If you eat cereal for breakfast, and perhaps a slice of toast, chances are you have consumed a quarter of your daily sodium allowance by the time you leave the house. Sodium isn't just in foods that seem like likely suspects - broths, or deli meats - it's abundantly present in most of the prepared foods we consume.

High sodium consumption is associated with health problems such as high blood pressure and heart disease, and the FDA has put out new voluntary guidelines for commercial food producers to cut down on sodium in their products.

The goal is to get individual sodium consumption down from 3,400 milligrams a day to 2,300. That's a decrease of about a third.

But - if you take salt out, what do you replace it with? That turns out to be a very complicated question, because salt plays a couple of roles in food beyond just being salty and delicious.

"Salt was put into commercial food because people like it. We love salt," said Gary Beauchamp of the Monell Chemical Senses Center in Philadelphia. He has done a lot of research on salt as a flavor.

"It plays a remarkable set of roles in food. It preserves it, and it makes other things taste better, it inhibits bitter tastes," he explained. "And because it is really, really cheap - virtually every food has some salt in it."

Trying to reduce it has given rise to a new line of products that are booming right now - sodium replacement systems.

Beauchamp says one potential option is potassium chloride. "It tastes salty, so could be a good salt substitute - but on the other hand, there's a reasonably high number of people who find that it tastes bad, they describe it as bitter, so it's not a perfect salt substitute."

Beauchamp said another approach has been something called umami.

"This is actually the sodium salt of glutamate, an amino acid, better known as MSG," he said. "With many foods, when you add MSG, you can reduce salt and retain the same level of taste with lower sodium."

Beauchamp says this option may not be very popular with American consumers, given MSG's bad reputation in this country. "But in moderation, there's nothing negative about eating MSG," he explained. MSG occurs naturally in lots of foods, such as tomatoes and cheese.

One of the companies working on ways to replace sodium is "Savoury Systems," a flavor company housed in an industrial park in Branchburg, New Jersey.

The hallways smell faintly of broth, and containers and boxes of beige powder await shipment to commercial food producers that make things like soups or broths.

"So in the flavor industry, we deal with the tongue," explained Savoury Systems' vice president, Kevin McDermitt. "So that's sweet, salty, sour, bitter, umami and oleogustus."

Kokumi describes compounds that enhance savory flavor - and oleogustus is the flavor that lipids or fats provide.

"It's very new, and it's not a pleasant taste, but in order to be classified as a taste, it needs to stimulate a G Protein which is the taste receptor cell on the tongue, when they find a new compound that's doing that, they classify it as a new taste," said McDermitt.

They use a baker's yeast protein to develop their flavors - the yeast goes through a natural breakdown process where the amino acids are simplified into smaller compounds. If you have ever heard of that strange Australian spread called Marmite - it's the same idea.

McDermitt says he always has a spoon in his pocket. "We taste broth all day every day," he said.
"It's a lot of dry-mixing, a different amino-acid profile is going to enhance different products in different ways. For example, right now they are trying to find a way to add flavor - but not salt - to a dry soup mix that you can make in a Keurig-style coffee maker.

McDermitt says the cost of these products are about 20 times higher than salt, but business is good anyway, since many food producers are trying to find ways to reduce sodium in a way that doesn't have consumers reaching for their salt shaker.