Defrosting the food, you’re about to cook is one of the most important procedure you should do. Anyone who knows what they are doing when it comes to cooking knows the importance of making sure the food about to be cooked is of room temperature.
But if you’re not careful, serious deterioration can occur when thawing. It is because of this, that several new thawing technologies have been reviewed. Example of these technologies are; Ultra-high pressure assisted thawing, ultrasound-assisted thawing, ohmic thawing and radio frequency thawing. However, more research is needed to make them more applicable to thawing of food industry.
The traditional way of thawing is rather slow, expensive and inconvenient. Moreover, thawing can lead to physical and chemical changes that can affect the overall quality of frozen foods if not done right. There are of course newer thermal and nonthermal food thawing methods such as microwave, dielectric, or resistive thawing that have the benefit of being rapid and convenient. However, these methods have challenges like preferential surface heating, high energy consumption and runaway heating.
Thermal methods (ultra-high pressure, ultrasound, vacuum thawing) leads to lesser food quality denaturing but also have poor penetration into the samples and localized heating and maybe complex to do. Besides, suboptimal thawing may accelerate physiochemical changes and microbial growth, which decreases the quality of the frozen foods.
But before you even think of thawing that food of yours, there’re few things you should never do
- Don’t try to run your ingredients especially meat under hot water as it can accidentally bring the temperature too high which can be harmful because bacteria will multiply.
- Watch out for the danger zone temperatures that are between 40 and 140 degrees Fahrenheit where bacteria like to grow and multiply rapidly. To be safe, but a meat thermometer and test the internal temperatures making sure your food does not go above 400 F before cooking.
- Do not cook meat or any perishable food substance that you left on the counter for the day or even for more than 2 hours. This is because, even if the food’s inner surface remains frozen as the item thaws on the counter, the outer layer of the food maybe in the danger zone (above 400F) where the bacteria will multiply rapidly.
How to thaw frozen food safely
When thawing food, it is considered best practice to plan ahead and thaw in the refrigerator where the food will remain at a safe constant temperature of 400F. The amount of time the food will take to thaw depends on the food. For example, a large frozen item will take longer to efficiently thaw compared with smaller food substance. There are things to consider when using this method:
- There are areas in the refrigerator that are colder than others.
- The higher the temperature, the less amount of time the food will take to thaw. For example, food will take longer to thaw in a refrigerator set at 350F compared to when set at 400F. It is to be noted that, no matter what, even if you’re in a hurry, the temperature should not be set at above 400F.
There are also other acceptable ways to thaw frozen food safely (prevents bacterial overgrowth that can lead to foodborne illness) according to the National restaurant association. These methods are:
- Cold water thawing – Under constant cold running water (preferably under temperature of 700F or lower) or fully covered/immersed in a cold bath to prevent bacteria from thawed liquid pooling on the food. When you use this method, the food should be in a leak-proof. package/plastic bag that should be changed after every 30 minutes to continue thawing. The food should then be cooked immediately after thawing. You cannot refreeze again when raw after using this method but should be refreeze only after cooking. This method is much faster than the refrigeration process but requires more attention.
- Microwave thawing – Thawing In the microwave if you want to cook the food immediately after thawing.
- Cooking without thawing – As a part of cooking process whereby, you cook the food directly without thawing
Here is a clip for thawing food properly.
How defrosting occurs
Thermodynamic goes hand in hand with defrosting. To explain how defrosting occurs, you need to understand the logic behind thermodynamic. Basically, it states that two objects/substance with different temperatures and in the same room will try to become the same temperature. When the temperature of the surrounding environment is higher than the frozen substance, the frozen item will gain some heat/temperature while the surrounding environment loses heat until the two are of the same temperature. This starts the defrosting process.
When you press the defrosting button on a microwave, the oven’s power is automatically set to about 30 to 50 percent lower than its full power. This low setting allows the heat waves to penetrate the center of the food first thawing it, before cooking its outer layer. Most of these buttons require you to know the approximate weight of the food.