The basis for modern freezing techniques originated 100 years ago, while canning techniques can be dated back to the 19th century. Each method uses a different process to preserve the quality and nutrients of food, but when it comes to choosing between canned and frozen greens, frozen is the better way to go.

Frozen produce is initially briefly immersed in boiling water or steam to kill bacteria and deactivate enzymes that would break down the food, then flash frozen and put in an airtight container. This blanching vegetable procedure is designed to lock in nutrition while stabilizing food quality, resulting in vegetables that are actually quite fresh.

Canning, on the other hand, is a process that requires additional steps and a longer exposure to heat than freezing. These extra steps impact taste, texture, and color, and might affect the nutritional profile as well, since brine solutions, sugar, and other substances are added that cause the contents to lose nutrients.

Beyond nutrition, frozen produce is also more convenient and cost-effective, as it lends to more portion control and can be microwaved without even removing it from the bag. However, it’s not without its flaws — some frozen foods might be riddled with extra salt, treated with ascorbic acid as a preservative, or contain binders or emulsifiers.