LPT 321: Meat Science (1+1)

RUST OR DAMAGE

• Rust 
  • Can showing external rust require careful consideration and it is conditions particularly liable to occur beneath can labels, when the adhesive contains hygroscopic substances.
  • Judgement
    • Can in which the external surface rusted without noticeable pitting of iron may be released for immediate sale and consumption.
    • But if the rust is removed with a knife and inspection with a hand lens reveals the iron plate to be definitely pitted, there is dangerous of early perforation and the can should be condemned.
    • Minute perforations of the plate to spoilage of the can content.
  • Pin holing may originate from the outside but also from the inside of the can where the tin plating is imperfect or has been fractured during seaming, and in this case lacquers lining aggravates the trouble, as the cracks which occur in the lacquer aids in concentrating the chemical action on a small area.
  • A can, which is a leaker or pin holed, may occasionally seal itself by blocking of holes with the contained foodstuffs, and may then proceed to blow up.
  • Such self-sealing can may blow early in its life, generally within the first few months.
• Unfilled cans
  • Where unfilled cans are stored and allowed to rust internally before being filled, the can edges may become rusted, with the result that during processing a chemical action may take place between the rust and meat juices and give rise to an unsightly grey precipitate of iron phosphate in the meat jelly.
• Damage
  • Considerable significance should be attached to cans damaged by rough handling, the important factor in their judgement being, the extent and location of the damage.
  • Marked deformation of the seam of the can is attended by considerable risk of leakage.
  • Judgement
    • Can showing seam damage should be condemned.
    • Slight indentations on the can body are permissible, but severe dents on the body may cause seam distention with danger of leakage and such can should be rejected.
    • Any can having a dent at one end should also be rejected for it is possible to reduce a springer to normal, at any rate temporarily, by hitting it upon the corner of a box.
    • Nail holes in cans cause during closing of packaging cases may also be encountered, and such cans should be rejected even if the contained foodstuffs appear perfectly normal.
    • It is a wise action to reject any can which is in the least suspicious or which shows lack of concavity of the end.