In an era of high expectations, the mood can quickly change when it comes to the microwave oven.
Consumers have come to rely on the microwave's speed in heating and reheating their food, but a palatable meal in a package is proving agonizingly slow to develop.
Recognizing that more than 80 percent of American households have at least one microwave oven and seeing the long-term market potential of foods prepared for the microwave, food companies are focusing more attention on making packaged products that will pass the elusive taste test.
But frustrating obstacles in microwave technology have slowed the pace in the search for zapped products that resemble what consumers expect from conventional means of cooking, food industry experts say.
"Consumers initially wanted the convenience, but now they're saying, 'Yes, quick and easy, but I don't want it if it doesn't taste good,' " said Sara Risch, director of research and development for Golden Valley Microwave Foods Inc.
"As we look at microwave products, there are key areas that still need attention," Ms. Risch concedes. "One is looking at the flavor of foods. You don't get any flavor development with certain items."
Other industry leaders, as well, contend the quality of microwave products has yet to match the gains in their popularity. Casseroles don't brown, cheese burns, bread dough toughens, breaded coating fails to get crisp, and the most cherished attribute of the microwave -- the speed -- inhibits the development of flavor.
But promising signs on the growth potential of the market have motivated companies to start fine-tuning the development of microwave products.
By the end of 1989, microwave products had become a $2.2 billion industry, and most categories are growing at a double-digit rate, according to Arbitron/SAMI, a major research firm.
Nearly 10 percent of new food products introduced in 1989 and 8 percent in 1990 were designed for the microwave, up from the 4 percent share in 1986, according to New Product News, a trade publication.
Golden Valley, the Edina, Minn.-based company that exclusively develops microwave foods, has doubled its net sales in the past several years and posted net sales of $170 million in 1989, Ms. Risch said.
And, in a recent poll of 300 women, the Campbell Microwave Institute learned women use microwaves 2.6 times a day, the average child uses the ovens about twice a day and employees use office microwaves about 17 times per month.
Only one-third of the respondents said they had used the microwave during a one-month period to make a meal from scratch.
Since 1985, when microwave sales started picking up, food companies have been investing more time and money in products made specifically for the microwave oven. Typically, they invest anywhere from $250,000 to $7 million in the research and development of an item, said Harry Rubbright, president of the Rubbright Group, a St. Paul-based microwave packaging and product development firm.
"Food companies that want to be successful are putting research and development into microwave products," Mr. Rubbright said.
For example, the Campbell Soup Co. has five engineers and five food scientists as well as representatives from 10 other disciplines devoted to the production of new microwave products, said Betty Cronin, director of the Campbell Microwave Institute.
In the early 1980s, when only 33.3 percent of households had a microwave oven, consumers used them primarily to heat water and reheat leftovers, giving food companies little incentive to develop new products, said Ginna Domm, vice president of retail marketing for Sara Lee Corp.'s sausage division.
As a result, "People are still consciously saying, 'I'm buying this for convenience, and I'm willing to compromise taste," Ms. Domm said. "But they're forcing manufacturers to find ways to deliver quality foods."
The crux of the problem is that microwaves heat materials by steaming, so any foods that cook best through other types of heating will be less palatable, said a microwave researcher with Kraft General Foods.
To tackle the problem, food companies have focused on new packaging and reshaping food products, Ms. Risch said. Through trial anderror, they have discovered that microwave heat travels unevenly in square-shaped foods, leaving the middle cold and the corners charred.
Shaping foods in circles, rounding their edges or removing the middle to shape it like a doughnut has helped even out the heat, Ms. Risch said.
But the biggest advances have been made in the packaging that stays on the product during cooking. The package design acts as an oven, distributing the heat evenly and, in some cases, even browning the products, microwave experts say.
"Susceptors," metal filaments inserted between sheets of paper in packaging, have helped in browning foods and were critical in the development of microwave popcorn, Ms. Risch said.