Alternative sieving method for extraction of light filth from cheeses: collaborative study.
A collaborative study was conducted on an alternative sieving method for the extraction of light filth from cheeses. The alternative method was developed that is applicable to broad variety of cheeses. A 225 g test portion is dispersed in a solution of 5.7% HCl, Igepal CO-730, and Igepal DM-710. Digested cheese is wet-sieved on a No. 230 sieve. The residue is treated with Tergitol Anionic 4, transferred to 1% sodium lauryl sulfate solution, heated, and maintained at 65 degrees-75 degrees C for 10 min. The residue is washed with these 2 surfactants a maximum of 4 times until it is reduced to an amount that is filterable. The residue is filtered and the filter papers are examined microscopically at a magnification of ca 30x. Average recoveries by 9 collaborators for 3 spike levels of rat hairs (5, 10, and 15) were 80, 68, and 81%, respectively; for insect fragments (5, 15, and 30) recoveries were 97, 90, and 92%, respectively. The alternative sieving method for extraction of light filth from cheeses has been adopted first action by AOAC INTERNATIONAL.
Nakashima
M J
MJ
U.S. Food and Drug Administration, Division of Microbiology, Washington, DC 20204.
D000818:Animals; D002611:Cheese; D005374:Filtration / Q000379:methods*; D005506:Food Contamination / Q000517:prevention & control*; D006197:Hair; D006358:Hot Temperature; D006851:Hydrochloric Acid; D007202:Indicators and Reagents; D007313:Insecta; D051381:Rats; D012967:Sodium Dodecyl Sulfate; D013501:Surface-Active Agents
D007202:Indicators and Reagents; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D006851:Hydrochloric Acid