Many people are unaware that “glutamate” is present in all protein-rich foods in the form of the amino acid glutamic acid. Glutamic acid also plays such an important role in cooking that most traditional dishes cannot do without it. The EURASYP newsletter spoke about this to the expert Prof. Dr. Thomas Vilgis, physician at the Max Planck Institute for Polymer Research in Mainz, author of numerous books on the science of cooking, and chairman of the German Culinary Academy (Deutsche Akademie für Kulinaristik).
Professor Vilgis, what role do glutamate-rich foods play in cooking?
Glutamate-rich foods are ultimately the essential thing in all cuisines and in all cultures. They rank among the basic ingredients and give the basic umami taste to many meals and preparations. The term comes from Japanese and can be translated roughly as “delicious” or “savoury, meaty taste”. Hardly any sauces, spicy roasts or aromatic vegetable ragouts can do without ingredients such as tomatoes, tomato puree, onions, mushrooms etc. – and they are all rich in glutamic acid. We humans are all hardwired for “sweet” and “umami” flavours from infancy. The other flavours – “sour”, “salty” and “bitter” – on the other hand, must be learned first.
As a scientist who is passionate about foods, how would you assess condimental ingredients such as soy sauce and yeast extract?
Soy sauce and yeast extract are excellent seasonings that appeal to the receptors for the basic umami taste. They therefore have an important culinary function, similar to traditional Japanese miso pastes or soups. Every dish depends on its variety of flavours. Every top chef knows that the overall taste impression of a dish can be enhanced by adding a pinch of sugar or salt, or a dash of lemon juice or vinegar, even if these ingredients are not prominent features of the dish. However, they modulate the taste. Even a dash of soy sauce or a small amount of yeast extract will trigger the umami receptors in quite striking and diverse ways. A little drop of soy sauce or a spoon tip of yeast extract can do wonders for the taste of a light summer salad that is rich in vegetables. This is especially true of vegetarian or vegan food dishes. Their cooking times are often shorter and the glutamic acid is therefore released from the proteins in smaller amounts. Here, condiments such as soy sauce, yeast extract or tomato concentrate provide an intense umami flavour.
How would you explain the role of glutamic acid to someone who is interested in cooking but doesn’t have any thorough background knowledge of food?
First and foremost, the amino acid glutamic acid is present multiple times in all proteins, so in all long chain molecules composed of various amino acids. Glutamic acid is present in large amounts especially in those proteins contained in yeast, wheat, soy beans and many legumes, but also in meat in the form of muscle proteins. Bean and meat stews, goulash, pot roasts and sauce bases therefore develop a deep, succulent flavour after long cooking. Some proteins break down into fragments and amino acids. In this case, glutamic acid becomes free and only then can it release the umami taste on the tongue. Incidentally, protein fragments from two or three amino acids containing glutamic acid can cause a strong feeling of a “full mouth”, similar to the sensation when enjoying a cheese variety that has matured over a long time. There is also a term for this in Japanese: kokumi.