The best bet in getting the most nutrients out of the food you eat is to eat only fresh foods, properly harvested and/or prepared. However, most people do not live on a farm or near one, which makes getting some fresh foods very difficult, particularly meat.
Refrigerating and freezing are two of the most common ways of preserving foods in modern society. Whether a loss of nutrients occurs or not, however, is more dependent on the process than the actual method. The U.S. Department of Agriculture (USDA) states that the freezing process does not destroy nutrients, and frozen foods are safe to eat after any length of time remaining frozen.
The USDA response is only valid as long as protocol is followed. Before vegetables are frozen, they go through a process called blanching that uses either hot water or steam to kill bacteria and destroy enzymes that cause food to spoil. This process itself causes some loss of nutrients, and the longer time between blanching and freezing, the more nutrients are destroyed. If the process is done quickly and efficiently, very little loss of nutrients occurs.
A study conducted at Penn State University shows that nutrients may deteriorate in the refrigerator, but the rate of deterioration depends on the specific nutrient. Biotin, Niacin, protein and carbohydrate deterioration is negligible. Other vitamins may deteriorate at a rate of up to 47 percent after eight days. This is a very acceptable rate since most fresh foods spoil before eight days in the refrigerator.
When it comes to nutrient loss in foods, other factors are more crucial than refrigeration. Proper harvest time is especially important in making sure the foods have sufficient nutrients to begin with. Both heat and light also destroy nutrients at a much greater rate than refrigeration. Many vegetables lose nutrients in low humidity. Because of these factors, frozen or refrigerated vegetables may actually have more nutrients than those kept at room temperature.
Posted 2844 day ago