Frozen products come in handy when you don’t have time to peel, wash and slice the vegetables or go to the fishmonger. And with the Covid-19 crisis, their consumption has further jumped by almost 8% in volume, according to the IRI-The frozen world barometer. But is this method of preservation in extreme cold, which enjoys a good image, as healthy as we imagine? Yes, explains Nathalie Négro, head of the nutritional center of the Brides-les-Bains thermal baths (Savoie)… As long as you respect a few rules of good practice.
Do frozen products provide good nutritional intake?
Nathalie Negro. Frozen fruits and vegetables have a priori a lower nutritional density than their fresh equivalents, insofar as they undergo blanching before freezing intended to destroy the enzymes and germs liable to alter the product. This step does not cause any loss of fiber and minerals, but it does generate a loss of vitamin C and certain group B vitamins. Spinach thus loses 28% of its vitamin B9 and broccoli 10%. In contrast, carrots and red peppers contain more beta-carotene right after freezing, which increases their antioxidant potential. But since frozen fruits and vegetables are processed immediately after picking, they are in no way inferior to fresh products, which sometimes suffer significant vitamin losses during storage in warehouses, during transport and on market stalls. Oily fish suffer for their part from freezing: their iodine, omega-3 fatty acid and vitamin E contents are reduced more than in the fresh section.
Can we store frozen foods indefinitely?
It is not because a product is frozen that it can be consumed several years later. Deep freezing slows down the aging of food but it does not completely prevent it. After a year, the losses of vitamin C in vegetables can reach 30% and those of salmon in vitamin E, 27%. It is therefore necessary to regularly check the state of its frozen stocks and to rotate the products. The ideal is to eat them after 3 to 6 months maximum. It is also better not to overfill your freezer otherwise the air circulates less well between the products and the optimum temperature of -18 ° C is no longer guaranteed.
What other precautions should you take?
Freezing stops the proliferation of pathogenic bacteria but does not kill them. This is why you should never refreeze a thawed product, even if it has been cooked in the meantime. Another rule of caution to observe: never thaw at room temperature a pastry containing cream (Paris-Brest, éclairs, etc.). Defrosting should be done in the refrigerator, even if it takes longer. When shopping, take the frozen food last, just before going to the checkout in order to preserve the cold chain as much as possible. And examine the composition of the products indicated on the packaging. Avoid ready-made meals that contain more than 5% fat, the equivalent of one teaspoon of oil per 100 g of product. For breaded fish, make sure they are made from fillets, not reconstituted fish.
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