Monosodium Glutamate - I want my umami!

Figure 1. Food containing monosodium glutamate.

Umami is the meaty, savoury flavor found in foods. The umami flavor can only be achieved by foods containing glutamates¹. High levels of natural glutamates are found in things like tomatoes and mushrooms^1,2. Monosodium glutamate, more commonly known as MSG³, is the other major source of glutamates in foods.

Figure 2. Prepackaged MSG

available for purchase.

Monosodium glutamate is a white crystalline powder, very similar in appearance to table salt¹. MSG is used as a food additive similar to the way we use salt in foods¹. In some countries you might even find a monosodium glutamate shaker on the table! You can go to some specialty Asian stores and buy packages of MSG just the same as you would go to the store to buy salt. MSG is most commonly used in Asian cooking, and is usually added during the cooking process to enhance the flavors already present in the food and add the umami aspect to the dish¹.

Figure 3. MSG crystals.

MSG was discovered in 1908 by a Japanese professor who was able to extract the savory flavor from the seaweed broth in his soup². Although seaweed broth is a great source of glutamates which can be used to produce MSG, bacteria are now used to biosynthetically produce this compound². After isolation, the MSG is crystallized and shipped out to food establishments all over the world.

 
Most people have only heard of MSG because of the big signs in Chinese restaurants claiming that their food is MSG free. These signs exist because MSG has gotten a bad rap in popular culture. Some individuals experience negative symptoms, ranging from headache to diarrhea, after eating Chinese food⁴. Monosodium glutamate is often the scapegoat. Despite the lack of scientific evidence⁵, MSG continues to be blamed for the whole host of symptoms resulting from eating Chinese food⁴. The small amount of MSG found in foods is not harmful⁶ and should not be avoided, especially because it makes food taste better!

References:

¹The Facts on Monosodium Glutamate, 2002. European Food Information Council. http://www.eufic.org/article/en/artid/monosodium-glutamate/ (accessed March 7, 2016)

²Questions and Answers on Monosodium glutamate (MSG), 2012. U.S. Food and Drug Administration. http://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm328728.htm (accessed March 3, 2016)

³Monosodium Glutamate. In Chemical Compound; N. Schlager, J. Weisblatt, D. E. Newton, Eds.; UXL: Detroit, 2006; Vol.  2, pp. 465-468

⁴Chinese restaurant syndrome. In The Royal Society of medicine health encyclopedia [Online]; Bloomsbury, Posted Online 2000. http://search.credoreference.com/content/entry/rsmhealth/chinese_restaurant_syndrome/0 (accessed March 7, 2016).

⁵Walker, R; Lupien, JR; The safety evaluation of monosodium glutamate. J. Nutr. [Online] 2000, Vol. 130, 1049S-1052S. PubMed. http://www.ncbi.nlm.nih.gov/pubmed/10736380 (accessed March 7, 2016)

⁶Monosodium glutamate [NF]. http://chem.sis.nlm.nih.gov/chemidplus/rn/6106-04-3 (accessed March 2, 2016)

Figure 1: pelican. Subgum chow mein. https://commons.wikimedia.org/wiki/File:Subgum_chow_mein.jpg (accessed March 7, 2016)

Figure 2: Dynomat. Ajinomoto msg. https://commons.wikimedia.org/wiki/File:Ajinomoto_msg.jpg (accessed March 8, 2016)

Figure 3: Miansari66. China Namak. https://commons.wikimedia.org/wiki/File:China_Namak.JPG (accessed March 3, 2016).