Dry rehydratable film for enumeration of total aerobic bacteria in foods: collaborative study.
A rehydratable dry-film plating procedure for aerobic plate counts has been compared to the standard agar plate method (966.23B and C, 15th ed.; 46.014-46.015, 14th ed.) in a collaborative study by 12 laboratories. Each laboratory analyzed the normal microflora of 3 samples in duplicate for 6 products. The aerobic plate counts ranged from 1.0 x 10(3) to 1.0 x 10(8) cfu/g. The products were flour, nuts, frozen raw shrimp, spice, frozen raw ground turkey, and frozen and refrigerated vegetables. Repeatability standard deviations of the 2 methods did not differ significantly for 13 of 18 test samples. For 1 shrimp and 2 turkey samples, the dry-film method had lower repeatability variances (P less than 0.05) and for 1 spice sample the agar method had lower repeatability variances (P less than 0.05). Relative standard deviations of repeatability were between 1.7 and 15.5% for the dry-film method and 1.2 and 16.0% for the agar method. Relative standard deviations of reproducibility ranged from 2.4 to 23.4% for the dry-film method and 2.3 to 18.8% for the agar method. The dry rehydratable film method has been adopted official first action for determination of the aerobic plate count.
Curiale
M S
MS
Silliker Laboratories, Chicago Heights, IL 60411.
Sons
T
T
McAllister
J S
JS
Halsey
B
B
Fox
T L
TL
D000818:Animals; D001420:Bacteria, Aerobic; D001431:Bacteriological Techniques / Q000295:instrumentation; D003212:Condiments / Q000032:analysis; D033364:Decapoda; D005433:Flour; D005516:Food Microbiology; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis; D009754:Nuts; D014422:Turkeys; D014675:Vegetables / Q000032:analysis
D007202:Indicators and Reagents