Extraction of light filth from oriental fish products containing spice: collaborative study

A collaborative study was conducted to validate a new method for the extraction of light filth from oriental fish products containing spice. A 100 g test portion is digested by boiling in a mixture of HCl, Igepal DM-710, and CO-730. Light filth is isolated by wet-sieving on a No. 230 plain-weave sieve with Tergitol, deaeration boiling in 40% isopropanol, and extracting with mineral oil-heptane (85 + 15) and 40% isopropanol in a Wildman trap flask. Three spiking levels for rat hairs and insect fragments were used in the study. For rat hairs, recoveries at the low, medium, and high levels averaged 80.0, 71.6, and 88.0%, respectively. Recoveries of insect fragments for low, medium, and high levels averaged 87.8, 83.7, and 89.4%, respectively. The method was adopted first action by AOAC International.