Strolling through the annual meeting of the Institute of Food Technologists the other day, I saw several signs offering to solve an urgent problem American bakers face. The signs advertised "egg replacement."

It's a hot business right now, because eggs are in critically short supply. Millions of egg-laying hens died this past spring as a result of avian flu, and egg prices have doubled. Liquid egg products, which the baking industry uses, are especially hard to find.

"All of a sudden, [baking] companies were being told they're not going to have supply. Their phones are ringing, and then our phones started ringing," says Nicole Rees, a manager of business development for Glanbia Nutritionals.

Glanbia is one of a dozen or so companies selling ingredients that can take the place of eggs. The difficult part, Rees explains, is duplicating all the different things that an egg can do. The yolk delivers moisture and richness. The egg white creates the structure in a sponge cake. And that's before you even get to flavor.

"It's so primal to baking and our food system, so to remove it requires a lot of work behind the scenes that no one sees," says Rees.

The easy part, she says, is replacing the yolk. You need an emulsifier — something that helps oils mix with other ingredients. Glanbia uses a gumlike substance extracted from flaxseed. "It can behave like guar gum, or xanthan gum. Or some of the emulsifiers that you see out on the market: sodium stearoyl lactylate; GMS-90," Rees says.

But food companies would much rather put "flax" on their list of ingredients, instead of sodium stearoyl lactylate. Shoppers want what the industry calls "clean labels" these days.

The hard part of egg replacement, Rees says, is coming up with a substitute for the protein in egg whites, especially in foods like angel food cake, where it's really important.

For this, some companies use protein from the whey that's a byproduct of making cheese. Some use bean protein; others, protein from algae.

Rees says that these products can get close to egg white, but they're never a perfect match. "Can we replace 100 percent of eggs in an angel food cake, the egg white? And make an angel food cake? Is it identical? No. Is it a cake? Yes," she says.

Then there's the final piece: the flavor.

For that, companies turn to flavor chemists like Michael Walsh, who works for Glanbia's flavor group, called Flavor Artistry.

According to Walsh, flavor chemistry is, in fact, art. "If you look at it like a painter, a painter has a palette of colors, and he's going to blend them together. Or a musician has a bunch of different notes. Flavor is very much the same. Each flavor component is a note," he says.

There's a symphony of flavor notes in each food. Some come from the egg itself; others are created in the cooking process. Walsh's job is to use the notes at his disposal — hundreds of flavor extracts, mostly distilled from products of nature — to re-create the smell and flavor of the original.

He comes up with an egg flavor formula, usually including anywhere from 10 to 20 different flavor extracts. The formula may be a bit different, depending on whether it's for a sponge cake or a custard.

Glanbia will add this flavor combination to the rest of the egg replacement product, which contains the flax and the whey protein.

Together, they're ready for their starring role in some commercial bakery, appearing as a collective understudy for the simple egg.

Copyright 2021 NPR. To see more, visit https://www.npr.org.