Packaging for Oil and Fat Foods and Condiments
(1) Cooking Oil Packaging
Cooking oils include soybean oil, rapeseed oil, peanut oil, sesame oil, salad oil, etc. Traditional cooking oils were all packaged in glass bottles, but in recent years, they have been replaced by plastic packaging containers.
Commonly used containers include PVC, PET, PS bottles, and PE injection molded containers. New packaging materials and containers for oils and fats are being developed.
Containers made of paper/PE/ionic resin composite materials have good heat sealing properties and are resistant to oils and fats; PA (or CPP)/Al/ionic resin can be used as box liners for packaging oils and fats, and can also be made into stand-up pouches. Large-volume packaging for oils and fats all use iron drums.
(2) Packaging for Peanut Butter, Sesame Paste and Other Oily Foods
Peanut butter, sesame paste, and others are foods with high oil content, which are prone to oxidation and rancidity, and produce a rancid smell. The traditional packaging method for these foods is to use glass jars or cans and add an appropriate amount of antioxidants.
Modern packaging for peanut butter, sesame paste, and other oily foods widely uses plastic films and thermoformed containers, supplemented by vacuum and gas flushing packaging technologies, which can effectively inhibit the oxidation and rancidity of the packaged food.
When selecting packaging materials, attention should be paid to the influence of environmental temperature and humidity on the gas permeability of the materials, so that the packaged products can maintain a stable atmosphere inside the package as much as possible under changing temperature and humidity conditions, ensuring the quality of the product within its shelf life.
For example, for nitrogen-packed peanut butter and sesame paste, PT/PE film can be used when the relative humidity of the environment is 50%, while PA (PET)/PE, BOPP/Al/PE (EVA) and other composite films with better gas barrier properties should be selected when the relative humidity of the environment is 80%.
(3) Packaging for Soy Sauce, Sauces, and Vinegar
Soy sauce, sauces, and vinegar are now basically all mandated to be packaged in glass bottles or other small packages, which can avoid contamination during storage and transportation; hard polyvinyl chloride bottles and biaxially oriented polypropylene bottles can also be used.
Currently, the shelf life of plastic soft-packaged soy sauce and vinegar can reach 6 months.
(4) Packaging for High-end Condiments such as Chili Sauce, Ketchup, and Mayonnaise
Chili sauce, ketchup, and mayonnaise contain rich nutrients and are prone to spoilage and off-flavors, requiring packaging materials with high gas barrier properties.
In addition to the commonly used glass bottle packaging, multilayer blow-molded containers such as PA/PE, PE/EVAL/PE co-extruded blow-molded bottles have been developed abroad for packaging these condiments.
Thermoformed containers made of composite sheet materials are also commonly used for packaging chili sauce condiments.
