Discuss the different packaging materials used for foods with their advantages and disadvantages.

1. 1 · Open in two lines. Packaging encloses food to contain, protect, preserve and inform. The material chosen decides how long and how well the food keeps.
2. 2 · Functions and levels.
   • Contain, protect, preserve, inform, convenience.
   • Primary, secondary and tertiary packaging.
3. 3 · Glass and metal.
   • Glass: inert, clear, reusable; heavy, breakable.
   • Metal cans and foil: full barrier, can be sterilised; corrosion, cost.
4. 4 · Paper and plastics.
   • Paper and board: cheap, light, printable; weak when wet.
   • Plastics (LDPE, HDPE, PP, PET): light, cheap, sealable; gas permeability, migration, pollution.
5. 5 · Draw a comparison table. [Table: material | uses | advantages | disadvantages]
6. 6 · Laminates and newer methods. Tetra Pak, retort pouches; vacuum, MAP, aseptic, active and intelligent packaging; biodegradable leaf plates.
7. 7 · Nutrition link. Light-proof, airtight packs protect vitamins and oils; read labels for sodium, sugar and fat.
8. 8 · Close in one line. The best package protects the food, informs the buyer and does least harm to the environment.

Scoring tip: One table of six materials with two pros and two cons each is the most efficient way to score.