For G. D. Searle & Co., the surprise was sweet. The corporation's NutraSweet Group had seven years of regulatory review to figure out what to do with its new sweetener before it hit the United States consumer market in the spring of 1983. For all its research, however, its forecasts weren't even close.
''I thought it would take years for consumers to accept the product,'' says Robert B. Shapiro, president of the group that markets the substance ''aspartame'' under the labels ''NutraSweet'' and ''Equal.''
Instead, sales of NutraSweet went from $12 million in 1981 - virtually all of it in Europe and Canada - to $73 million in 1982, after Equal was approved by the US Food and Drug Administration (FDA), to $336 million last year. During the first three months of 1984, revenues for the sweetener totaled $130 million.
''We went out and did a lot of consumer research before the product was ever produced,'' Mr. Shapiro said. ''We'd tell consumers about a new product that we'd describe as a new sweetener with ingredients that tasted like sugar, that was low in calories, was safe, and didn't cause cavities, and then we'd ask for their reactions.
''There were two reactions: 'It sounds terrific' or 'I don't believe a word of it.' ''
It was December of 1965 when two Searle scientists, James M. Schlatter and Robert Mazur, put two naturally occurring amino acids together during their medical research. Dr. Schlatter absent-mindedly licked his finger, so the story goes, and experienced a profoundly sweet taste, 200 times as sweet as sugar but with about the same flavor as sugar.
Aspartame was born, but it took years of protracted studies and FDA deliberations before Equal, the individually packaged tabletop sweetener, appeared on grocers' shelves.
The years-long investigation of the substance by the FDA was concluded in Searle's favor, but not without continued questioning by scattered critics. The criticism, however, has had no apparent adverse effect on the marketing of aspartame.
''We see no effect on the buying behavior of the consumer,'' a Searle spokeswoman says. ''If there were to be an adverse effect in the future, I think we would have seen some signs of it by now. The critics are still going to be there; they're not going to go away. But the consumers haven't reacted to them as far as we can tell. The FDA has spoken, and that's that.''
The consumer never sees NutraSweet, but tastes it in a variety of soft drinks. In most, the substance is mixed with saccharin, largely for reasons of cost: NutraSweet is 30 times as expensive as saccharin. But three drinks are now sweetened entirely by the substance: Diet Squirt, Sugar Free Crush, and Sugar Free Hires.
Although aspartame breaks down when subjected to cooking temperatures, it is now found in products ranging from children's drink mixes to whipped toppings, puddings, and even yeast.
Surprisingly, Shapiro says he does not believe NutraSweet has hurt its major competitors, saccharin and sugar, much: ''Everything we've seen says that NutraSweet represents a third alternative; we don't compete directly. We know we've sold a lot of Equal to people who previously drank their beverages without sweeteners at all - because of taste or safety concerns. So we've enlarged the market.
''We've added $200 million in wholesale sales to the powdered soft drink market, and that's an expansion of about 30 percent. And we're already seeing signs of the same thing in the soft drink market. People are buying soft drinks now who never did at all. I believe they've increased sales 7 or 8 percent in what has for years been a stagnant marketplace,'' Shapiro says.