Modified starch
Encyclopedia
Modified starch, also called starch derivatives
, are prepared by physically
, enzymatically, or chemically treating native starch
, thereby changing the properties of the starch. Modified starches are used in practically all starch applications, such as in food products as a thickening agent
, stabilizer or emulsifier; in pharmaceuticals as a disintegrant; as binder in coated paper
. They are also used in many other applications.
Starches are modified to enhance their performance in different applications. Starches may be modified to increase their stability against excessive heat, acid, shear, time, cooling, or freezing; to change their texture; to decrease or increase their viscosity
; to lengthen or shorten gelatinization
time; or to increase their visco-stability.
1401),, also called thin boiling starch, is prepared by treating starch
or starch granules with inorganic acids, e.g. hydrochloric acid
breaking down the starch molecule and thus reducing the viscosity.
Other treatments producing modified starch (with different E numbers) are:
and combined modifications such as phosphated distarch phosphate
(E1413), hydroxypropyl distarch phosphate
(E1442), acetylated oxidized starch (E1451).
Modified starch may also be a cold water soluble, pregelatinized or instant starch which thickens and gels without heat, or a cook-up starch which must be cooked like regular starch. Drying methods to make starches cold water soluble are extrusion
, drum drying
or spray drying
.
Other starch derivates are glucose
, high fructose syrup and glucose syrup
s, starch degraded with amylase
enzyme
to make a sweetener
.
s, allowing the food to thicken with the addition of cold water or milk. Similarly, cheese sauce granules (such as in Macaroni and Cheese
or lasagna
) or gravy
granules may be thickened with boiling water without the product going lumpy. Commercial pizza toppings containing modified starch will thicken when heated in the oven, keeping them on top of the pizza, and then become runny when cooled.
A suitably modified starch is used as a fat substitute
for low-fat versions of traditionally fatty foods, e.g., reduced-fat hard salami having about 1/3 the usual fat content. For such uses, it is an alternative to the product Olestra
.
Modified starch is added to frozen products to prevent them from dripping when defrosted. Modified starch, bonded with phosphate
, allows the starch to absorb more water and keeps the ingredients together. Modified starch acts as an emulsifier for French dressing
by enveloping oil droplets and suspending them in the water. Acid-treated starch forms the shell of jelly bean
s. Oxidized starch increases the stickiness of batter
.
Carboxymethylated starches are used as a wallpaper adhesive, as textile printing
thickener, as tablet
disintergrant, excipient
, in pharmaceutical industry.
Cationic starch is used as wet end sizing
agent in paper manufacturing.
starch, which refers to starch from genetically engineered plants
, which have been genetically modified to produce novel carbohydrates which might not naturally occur in the plant species being harvested. The modification in this sense refers to the genetic engineering of the plant DNA
, and not the later processing or treatment of the starch or starch granules.
Genetically modified starch is of interest in the manufacture of biodegradable polymer
s and noncellulose feedstock in the paper industry, as well as the creation of new food additives.
Derivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...
, are prepared by physically
Physical change
Physical changes are changes affecting the form of a chemical substance, but do not change the chemical composition of that substance. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler...
, enzymatically, or chemically treating native starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
, thereby changing the properties of the starch. Modified starches are used in practically all starch applications, such as in food products as a thickening agent
Thickening agent
Thickening agents, or thickeners, is the term applied to substances which increase the viscosity of a solution or liquid/solid mixture without substantially modifying its other properties; although most frequently applied to foods where the target property is taste, the term also is applicable to...
, stabilizer or emulsifier; in pharmaceuticals as a disintegrant; as binder in coated paper
Coated paper
Coated paper is paper which has been coated by a compound to impart certain qualities to the paper, including weight, surface gloss, smoothness or reduced ink absorbency. Kaolinite or calcium carbonate are used to coat paper for high quality printing used in packaging industry and in magazines...
. They are also used in many other applications.
Starches are modified to enhance their performance in different applications. Starches may be modified to increase their stability against excessive heat, acid, shear, time, cooling, or freezing; to change their texture; to decrease or increase their viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
; to lengthen or shorten gelatinization
Starch gelatinization
Starch gelatinization is a process that breaks down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water. This irreversibly dissolves the starch granule...
time; or to increase their visco-stability.
Modification methods
Acid-treated starch (EE number
E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...
1401),, also called thin boiling starch, is prepared by treating starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
or starch granules with inorganic acids, e.g. hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
breaking down the starch molecule and thus reducing the viscosity.
Other treatments producing modified starch (with different E numbers) are:
- dextrinDextrinDextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α- or α- glycosidic bonds....
(E1400), roasted starch with hydrochloric acidHydrochloric acidHydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid.... - alkaline-modified starch (E1402) with sodium hydroxide or potassium hydroxidePotassium hydroxidePotassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
- bleached starch (E1403) with hydrogen peroxideHydrogen peroxideHydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
- oxidized starch (E1404) with sodium hypochlorite, breaking down viscosity
- enzyme-treated starch (INS: 1405), maltodextrinMaltodextrinMaltodextrin is a polysaccharide that is used as a food additive. It is produced from starch by partial hydrolysis and is usually found as a creamy-white hygroscopic spraydried powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might be either moderately sweet or...
, cyclodextrinCyclodextrinCyclodextrins are a family of compounds made up of sugar molecules bound together in a ring .... - monostarch phosphate (E1410) with phosphorous acidPhosphorous acidPhosphorous acid is the compound described by the formula H3PO3. This acid is diprotic , not triprotic as might be suggested by this formula. Phosphorous acid is as an intermediate in the preparation of other phosphorus compounds.-Nomenclature and tautomerism:H3PO3 is more clearly described with...
or the salts sodium phosphate, potassium phosphatePotassium phosphatePotassium phosphate is a generic term for the salts of potassium and phosphate ions including:* Monopotassium phosphate * Dipotassium phosphate * Tripotassium phosphate...
, or sodium triphosphate to reduce retrogadationRetrogradation (starch)Retrogradation is a reaction that takes place in gelatinized starch when the amylose and amylopectin chains realign themselves, causing the liquid to gel.... - distarch phosphate (E1412) by esterification with for example sodium trimetaphosphateSodium trimetaphosphateSodium trimetaphosphate , with formula Na3P3O9, is a metaphosphate of sodium. It has the empirical formula NaPO3. It is the sodium salt of trimetaphosphoric acid....
, crosslinked starch modifying the rheologyRheologyRheology is the study of the flow of matter, primarily in the liquid state, but also as 'soft solids' or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force....
, the texture - acetylated starch (E1420) esterification with acetic anhydrideAcetic anhydrideAcetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolatable acid anhydride and is a widely used reagent in organic synthesis...
- hydroxypropylated starch (E1440), starch etherEtherEthers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
, with propylene oxidePropylene oxidePropylene oxide is an organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid is produced on a large scale industrially, its major application being its use for the production of polyether polyols for use in making polyurethane plastics...
, increasing viscosity stability - hydroxyethyl starchHydroxyethyl starchHydroxyethyl starch is a nonionic starch derivative. It is one of the most frequently used volume expander under the trade names Hespan by B. Braun Medical Inc...
, with ethylene oxideEthylene oxideEthylene oxide, also called oxirane, is the organic compound with the formula . It is a cyclic ether. This means that it is composed of two alkyl groups attached to an oxygen atom in a cyclic shape . This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered... - Octenyl succinic anhydride (OSA) starch (E1450) used as emulsifier adding hydrophobicity
- cationic starch , adding positive electrical charge to starch
- carboxymethylated starch with monochloroacetic acid adding negative charge
and combined modifications such as phosphated distarch phosphate
Phosphated distarch phosphate
Phosphated distarch phosphate, is a modified resistant starch. It is derived from high amylose maize starch and contains a minimum of 70% dietary fibre...
(E1413), hydroxypropyl distarch phosphate
Hydroxypropyl distarch phosphate
Hydroxypropyl distarch phosphate is a modified resistant starch. It is currently used as a food additive . It is approved for use in the European Union , the United States, Australia, and New Zealand.- External links :...
(E1442), acetylated oxidized starch (E1451).
Modified starch may also be a cold water soluble, pregelatinized or instant starch which thickens and gels without heat, or a cook-up starch which must be cooked like regular starch. Drying methods to make starches cold water soluble are extrusion
Extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
, drum drying
Drum drying
Drum drying is a method used for drying out liquids; for example, milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off with a knife...
or spray drying
Spray drying
Spray drying is a method of producing a dry powder from a liquid or slurry by rapidly drying with a hot gas. This is the preferred method of drying of many thermally-sensitive materials such as foods and pharmaceuticals. A consistent particle size distribution is a reason for spray drying some...
.
Other starch derivates are glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, high fructose syrup and glucose syrup
Glucose syrup
Glucose syrup is a food syrup, made from the hydrolysis of starch. Maize is commonly used as the source of the starch in the USA, in which case the syrup is called "corn syrup", but glucose syrup is also made from other starch crops, including potatoes, wheat, barley, rice and cassavap.21...
s, starch degraded with amylase
Amylase
Amylase is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion. Food that contains much starch but little sugar, such as rice and potato, taste slightly sweet as they are chewed because amylase turns...
enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
to make a sweetener
Sugar substitute
A sugar substitute is a food additive that duplicates the effect of sugar in taste, usually with less food energy. Some sugar substitutes are natural and some are synthetic. Those that are not natural are, in general, called artificial sweeteners....
.
Examples of use and functionality of modified starch
Pre-gelatinized starch is used to thicken instant dessertDessert
In cultures around the world, dessert is a course that typically comes at the end of a meal, usually consisting of sweet food. The word comes from the French language as dessert and this from Old French desservir, "to clear the table" and "to serve." Common Western desserts include cakes, biscuits,...
s, allowing the food to thicken with the addition of cold water or milk. Similarly, cheese sauce granules (such as in Macaroni and Cheese
Macaroni and cheese
Macaroni and cheese, also known as "mac and cheese", "macaroni cheese" in British English, or "macaroni pie" in Caribbean English, is a casserole consisting of cooked macaroni and cheese sauce...
or lasagna
Lasagna
Lasagna is a wide and flat type of pasta and possibly one of the oldest shapes. As with most other pasta shapes, the word is generally used in its plural form lasagne in Italy and the U.K. Traditionally, the dough was prepared in Southern Italy with semolina and water and in the northern regions,...
) or gravy
Gravy
Gravy is a sauce made often from the juices that run naturally from meat or vegetables during cooking. In North America the term can refer to a wider variety of sauces and gravy is often thicker than in Britain...
granules may be thickened with boiling water without the product going lumpy. Commercial pizza toppings containing modified starch will thicken when heated in the oven, keeping them on top of the pizza, and then become runny when cooled.
A suitably modified starch is used as a fat substitute
Fat substitute
A fat substitute is a food product with the same functions, stability, physical, and chemical characteristics as regular fat, with fewer kilocalories per gram than fat. They are utilized in the production of low fat and low calorie foods. -Background:...
for low-fat versions of traditionally fatty foods, e.g., reduced-fat hard salami having about 1/3 the usual fat content. For such uses, it is an alternative to the product Olestra
Olestra
Olestra is a fat substitute that adds no fat, calories, or cholesterol to products. It has been used in the preparation of traditionally high-fat foods such as potato chips, thereby lowering or eliminating their fat content...
.
Modified starch is added to frozen products to prevent them from dripping when defrosted. Modified starch, bonded with phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
, allows the starch to absorb more water and keeps the ingredients together. Modified starch acts as an emulsifier for French dressing
French dressing
French dressing is a term used for different salad dressings in different countries. It was originally the English translation for “Vinaigrette”, the French word for salad dressing.It can refer to:-Foods:...
by enveloping oil droplets and suspending them in the water. Acid-treated starch forms the shell of jelly bean
Jelly bean
Jelly beans are a small bean-shaped type of confectionery with a hard candy shell and a gummy interior which come in a wide variety of flavors. The confection is primarily made of sugar.-History:...
s. Oxidized starch increases the stickiness of batter
Batter (cooking)
Batter is a semi-liquid mixture of one or more flours combined with liquids such as water, milk or eggs used to prepare various foods. Often a leavening agent such as baking powder is included to aerate and fluff up the batter as it cooks, or the mixture may be naturally fermented for this purpose...
.
Carboxymethylated starches are used as a wallpaper adhesive, as textile printing
Textile printing
Textile printing is the process of applying colour to fabric in definite patterns or designs. In properly printed fabrics the colour is bonded with the fiber, so as to resist washing and friction...
thickener, as tablet
Tablet
A tablet is a pharmaceutical dosage form. It comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose...
disintergrant, excipient
Excipient
An excipient is generally a pharmacologically inactive substance used as a carrier for the active ingredients of a medication. In many cases, an "active" substance may not be easily administered and absorbed by the human body; in such cases the substance in question may be dissolved into or...
, in pharmaceutical industry.
Cationic starch is used as wet end sizing
Sizing
Sizing or size is any one of numerous specific substances that is applied to or incorporated in other material, especially papers and textiles, to act as a protecting filler or glaze....
agent in paper manufacturing.
Genetically modified starch
Modified starch should not be confused with genetically modifiedGenetically modified food
Genetically modified foods are foods derived from genetically modified organisms . Genetically modified organisms have had specific changes introduced into their DNA by genetic engineering techniques...
starch, which refers to starch from genetically engineered plants
Genetically modified organism
A genetically modified organism or genetically engineered organism is an organism whose genetic material has been altered using genetic engineering techniques. These techniques, generally known as recombinant DNA technology, use DNA molecules from different sources, which are combined into one...
, which have been genetically modified to produce novel carbohydrates which might not naturally occur in the plant species being harvested. The modification in this sense refers to the genetic engineering of the plant DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
, and not the later processing or treatment of the starch or starch granules.
Genetically modified starch is of interest in the manufacture of biodegradable polymer
Biodegradable polymer
Biodegradable polymers are polymers that break down and lose their initial integrity. Biodegradable polymers are used in medical devices to avoid a second operation to remove them, or to gradually release a drug TYPES OF BIODEGRADABLE POLYMERS1...
s and noncellulose feedstock in the paper industry, as well as the creation of new food additives.
See also
- Acceptable daily intakeAcceptable daily intakeAcceptable daily intake or ADI is a measure of the amount of a specific substance in food or drinking water that can be ingested on a daily basis over a lifetime without an appreciable health risk...
- Retrogradation (starch)Retrogradation (starch)Retrogradation is a reaction that takes place in gelatinized starch when the amylose and amylopectin chains realign themselves, causing the liquid to gel....
- Starch gelatinizationStarch gelatinizationStarch gelatinization is a process that breaks down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water. This irreversibly dissolves the starch granule...
- Resistant starchResistant starchResistant starch is starch and starch degradation products that escape digestion in the small intestine of healthy individuals. Resistant starch is considered the third type of dietary fiber, as it can deliver some of the benefits of insoluble fiber and some of the benefits of soluble fiber.Some...