The Process of Making Monosodium Glutamate (MSG)

What is MSG?

MSG (monosodium glutamate) or mono natrium glutamate is a sodium salt of the glutamate acid .

Glutamate acid is an amino acid that is one of the important component of protein that our bodies need.

Glutamate acid naturally found in our food everyday, such as meat, fish, eggs, milk, cheese, tomatoes and various vegetables.

MSG is used as a food additive with umami taste and is commonly marketed as a flavour enhancer.

History of MSG Production

MSG was discovered in 1908 by Dr. Kikunae Ikeda as a basic taste substance of kelp that is a traditional seasoning in Japan.

Originally, MSG was manufactured by extraction from acid hydrolysate of plant protein.

In the late 1950s, fermentation technology was established and used for the commercial production of MSG. This was the beginning of modern amino acid production.

Since then, fermentation technologies for various amino acids have been established. Production of L-Gln by fermentation started in the late 1960s.

Manufacturing process

The manufacturing methods of amino acids are categorized as:

extraction from hydrolysates of animal or plant protein,

chemical synthesis,

fermentation, and

enzymic.

Production of MSG by fermentation as other amino acids production. It is more cheaper and simplest.

The manufacturing process of an amino acid by fermentation comprises fermentation, crude isolation and purification processes.

Raw Material of MSG

In Indonesia, MSGcomes from sugar cane molasses, which is the result of sugar cane milling process as a secondary product.

Chemical and Physical Properties of molasses:

Form : Liquid

Color : Black

Density : 1.47 g/ml

Vicosity : 4. 323 Cp

Specific Heat : 0.5 Kcal/Kg °C

Component :

Sugar : 62 %

Water : 20 %

Non Sugar : 18 %

Other materials

Urea, needed as bacterial nutrient source

Molecular formula : (NH2)2CO

Molecular Weight : 60.06

Form : White Powder

Solubility : easily dissolved in water

NaOH

Sodium hydroxide use in the neutralizing process and the forming process of MSG, which reacts with the Glutamic Acid.

Physical and Chemical Properties :

Molecule Mass : 40

Color : White

Solubility : easily dissolved in water

How to Make MSG ?

MSG is normally obtained by the fermentation of carbohydrates, using bacterial or yeast species from genera such as Brevibacterium, Arthobacter, Microbacterium, and Corynebacterium.

Yield of 100 g/litre can be prepared in this way.

From 1909 to the mid 1960’s, MSG way prepared by hydrolysis of wheat gluten, which is roughly 25 % glutamic acid. Glutamic Acid is one of the least soluble amino acids, which facilities its purification.

Production of Monosodium Glutamate by Fermentation

Process Diagram of MSG

Fermentation

Raw material : molasses as a source of carbon converted into glutamate acid (GA)
fermentation process : microbes, changes sugar into acid glutamate.
The fermentation process is conducted in the fermentor/bioreactor with the set temperature and pH optimum as well as additional supporting materials such as urea as a source of carbon, salt and organic growth factors as nutrition.

Bioreaktor

Instrumentation and control processing make sure that:
Temperature : 320C oxygen consumption
pH : 7.3 CO2 production
Dissolved oxygen supply cells

Separation Glutamate Acid (GA)

The fermentation last 35-45 hours and then the fermentation is centrifuged to remove biomass and the other solid organic materials.
Glutamate acid is in solution with the separated parent resin, where the acid glutamate will be detained in the resin.

To get MSG, resin which already contain glutamate acids is regenerate with NaOH solution, where the solvent has been used to regenerate resin, already contain MSG.
Then to get MSG becomes white, this decolorized with active carbon solution. The establishment of the MSG can be seen from the chemical reaction following :

FormationPhase of MSG Crystals

Main solution that has been decolorizing contain MSG in the low concentration, to increase the concentration of MSG in the solution, it is necessary to evaporate it.
To get MSG crystal done with decreasing the temperature of the basic solution by crystallization process.

Characteristic Product

Monosodium Glutamate (MSG)
Molecular Formula : HOOCCH2CH2CH
(NH2)COONa.H2O
Molecular Weight : 187.13
Form : Crystal White
Solubility : Easy soluble in water
PH : 7.0
Melting Point : 232 oC