Twinkie, Deconstructed (13 page)

Lecithin, discovered in 1805, when French scientist Maurice Gobley identified it in egg yolks, is found in trace amounts in almost all living cells. Lecithin makes up an astonishing 30 percent of the yolk in an egg, as opposed to 1.5 to 3 percent in soybeans. That must be why Monsieur Gobley named it after the Greek word for “egg yolk,”
lekithos
.

It is not easy to extract lecithin from egg yolks, but for years no one knew where else it could be found. And it was likely worth a search, considering the amazing capacity for egg yolks to emulsify, best demonstrated by the ability of one yolk to absorb more than a cup of oil to make mayonnaise. Cooking guru Shirley O. Corriher calls egg yolk the “superemulsifier.” Whip up some mayo in your kitchen, if you haven’t done so before, and you’ll no doubt be impressed.

Soybean oil processing became popular in Europe after 1908, during which refiners found themselves with a stinky, residual waste sludge. In 1920, German food scientists, examining that waste for hidden assets, identified it as lecithin. ADM started refining it in Chicago, under German license, in 1934. By 1939, the Germans had come up with more than a thousand new uses for it. Considering that it’s separated with only water and force, and that it is still “all-natural,” it’s a darn good deal.

Lecithin’s primary job in Twinkies, as well as in most foods, is to emulsify, or tie water and fat together, on a molecular level. Each molecule has two tails, one of which targets fat, the other of which gloms on to water. Because of this unique ability, and because it has been around for so long, it’s practically ubiquitous in processed foods. Lecithin is also famous for being one of the first emulsifiers to be used in baked goods, starting in the 1920s. One of the most widely used, naturally occurring emulsifiers in the world, lecithin is often paired (as it is in Twinkies) with its synthetic counterparts, mono and diglycerides and the more modern polysorbate 60, in order to emulsify a wider range of water and oil mixtures.

In addition, lecithin does a lot more than simply blend fat and water. In the annals of Great Accomplishments, lecithin serves a purpose for which I’d bet many of us are especially grateful: it makes chocolate smooth and prevents “bloom” (fat) on the surface. Look at almost any chocolate bar label, even the very best, and there it is. As if that weren’t enough to make it our favorite ingredient on the Twinkie label, it also binds and smooths out ingredients in ice cream, chewing gum, and peanut butter. It even helps keep margarine from spattering when heated. Lecithin makes batters easier to mix and cuts down on lumping. It whips toppings, whitens coffee, smooths out processed cheese, fills out ice cream cones and waffle mixes, and even helps disperse dry beverage mixes. In bread, it’s essential to just about everything: distribution of shortening, dough handling, moisture retention, texture, volume, and shelf life (“anti-staling”—it reduces crumb firming). But its greatest contribution is when it functions as an egg yolk replacement and “egg yolk sparing agent” (as it’s known). Certainly, that is its most distinctive function in Twinkies—another way to cut down on ingredients that might spoil. Also, like egg yolks, it invites the gentle, uniform browning of Twinkies’ bottom (the top, in reality), and keeps the texture of the crumb soft yet strong enough to stay together.

The fact that it comes from a vegetarian source is an added bonus, and why it’s listed on the Twinkie ingredient label as “soy lecithin”—to distinguish it from “chicken” lecithin extracted from eggs. Lecithin can be included on the label of an “all-natural” food product, which accounts for a lot of its popularity, and almost all the major producers make it certified kosher. Though it functions primarily as an emulsifier, it is also called a wetting agent, an “instantizer” (helping things dissolve), a release agent (in PAM
^®
cooking spray), a viscosity modifier, a mixing aid, an antidusting agent, and more. It is high in polyunsaturates and is cholesterol-free and totally safe to eat.

Lecithin is big in industry, too. It’s an excellent pigment dispersant in paints, water-based printing inks, plastic, and even videotapes (it’s known as a surfactant, not an emulsifier, in the paint and coating industry). It softens the skin when blended into cosmetics, helps oil penetrate leather, and plays a role in paper coating, waxes, caulks, adhesives, lubricants, and explosives. All in all, a rather impressive, wonderful range of uses for a former waste product.

These days, scientists are looking for ways to make new lecithin products by modifying it genetically and enzymatically, and by using filtration, compounding, and other specialized techniques. But it seems satisfying enough (for our purposes, at least) that it is used in Twinkies.

As good as lecithin is, it pales by comparison in usefulness to the most important soy product of all, partially hydrogenated vegetable shortening, the next item made in this production line.

T
HE
F
RENCH
C
ONNECTION

It’s a long way to shortening, and a long way from France. The newly degummed oil leaving the lecithin station is still crude. Before it can become shortening, even now that it is lightened of its lecithin, it must be leavened, meaning refined, bleached, and deodorized.

We consumers like our oils clear, so the crude oil, after being cleansed with a hit of sodium hydroxide (caustic soda), is mixed with a claylike product that removes chlorophyll and the remaining carotenoid pigments that color it yellow. We also like our oils tasteless and deodorized, so next the oil is heated to about 500°F for up to an hour under virtually a vacuum—vaporizing any remaining free fatty acids, off-flavors, and moisture. Blasts of steam remove any residual leftovers. Finally, the oil achieves the light, bland color and consistency that we like to use at home—for salad dressings, baking, and frying. Beyond food, some will end up in an amazing array of industrial goods, including (after more processing, of course) alkyd paints—the current version of oil paint—rubber, caulk, adhesive tape, leather softeners, and, surprisingly, diesel fuel. And all of it stems from a simple bean.

It takes about six hours to turn beans into salad oil, which is an ambitious feat. But it’s at this point in the process where oil refining gets really interesting. Plain vegetable oil, despite being 100 percent fat, is a pourable liquid. What the bakeries seek is a soft solid that resembles butter or lard. The magic happens in turning a liquid into a solid, which apparently isn’t as hard as it sounds, so long as you have the knowledge and the equipment to force some hydrogen molecules into it. Hydrogenation creates a semisolid oil that behaves like butter
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but costs a whole lot less, contains as much as 50 percent less saturated fat, and is so stable that it doesn’t require refrigeration for up to a year. That’s a shelf life. And that’s Crisco
^®
.

An oil to which only
some
hydrogen has been added is called partially hydrogenated. Oils that are even more lightly hydrogenated are liquid shortenings; an oil with as much hydrogen as chemically possible added is called “fully hydrogenated” and is as solid as candle wax (you can actually buy candles made of vegetable oil, called stearin, or “soy” candles, which burn more cleanly than traditional candle wax, which is mostly made of paraffin, a petroleum product). All it takes is high heat, high pressure, a maze of steel towers, and a dose of hydrogen.

In a hydrogenation facility, upward of 60,000 pounds of the newly refined oil is pumped into a pipe-covered, two- to three-story-high, pressurized, vertical tank called a converter, where it is heated to over 400°F while hydrogen gas is pumped in under 150 pounds per square inch (psi) pressure, along with a catalyst in the form of a bunch of little metal (nickel) balls that look like BBs. The whole operation is so hot that it has to be located outside the plant building, and I can only observe from a safe distance. The mixture is stirred by several large propellers on a central shaft, which means the converters are really nothing more than giant blenders. The oil becomes hydrogenated in this way, but it’s not quite shortening yet.

Depending on how solid the desired outcome, and depending on the beans themselves (affected as they are by the growing season’s rainfall, sun, and average temperatures), the chefs (aka engineers) in the control room cook the mixture for anywhere from fifteen minutes to two hours. They can make it pourable, brushable, spreadable, or hard as soap—each batch is made to order in this giant, industrial café.

Shortening as we know it is not made in one tank in one batch—that would be too simple—but is a blend of partially and sometimes fully hydrogenated oils and up to 80 percent unhydrogenated, liquid oil. The solid, edible, hydrogenated oil forms a honeycomb framework into which the liquid oil seeps, just like a honeycomb holds honey. As it happens, hydrogenated soybean and canola oils boast the most stable and dense crystalline structure (hence the highest melting and smoke point) of all of the fats, while palm oil’s looser structure makes it easier to incorporate air during mixing. That is one reason all three oils show up on the Twinkies ingredient list (the other reason is pricing and availability).

The same process is used for hydrogenating two other Twinkies subingredients: stearic acid (which is used in polysorbate 60 and sodium stearoyl lactylate) and sorbitol (which is used in polysorbate 60).

When the proportions are right, the shortening is blended with emulsifiers (mono and diglycerides, which are also used on their own in Twinkies) to make it water-friendly and to raise the melting point—two characteristics required for baking. (Add lots of water, some artificial flavors and colors, more emulsifiers, and preservatives, and you’ve got margarine; add even more water and you’ve got Dairy Fresh Non-Dairy Creamer.™) The shortening then gets whipped while being chilled to introduce as much air (and sometimes nitrogen) as possible, air that will later be trapped in batter to make an airy Twinkie, pie crust, or creamy filling.

Wouldn’t you know it? We have the French to thank for this magnificent culinary achievement, which enables us to enjoy fine, packaged pastries for a dollar a hit. Hydrogenation was invented in 1905 by French chemist Paul Sabatier. (Procter & Gamble claims the title, though, saying they developed it in 1907 with a German scientist.) In 1912, Sabatier won the Nobel Prize in Chemistry for discovering that nickel (along with platinum) is a good hydrogenation catalyst. Crisco—then made from cottonseed oil (its name, selected in a Procter & Gamble employee contest, is a near-acronym derived from
cry
stalized
c
ottonseed
o
il)—came on the market in 1911, pitched even then by Procter & Gamble as a healthy alternative to butter and lard. In 1913, it sent a team of home economists around the country to demonstrate cooking with Crisco, with much success. Well into the twenty-first century, shortening made of partially hydrogenated oils was still seen as a godsend, until research began to reveal that it was almost killing us.

What You Don’t Know Can Kill You

While the actual hydrogenation process is relatively simple, the science and technology behind it is not.

All fat molecules are made of long chains of carbon atoms (among other things). In oils (fats that are liquid at room temperature) most carbon atoms have two hydrogen atoms attached to their two “arms.” Those carbon atoms that have only one hydrogen atom attached have, therefore, an available arm for another hydrogen atom to attach itself. When hydrogen atoms are forced onto only some of the available carbon atoms’ arms, the oil becomes a little more solid, or “partially hydrogenated.” If hydrogen atoms are forced onto every one of the available carbon atoms’ arms, the oil becomes solid and is called “fully hydrogenated.”

What’s important to know from a health perspective is that the molecules in unsaturated fats—most vegetable fats, such as those in salad oils—are shaped in a way that is supposedly easily digested by our bodies. On the other hand, the molecules found in saturated fats—naturally occurring in animal fats such as butter, tallow (beef fat), and lard (pork fat) that shortening is supposed to replace—are shaped in a way that many authorities think is not easily digested by the body and therefore, some believe, raise our “bad” cholesterol by converting into artery-clogging plaque.

Alarmingly, unpredictable events have been known to transpire during the hydrogenation process—things neither the scientists nor the engineers can control nor fully explain. Hydrogen atoms have been known to “jump” across the molecule creating what we call trans fats (“trans” means “across”; “trans fats” is short for “trans-fatty acids”), resulting in slightly deformed molecules. When this happens, you’re left with an oil that behaves like a solid, a fat that not only raises bad cholesterol but lowers the good. Since January 1, 2006, federal law has mandated that trans fats be noted on the Nutrition Facts label of all packaged foods, which has caused many a manufacturer to change their recipes—Twinkies included.

When hydrogenating oils, reducing or eliminating trans fats is a challenge, causing the guys in the control room and the folks at the labs to work hard to manipulate the temperature, pressure, ingredients, and timing that, even in the best possible circumstances, does affect the shortening’s texture, melting point, and cost. Crisco seems to have pulled it off by including high-oleic sunflower oil and continuing the hydrogenation process about twenty or thirty minutes longer until the soybean oil is fully hydrogenated, or fully saturated (meaning there is no space for trans fats on the molecules), then mixing a little bit of it with unhydrogenated oil. The University of Iowa has spent thirty years developing an ultralow linolenic soybean that requires no hydrogenation; some European food companies have changed their shortening recipe by mixing in palm oil or beef fat, which are naturally highly saturated, obviating the need for partial hydrogenation and avoiding the creation of trans fats.
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Young food scientists (along with their employers) dream of finding the “killer app” of ingredients, the perfectly healthy, guilt-free, fat substitute.