SOP: Determination of Resistance of Lacquer to Sulphur Staining

GIFSQ — Global Institute for Food Safety & Quality

Principle

Resistance of lacquer to stains caused by sulphur-containing foods during processing is tested by packing sulphur-containing foods in lacquered cans or with test panels in Kilner jars, processing as specified, and examining for adhesion and staining.

Procedure

Prepare test panels and place in Kilner jars — lacquered cans may also be used

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1. Onion: place 100 g of peeled prepared onions in Kilner jars; fill with hot water (90°C) leaving 0.25 in. head space; immerse the panel in the jar in cylindrical form and close; repeat the test using an A-1 Tall (307 × 411) lacquered can in place of the Kilner jar and test panels; process the cans and jars at 120°C for 90 min and cool; examine after 2 days

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1. Cauliflower: blanch prepared cauliflower for 2 min in boiling water; fill 100 g into the Kilner jar; immerse lacquered panels in the jar; cover with 2% brine, close the jar, process at 115.5°C for 30 min and cool; repeat the test using a lacquered can in place of the Kilner jar and test panel

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1. Ox kidney: place 2 oz of minced ox kidney in 301 × 411 cans or Kilner jar with test panel; cover with 2% hot brine, seal and process at 115.5°C for 3 hr; cool and examine the can

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Consider the material satisfactory if the film stays firmly stuck down and staining stays within bounds

References

1. Sturge, P. A. J., Food Can Lacquers, p. 20.
2. Davis, E. G., Food Pres. Quart., 18, 66 (1958).