A carton of raspberries can look perfect at the grocery store but turn fuzzy three days later, while the frozen bag beside it may cost less, last for months and contain fruit that’s already been cut, washed and is ready to eat.
Does such convenience come with a nutritional disadvantage? While "a bag of frozen fruit almost always means a nutritious choice," says Bonnie Taub-Dix, a registered dietitian nutritionist and author of "Read It Before You Eat It – Taking You from Label to Table," there are a few considerations to keep in mind.
The type of fruit that's been frozen, how and when it’s stored afterward and a few food safety concerns all deserve a closer look.
How is frozen fruit produced?
Commercially frozen fruit starts much like fresh fruit, with growers harvesting the
crop and processors inspecting it and removing damaged or unripe pieces. As with fresh fruit, "frozen fruit is also picked at its peak," says Abbie Gellman, a registered dietitian and New York City-based chef.
What happens next depends on the fruit. Berries may remain whole, while mangoes, peaches and pineapples usually need to be peeled, pitted or sliced. After such decisions are made and executed, the fruit is "sorted, cleaned, flash frozen and then packaged," before distribution, Gellman explains. These steps often happen within hours of harvest, "in order to preserve freshness" and limit quality loss, Taub-Dix adds.
The freezing process is fascinating, too, as many fruits are frozen as individual pieces so they don’t form one solid block. Rapid freezing creates smaller ice crystals than slow freezing, Gellman explains, which limits – but doesn't eliminate – damage to the fruit’s cell walls. This can help the pieces retain their shape and quality during distribution and storage.
No matter how it's done, freezing still changes the fruit’s structure – and ice crystals can still rupture cell walls, which is why berries sometimes leak juice or collapse "and become softer once thawed," Taub-Dix says. Contrary to a common assumption, freezing does not reliably kill harmful viruses or make fruit sterile, Gellman cautions. Because of this, she advises that if a product is recalled, you'll want to check its lot information and discard it if it’s been affected.
What are the health benefits of frozen fruit? Are there any downsides?
Whether it’s fresh or frozen, fruit always offers a range of important nutrients – though the specifics depend on which fruit you're choosing. Strawberries, kiwis and oranges are good sources of vitamin C, which the body needs to make collagen, absorb iron from plant foods and to support immune function, Gellman explains.
Frozen bananas, mangoes and cantaloupe provide potassium, which maintains fluid balance, aids muscle and nerve work "and is important for healthy blood pressure" says Taub-Dix. Cantaloupe and mangoes also provide meaningful amounts of vitamin A, which supports healthy vision, immune function, cell growth and reproductive health.
Frozen deeply-colored berries, cherries and grapes also contain polyphenols such as anthocyanins, which have been studied for their roles in limiting oxidative stress and inflammation, Gellman notes.
And most whole fruits also provide fiber, "which supports our digestion and GI tracts and improves heart health by lowering cholesterol," says Gellman. Fiber also promotes fullness, which can help with healthy weight management.
Frozen fruit has the added benefit of "providing natural sweetness," says Taub-Dix, which can make it appealing in place of foods with added sugar.
This also illustrates one of the downsides of frozen fruit, namely that some frozen fruit is packaged with added sugar or syrup. Because of this, Gellman advises checking the label and "choosing options without added sweeteners."
Frozen or not, due to its high fiber content, eating a lot of fruit at once can also cause an upset stomach or bloating, particularly for people with irritable bowel syndrome or sensitivity to certain fruits. Taub-Dix notes that acidic fruits, especially citrus ones like oranges and limes, may aggravate symptoms for some people with acid reflux or GERD.
Is frozen fruit healthy?
When it comes to fresh versus frozen, "the nutritional differences are generally minuscule, if any," Taub-Dix says. Indeed, research comparing fresh, refrigerated and frozen produce has found that frozen versions retain vitamins well and sometimes even contain more of a particular nutrient than fresh produce that has been stored for several days.
Nutritional value varies with the type of fruit you're eating and stage of ripeness, as well as with how it’s processed and how long it’s been stored. "Some fresh fruit can also lose some of its nutrition as it travels and ages," Gellman explains. Vitamin C, for instance, is sensitive to time, heat, oxygen and light. Though freezing can slow its deterioration, it doesn’t stop it indefinitely.
The choice of which option you choose should come down to the one you’re more likely to eat, and not out of any supposed nutritional advantage.
This article originally appeared on USA TODAY: That bag of frozen berries may be healthier than you think
