The Science of Umami: Understanding Natural Glutamate
MSG, or monosodium glutamate, is the sodium salt of glutamic acid, an amino acid found in virtually all proteins. While many people associate MSG with the white crystal powder added to certain dishes, it is important to recognize that the body processes naturally occurring glutamate and added MSG in the same way. The distinct savory taste derived from free glutamate is known as 'umami,' considered the fifth basic taste along with sweet, sour, salty, and bitter. The key to experiencing this flavor lies in the concentration of free glutamates—those not bound within a protein structure.
Certain culinary processes, such as aging, fermenting, and cooking, break down proteins and increase the amount of free glutamate, intensifying the umami taste. For example, a ripe tomato will have higher levels of free glutamate than an unripe one, and a cured ham will have more than fresh pork.
Natural Umami Sources from Fermentation and Aging
Fermentation and aging are ancient techniques that naturally amplify glutamate content in foods, leading to complex and rich flavors. These processes, often involving yeast or bacteria, break down protein molecules and release free glutamates.
Aged Cheese: Parmesan is a prime example, with its high concentration of glutamate resulting from the long aging process. Other aged cheeses, like Roquefort and mature cheddar, are also excellent sources.
Fermented Soy Products: Soy is naturally rich in protein, and fermenting it concentrates the free glutamates. This is why soy sauce, miso, and tempeh are renowned for their umami depth.
Yeast Extract: Products like Marmite and Vegemite are concentrated yeast extracts. During their production, the yeast cell's proteins are broken down, creating a high level of free glutamates that provide their distinctive, meaty flavor.
Cured and Processed Meats: Curing meat, as with ham and bacon, allows enzymes to break down proteins, releasing significant amounts of glutamate. Even fresh meat and seafood contain natural glutamate, which is why a perfectly cooked steak or scallop has a savory, delicious flavor.
Umami from the Garden: Vegetables and Fungi
Many common plant-based foods are rich in natural glutamate, particularly as they ripen or are dried.
- Tomatoes: Ripe tomatoes are a cornerstone of umami in Western cooking, with levels of glutamate increasing significantly as they mature. Dried or concentrated tomatoes, like sun-dried tomatoes or tomato paste, offer an even more potent dose of umami.
- Mushrooms: Mushrooms, especially dried shiitake, are exceptional sources of free glutamate. Cooking mushrooms also helps to release and intensify their savory, earthy flavor.
- Seaweed: The original source of MSG's discovery, kelp (kombu) and other seaweeds are naturally high in glutamate and are a staple in many Asian cuisines for creating umami-rich broths.
Reading Ingredient Labels for Natural Glutamate
While added MSG must be labeled as such, several ingredients naturally contain high levels of glutamate and are used as flavor enhancers. Food labels don't need to specify that these ingredients naturally contain glutamate, so it helps to know what to look for.
Common ingredients that signal the presence of natural glutamate:
- Hydrolyzed Vegetable Protein (HVP)
- Hydrolyzed Yeast
- Yeast Extract
- Soy Extracts
- Protein Isolate
- Fermented Soy Sauce
Comparison of Glutamate Content in Natural Foods
This table illustrates the free glutamate content in various natural food sources. Note that these are average values and can vary based on ripeness, processing, and other factors.
| Food Item (per 100g) | Free Glutamate (mg) | Processing/Condition | Key Umami Contribution |
|---|---|---|---|
| Parmesan Cheese | 1200–1680 | Aged/Matured | High concentration from aging |
| Soy Sauce | 400–1700 | Fermented | Concentrate from fermented soybeans |
| Dried Shiitake Mushrooms | 1060 | Dried | Drying concentrates natural glutamate |
| Cured Ham | 337 | Cured | Curing releases free glutamate |
| Ripe Tomatoes | 150–250 | Ripe | Ripening increases glutamate levels |
| Walnuts | 658 | N/A | Naturally high protein content |
Conclusion: Savoring Natural Umami
MSG, in its natural form as glutamate, is an integral part of countless nutritious and delicious whole foods. By appreciating the presence of natural glutamate in ingredients like aged cheeses, ripe tomatoes, mushrooms, and cured meats, we can make more informed dietary choices and enjoy richer, more satisfying meals. These foods not only provide great flavor but also contribute essential amino acids to our bodies. Instead of viewing MSG solely as an additive, recognizing its natural origins can change our perspective on cooking and the ingredients we use. For further reading, a wealth of information is available from the Umami Information Center.
