Who doesn’t appreciate the convenience of frozen produce every once in a while? It’s ready to cook, requires zero prep, and there’s no risk of losing a finger while chopping away.

Yet with so many options lining the grocery store aisles, choosing how to buy veggies (and then prepare them once at home) can be mind boggling.

When nutrition is the deciding factor, what’s the best way to get the biggest bang for your nutritional buck?

The prevailing belief is that uncooked, fresh produce is more nutritious than frozen… yet that’s not necessarily true.

One recent study compared fresh and frozen produce and the experts found no real differences in nutrient content.Li Linshan, et al. (2017). Selected nutrient analyses of fresh, fresh-stored, and frozen fruits and vegetables DOI: 10.1016/j.jfca.2017.02.002 In fact, the study showed that fresh produce scored worse than frozen after 5 days in the fridge.

Scratching your head yet? It turns out that fresh produces loses nutrients when refrigerated for too long.

To add to the confusion, slight differences in nutrients may depend on the type of produce you buy. In another recent study, fresh peas had more riboflavin than frozen ones, but frozen broccoli had more of this B vitamin than fresh ones.

Researchers also found that frozen corn, blueberries, and green beans all had more vitamin C than their fresh equivalents.Bouzari A, et al. (2015). Vitamin retention in eight fruits and vegetables: a comparison of refrigerated and frozen storage. DOI: 10.1021/jf5058793

The farm-to-store process may be to blame for the nutrient loss in fresh veggies. The freshness of a tomato or strawberry isn’t measured from when it hits the grocery store shelf — it begins right after harvesting.

Once a fruit or veggie is picked, it begins to release heat and lose water (a process called respiration), impacting its nutritional quality.

Then, pest-controlling sprays, transportation, handling, and plain ol’ time cause fresh produce to lose some of its original nutrients by the time it reaches the store.

The longer you keep produce, the more nutrition you lose. Those bagged salad greens, for example, lose up to 86 percent of their vitamin C after 10 days in the fridge.Dewhirst RA, et al. (2017). Novel insights into ascorbate retention and degradation during the washing and post-harvest storage of spinach and other salad leaves. DOI: 10.1016/j.foodchem.2017.04.082

To maintain the most nutrients, keep these veggies in the crisper drawer of your fridge:

  • apples
  • berries
  • broccoli
  • carrots
  • eggplant
  • peppers
  • salad greens

Feel free to keep these on the counter:

  • hot peppers
  • oranges
  • melons
  • pumpkins
  • winter squash
  • sweet potatoes

As a rule of thumb, it’s best to keep this group in a cool, dry place:

  • bananas
  • garlic
  • lemons
  • onions
  • potatoes
  • tomatoes

How long produce stays fresh varies. Generally, you don’t want to hold on to it for more than a few days before eating it or putting it in the freezer.

The blanch-and-freeze method is a popular one to deactivate the enzymes that cause fruits and veggies to lose color, flavor, and nutrients.Xio HW, et al. (2017). Recent developments and trends in thermal blanching – A comprehensive review. DOI: 10.1016/j.inpa.2017.02.001

Before blanching (i.e., dropping produce into boiling hot water for a few minutes before drying), be sure to look up cooking times, because each type of produce is different.

Foods that are best frozen are those with high amounts of fat-soluble nutrients, like vitamin A (broccoli), carotenoids (carrots), and vitamin E (spinach and kale). They’re more stable during food processing and storage.

Sorry, raw foodies. The bag is still mixed on whether cooked veggies are “worse” nutritionally. How you cook these foods may be the deciding factor.

According to the research, steaming is the best way to preserve the nutrients in many foods, like broccoli. This cooking method boosts levels of antioxidants, B vitamins, and phytochemicals like carotenoids.Wang GC, et al. (2012). Impact of thermal processing on sulforaphane yield from broccoli ( Brassica oleracea L. ssp. italica). DOI: 10.1021/jf2050284

For others, like potatoes and peas, boiling is the ideal way to keep folate levels high.Fabbri ADT, et al. (2016). A review of the impact of preparation and cooking on the nutritional quality of vegetables and legumes. DOI: 10.1016/j.ijgfs.2015.11.001

In general, the best bet to get the most nutrients is to go easy on the temperature and cooking time. Also, limit the amount of water you use for cooking veggies loaded with vitamins B and C.

Remember: water-soluble vitamins will vanish in the presence of H2O.

It turns out that frozen produce has just as many nutrients (if not more) as fresh. To get the most nutrients out of the fresh fruits and veggies you do have, store them properly and don’t hang onto them for too long.

Cooking produce may be beneficial, too. Boiling or steaming veggies like broccoli and carrots may actually boost levels of free radical-trapping antioxidants and phytochemicals, like carotenoids and polyphenols.

The best bet for getting the most nutritional value out of cooked veggies is to keep the temperature low and the cooking time short, while preparing with as little water as you can get away with.