencies are inferred from the claim text.