The Greek pasta salad with chicken and fig skewer, the chicken Caesar, or the chef salad? A hot Florentine turkey sandwich, the sausage, mushroom and onion pizza, or the zesty club?

Every 10 minutes for almost an hour, a new tray landed in front of the taste testers sampling potential lunch offerings for Northwest Airlines' domestic first-class flights.

The diners, including travel managers from leading corporate customers such as 3M Co. and Medtronic, dutifully recorded their preferences on items that coach passengers would be lucky to catch a glimpse of on a passing food cart.

Taste testing with corporate customers is new, and something Northwest plans to do more of.

"What we're trying to do is get more variety out of this," said Susan Henry, Northwest's managing director of onboard services and catering. Often times, the airline will test 150 entree ideas before narrowing it down to the eight that will end up on planes, she said.

When Henry asked diners Friday how they would rate Northwest food on a scale of 1 to 5, the group was quiet. Thomas Heim, 3M's director of administrative services, who flies about every three weeks, offered up a "3."

In surveys it gives to customers, Henry said, Northwest's food ratings average a 3.5 on a 5-point scale. "We want to get it to a 4 or higher," she said.

Northwest also wanted to find out how much food first-class passengers would expect, so they showed the testers real-size servings.

Gerry Williams, director of Medtronic's travel and expense reporting, said he sometimes skips meals, including breakfast, so when he's flying and lunch arrives, he prefers a sandwich with a lot of meat on it, he said. "If I'm flying, this will be it for me," he said.

The testing took place in a small dining room across the hall from Northwest's test kitchen near the Humphrey Terminal at the Twin Cities airport. Corporate chef Jo Ragozzino, who has 25 years experience, runs the test kitchen at the LSG Sky Chefs facility along with Jessie Zuravle, who specializes in menu development for domestic flights.

Preparing a menu for in-flight service does come with some limitations. Nothing on a plate can be taller than 1 1/4 inches. Everything has to stand up well to hours of refrigeration. And any item that can get easily jostled in transit � ruining its presentation by the time it lands on your seat tray � is suspect.

"We really try to look for durable items," Ragozzino said.

Each day the LSG facility prepares meals for about 350 flights leaving MinneapolisSt. Paul, and the operation has to take several variables into account. About 60 percent of Northwest's first-class passengers prefer a sandwich for lunch, while 40 percent take a salad. Are those percentages influenced by passenger mix? Possibly. Henry noted that an estimated 90 percent of Northwest's first-class passengers are male.

Friday's taste test also served to demonstrate that day-to-day business continues at Northwest, even as the airline's high-profile dalliance with Delta Air Lines appears stalled. There was no word Friday from pilots groups whose disagreement about how to merge their seniority lists could still scuttle a potential merger.

After several trays of salads and sandwiches at Friday's testing, it was time for dessert. Besides the ever-popular Dove bar or a small carton of Ben & Jerry's ice cream, there was a table loaded with cake slices, including sampler plates featuring fudge sundae cheesecake and a cake called "chocolate beyond reason" � three layers of chocolate. By the time diners were asked which dessert they'd like best on their next flight, it appeared preference fatigue was starting to set in.

"The sampler cake plate would be really good," Heim said.