Fresh versus Frozen Foods
There is an age-old debate among chefs, cooks and scientists that asks the question, “Which is better: fresh or frozen?” Like most of these kinds of debates, personal preferences seem to over-ride the science and the science tells us that how food is frozen and the type of food to be frozen influences the result.
Two key arguments rage in the debate. One is centered on the nutritional value of food that is frozen versus fresh. Second, frozen foods, which certainly do suffer from freezer burn and the like if left too long or frozen improperly, may be affected by freezing water in the food and damage by the resulting water crystals.
Nutritional Value of Frozen Foods
Anything that is fresh should have more nutrition than something that isn't — the older food gets, the more nutrition it loses. But frozen food can have more nutrition if it's frozen quickly and efficiently, because it decays more slowly. Fresh food that's been kept longer will have less nutrition than frozen.
Water Crystals is Frozen Foods
Another issue is that freezing creates ice crystals. Large crystals that form when food is frozen slowly, or partially thawed then refrozen, or repeatedly frozen, or held at not-quite-low-enough temperature - these crystals tear cells and lead to more fluid leaking out of the food when it cooks.
Arguments in the debate first require a segmentation of foods. There are different theories and opinions for red meats, white meats, vegetables and fish. Probably one of the most common pieces of food we all store in the freezer, meat fares very well when frozen. However, red meat stays better in the freezer than white meat. White meat such as chicken and pork lacks high fat content, and therefore has higher water content. Water in the meat freezes and turns to crystals, which eventually alters the structure of the meat. Looking at freezing vegetable first, the arguments are as follows:
Vegetable Freezing Pros and Cons
- Can taste better than frozen.
- Usually have a better texture.
- If you've picked them straight from the garden, they will be bursting with nutrients.
- But produce can be more than a week old by the time we eat it.
- Nutrients are 'frozen in' soon after picking.
- Convenience (can store for months)
- Allows us to have vegetables and fruit that are out of season
- Adds variety to our diet.
After defrosting, vegetables can have a soggy texture, because ice crystals damage the vegetable cell walls.
White meat such as chicken and pork lacks high fat content, and therefore has higher water content. Water in the meat freezes and turns to crystals, which eventually alters the structure of the meat. However, in a study in 1981 by the National Center for Biotechnology Information, a professional taste panel could not significantly distinguish between fresh and frozen thawed paired halves of roast poultry. Objective testing by shearing and expressible moisture losses also failed to show a significant difference.
Frozen FishTo better understand freezing's effect on fish, "it should be noted that all wild-caught fish – by law – has to be frozen in order to kill parasites." says Aliza Green, a Philadelphia-based chef and author of "The Fishmonger's Apprentice".
In other words, unless you’re catching it yourself, there is no such thing as fresh, wild-caught fish. Farm-raised fish, on the other hand, often is shipped and sold without being frozen first. Lean, white varieties such as cod tend to become dry when frozen, but the fattier types, such as tuna and salmon, should be fine even when frozen. Higher fat content seafood such as prawns, shrimp and other crustaceans freeze quite well and retain their flavor consistently.
According to Sustainable Agriculture Research & Education in 2012, "Our experience has been that there is no difference in quality [between frozen and fresh]. In fact, our frozen beef may be more tender because fresh, conventionally marketed beef goes through its aging process during trans-port.". Frozen Meat must be aged before frozen. This results in variable aging periods for fresh meat versus the consistency of frozen. Stanbroke Steak School further states, in 2018:
Some people think that freezing dry-aged beef is a bad idea because it can further dry out your already dry-aged steak, but in actual fact, having less water in the cut is a good thing when it comes to freezing. Because it doesn’t have the water that a normal fresh cut of beef does, it isn’t affected in the same way.
How to Freeze and Thaw
There seems to be consensus that how it is frozen and thawed is a strong determinant of the quality of frozen meats. According to Jerry Lanuzza, dean of culinary education at Johnson & Wales University in Charlotte, N.C, " If you handle it right, frozen meat should be just as good as fresh." The answer is to freeze the meat very quickly and thaw it in the refrigerator over night.
To freeze meat faster at home, wrap it well to keep out air, then put it in a single layer on a metal sheet that you have placed in the freezer for a few hours. Once frozen, put it in another bag, vacuum seal-able if you have it, and replace in the freezer. Of course, be certain the freezer maintains temperatures well below freezing.