Researchers analyzed the anthocyanin content of blueberries frozen for one, three and five months and found no decrease in antioxidants over fresh berries. They also retain similar or greater concentrations of thiamine, riboflavin, vitamin B-6, folate and fibre.
Studies conducted at the South Dakota State University show that freezing blueberries makes their powerful antioxidants more available to the human body. This is because anthocyanins, the antioxidant compounds that make blueberries blue, are found in the skin of the berry.
Numerous studies have found that frozen berries contain the same nutritional elements as fresh berries that have just been harvested. However, this does not mean that “fresh” berries found in the produce section of a grocery store are a better choice than frozen berries.
Frozen blueberries can last up to 10 months in the freezer. However, for the best quality, plan to use frozen blueberries within six months of freezing. The longer the blueberries sit in the freezer, the greater the chance of freezer burn, which can ruin the taste and texture of the berries.
In particular, if enzymes that accelerate the oxidation of antioxidants such as vitamin C are inactivated by blanching, freezing causes negligible losses of these compounds [111].
It is observed that the decomposition of the antioxidant starts at around 120 °C. The DSC curve shows an evident endothermic peak at around 60 °C indicating the melting point of the compound, which is volatile in the temperature range of 100-240 °C.
Generally speaking, freezing destroys vitamins and minerals only to a very limited extent. Except for vitamin C, which is very fragile, and most of it is destroyed. Frozen fruits and vegetables, therefore, have very little vitamin C.
Ideally, freeze your blueberries as they are and wait to rinse them when you take them out of the freezer. If you do prefer to rinse the blueberries first, be sure to dry well with paper towels, then transfer them to freezer containers or resealable plastic bags for freezing.
While there are proper ways to store berries in the fridge to ensure optimal freshness, freezing berries is an even better way to extend their usefulness and ensure you'll have fresh fruit on hand whenever you fancy it. The main enemy of all berries is moisture.
You can leave blueberries at room temperature if you plan to eat them in the next day or so, but after that you should transfer them to the fridge—they can stay there for five to 10 days. Of course, you can freeze them if you want to keep them longer than that. Frozen blueberries will last about six months.
During the blanching process, heat-sensitive nutrients like Vitamins B and C may be diminished. Freezing may also reduce the antioxidant content of fruits and berries. Frozen fruits and veggies also often contain preservatives in order for them to maintain longer shelf life.
How many blueberries a day? Blueberries are something that can be enjoyed every day, and two handfuls of blueberries, which is the equivalent of 4 heaped teaspoons, counts towards one of your five-a-day portions. Research has found that eating a cup of blueberries a day reduces risk factors for cardiovascular disease.
Another benefit of blueberries is they are by far the easiest fruit to freeze, and when done properly they do not get mushy and retain a lot of their flavor. So whether they are from your own backyard, or you got a great deal at the market, keep those berries as fresh as possible all year long.
Yes they are! A daily handful of frozen blueberries offers nutrition and powerful benefits.
The secret to freezing blueberries without them getting that mushy texture is to let them fully dry after washing and let them chill on a baking sheet (or cookie sheet) in the freezer before storing in airtight containers.
The American Frozen Food Institute (AFFI) clarifies that frozen fruit is safe and ready-to-eat straight from the package, no need to wash it. This is due to its higher levels of acidity and sugar, making it unlikely that harmful bacteria could grow on it at freezer temperatures.
It is convenient to toss your blueberries in a Ziploc and toss them in the freezer. That works.
Cold Water Method
Fill a large bowl with cold water and submerge the bag of blueberries, then leave this setup on your kitchen counter for 15-20 minutes. The blueberries should be defrosted after this timeframe, but if not, refresh the cold water and repeat the process.
If you are wondering how how long can you freeze blueberries, if they are flash frozen and properly stored in a freezer bag they last about 6 months but if you freeze them with a vacuum sealer, they last a few months longer, about 12 months.
Vitamin B: Most kinds of vitamin B are lost during the canning process, but freezing traps the majority of complex vitamin B types, including niacin, riboflavin, biotin, folate, and B12 vitamins.
According to the USDA, 1 cup of frozen blueberries contains 13 grams of natural sugar and 4 grams of fiber. You may have noticed that they are higher in sugar than strawberries and raspberries. However, it is important to remember that the fiber in whole fruit helps to slow the absorption of sugar.
Nutrients in fruit are at their peak right after being picked. Because fruit is frozen quickly, it retains nutritional value. If your fresh fruit is truly fresh, the nutrient value may be similar. If your fresh fruit was shipped and sat on store shelves for a while, it may contain fewer nutrients.