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Frozen Blueberries


K we all know blueberries are the shiz...

I buy them frozen but I've also heard that cooking stuff, especially microwaving, screws up the potentially beneficial nutritional properties of said stuff.

So... when I microwave my blueberries for a minute to thaw them, does this take away the blueberry nutritional goodness?


Short answer? Yes, probably a little bit. But don't worry about it, the important thing is to just eat the food. Anyway is much better than noway.


Good question I've wondered this too 'cuz I bake blueberry muffins and wonder if im missing out on some of the benefits.

Anyone else know if the phytochemicals are reactive to heat?


I love frozen Blueberries.I wouldn't microwave them though.They usually melt when I put them in my shake or oatmeal anyway.I don't use a microwave,so cooking them would be my next move.


Just put the frozen berries in a bowl in the fridge before bed the night before. 1/2 blueberries and 1/2 other mixed berries is a good mixture as other berries have other useful phytochemicals.


Graet idea SCOTTL!


there's a very good chance even warming them in the microwave destroys almost all their antioxidants. Studies have shown cooking veggies in the microwave kills 97% of the antioxidants. Whether it's that bad when you only warm them is anyone's guess - but considering what they cost, are you okay with losing even half the antioxidants? I'm not.


I'm very interested in this study because I'm skeptical of the claim that microwaving kills 97% of a vegetables antioxidants.

Can you post more information on it?


Toss the frozen ones in your oatmeal in the morning along with some vanilla Grow!. Cools off the oatmeal and thaws the berries at the same time. AND, it tastes great!


Id LOVE to see this as well.


Microwave = bad when it comes to nutrients in your food. Just thaw them out or stick in a small bowl of warm water.


the results of a quick google search - there's loads more out there if you want to search around some more....

Posting date: 16-OCT-2003

By Amanda Gardner
HealthDay Reporter

THURSDAY, Oct. 16 (HealthDayNews) -- Getting the necessary nutrients from vegetables may be even harder than you thought.

New research shows that different ways of preparing, storing and processing vegetables can affect how good they are for you.

Broccoli, for instance, can lose as much as 97 percent of some antioxidants, or cancer-fighting compounds, when it is zapped in the microwave.

Vegetables that are blanched before freezing (a common processing technique) can lose up to one third of their antioxidants. Frozen storage can also cause losses, albeit much smaller ones.

Two studies detailing these findings appear in the November issue of the Journal of the Science of Food and Agriculture.

Antioxidants are plentiful in vegetables and work to eliminate free radicals, which can damage cell DNA and contribute to various diseases. That's why eating fiber, fruits, and vegetables, all of which contain antioxidants, can help prevent cancer and cardiovascular disease.

As it turns out, though, that protective effect is most pronounced when the vegetable is in its natural state.

The first study found that the simplest cooking method was also the worst when it came to preserving nutrients. Broccoli lost 97 percent of flavonoids, 74 percent of sinapics and 87 percent of caffeoyl-quinic derivatives (three different types of antioxidants) when it was microwaved.

When boiled the conventional way (i.e., not in a pressure-cooker), this green lost 66 percent of its flavonoids; when tossed in a pressure cooker, broccoli lost 47 percent of its caffeoyl-quinic acid derivatives.

Steamed broccoli, on the other hand, lost only 11 percent, 0 percent and 8 percent, respectively, of flavonoids, sinapics, and caffeoyl-quinic derivatives.

The advantage of steaming vs. conventional boiling is that you're "not using water directly in contact with the vegetable. The nutritional compounds don't go into the water," says Cristina Garcia-Viguera, lead author of this paper. "Once the compounds are in the water, the temperature destroys them much easier."

A microwave wreaks havoc because it heats the inside of the vegetable. That, combined with the fact that you normally use water when microwaving, causes the destruction of valuable nutrients.

Even reheating steamed broccoli in a microwave would probably have the same effect, Garcia-Viguera says, although she did not specifically examine this in her research.

The findings can probably be extrapolated to many other vegetables but, again, the researchers did not specifically address this.

The second study looked at the effects of blanching and freezing and of long-term freezer storage on more than 20 common vegetables. As it turned out, different species showed different effects from these processing techniques.

In general, dietary fiber components were not affected or even went up slightly. Mineral content, also, tended to remain stable.

On the other hand, antioxidant activity went down 20 percent to 30 percent during blanching.

Carrots, peas, and broccoli lost 30 percent of their vitamin C during blanching/freezing, while green beans lost 10 percent and spinach lost 40 percent (with an additional 30 percent lost during deep frozen storage).

Spinach also lost almost 40 percent of its potassium and 70 percent of its folic acid during blanching.

Don't despair just yet, says Samantha Heller, a senior clinical nutritionist at New York University Medical Center in New York City.

The use of these vegetables in the studies meant they were nutritious in the first place, she says. "Then I'm still reaping the benefits even if they're losing some of their qualitative values," she says.

Moreover, Heller points out, not all of the healthy properties of vegetables are being eliminated. "You're still getting plenty of healthy compounds as well as fiber, so there's absolutely no reason not to eat vegetables -- although, of course, the fresher the better," she says.

"If people are willing to have vegetables anyway, shape or form, even if they are going to nuke then, I'd rather have them do that," she adds.

More information

For more on eating enough fruits and vegetables, visit the Centers for Disease Control and Prevention . The American Dietetic Association has a series of nutrition fact sheets.

What goes on when you microwave food? Read about it at HowStuffWorks.

SOURCES: Cristina Garcia-Viguera, Ph.D., department of food science and technology, CEBAS-CSIC, Murcia, Spain; Samantha Heller, M.S., R.D., senior clinical nutritionist, New York University Medical Center, New York; November 2003 Journal of the Science of Food and Agriculture.



I like to stick them in a blender(still frozen) with a little ice, juice, and a vanilla meal replacement. One of my buddies who I work out with also throws a Grahm cracker or two in there with it. It's worth a shot and you don't have to worry about the microwave.


Thanks that was pretty interesting.


In addition to the postings already made, you can consider this from a basic chemistry perspective, too. Here's my attempt:

Firstly, consider that an antioxidant (AO) is just a chemical. There are thousands of different types of AO, but they all do essentially the same thing: AO's are very reactive towards "free radicals". The idea is that if you have an AO in the presence of a free radical, it will preferentially react with the AO and hopefully leave everything else (e.g your DNA) alone.

Microwave radiation is electromagnetic radiation (a form of light, if you will). When it strikes a molecule, a variety of outcomes are possible - from nothing through to devastating breakdown of the molecule into fragments (there is a spectrum of possibilities). If the molecule is broken down by the "light", the resultant species formed are almost certainly "free radicals".

So, when you nuke your blueberries, some of the microwave radiation will breakdown some of the organic matter present in the berries; these breakdown products are highly reactive and will react with many many compounds (including themselves - two free radicals can recombine, but they probably will not). All other things being equal, free radicals preferentially react with the AO's, but inevitably, some of the blueberry proteins etc. will also be initially affected (causing further free radicals). But within a few fractions of a second after nuking, all the free radicals will be mopped up by an AO or some other organic matter.

So what does this mean for us mortals? On the plus side, your nuked berries are very probably quite safe (note: "very probably" as opposed to "definitely") - because the free radicals formed by nuking have probably been largely mopped up by the AO's in the berries. On the down side, you have fewer AO's left in the berries to mop up free radicals formed when you're pumping iron.

This is all well and good. But let me pose a question, which disturbs me when I consider the extensive use of microwaves: what happens to nuked food that does NOT contain AO's - such as highly processed white flour products, for example (anyone ever defrosted white bread in a microwave)?

The nuked food will decompose in a manner DIFFERENT to that by, e.g. bacteria or regular oxidation. Begs a question: does nuking such fodds result in a product that is (i) as safe; (ii) safer; or (iii) less safe than un-nuked food?

Food for thought. :slight_smile:



I buy the 5 pound frozen bags myself. Every night i fill up a cup with the berries and put it in the fridge by the morning time they are thawed, without having to microwave em.

Then you just chew/chug em down, or add them to your shakes or oatmeal with ease.


Sorry but, much of that info is a load of bollocks. I'll tell you for free, and I'm not a dunce got doctorate in food science and previous food science post grads that I can show you a boatload of studies that show that the info here is senstationalising cooking.

I mean the brocolli think, Indole 3 Carbinol for example a potent anti - estrogenic compund becomes more bio available in cooked brocolli and the main potent chemical in Brocolli, sulforaphane is not largely put out of the picture by heating. Vitamin C and stuff, i.e vitamins rather than phytochemicals are another matter, but anyone relying on veg for vitamin C would be beter off ataking a supplement, but phytonutrients are another matter.


Its best to eat raw and cooked vege's. Then you won't miss anything. You gotta remember many vege are not particularly digestible when eaten raw, that includes tomatoes, another candidate for eat them cooked, richer in lycopene.


I'm glad that there's someone else around here that can see through this BS.

There's nothing but conjecture about microwaving in this article.


The raw vs cooked brigade cite animal studies saying things like, animals who ate only cooked vege's developed tumours and other issues and died young. If its possible to feed any animal besides a hamster or rat, that lives beyond 2 years only cooked food then that study might hold some truth.

More's to the point, feeding a large animal cooked vege would probably lead to some calorie defficiencies and the animals would die of malnutrition which the people who 'conducted' these 'scientific' studies are confusing with dying from some defficiency disease like scurvy or pellagra or whatever animals get. They are obviously not wild animals anyway, but lab or heavily farmed animals which is not a good test bed anyway. How many wild animals cook their food !!!!!?

Perhaps these animal studies relate to humans perhaps they don't. But just eating cooked veg, in fact eating just cooked veg will need to malnutrition or more specifically, Kwashiorkor and marasmus in children. Even if by some miracle you managed to get enough protein by some bizaar food combining you'd have to eat a ton of veg. How do these pure vege eaters (not vegans) do it ? Answer, they don't, at least not healthily.

The answer is always balance, in this case, eat raw where poss (particularly fruit) and then eat raw and cooked veg. Raw Veg freaks say stuff like, 'yeah but you have to eat TWICE as much cooking veg to get the nutrients. Well seeing as cooking a veg makes it more digestible, plus redices the size then that's a nonsensical statement.