THE ANNUAL Food Marketing Institute convention provides a forum for food manufacturers to display their latest and greatest. At last week's convention at Chicago's McCormick Place, the old standbys were still around, though; women dressed in sailor suits handed out fresh warm Cracker Jacks in old-fashioned boxes for the Borden Company. And the 62-year-old Good Humor company, dispensing mix-and-match ice-cream-and-cookie sandwiches, is still known for good old ice-cream-on-a-stick.

The newest item to be previewed at the convention was probably the shelf-stable milk, called ultra-high-temperature (UHT) milk. Although the actual product wasn't there, salesmen pointed out that it has been used for over a decade in Europe. Dairymen Inc., of Louisville, which represents many southeastern dairy farmers, is building a $16 million plant in Savannah, Ga. It will begin test marketing in south Georgia and Florida in June and will work up the East Coast. It should be in Washington area stores within a year, according to a spokesman.

These are just a few of the foods that made an appearance at the three-day gathering:

Favorite junk: Flavored melba rounds, high in fat content, long on artificial flavor. They shared the honors with bite-sized cheese crackers, wheat crackers and Goldfish.

Also, Morey's Fish House, based in Motley, Minn., sells a smoked fish spread made of salad dressing, cream cheese, smoked whitefish and horseradish. Unfortunately, it probably won't be distributed in this area, according to the salesman.

Tackiest: Wine on tap. We're sorry, but even if it were good wine, the esthetics have a long way to go. Taylor wine comes in a plastic bag in a box with a tap that sits in the fridge. Even candlelight and soft music wouldn't help.

Most popular: The Ball Park Franks booth -- situated, naturally, close to a beer booth -- had as many as 30 men at a time waiting in line for a free hot dog (complete with ball park mustard, of course). Or maybe the franks people were just the slowest at giving away the goods.

Most convenient: One company has established a test market for three-ounce packages of cleaned and trimmed vegetables -- broccoli and cauliflower florets, crinkle-sliced carrots and celery. They aren't cheap (the broccoli runs about 79 cents), but they are the perfect amount for salad, stir-fry and side dishes.

Premium products: There are a few left, and even a few new ones. Bridgford Foods Corporation makes a pizza kit that keeps in the freezer. Dough, sauce and topping come in one package. You buy it, thaw it and cook it in a 10-ounce pizza pan. This isn't straight-from-box-to-oven pizza, but then again, the crust isn't cardboard either. Arizona and California have test markets now; the pizza sells for about $3.29.

La Preferida makes mild to hot Mexican salsas. Its Salsa Ranchera, with tomatoes and jalapeno peppers, is the stuff that makes men macho. There's a real kick to the product which reminds you of real Mexican food.

Rubschlager deli-style rye and pumpernickel breads made an appearance. They are always good.

Most deceptive: Frito Lights. Touted as a light-style snack cracker. They'll tell you it's crispier, but it isn't lower in calories than other junk foods. These weigh in at 270 calories for 1 3/4 ounces.

Most noncommittal: French's has come out with a new brown mustard which one salesman says is "better than dijon." Actually, it looks sort of like dijon, but it tastes like good old ball park.

Major disappointment: Sara Lee pudding cake. It's a shame to see the makers of formerly good frozen bakery products stoop to gimmicks. And the cakes don't taste very good, either.

Most revolting: Food color manufacturers tinted doughnut icing with circus colors. Innocent doughnuts were drenched in lemon yellow, M & M orange, chartreuse and fire truck red.