CANTON - The project was so secret that only five people in the entire company knew its code name. For more than four years, a small team huddled in the Dunkin' Donuts research lab trying to crack the code for a doughnut without trans fats that tasted just like those on which the chain had built its reputation over the last half century.
At times, the quest seemed impossible. Batches of doughnuts cooked with oils containing zero grams of trans fat turned into baking disasters: frosting slid off doughnuts, oils bled through the sugary treats, and the stench of palm oil replaced the sweet powdery scent that used to waft through the firm's test kitchen.
In a few weeks at its 5,300 stores nationwide, the Canton-based company will become the first doughnut chain in the country to introduce doughnuts with zero grams of trans fats. McDonald's and other chains have invested huge amounts of time and money trying to banish trans fats because of growing concerns that they increase the risk of coronary heart disease.
Trans fat can be found in vegetable shortening made with or fried in partially hydrogenated oils.
Dunkin's journey was particularly difficult because conventional shortening lends baked goods such as doughnuts their characteristic texture and a longer shelf life. And even with zero grams of trans fats, doughnuts - rings of dough fried in oil and then sprinkled with sugar or coated with frosting - can hardly be marketed as a health food. The movement to ban artery-clogging trans fats is probably just the first in a series of health initiatives (efforts to reduce sodium in the United Kingdom are already underway) that the food industry faces in the coming years, according to restaurant analysts and company executives.
"This is one of the biggest things we've ever undertaken," said Jon Luther, chief executive of Dunkin' Brands, which includes Dunkin' Donuts and BaskinRobbins. "Failure was not an option."
Dunkin' Donuts began exploring ways to eliminate trans fats from doughnuts in 2003, as concerns about labeling fats in packaged goods started surfacing on Capitol Hill. The chain uses about 60 million pounds of oil for the estimated 1.2 billion doughnuts served annually. First, Dunkin' had to figure out the fat content in its doughnuts, which are typically cooked with a partially hydrogenated soybean oil. So the research team sent batches to a secret outside company to test them independently. Doughnuts, they found, ranged from 9 grams to 20 grams of total fat, including 2 to 4 grams of trans fat. A chocolate frosted cake doughnut, for example, has about the same amount of total fat and trans fat found in a medium-size serving of McDonald's fries.
Initially, Dunkin' Donuts did not think it could eradicate trans fats without sacrificing quality or disrupting the way it does business, according to Katie LeClair, the company's director of innovation management. Available shortening alternatives failed. Using liquid soybean oil, with its shorter shelf life, would have required that doughnuts be made three to four times a day instead of the typical one or two batches daily - a cost increase and inconvenience that Dunkin' was not willing to take on.
Doughnuts cooked with cottonseed oil had a bad aftertaste. The 100 percent palm oil bled right through the pastry, leaving an oily mess on Dunkin's signature pink tray paper. Anyone daring enough to try one discovered a dry, yet waxy dough with a distinct flavor of palm. Nearby employees who were developing other products in the research lab would curse at them, LeClair recalled, yelling "Are you crazy?" after the team left out batches of the mystery doughnuts for them to try.
Soon it became clear that only a careful blend of oils would work.
The doughnuts had to pass a series of tests based on overall appearance, texture, aroma, and flavor before the team sent out batches to get tested by the secret outside firm. The group baked in the afternoon and tested the creations the next morning to see how the doughnuts stood up overnight. More than 28 proprietary custom blends of oil were developed, the most promising included a combination of soybean, palm, and cottonseed oils.
"One bite was often enough to know when things went wrong," LeClair said. "We knew we were in a good place when we would eat half the doughnut."
This spring, after rejecting endless batches, the team was ready to take its secret operation on the road. The new oil blend (a proprietary recipe) has the same amount of fat; it just redistributes trans fats into saturated fats. Some doughnuts still have trace amounts of trans fats, but federal regulations allow foods with less than one-half gram of trans fat per serving to be labeled as zero grams of trans fats.
Trans fats are less healthy than the average saturated fat, according to Dariush Mozaffarian, a Harvard School of Public Health cardiologist and epidemiologist, though he notes that there is some disagreement among medical specialists. Still, the lack of trans fats does not give doughnuts a nutritional halo.
Several Boston franchisees agreed to participate in a blind trial, and only four people in the company knew which test stores were serving doughnuts with zero grams of trans fats to unknowing customers and which ones were baking the regular doughnuts. Dunkin's research and development manager, Rick Golden, one of the few people in the know, slept with his cellphone by his pillow every night during the trial, waiting for someone to call with a doughnut crisis. No one did.
Baking with the new oil blend, a deeper shade of brown than the old one, costs less than a penny more per doughnut. Dunkin' says it is not recommending a price increase, but the decision is up to franchisees.
"Whether a trans-fat-free doughnut is going to increase sales or not, it doesn't matter. If your competitors are making claims about trans fats, you just have to be on the right side of the issue. It's like keeping up with the Joneses," said Ron Paul, president of Technomic Inc., a food industry consulting group in Chicago.
Doughnut rivals including Krispy Kreme Doughnuts Inc. and Honeydew Donuts said they are working to remove trans fats from their products but are not ready to offer them yet. In 2002, McDonald's Corp. pledged to introduce a healthier oil and then reneged months later because of concerns about changing the taste of its fries. Five years later, the Golden Arches is using a canola oil blend with zero grams of trans fat at 3,500 restaurants - about one quarter of its US stores, said spokeswoman Danya Proud.
"These restaurants and chains should be making every effort to make their products healthier, especially with this obesity epidemic," said Catherine Daly, 78, as she sat yesterday morning sipping her regular coffee and munching on a French cruller at Dunkin' Donuts in West Roxbury, one of the first test stores to introduce doughnuts with zero grams of trans fats. Daly has not noticed a different taste in her morning treats and she is all for the change, though she said that whatever she has eaten has kept her pretty healthy so far.
Jenn Abelson can be reached at email@example.com.