Science's Quest to Banish Fat in Tasty Ways
Low-fat fried chicken may seem like a contradiction in terms, but not to
Stephen Kelleher. On a recent summer morning, he hovered over a whirling
assembly line as a waterfall of gray liquid cascaded over slabs of breaded
chicken. Then the magic began.
During the bath in the liquid solution, which consisted of water and protein
molecules extracted from a slurry of chicken or fish tissue, a thin,
imperceptible shield formed around the meat. When the chicken was submerged
in oil, the coating blocked fat from being absorbed from the fryer.
Voila! The chicken contained 50 percent less fat than a typical piece of
fried chicken.
Just another day in the strange world of food scientists. Mr. Kelleher, the
founder of Proteus Industries in Gloucester, Mass., is one of many chemists
who work, often in secret, in a little-understood part of the $550 billion
processed-food industry. These are the people who ultimately put food
together, and their mission is critical: developing foods that let consumers
have their cake and eat it, too.
With two-thirds of Americans considered overweight and yet many professing a
desire to eat healthier, every major food producer and food-ingredient
company has ordered its scientists to find the holy grail: products that
either have less bad stuff - fat, white flour, sugar and salt - or more good
stuff like whole grains, fiber and fish oil.
Some of these food additives are natural and some are not. But even those
that are natural hardly evoke images of a country harvest. Fat-repellent
coatings, after all, do not grow on trees.
Coming soon to your grocery store, for example, could be salty corn chips
cooked in oil but that are marketed as healthy because the addition of
chemically modified starches make them high in fiber. Labeled simply as
"modified cornstarch," this additive cannot be broken down until it reaches
the
colon, much like the natural fiber found in fruit and vegetables. Also
coming soon: bread containing microscopic capsules of fish oil, enabling
food companies to contend that the bread is "heart-healthy" because of the
cholesterol and triglyceride-lowering omega-3 fatty acids found in fish oil.
Some nutritionists question whether all this alchemy will further confuse
consumers about the basics of good nutrition. Marion Nestle, a professor of
nutrition at New York University, maintains that the best way to get fish
oil into your diet will always be to eat fish.
"What this does is to turn food into medicine," said Professor Nestle.
"Omega-3's occur naturally in food like fish, chicken and eggs, and plants
to a lesser extent. Why do we need to get it from bread?"
One reason may be that products that can be marketed as healthier often
generate higher sales and fatter profits for food companies. PepsiCo, for
instance, reports that sales of its healthier "Smart Spot" items - products
like Baked Lay's potato crisps, Tropicana orange juice, Diet Pepsi and
Quaker oatmeal - are growing at double the pace of other products.
Foods labeled as healthy also present a show of good faith to administration
officials, members of Congress, consumer groups and trial lawyers, who all
monitor the food industry's response to the nation's obesity problem.
Ingredient companies today sell $4 billion worth of additives to the food
industry a year and are responsible for many of the common properties of
processed food. Additives, for instance, keep the fruit in yogurt suspended,
not plopped at the bottom. They make sure that chicken dinners do not come
out of the microwave hot around the edges and cold in the middle, and they
allow many foods to stay in warehouses or on supermarket shelves for up to
nine months without spoiling.
Tate & Lyle of London, one of the largest food-ingredient companies in the
world, makes the popular sweetener Splenda. It recently started selling a
whole-grain "cracker system" composed of Splenda and hydrolyzed wheat
protein, an additive that has been manipulated - either chemically or
through enzymes - to give the softness of white flour without adding
carbohydrates.
Other ingredient companies are focusing on what they can add to food to make
it healthier. Both Cargill, the commodities giant that has a large
food-ingredient business, and National Starch Food Innovation, the food arm
of National Starch and Chemical based in Bridgewater, N.J., and itself a
unit of the giant Imperial Chemical Industries of Britain, have seized upon
the fact that the average American consumes less than half the fiber each
day that the government recommends.
Nutritionists consider fiber beneficial because it prompts slower, steady
digestion, preventing spikes in blood sugar and insulin. It has also been
shown to lessen the risk of colon cancer.
The most obvious way to get more fiber into the diet is to increase
consumption of whole and unprocessed fruit, vegetables and beans. But food
companies say that many Americans are unwilling to make significant changes
in their eating choices to do this, and food companies are more than willing
to fill in the gaps.
Rather than simply add a fiber like bran to foods, which can produce a
coarse consistency that some dislike, Cargill and National Starch are
selling something called resistant starch. They start with starch that has
been extracted from either tapioca or corn and then modify it through a
patented
process - Cargill uses chemicals and National Starch uses enzymes - so that
it will resist digestion in a way that mimics naturally occurring fiber.
Judy Marlett, a fiber expert and former nutrition professor at the
University of Wisconsin, explains that when starch is modified to be
resistant, the molecular structure changes. The bonds between glucose
molecules are covered up so that digestive enzymes cannot get to them. As a
result, resistant starch, like natural fiber, is not digested until it
reaches the lower intestine, where bacteria are finally able to break it
down.
Dorothy Peterson, a starch specialist for Cargill, says that the company is
marketing resistant starch as an additive for products including bread,
muffins, pasta and corn chips, allowing companies to increase the fiber
content by several grams a serving. "It's a simple way to do fiber
addition," Ms.
Peterson said. "We've gotten a tremendous amount of interest from
customers."
One corporate customer already using National Starch's Hi-maize resistant
starch is Sara Lee, which has added it to several products in its Delightful
line of low-calorie bread. Listed on the label as cornstarch, it adds just
under a gram of fiber for each two-slice serving. Dannon is using a similar
product, resistant maltodextrin, in its Light 'n' Fit With Fiber yogurt,
which has three grams of fiber a serving.
Omega-3 fatty acids, which studies have shown to protect against heart
disease and are essential for brain development in infants, is another
ingredient that food companies are clamoring over. Last September, the
F.D.A. approved the health claim for omega-3 that it may reduce the risk of
heart disease.
The best source of omega-3's is the oil in fish. But fish oil is, well,
fishy, and is not a natural fit for inclusion in the likes of bread, muffins
and cereal bars. To deal with this, National Starch recently perfected
technology that encapsulates fish oil, so it can be added to foods without
an unappealing taste or smell.
A specially modified cornstarch and a vegetable protein, usually soy, are
mixed with water and fish oil and then cycled through machines that
evaporate the water. In the process, the starch and protein molecules attach
themselves to the droplets of fish oil, forming a shield. The concoction
emerges from the machines as a beige powder.
Jim Zallie, a food scientist and National Starch group vice president, says
that a company in Seattle is testing the product for its bread. The label on
the bread, he says, is unlikely to advertise the fish oil content, but
simply cite the presence of omega-3's.
Kellogg has signed a 15-year licensing deal with Martek Biosciences, a
company that sells omega-3 fatty acids derived from algae, which have a
milder smell and do not necessarily need to be encapsulated. Kellogg
declined to comment on the deal or when the algae-based omega-3's might
appear in its products.
Kerry Ingredients, a Wisconsin-based subsidiary of the Kerry Group, a
European food giant, is doing similar encapsulation with fiber, also to
avoid the unseemly taste and texture issues. Without encapsulation, the
ground-up soybean hulls the company is using as fiber make food taste a bit
like sawdust.
But guar gum, which comes from the seeds of the guar plant and is used
widely in food as an inexpensive thickener and stabilizer, is even more
problematic. Kerry Ingredients is using guar, which has a neutral flavor, as
a fiber source, "but it's the consistency of mucus," said Jack Maegli, a
food scientist who heads research and development for new products at Kerry
Ingredients. "If
you eat too much of it, it invokes the gag reflex. I know it sounds
unpleasant, and it is unpleasant. That's why we encapsulate it."
The problem, Professor Nestle said, is that ingredients that are extracted
from their natural sources are never as good as the real thing. She cited
plant sterols, another seemingly healthy ingredient popping up in various
foods.
Extracted from soybeans using a chemical solvent, plant sterols are promoted
for their cholesterol-reducing benefits and have been added to yogurt,
orange juice and cereal.
But, Professor Nestle said: "No way do plant sterols replace whole fruits or
vegetables, or even beans for that matter. The evidence is pretty clear that
foods work, but single nutrients don't."
Food companies insist that, unlike their critics, they are pragmatists. They
say their consumer research shows that convenience and taste still outrank
nutrition as the top priority for most people and that consumers have no
intention of giving up their favorite foods.
That is good news for the industry. If Americans stopped eating large
quantities of fried chicken, sweetened breakfast cereal, cookies and snack
chips, the financial health of many companies would suffer.
And that is why food scientists like Mr. Kelleher of Proteus Industries keep
searching for the perfect recipe for low-fat chicken.
Pat Verduin, head of research and development at ConAgra Foods, which sells
fried chicken and fish to restaurants and schools through its food-service
operations, says that other companies have tried other coatings using a
pectin-based solution, which leads to a gummy texture and oil that pools
unevenly on the surface of the product.
"I think what Proteus is doing is novel," Ms. Verduin said, adding that
ConAgra is looking at the technology. "They may be on to something."
New York Times