Is fresh always the best? And what should you never eat frozen? Produce at your grocery store may not be as "fresh" as your think. Find out how it measures up to canned and frozen, and how you can shop better the next time you're at the supermarket.
It's easy to assume that the fresh produce at your grocery store is ripe and full of nutrients, but looks can be deceiving. "Fresh" doesn’t always mean fresh. Produce is harvested before ripening and travels long distances to get to your grocery store, and the quality of your food decreases as more time passes. In addtion, if you do not eat produce soon after purchasing, they will continue to lose nutrients while chilling in your refrigerator. According to a nutritional comparison of fresh, frozen and canned fruits and vegetables conducted at the University of California, Davis, fresh produce can lose up to half of their original nutrients after storage and cooking. To truly eat fresh, shop at your local farmer’s markets or grow your own fruits and vegetables.
How does canned and frozen stack up? Canned items go through a thermal treatment that causes varying amounts of initial nutrient loss; for example, canned items can lose between 10 and 90 percent of vitamin C. An exception exists for canned tomatoes, where the heat actually induces the release of phytonutrient lycopene. When in storage, the lack of oxygen means there is very little nutrient change up until when it reaches the consumer for cooking. If you're not going to immediately use an ingredient, it is a good idea to buy it in canned form. Try to avoid canned items high in trans fat, sodium and preservatives.
Unlike fresh produce at the store, frozen items are picked and processed at the peak of ripeness and therefore start as excellent sources of nutrients. Frozen food undergoes a short heating time called blanching, which causes initial loss of some water-soluble B and C vitamins, before freezing, during which oxidation leads to slow nutrient loss. Blanching does not significantly affect fat soluble nutrients like vitamins A and E and carotenoids, so sourcing frozen fruits and vegetables high in these nutrients will have less compromised nutritional profiles.
Contrary to popular belief that fresh is best, research suggests that produce, once it reaches the consumer, may be nutritionally similar whether fresh, canned or frozen. Knowing this, shoppers can exercise greater choice in how they consume their food as each type can be part of a healthy diet.
