Date: December 2011
When the world has more industrial development, the scope of starch use for industrial purpose expands, causing limitation of use of the Native Starch in the industries due to the specific properties, limited types and species of plants, causing the research for properties and broader scope of use of Native Starch by developing and improving the structure within the molecule of the starch “Modified Starch”.
Modified Starch is the Native Starch being improved and changed the properties to be different from the Native Starch. Physical or chemical changes of the starch properties causes the molecule structure change within the starch. There are several methods of molecule structure change. Each method is different based on the present demand for use and could be categorized mainly as follows:
- Chemical modified starches
- Physical modified starch
- Starch with molecule structure change within the starch and/or external structure change with biological method (Biological modified starch)
In the future, when the technology is developed, modified starch may be changed, but at this time, the writer would like to describe about the technology, about which the writer has the production experiences.
1. Starch with molecule structure change by mean of chemical (Chemicals modified starches)
Categorization of the modified starch by mean of chemical (Chemicals modified starches) is done in several methods, but the writer would like to do categorization based on the writer’s mind and consider it for easy understanding by reader. (Never mind if you don’t understand it.)
Group 1: Derivertization
This starch group is the starch caught be the chemical in the starch molecule in form of single molecule or more, causing the starch molecule to be larger i.e.
- 1.1) Etherification reaction type
- 1.1.1) Hydroxyethylated Starches
- 1.1.2) Hydroxypropylated Starches
- 1.1.3) Cyanoethyl starch
- 1.2) Carboxymethyl starch or negative starch
- 1.3) Carbonic Starches or positive starch
- 1.3.1) Tertiary aminoalkyl starch ether
- 1.3.2) Quaternary ammonium starch ether
- 1.4) Esterification reaction type
- 1.4.1) Starch acetate
- 1.4.2) Succinate and Substitues Succinated Starches
- 1.4.3) Starch phosphate monoester
- 1.5) Cross linking type reaction
- 1.5.1) Di-starch adipate
- 1.5.2) Di-starch phosphate
- 1.5.3) Di-starch glyceral
Group 2): Converted starch
This starch group is the diminishing of starch molecule either by cutting between glucose unit or breaking the glucose unit i.e.
- 2.1) Acid Conversion or Acid Modified Starch
- 2.2) Oxidized Hypochlorite - Modified Starch
- 2.3) Pyroconversion or Pyrodextrins
- 2.4) Enzyme conversion starch
From the principle and technology on structural change of the molecule of starch in main groups, it could be combined as new types of Modified Starch with broader properties of use:
Group 3): Combination Starches
- 3.1) Hydroxypropylated with Cross-Linked Starches
- 3.2) Hydroxypropylated with Oxidized Starches
- 3.3) Cross-Linked with Oxidized Starches
- 3.4) Acid Converted with Hydroxypropylated Starches
- 3.5) Oxidized with Acetylated Starches
And others on market demand and manufacturing potential
2. Molecule structure modified starch by physical mean (Physicals modified starch)
Modification of molecule structure within the starch by physical mean (Physical modified starch) causes change without using chemical mainly to change the molecule structure within the starch, but uses the heat or dynamic energy or both. When the molecule structure within the starch is changed, the properties of the starch are changed also. The starch of this group includes:
- 2.1) Pregelatinized starch
- 2.2) Granular cold water soluble starch
- 2.3) Annealing starch
- 2.4) Heat treatment starch
- 2.5) Mechanical milling starch
3. Molecule structure modified starch by biological mean (Biological modified starch)
Presently, biological and genetic engineering technology is developed so much and is the main factor to cause the industrial development to obtain the starch with properties based on the application demand by using biological technology, and presently, we use the products from biological technology i.e. High amylase starch (Hylon V, VII) and Waxy starch (High Amylopectin ie Waxy corn). Change of the proportion of amylase and amylopectin shall change the properties of the starch.
Before comprehension of the technical details of the modified starch production technique, we should learn the technical keywords for better understanding on the next topic.
1) Carbon Position (C) in Anhydroglucose Units
Carbon atom or Hydroxyl Group in Anhydroglucose Monomer is positioned for purpose to support the explanation of the reactions towards Anhydroglucose Unit by counting or specifying the position of carbon at position of Primary Hydroxyl; position No. 6 (based on the picture shown above).
2) Degree of Polymerization (DP)
DP value of the product shows the number of Monomer units in molecules of the product. In the topic about the starch, it could be explained that DP is the average number of Anhydroglucose Units per 1 molecule line i.e.
Dextrose DP = 1
Maltose DP = 2
Amylose shall consist of 200 Anhydroglucose Units DP = 200
3) Dextrose Equivalent (DE) or Reducing Valve
DE is the explanation or showing of the quantity calculated in comparison in units of Dextrose and shown in units of the dry weight i.e.
DEXTROSE : DE = 100
MALTOSE : DE = 50
1 molecule of Hydrolyzed Amylose or Amylopectin consisting of Anhydroglucose of 100 units, which may consist of 1 Reducing end group, DE = 1. Generally, DE value applies for Depolymerized starch or Converted Starch i.e. DEXTRINS or SYRUPS and sugar.
4) Percent Substitution
Means the substitution of the substances in the starch being shown in weight of the substance caught or substituted in the starch in percentage per dry starch weight.
5) Degree Of Substitution (DS)
Means the average number of the substance substituted in position of Hydroxyl Group of each unit of Anhydroglucose, for example;
- Esterified with Acetyl group
If DS = 1, it means that in all units of Anhydroglucose, Acetyl group shall catch at C position for one position.
If DS = 3, it means that in all units of Anhydroglucose, Acetyl group shall catch at C position for three positions.
If DS = 0.1, it means that in every 10 units of Anhydroglucose, Acetyl group shall catch at C position for one position.
6) Beta Amylose Digestibility
- Beta Amylose is a type of enzyme in plant.
- Beta Amylose Digestibility means the display of ability potential of enzyme on digestion of starch, Amylose, Amylosepectin or Modified Starch.
Position digestible by Beta Amylose Enzyme is the position –D-(1-4) Glucosidic bond and shall stop the digestion upon arriving at the position –D-(1 6) Glucosidic bond.
7) Alkali Number
Alkali Number means the mole sum of alkali used per 10 grams of the dry starch on digestion of the starch for 1 hour in the solvent 0.1 M Sodium Hydroxide at the boiling point of the water. Alkali shall be used by the acid caused from the Reducing ends of the polymer line, and from this method, it is believed that the length of the polymer line of the starch being caused from the hydrolysis could be calculated better than the quantitative analysis method by calculating the elements of Aldehyde, alkali number in direct relation with the actual viscosity value and fluidities value.
Model sample on explanation about the chemical; reaction of the starch groups
Group 1): Derivertization
Catonic Starches or positive starch
Quaternary ammonium starch ether
Esterification reaction type
Cross linking type reaction
1.5.2) Di-starch phosphate
Group 2: Converted Starch
2.1) Acid Conversion or Acid Modified Starch
2.2) Oxidized Hypochlorite - Modified Starch
2.3) Enzyme conversion starch
Used of modified starch
Because the modified starch has the different properties from the native starch and designed to be suitable for typical application, the development is caused to use this modified starch in several industries i.e.
- Food industry
- Paper industry
- Pharmacy industry
- Paper industry
- Adhesive industry
- Biological plastic industry
- Ceramic industry
- Textile industry
- Building industry
- Non-woven industry
- Rubber glove industry
- Agricultural industry
- Oil drilling industry
- And several industries depending on design of the modified starch and production cost
Sample of starch application in different aspects
High amylase cornstarch is usually used in the product of extruded and fried snack to keep crispiness and consistent color and prevent oil leakage to the snack.
Starch softens and stiffens the stuff.
Cause the sauce to be appetizing.
Starch used in the meat industry absorbs water and causes the meat to be soft and not wither.
Starch causes ice cream to be smelted slower, causes the stuff to be more sticky and instead of milk.
Starch causes gel of jelly and candy to be strong.
Starch causes feeling that sauce is intense.
Starch is the main factor to fix the metal welding mold.
Starch is used as adhesive of food on process of animal feed production.
Starch reduces time of cement hardening.
Starch increases the viscosity of drilled mud and fills the partition of the well to prevent the oil leakage.
Gypsum & Mineral Fiber
Starch is used as cohesive of production of gypsum plaster, gypsum and mineral fiber board.
Nappy / Diaper
Starch is used as adhesive and modified starch is used instead of sodium polyacrylate polymer as the water absorber.
Starch agglomerates the large sediment and precipitates rapidly.
Starch is used as cohesive of coal powder and causes the coal powder in form and increases the value of the coal powder.
Starch is used in the detergent industry to prevent re-coating of dirt on clothes.
Starch is used as cohesive on pill production and causes the pill not to be broken or corrosive on transportation, and the modified starch causes the pill to be dissolved in stomach.
For use in combination with acrylonytro, causes the starch to absorb water more, suitable for coating the plant seed and causes the plant seed to grow rapidly and in the high growing rate and absorb water in earth.
Use the starch to remove the iron stain.
Starch of this group prevents adhesion of gloves at time of storage and causes flow on wearing.
Starch is usually used in the paper industry of all types with different purposes, depending on the paper type i.e. to increase the paper strength, increase the opaqueness for use of both paper pages, increase the brilliance of paper surface, lessen the penetration of ink etc.
Starch acts as adhesive to fix the crepe paper and causes the paper box to be strong and suitable for application.
Starch causes the thread to be strong and reduces the friction force on weaving and causes slower deterioration of the weaving machine and causes beautiful fabric printing.
Plastics & Packaging
Starch used in this industry protects the environment because plastic made of the starch shall be decomposed naturally quicker than the pure plastic.
The modified starch could be used instead of foam made of Polystyrene with more advantages; quicker decomposition and environmental friendliness and foam from the starch prevents the static electricity. In addition, it could be used as the disposable food container i.e. saucer, bowl etc.