The Principle Of Plastic Wrap
Plastic wrap delays food spoilage and preserves its freshness by isolating air, reducing moisture evaporation, and blocking external contaminants. Its main functions include:
1. Oxygen isolation: Prevents oxygen from coming into contact with food, slowing oxidation reactions and preventing food from spoiling, discoloring, or developing an unpleasant odor.
2. Moisturizing: Reduces moisture loss, keeps food moist, and prevents drying out.
3. Isolate microorganisms: prevent external microorganisms and dust from entering the food surface, reducing the risk of spoilage.
4. Sealing: locks in the aroma of food and prevents it from mixing with other foods.
Commonly Used Plastic Wrap Materials
1. Polyethylene (PE):
Features: Non-toxic, odorless, highly safe, and temperature-resistant between -60°C and 110°C.
Applications: Suitable for refrigeration and short-term preservation. Not recommended for use in high-temperature environments (such as microwave heating).
2. Polyvinyl Chloride (PVC):
Features: High transparency, good flexibility, and strong adhesion, but may contain plasticizers (choose a food-grade, non-toxic product).
Applications: Widely used in the packaging of fresh produce, fruits and vegetables, but cannot be in direct contact with high-fat foods or heated at high temperatures.
3. Polyvinylidene Chloride (PVDC):
Features: Stronger barrier properties, effectively preventing oxygen and moisture penetration, and good temperature resistance.
Applications: Commonly used to preserve premium foods (such as meat and dairy products), but is more expensive.
How To Choose Plastic Wrap
1. Food Safety:
Confirm the product is food-grade cling film and avoid any harmful plasticizers (such as phthalates).
PE material is generally safer and suitable for daily household use.
2. Application Requirements:
Refrigerated Foods: PE or PVC materials are suitable, as they offer good flexibility and adhesion.
High barrier properties are required: PVDC material can be used to better extend the shelf life.
Microwave heating: Use plastic wrap marked "high temperature resistant", such as PE material suitable for microwave ovens, and avoid using PVC.
3. Pay Attention To Labels:
Check the packaging for food contact certification (such as FDA certification or other food safety symbols).
Select the appropriate temperature resistance range according to the temperature.
The Main Purpose Of Plastic Wrap
1. Food Preservation:
Wrap fresh food, cooked food, fruits, vegetables, bread, etc. to extend food storage time.
2. Freezer Protection:
Prevent moisture loss from the surface of frozen foods and prevent freezer burn.
3. Prevent Odor Transfer:
Wrap different foods separately to prevent odor transfer during refrigeration or storage.
4. Sealed Heating:
You can microwave food using heat-resistant plastic wrap to retain moisture (make sure the plastic wrap does not come into direct contact with the food).
5. Non-Food Uses:
Moisture-Proofing: Used to protect books, clothing, or electronic products.
Temporary Sealing: Wrap unused bottles and containers to prevent leakage or contamination.
Precautions For Using Plastic Wrap
1. Avoid contact with high temperatures: Most plastic wrap is not suitable for direct contact with high-temperature food and may release harmful substances.
2. o not wrap oily foods directly: especially PVC materials, which may react with fat and dissolve harmful substances.
3. Not suitable for long-term storage: Plastic wrap is suitable for short-term preservation, and it is recommended to use professional storage containers for long-term storage.
