Vacuum bag

A vacuum bag is a flexible pouch that is sealed after a vacuum machine has drawn most of the air out. Reducing contact with oxygen helps slow oxidation and spoilage, especially in fresh and chilled foods.

Typical structure

Most vacuum bags are three-side seal pouches made from OPA (nylon) laminated or co-extruded with PE. The nylon contributes oxygen barrier and puncture resistance, while PE provides the seal and moisture barrier. EVOH can be added for a higher oxygen barrier. Bags for domestic or external-suction machines have an embossed side that creates air channels; chamber machines can use smooth bags.

Applications

Fresh meat, poultry, fish, cured meats, cheese, coffee and dry foods for long storage, plus moisture-sensitive technical parts.

Considerations

• Vacuum packing complements, but does not replace, refrigeration or freezing.
• Bone-in meat and sharp edges need thicker or tougher film, usually specified in microns.
• Cook-in or pasteurised products need a structure rated for that heat; full sterilisation calls for a retort pouch.
• Ask for food-contact declarations and migration data for food uses.