Tuesday, 20 August 2013

Amines Part 8 - Non Essential Amines (Glutamic Acid)

Amino acids are the building blocks of proteins and muscle tissue.

When amino acids are ingested into the body, the standard 22 amino acids are used to synthesize proteins and other biomolecules. They are also used to oxidized to urea and carbon dioxide to be translated into energy.

Amino acids are divided into two groups: essential and non-essential.

Essential Amino Acids

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan
  9. Valine
Non-Essential Amino Acids

  1. Alanine
  2. Arginine
  3. Asparagine
  4. Aspartic acid
  5. Cysteine
  6. Glutamic acid
  7. Glutamine
  8. Glycine
  9. Ornithine
  10. Proline
  11. Selenocysteine
  12. Serine
  13. Tyrosine
Glutamic Acid

Glutamic acid's carboxylate anions and salts are known as glutamates.

Functions & Uses in Our Bodies

In neuroscience, glutamate is an important neurotransmitter that plays a key role in long-term potentiation and it is important for learning and memory. Glutamate is the most abundant excitatory neurotransmitter in the vertebrate nervous system.

Glutamate is also a key compound in cellular metabolism.

Excessive glutamate release in the body can cause excitotoxicity. (This means that the nerve cells are killed by excessive stimulation by our neurotransmitters.) It can cause stroke, amyotrophic lateral sclerosis (Lou Gehrig's disease), lathyrism, autism and even Alzheimer's disease.

The History of MSG

In 1866, a German chemist by the name of Karl Heinrich Leopold Ritthausen treated wheat gluten with sulphuric acid. He discovered glutamic acid. In 1907, Kikunae Ikeda, a Japanese researcher of the Tokyo Imperial University identified the brown crystals left behind after the evaporation of a large amount of kombu broth as glutamic acid.

The Professor tasted the crystals and discovered that the flavour highly resembled the taste in many foods especially in the seaweed. This flavour was named umami. He patented the method of mass producing the crystalline salt of glutamic acid, called monosodium glutamate (MSG).

Manufactured monosodium glutamate contains over 99.6% of the naturally predominant L-glutamate form. This form is higher than the naturally occurring L-glutamates found in fermented food. Ajinomoto uses selected strains of Micrococcus glutamicus bacteria to excrete glutamic acid. This is then separated and processed into sodium salt, which is monosodium glutamate (MSG).

Naturally Occurring Glutamates in Common Food (Free Glutamate Form)

  • Makombu (Kelp) - 3190 free glutamate per 100gm
  • Rausu Kombu (Kelp) - 2286 free glutamate per 100gm
  • Rishiri Kombu (Kelp) - 1985 f.g. per 100gm
  • Hidaka Kombu (Kelp) - 1344
  • Nori (Seaweed) - 1378
  • Marmite - 1960
  • Vegemite - 1431
  • Japanese Fish Sauce - 1383
  • Roquefort Cheese - 1280
  • Parmesan Cheese - 1200
  • Korean Soy Sauce - 1264
  • Chinese Soy Sauce - 926
  • Japanese Soy Sauce - 782
  • Oyster Sauce - 900
  • Green Tea - 668
  • Cured Ham - 337
  • Sardine - 280
  • Grape Juice - 258
  • Clam - 208
  • Peas - 200
  • Scallop - 159
  • Squid - 146
  • Tomatoes - 140
  • Oyster - 137
  • Corn - 130
  • Mussel - 105
  • Potatoes - 102
  • Duck - 69
  • Chicken - 44
  • Beef - 33
  • Pork - 23
  • Human Milk - 22
  • Salmon - 20
  • Cow Milk - 2

Naturally Occurring Glutamates in Common Food (Protein Glutamate Form)

  • Parmesan cheese - 9847 protein glutamate per 100mg
  • Peas - 5583 protein glutamate per 100mg
  • Tomatoes - 238 p.g. per 100mg
  • Corn - 1765
  • Cow milk - 819
  • Human milk - 229
  • Eggs - 1583
  • Chicken - 3309
  • Duck - 3636
  • Beef - 2846
  • Pork - 2325
  • Salmon - 2216

Hydrolyzed Protein

Hydrolyzed proteins are proteins treated enzymatically or acidic-ally from certain foods. These hydrolyzed proteins contain free amino acids such as glutamates at levels of 5% to 20%. An example would be yeast extract. (I've seen organic shops selling hydrolyzed soy protein which is used by vegetarians to stir fry their vegetarian dishes with.)

Hydrolyzed proteins are used in the same manner as MSG, which is to flavor/enhance the taste of dishes. It is also used in canned vegetables, soups and processed meats.

The MSG Syndrome

Many times, people who consume food with high levels of MSG complain of migraines, extreme drowsiness, mouth tingling sensations, flushing, palpitations or a hangover. Some even develope chest pains or difficulty breathing. Some call it the 'Chinese Food Syndrome' as Chinese restaurants are famous for using MSG to flavour practically everything!

Labeling MSG

Glutamate acid is labelled as E620.
Monosodium glutamate is labelled as E621. (This is a flavour enhancer)
Monopotassium glutamate is labelled as E622. (This is a flavour enhancer)
Calcium diglutamate is labelled as E623. (This is a flavour enhancer)
Monoammonium glutamate is labelled as E624. (This is a flavour enhancer)
Magnesium diglutamate is labelled as E625. (This is a flavour enhancer)

In the European Union, all these enhancers are not allowed to be added to milk, emulsified fat and oil, pasta, cocoa and chocolate products and fruit juice.

The FDA of US requires that monosodium glutamate be listed in the label's ingredient list. But as glutamate is also commonly found in food (from protein sources), these are not labelled. The term 'natural flavour' is also used by the food industry when using glutamic acid.

It is indeed misleading and deceptive when the 'No MSG' or 'MSG-Free' terms are used as there are other sources of free glutamates which can be used.

MSG Trivia

  1. Disodium glutamate (DSG) is a flavouring agent which is used to impart a meat-like flavour!
  2. During the Roman Empire times, glutamic acid was found in a sauce called garum. This was made from fermenting fish in saltwater. It was so famous and widely used that it was called the 'ketchup' of ancient Rome. 
  3. Fermented products such as soy sauce, steak sauce and Worcestershire sauce have high levels of glutamate which is similar to foods with added MSG!
  4. Auxigro (a chemical based growth enhancer for crops) is a plant growth preparation which contains 30% glutamic acid!
  5. In 2006, the largest producer of glutamic acid in the world was Fufeng Group (a China-based company). At the end of 2006, they were producing 300,00 tons of glutamic acid! 
  6. The Chinese demand for glutamic acid is 1.1 million tons per year. The world's demand is 1.7 million tons per year!
  7. Since 1998, MSG can no longer be termed under 'spices and flavourings'.
  8. MSG is known by MANY other names. They are:
  • Hydrolyzed Vegetable Protein
  • Textured Vegetable Protein
  • Autolyzed Yeast, Yeast Extract, Yeast Food or Yeast Nutrient
  • Glutamic Acid or Glutamate (E 620)
  • Monopotassium Glutamate (E 622)
  • Calcium Glutamate (E 623)
  • Monoammonium Glutamate (E 624)
  • Magnesium Glutamate (E 625)
  • Natrium Glutamate
  • Calcium Caseinate or Sodium Caseinate
  • Textured Protein
  • Soy Protein, Soy Protein Concentrate, Soy Protein Isolate
  • Whey Protein, Whey Protein Concentrate

To read more on glutamic acid, click on LINK.
To read more on glutamic acid the flavour, click on FLAVOUR.

No comments:

Post a Comment