Of all our favorite foods, fruits and vegetables are the most likely to end up in the garbage. Consumers throw out well over a quarter of the produce they buy. Knowing that, certain manufacturers of food-storage containers are making claims that their products can prolong the life of fruits and veggies by anywhere from 33 to 80 percent. We bought seven preservation systems with freshness claims and tested them. We followed the directions for each, adding water where indicated and setting vents to the proper position.

We also kept some produce samples in their original containers. Although clamshells and other containers might seem flimsy, some forethought has gone into their design, says Julia Collin Davison, the executive editor of the book division and co-host of the America's Test Kitchen shows on PBS. And some produce does better when left alone, especially if handling it can cause bruising.

For our tests, we bought supermarket containers of strawberries, raspberries, and two kinds of lettuce—mesclun mix and heads of leaf lettuce. We transferred produce to containers made by Debbie Meyer, Oxo, Prep­works, and Rubber­maid, and kept some in original containers. We put the strawberries in one refrigerator, the lettuce in another, and so on, with one original container in the produce drawer with an ExtraLife Produce Saver disc and a second (our control) in the main compartment. The third original container of each type went into the main compartment of a dual-­evaporator fridge.

Then we waited, checking every few days during the next two weeks to see how the produce looked, smelled, and felt. In the first week, certain containers extended produce life a bit, but none were much better than the original containers. After two weeks none of the food was good enough to eat.

The bottom line: Use produce as soon as possible. That said, the containers have some convenience features and the virtue of being stackable. Here are the results of our tests.

Read our special report on food waste, "Spoiler Alert: You're Wasting 1 in 4 Bags of Groceries."

Best for Strawberries

Rubbermaid FreshWorks Produce Saver, $20 for a two-piece set (square container shown top left, above)
Elevates food on a tray; lid has a vent. The strawberries in the FreshWorks and those in the original container in the dual-evaporator fridge fared best. Those in the control container became dry but not moldy. The others all developed mold by the end of two weeks.

Best for Raspberries

Debbie Meyer UltraLite GreenBoxes, $25 for a 16-piece set (green container shown bottom left, above)
Resemble regular food containers. At the end of weeks one and two, the raspberries in these and the berries still in the original containers stored in the main compartments of the test refrigerator and the dual-evaporator fridge looked best. All of the others were moldy at the two-week mark.

Best for Salad Greens

Oxo Good Grips GreenSaver Produce Keeper, $20 (container with colander shown top right, above)
Features a colander, an adjustable vent, space for water, and an activated charcoal filter to capture off-gasses. A week in, both kinds of lettuce were doing well in the Oxo, and the mixed greens in the original containers were fine. After two weeks, they all smelled funky and bits and pieces were rotting. By then, the top layer of the mesclun in the Oxo was the most wilted.

Editor's Note: This article also appeared in the September 2016 issue of Consumer Reports magazine.