Improved method for extraction of light filth from 90% rye brain crisp bread

A new technique has been developed for the analysis of light filth in a high bran rye product. Compared with the official AOAC method, 44.063, the plates were much easier and less time-consuming to read microscopically (about 8 min compared with about 34 min for the AOAC method). Average recoveries for insect fragments and mouse hairs were 93.4 and 90.8%, respectively, with coefficients of variation (32 samples) of 7.7 and 7.9%, respectively. Average recoveries by the AOAC method were 87.5% for insect fragments and 62.5% for mouse hairs, with coefficients of variation (6 samples) of 7.9 and 14.1%, respectively. A ruggedness test for 7 variables in the extraction indicated that 2 variables caused significant changes in the results.