This document discusses flavor potentiators, which are substances that enhance or modify the flavor of food without contributing much flavor of their own. It describes several naturally occurring and synthetic flavor potentiators, including monosodium glutamate (MSG), guanosine 5'-monophosphate (GMP), inosine 5'-monophosphate (IMP), maltol, and ethyl maltol. It also discusses their sources, chemical structures, production methods, applications in the food industry, and postulated modes of action in potentiation flavor.

1. FLAVOR
POTENTIATORS
PALLAVI DHOTRA
ROLL No. 06
M.Sc 4th SEMESTER
FOOD SCIENCE & TECHNOLOGY

2. FLAVOR
Flavor is the term used to describe the sensory impression of
food, which is a combined effect of taste, odour and trigeminal
impressions in the oral and nasal cavities.
Flavor is one of the three main sensory properties which is
decisive in the selection, acceptance and ingestion of food.
Flavor compounds arise mainly from normal biosynthetic
processes of animals and plant metabolism.
These compounds exist as precursors and develop
characteristic flavoring effects during processing or cooking.

3. Odour
Trigeminal
Taste impression
Flavor

4. Apart from the food components that trigger
the taste, odor and trigeminal impressions,
there are some components that are capable
of supplementing, enhancing or modifying the
flavor of food.
Although they have little or no flavor of their
own at typical usage levels.
These substances are commonly known as
flavor potentiators.

5. FLAVOR POTENTIATORS
Flavor potentiators are chemicals which
themselves have little or no odor or taste.
But yet intensify or enhance the flavour of food
at usage levels.
The effect of flavor potentiators is accompanied
by changes in the mouth feel of the product
thereby inducing a sensation of fullness or
satisfaction.

6. NATURALLY OCCURING FLAVOR
POTENTIATORS IN FOOD
FOODS AMOUNT(%)
MSG IMP GMP
Beef 0.013-0.088 0.163 0.002
Cheese 1.333 NR NR
Cod 0.011 0.043 NR
Scallop 0.012-0.024 0.000 0.000
Orange juice 0.015 NR 0.00002
Nectarine 1.219 NR NR
Corn 0.102 NR NR
Mushroom 0.177-0.635 NR 0.56
Potato 0.254 NR 0.001
Tomato 0.177 NR 0.001
Tea, green 0.264-0.640 NR NR

7. COMPOUNDS USED AS FLAVOUR
POTENTIATORS IN FOOD INDUSTRY
Monosodium glutamate
Monopotassium glutamate
Monoammonium glutamate
Guanosine 5´-monophosphate
Inosine 5´-monophosphate
Maltol
Ethyl maltol
Dioctyl sodium sulfocuccinate
N, N´ -di-o-tolylethylenediamine

8. MONOSODIUM GLUTAMATE
Monosodium glutamate(MSG) is a neutral salt of L-
glutamic acid which occurs naturally as one of the amino
acids building blocks of food proteins.
MSG was first isolated in a laboratory by a Japanese
scientist in 1908 and subsequently patented by
Ajinomoto Corporation of Japan in 1909.
It heightens and intensifies natural flavor without adding
significant flavor of its own.
MSG draws out hidden flavor attributes and tends to
enhance weaker flavor character.

9. There is practically no aroma associated with
MSG.
The functioning of MSG is pH dependent i.e. it
must exist in the food as monosodium salt.
Therefore its use is limited to those foods that
are in the pH range of 5.0-8.0.
It has the HS code 29224220 and the E number
E621.

10. CHEMICAL STRUCTURE OF
GLUTAMIC ACID & MSG

11. CHARACTERISTICS OF MSG
Coarsely crystalline substance.
Molecular formula:C5H8NNaO4
5% solution of MSG has pH: 6.7-7.2
Melting point: 232° C
Solubility at 25°C: 74.2g/100ml of water
at 60° 101.4g/100ml of water
C:
Sodium content: 12.3%
Bulk density: 11.0 to 13.8g/ cu in.
Calories: 2.88 cal/ g

12. PRODUCTION OF COMMERCIAL
MSG
The vast majority of MSG is produced through bacterial
fermentation process.
Bacteria of genera Corynebacterium glutamicum and Brevibacterium
are widely employed.
Starch, cane and beet molasses are used as carbon source.
Ammonium chloride, ammonium sulfate and urea are used as
nitrogen source.
Yields of 100 g/litre can be prepared in this way.

13. TOXICITY OF MSG
MSG has low toxicity from an acute stand point.
Injection of MSG has been shown to induce rapid
degeneration of neurons in the inner layers of retina.
Degeneration of nerve cells in brain due to
subcutaneous injections of large doses of MSG have
also been observed in various species.

14. HEALTH CONCERNS
MSG is called an “excitotoxin” by leading neuroscientists because of
its degenerative and deadly effects on the brain and central nervous
system.
Monosodium glutamate has been associated with the Chinese
Restaurant syndrome (CRS). The symptoms include:-
Racing pulse
Burning sensation in the back of neck
Facial pressure
Chest pain
Sweating
Headaches
Hypertension
Weakness & thirst.

15. Studies have found that typical CRS symptoms could not
be included in 99% healthy males given 5g of MSG.
The symptoms of CRS are shown by highly sensitive
people.
Children, Unborn & Elderly are most vulnerable.

16. 5´- NUCLEOTIDES
5´- Nucleotides are the building blocks of
ribonucleic acid (RNA).
It consists of a purine base, ribose and
phosphoric acid linked to 5´- position of ribose.
The most commonly used 5´- nucleotides as
flavor potentiators are:-
1. Guanosine 5´-monophosphate (GMP)
2. Inosine 5´-monophosphate (IMP)

17. GUANOSINE 5´-MONOPHOSPHATE
It is an ester of phosphoric acid with the nucleotide
Guanosine and ribose sugar.
Guanosine monophosphate is commercially available in
the form of its salt “disodium guanylate”.
The E number for disodium guanylate is E627.
Molecular formula of Guanosine 5´-monophosphate is
C10H14N5O8P.

18. CHEMICAL STRUCTURE OF
GUANOSINE 5´-MONOPHOSPHATE

19. INOSINE 5´-MONOPHOSPHATE
Inosine 5´-monophosphate is commercially
available in the form of its salt “disodium
inosinate”.
The E number for disodium inosinate is E 631
Molecular formula of Inosine 5´-monophosphate
is C10H11N4Na2O8P.

20. CHEMICAL STRUCTURE OF
INOSINE 5´-MONOPHOSPHATE

21. COMMERCIAL PRODUCTION
OF 5´- NUCLEOTIDES
Degradation of RNA by 5´-phospho-diesterase.
Fermentation to produce nucleotides followed by
chemical phosphorylation to produce the 5´-nucleotides.
Direct fermentation to yield 5´-nucleotides.
Chemical decomposition of RNA to produce nucleotides
followed by chemical phosphorylation to produce the 5´-
nucleotides.

22. TOXICITY OF 5´-NUCLEOTIDES
Administration of lethal doses of 5´-nucleotides causes
temporary depression, clonic convulsions and dyspnea.
Dietary intake of 2% of total diet or less 5´-nucleotides
have not been found to cause observable effects in any
species of animals in long term feeding studies.
Studies suggest that there are no significant toxicity
concerns in humans for 5´-nucleotides in the diet.

23. MALTOL
Maltol occurs naturally in many plants and is formed in
roasted malt, baked goods etc.
It was introduced as a flavor potentiator in 1942.
The E number for maltol is E636.
Toxicity of maltol is not known.
It is commercially produced by the fermentation of
soyabean proteins or glutinin.

24. CHEMICAL STRUCTURE OF
MALTOL

25. ETHYL MALTOL
Ethyl maltol is derived from maltol (E636) by
replacing one methyl group with an ethyl group.
Ethyl maltol is 4 to 6 times stronger than maltol.
The E number of ethyl maltol is E637.
It has no known effect.

26. CHEMICAL STRUCTURE OF ETHYL
MALTOL

27. OTHERS
Dioctyl Sodium Sulfosuccinate is used as a
flavor potentiator in canned milk where it
improves and maintains the flavor and
freshness of the sterilized milk during
storage.
N, N´ -di-o-tolylethylenediamine is also used
as a flavor potentiator in dairy industry.

28. MODE OF ACTION
The means by which flavor potentiators
enhance flavor is poorly understood.
However some indirect evidence has been
gathered which supports some basic
theories, which will be discussed briefly.

29. Strong (1968) suggested that flavor potentiators may
function by either increasing the amount of flavor
compounds actually arriving at the olfactory cells or by
increasing the magnitude of the signal generated by the
flavor compound
Schinneller et al. (1972) suggested that 5´-nucleotides
unmasked certain flavor receptor sites, hence making
more receptor sites available for reaction with the
stimulus.
Saint-Hilaire and Solms (1973) proposed that flavor
potentiators interacted with collagen like proteins at the
receptor sites. This would create an improved
environment for taste receptor stimulation.

30. APPLICATIONS OF FLAVOR
POTENTIATORS
Flavor potentiators find wide usage in food
products.
Vegetables, sauces, meats and other savory
foods constitute the major food application.
The ability of flavor potentiators to impart
viscosity, drying and fullness is a useful property
in soups, gravies, sauces and juices.

31. USAGE LEVELS OF MSG AND 5´-NUCLEOTIDES IN
VARIOUS FOOD PRODUCTS
FOODS USAGE LEVELS %
MSG% 5´NUCLEOTIDES
(50/50 IMP &GMP) %
Dehydrated soups 5-8 0.10-0.20
Canned soups 0.12-0.18 0.0022-0.0033
Canned asparagus 0.08-0.16 0.003-0.004
Canned fish 0.10-0.30 0.003-0.006
Sausages 0.30-0.50 0.002-0.014
Sauces 1.0-1.2 0.010-0.030
Ketchup 0.15-0.30 0.010-0.020
Mayonnaise 0.40-0.60 0.012-0.018
Snacks 0.10-0.50 0.003-0.007
Vegetable juices 0.10-0.15 0.005-0.010
Processed cheese 0.40-0.50 0.005-0.010

32. USAGE LEVELS OF MALTOL AND ETHYL
MALTOL IN VARIOUS FOOD PRODUCTS
FOODS USAGE LEVELS (ppm)
MALTOL ETHYL MALTOL
Baked goods 75-250 25-150
Beverages 2-250 1-100
Candies 3-300 1-100
Chocolate foods 30-200 5-40
Dairy products 10-150 5-50
Desserts 30-150 10-75
Jams 40-200 15-60

33. REFRENCES
Ashurst. P. R.(1999), Food flavourings, 3rd edition, Aspen publications, Pp
367-394.
Heath. H.B.(1981), Source book of flavors, 1st edition, Springer publications,
Pp 323-325.
Heath. H.B., Reineccius. G.(1999), Flavor chemistry and technology, 2nd
edition, CBS publishers, Pp 318-329.
Reineccius. G.(1994), Source book of flavors, 2nd edition, Aspen
publications, Pp 642-647.
http://www.crcnetbase.com/doi/abs/10.1201/9780203485347.ch11
http://www.msgtruth.org/NEWUNIFIEDTHEORY.pdf

34. http://www.msgtruth.org/states.htm
http://www.ajinomoto.com/features/aji-no-moto/en/truth/qa.html
http://www.msgtruth.org/body.htm
http://www.healthboards.com/boards/archive/index.php/t-516325.html
http://www.ehow.com/about_5432119_health-risks-monosodium-
glutamate.html
http://chemistry.about.com/od/imagesclipartstructures/ig/Amino-Acid-
Structures/Glutamic-Acid.htm