Starch liquefaction with alpha amylase mixtures

• US 4,933,279 A
• Filed: 01/09/1989
• Issued: 06/12/1990
• Est. Priority Date: 07/09/1986
• Status: Expired due to Term

• Current Assignee: Novozymes A/S (Novozymes)
• Original Assignee: Novo Industri A/S (Novo Nordisk A/S)
• Inventors: Trackman, Philip C., Swanson, Timothy R., Carroll, John O.
• Primary Examiner(s): Lilling, Herbert J.
• Application Number:
  US07/294,813
• Time in Patent Office: 519 Days
• Field of Search: 435/42, 435/99, 435/202, 435/836, 435/252.4
• US Class Current: 435/42
• CPC Class Codes: C12N 9/2417 from microbiological source
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: Y10S 435/836 Bacillus licheniformis

Abstract

A mixed enzyme product comprising a mixture of the alpha-amylase from Bacillus licheniformis and the alpha-amylase from B. stearothermophilus, said mixture containing from 10%-90%, preferably 25%-90%, more preferably 25%-75% by activity as NU/g DS of the Bacillus licheniformis enzyme and is usable with advantage for liquefaction of starch or starchy grains.

Claims

1. A mixed enzyme product comprising a mixture of the alpha-amylase from Bacillus licheniformis and the alpha-amylase from B. stearothermophilus, said mixture containing from 25%-90% by activity as NU/g DS of the Bacillus licheniformis enzyme.

3. A mixed enzyme product as in claim 1 containing from 25-75% of the Bacillus licheniformis enzyme.

2. In a process for liquefying starch or starchy grains which comprises subjecting an aqueous slurry of 32-38% dry substance by weight and an alpha-amylase in dosage of from 20-80 NU/g dry starch to jet cooking at a temperature in the range of 100°

C.-115°

C. for 1-60 minutes, followed by reducing temperature to a temperature in the range of 90°

C.-100°

C. for 30-180 minutes after which so liquefied starch is stable against retrogradation, the improvement which comprises conducting said liquefaction in the range of about pH 5.5-6.2 with an enzyme mixture of the alpha-amylase from Bacillus licheniformis and the alpha-amylase from B. stearothermophilus containing from 10%-90% by activity as NU/g DS of the Bacillus licheniformis enzyme.

4. A liquefying process as in claim 2 which further comprises liquefying with an enzyme mixture containing from 25-90% of the Bacillus licheniformis enzyme.

5. A liquefying process as in claim 2 which further comprises liquefying with an enzyme mixture containing from 25-75% of the Bacillus licheniformis enzyme.

6. A liquefying process as in claim 2 which further comprises liquefying with an enzyme mixture containing about 2/3 thereof of the Bacillus licheniformis enzyme at a pH in the range of about pH 5.8-6.0.

7. A mixed enzyme product comprising a mixture of the alpha-amylase from Bacillus licheniformis and the alpha-amylase from B. stearothermophilus, said mixture containing about 2/3 by activity as NU/g DS of the Bacillus licheniformis enzyme.