2. Introduction
The U.S. Food and Drug Administration has defined maltodextrins as a
"nonsweet nutritive saccharide polymer that consists of D-glucose units linked
primarily by (alpha)-1,4 bonds and that has a dextrose equivalent (DE) of less than 20.
It is prepared as a white powder or concentrated solution by partial hydrolysis of corn
starch or potato starch with safe and suitable acids and enzymes.“
In the United States it is typically made from corn, rice or potato starch, while in Europe wheat is
commonly used. Barley is another possible source.
For non-corn or non-potato products, too, manufacturers typically keep the DE under 20.
However, depending on the starting material, these also may contain compounds other than
glucose polymers. For example, one rice maltodextrin manufactured from hydrolyzed rice flour
starts out with 5% to 7% protein.
It is usually found as a white hygroscopic spray-dried powder
3. Structure of Maltodextrins
The chemical structure of maltodextrins falls somewhere between the complex polysaccharide
chains of starch and the simpler molecules of corn syrup solids or sugars.
They do consist of a mixture of different saccharide polymers by virtue of the hydrolysis process.
A starch molecule undergoes enzymatic or acid hydrolysis or a combination of the two. This
cleaves the molecule into smaller, random-length chains.
The process, its conditions, and the type of starch used as the starting material, affect the exact
composition and structure of the resulting chains.
This, in turn, affects the functionality.
4. Dextrose Equivalent (DE) of Maltodextrins
DE is a wet-chemistry method that indicates the amount of hydrolysis done
on a starch molecule.
DE indicates the degree of polymerization (DP) of the starch molecule - the
number of monosaccharide units in the molecules.
DE is derived from the formula
The higher the DE, the higher the level of monosaccharides and short chain
polymers.
Glucose (dextrose) possesses a 100 DE; starch is approximately zero.
Because maltodextrins and other hydrolyzed starches consist of a mixture of
polymer lengths, the DE is an average value.
For example, a 5 DE maltodextrin generally ranges from 4 to 7 DE; a 10 DE
may range from 8 to 12.
Generally maltodextrins have DE between 3 to 20
DE = 100 ÷ DP
5. Relation of DE with properties of maltodextrins
As DE increases (DP decreases), so do the following characteristics:
1) browning (due to the increased level of reducing sugars);
2) hygroscopicity/humectant properties;
3) plasticity;
4) sweetness;
5) solubility;
6) osmolality.
As DE decreases (DP increases) , the following characteristics increase:
1) molecular weight;
2) viscosity;
3) cohesiveness;
4) film-forming properties;
5) prevention of large sugar-crystal formation.
6. Production of Maltodextrins
Maltodextrins may be manufactured either by acid or by acid–enzyme processes.
(I) Acid process
Maltodextrins produced by acid conversion of starch from dent corn
contain a high percentage of linear fragments, which may slowly reassociate into
insoluble compounds causing haze in certain applications.
Haze formation, which results from retrogradation, can be overcome by
use of alpha-amylases.
(II) Enzymatic process using alpha-amylases
Alpha-amylases preferentially cleave the alpha-l,4-D-glucosidic bonds
of amylose and amylopectin, leaving a higher proportion of branched fragments,
decreasing the ability of the fragments to reassociate.
Maltodextrins made from waxy corn starch also have a lower tendency
to haze, because such starch is composed almost entirely of the highly branched
molecule, amylopectin.
7. Starch slurry (30% to 40% dry solids) is pasted at a temperature of 80-90°C
Treatment with a ‘heat-stable’ bacterial alpha-amylase for liquefication.
When stabilized with calcium ions, alpha-amylases from B. licheniformis or B.
stearothermophilus can withstand temperatures of 90–105°C for at least 30
minutes,10 allowing sufficient process time to split the 1,4 bonds and form
maltose and limit dextrins
The fragmentation reaction proceeds until there
is a preponderance of maltohexoses and
maltoheptoses and the liquor has a DE of 12–15
After conversion, the pH of the crude slurry is adjusted to about 4.5
and the solution is filtered to remove protein and fats.
The clarified liquor is then refined using carbon
treatment and ion exchange
After refining and decolorization, the liquor is evaporated to a solids level of
approximately 77% or dried to about 5% moisture.
Enzyme catalysed process
8.
9. Applications of Maltodextrins
(I) Confections
Improves taste,tenacity & structure; Prevents recrystallisation & extends shelf life
(II) Beverages
Beverage DE Functions
Cool food 5-15 More flavor, soluble, consistent &
delicious
Coffee 5-15 Stuffing, less coat, more taste
Milk powder for infant 5-20 Improve nutritional ingredient ratio
& increase function
Fruit freshness 5-15 Increase storage quality, reduce
loss
Ice-cream powder 10-25 Improve structure, emulsification
& consistency, taste & less cost
10. (III) Fast foods
(IV) Tinned foods
Food DE Functions
Foods for health
care
5-15 Reduce nutrition loss,
improve taste & health
functions
Infant foods 5-15 Add consistency, improve
structure
Soups 5-10 Add consistency, improve
taste
Fast foods 5-15 Add consistency, improve
structure
Name DE Function
Cans 5-10 Add consistency & flavor
Jelly foods 5-15 Add consistency & flavor
Fruit paste 10-20 Add consistency & flavor
11. (V) Paper Industries
Used as bond material because of good fluidity and strong cohesion-tension
improving quality, structure & shape of paper.
(VI) Pharmaceuticals
Used in cosmetics that may have more effect to protect skin with more luster
& elasticity.
Used in toothpaste as a substitute for CMC
(VII) Sports drinks as a source of rapidly absorbed carbohydrates.
(VII) Filler in sugar substitutes like Splenda and Equal. Splenda contains
sucralose, which is approximately 600 times sweeter than table sugar
(sucrose), so only a tiny amount of sucralose is used in a packet of
Splenda—the rest is maltodextrin. This also means that sugar substitutes
containing maltodextrin are not truly sugar-free.
12. (VIII) Frozen assets
o Maltodextrins act as cryoprotectants in frozen products and desserts. Because of their higher
molecular weight, they do not lower the freezing point as much as sugars on an equivalent weight
basis.
o For ice cream and other frozen desserts, a decrease in freezing point can result in several negative
effects. A lower melt point imparts an undesirable icy mouthfeel, and makes the product difficult to
scoop; it also negatively affects aeration and requires more energy to freeze solidly.
o Maltodextrins also inhibit lactose and ice-crystal formation, and prevent the resultant graininess
and loss of quality.
(IX) Carriers and bulking
(because of low hygroscopicity & more water solubility)
o Mixing maltodextrins with gums and other hydrocolloids aids in dispersion, wetting without
clumping, and proper hydration.
o They are particularly valuable in the flavor industry, where they supply a matrix for spray-drying or
plating oil-based flavors or emulsions. Maltodextrins allow these liquids to be converted into a free-
flowing powder without changing or masking the flavor.
o In plating, oil-based ingredients are coated on the surface of the maltodextrin particle by using a
fine spray. This process can be used for flavors or to help distribute small quantities of oil in
products like coffee whiteners.
(X) Others
The film-forming characteristics of maltodextrins can improve the adherence of icings to
baked products, without increasing sweetness.
13. Side-effects of maltodextrins
Like all carbohydrates, maltodextrin contains 4 calories per gram. It is not as sweet
to the taste as sucrose (table sugar) or glucose because of its chemical structure, but
it does have high glycemic index. It’s easily digested and absorbed, and it will have
an effect on blood sugar
The plant source of maltodextrin in products is a pain point for people suffering
from celiac disease (ingestion of gluten leads to damage of small intestine)or gluten
intolerance. Wheat derived maltodextrin may contain traces of gluten. Other than
this issue, maltodextrin is considered a safe product.
Regulatory status of maltodextrins
1. Maltodextrins are all-natural food ingredients that have not been chemically
modified.
2. In Europe they are allowed for use in foods as food ingredients and are not classified
as food additives; therefore they have no E-number in European countries.
3. In the U.S., maltodextrins are approved as direct food substances.
4. In 1995, the FDA affirmed the GRAS status of maltodextrin derived from potato
starch as a direct human food ingredient.
5. It is allowed in India too.