ABSTRACT
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.
Subject(s)
Cheese , Filtration/methods , Food Contamination/prevention & control , Animals , Hair , Hot Temperature , Hydrochloric Acid , Indicators and Reagents , Insecta , Rats , Sodium Dodecyl Sulfate , Surface-Active AgentsABSTRACT
Results are reported for a collaborative study of a method for the extraction of light filth from oriental sauces containing soy sauce, thickeners, and spices. A 100 g test portion is pretreated in a 2% solution of Tergitol Anionic 4 over a steam bath, and oils are removed by wet-sieving on No. 230 sieve. Filth is isolated from 40% isopropanol by using Na4EDTA and mineral oil. Average recoveries by 9 collaborators for 3 spike levels of rat hairs (5, 10, and 15) were 84, 78, and 79%, respectively; for insect fragments (5, 15, and 30), recoveries were 92, 95, and 96%, respectively. The method was adopted first action by AOAC International.
Subject(s)
Condiments , Food Additives , Food Contamination , Spices , 1-Propanol , Edetic Acid , Food Analysis/methods , Mineral OilABSTRACT
Results are reported for a collaborative study of a method for the extraction of light filth from tofu. A 100 g test portion is digested in HCl solution with Igepal CO-730 and Igepal DM-710. Hairs and insect fragments are isolated by wet-sieving on a No. 230 sieve, dispersing remaining residual product with Aerosol OT 75%, and filtering. Average recoveries by 9 collaborators for 3 spike levels of rat hairs (5, 10, 15) were 80, 78, and 84%, respectively; for 3 spike levels of insect fragments (5, 15, 30), recoveries were 97, 99, and 99%, respectively. The method was adopted first action by AOAC International.
Subject(s)
Food Contamination , Glycine max , Food Analysis/methodsABSTRACT
Results are reported for a collaborative study of a method for the extraction of light filth from spirulina (a blue-green alga) powder and tablets. A 50 g portion of either powder or tablets is dispersed in water, and then boiled with dilute HCI solution. Hairs and insect fragments are isolated by wet sieving on a No. 230 sieve, flotation with mineral oil, and washings of the mineral oil in a percolator. Average recoveries by 12 collaborators for tablets and powders were 70.6 and 70.2%, respectively, for 10 rat hair spikes and 68.3 and 84.4%, respectively, for 20 insect fragment spikes. The method has been approved interim official first action.
Subject(s)
Cyanobacteria/analysis , Food Contamination/analysis , Powders/analysis , Tablets/analysisABSTRACT
Results are reported for a collaborative study to extend AOAC method 44.A06-44.A08 to extraction of light filth from whole leaves of alfalfa, lemon balm, papaya, and spearmint. A 5 g (spearmint) or 10 g (alfalfa, lemon balm, papaya) test portion is defatted with isopropanol in a simple reflux apparatus. Rat hairs, insect fragments, and whole insects are isolated by wet sieving on a No. 230 sieve, a deaerating boil in 40% isopropanol, and flotation with mineral oil-heptane (85 + 15) from Tween 80-Na4EDTA (1 + 1) and 40% isopropanol in a Wildman trap flask. Each product was spiked at a different level. For rat hairs, recoveries averaged 82.2% from alfalfa, 88.9% from lemon balm, 80.6% from papaya, and 79.6% from spearmint. Recoveries of whole or equivalent insects from these products averaged 66.1, 218.8, 69.4, and 85.4%, respectively; recoveries of insect fragments from these products averaged 89.6, 94.4, 94.1, and 88.1%, respectively. The method has been adopted official first action for extraction of light filth from whole leaves of alfalfa, papaya, and spearmint. The extension of the method to lemon balm was not recommended because of interferences by intrinsic whole insects, which were the same species as the spike material.
