There are three versions of the black and gold stamp: the "good source" stamp for foods containing a half serving of whole grains (8g) ; the "excellent source" stamp goes on products offering a full serving of whole grains (16g); and the third level - "excellent Source / 100%" - is for foods with a full serving of whole grains and containing no refined grains.
The Whole Grains Council has developed the packaging symbol over the last two years and launched it officially to the food industry in January.
Since then, of the 53 members of the council, Harriman believes that "about half have gone through the regulatory procedure to put the stamp on their packaging. Fourteen of those have publicly told us their plans".
However, few have had the new packaging on the market long enough for Harriman to say whether the stamp is worth food companies investing in to win over more customers.
"The only company that has had its products out there long enough is the Great Harvest Bread Company, which has seen a 20 percent increase in sales since it placed the stamp on its packaging. However, the increase is also since the new dietary guidelines were announced and so we can't take all the credit," said Harriman.
She added that this is also a "somewhat limited test because the company specializes in whole grain and therefore people go to their stores to buy wholegrain products". In other words, they are probably not being won over by the whole grain stamp.
She expects the real test to happen when products start appearing on the supermarket shelves with the stamp.
"When one company sees that its product is not doing so well because others on the shelf have a wholegrain stamp, that's when we'll see the difference."
And she has no doubts that this moment is not far away as the among the members of the council she can count representatives from the big food companies such as General Mills, Kellogg and Campbell's Soup.
"Probably the largest firm that I can say we have been in discussions with is Kashie, a division of Kellogg," added Harriman, affirming that it was the more specialized producers who were willing to make their decisions public at present.
She said, however, that food manufacturers were positive about the stamps because they felt they had been given attainable goals for their products. In the past, their only benchmark was the FDA's regulation that whole grain ingredients had to account for 51 percent of the total weight of a product for a health claim.
"One company for example decided to reformulate its product so it contained 8g not 7g of fiber," she said.
Companies have to be a member of the council to have the stamp and membership is based on a sliding scale costing between $1500 and $7500 depending on the size of the company.
But, getting people to join the organization has posed few problems. Harriman explained that she and her colleagues had been "flabbergasted" with the small amount of marketing they have had to do.
"The food companies have been coming to us. McCann's in Ireland, for example, joined this week without any preliminary contact."
She thinks this interest is part of a sea-change as manufacturers realize they have to do something to help consumers reach their three servings or more of whole grains a day as recommended by the new federal dietary guidelines. She highlights, for example, the fact that in the past, whole grain foods tended to be sold at a premium, whereas this is no longer necessarily the case.
"For example, when General Mills reformulated its cereals to whole grain, it didn't put up the price."
There will obviously be some cost to the manufacturer when changing from refined to whole grain, but manufactuers who have already done so hope they will be able to win over more consumers to their products.
Moreover, as Harriman points out, nearly 20 percent more of the bushel is used to make whole meal flour than to make refined flour. According to the Kansas Wheat Commission, one bushel of wheat yields approximately 42 pounds of refined flour, while the same bushel would yield about 60 pounds of whole wheat flour.
As Harriman explained: "This means in the long run that prices for whole grain products do not need to be higher than refined-flour products".
The only problem that Harriman can forsee with the movement towards whole grain is with the issue of fortification.
"If we all turned to eating only whole grain products tomorrow - which isn't going to happen - folate consumption would go down as the flour is not enriched. Sara Lee, as far as I know, is the only company to offer enriched whole grain breads."
But most Americans have a long way to go before this is the case. According to Dr Eric Hentges, executive director for the USDA center for nutrition policy and promotion and in charge of the dietary guidelines, as of 2000, the average whole grain intake in the US was 0.85 servings/day. Moreover, he found that fewer than 10 percent of Americans consumed three servings per day, while 46 percent of the adult population reported no whole grain consumption whatsoever.