Bacterial Alpha-Amylases for Starch Liquefaction

Description

Liquamil is a food grade, bacterial alpha-amylase of Bacillus subtilis origin. The enzyme is an endoamylase capable of randomly hydrolyzing the predominating alpha-D-(I-4) glucosidic linkages of starch. Consequently, the viscosity of gelatinous starch is rapidly reduced. Licuamil converts starch, amylase and amylopectin to soluble dextrin`s and small quantities of glucose and maltose.

Liquamil demonstrates exceptional themostability. It may be added to starch slurries at temperatures below that of gelatinization. Liquefaction can occur during the cooking process at and above the gelatinization temperature. Higher solids can therefore be easily handled and the need to cool prior to enzyme addition is alleviated.

Product	Activity
Liquamil-1200	1,200,000 MWU/G
Liquamil L-1200	1,200,000 MWU/G
Liquamil L-340	340,000 MWU/G
Liquamil 7000 concentrate	Sold on activity basis. Typically 6-8,000,000 MWU/G

Properties	Powders	Liquids
Form	Impalpable dry power	Nonviscous
Color	Light tan to white	Amber to brown
Odor	Free of offensive odor	Free of offensive odor
Taste	Free of offensive taste	Free of offensive taste

Activators

No activators are required for the complete activity of the Liquamil.

Cofactors

Liquamil is a calcium metalloprotein. In the presence of sufficient calcium ions, the enzyme is quite resistant to denaturation at extremes of temperature and pH. When improved enzyme stability is desired at temperatures above 60C, calcium ions (200 - 400 ppm) should be added to the conversion. Sodium chloride (2,000 - 5,000 ppm) also contributes to improved thermostability.

Activity

One Modified Wohlgemuth Unit is that amount of activity that dextrinizes one milliliter of soluble starch to a defined blue value in 30 minutes under the conditions of the assay. A copy of the Determination of Liquefying Amylase (Modified Wohlgemuth Method) is available upon request.

Effect of pH

Liquamil has an optimum pH of 6.0 at 40C in the presence of 2% soluble starch. In the presence of 10-50% starch (DSB) and mfficient calcium ions, the enzymes demonstrate optimum hydrolysis over the range of pH 6.5 to 7.5 at temperatures above 70C. Liquamil can effectively hydrolyze starch over the range of pH 5.0 to 7.5 at 70C. Although the rates of hydrolysis are diminished at the extremes, the Liquamil is stable in solution at 70C over the range of pH 5.0-10.0.

Optimum pH Range	pH 6.0 to 7.0
Effective pH Range	pH 5.0 to 7.5
pH Stability	pH 5.0 to 10.0

Effect of Temperature

Liquamil has a temperature optimum of 70C at pH 6.0. In the presence of 10-50% starch (DSB) and sufficient calcium ions, the enzyme demonstrates excellent thermostability effectively hydrolyzing starch at temperatures up to 90C . Temperatures of 60C to 70C at pH 6.5 to 7.5 give extended stability, and higher temperatures (70 - 85C) at pH 6.5 to 7.5 give an accelerated rate of hydrolysis but also an increase in the rate of enzyme inactivation.

Optimum Temperature Range	65-75C
Effective Temperature Range	Up to 90C

Inactivation

Inactivation can be achieved thermally by raising the temperature to 90-100C and holding for approximately 10-20 minutes. It should be noted that as a result of raising the temperature the enzymes demonstrated accelerated action prior to complete inactivation. When high temperature inactivation is not desirable, the enzyme may be inactivated by lowering the pH below the active pH range with hydrochloric or sulfuric acid. At pH 5.0 and 90C, or at pH 3.5 - 4.0 and 80 to 85C, the enzyme should be inactivated in approximately 15 minutes. After inactivation is complete the starch slurry should be neutralized with sodium carbonate or calcium carbonate. Inactivation can be achieved chemically by adding 1.0% available chlorine as sodium hypochlorite. In non-food use, 0.15% copper sulfate may be used.

Solubility

The enzyme portion of Liquamil is readily water-soluble. Any turbidity in solution is due to minor insolubility of the stabilizing agent. Improved enzyme dispersion throughout the substrate will result if the enzyme preparation is solubilized in pH 6.0 to 7.0 potable water prior to addition.

Substrate

Liquamil may be used to liquefy corn, maize, potato, wheat sorghum or other types of starch.

Use Level

Enzyme requirements are generally dictated by processing conditions. Under optimal conditions, 0.03 to 0.06% Liquamil-L-1200 on a dry starch basis (DSB) will adequately liquefy a 40% starch slurry (DSB) in approximately 10 to 30 minutes.

Other Enzymes Present

In addition to alpha-amylase, Liquamil series contains a low level of protease, and beta glucanase.

Storage Stability

In scaled containers, under cool dry conditions, the loss of activity is normally less than 10% over one year. Storage life can be extended by storing under refrigeration at 5C.

Applications

Food Industry

Baking	Anti-staling agent
Brewing	Liquefaction of adjuncts and removal of starch haze
Candy	Scrap candy recovery
Cereal	Production of pre-cooked cereals. Reduces the viscosity of the cereal prior to roll drying
Cocoa	Reduce the viscosity of chocolate syrups
Distilling	Mash liquefaction
Fermentation	Liquefaction of starch fermentation media
Starch	Reduction of high viscosity starch slurries. Production of low DE syrups. Production of substrates for dextrose production. Production of substrates for further enzyme conversion. Removal of starch haze from syrups.

Other Industries

Paper	Preparation of size coatings
Textile	Desizing
Starch	Preparation of starch adhesives
Other	Cleaning starch processing equipment. i.e. extruders. Licuamil is compatible with most surfactants. Non-ionic surfactants are recommended.