EVALUATION OF HEATED SOYBEAN MEAL USING CRESOL RED TECHNIQUE

Occasional problems with improperly heated soybean meal persist even though methods and rather good evaluation procedures are available. The technique of Olomucki and Bornstein (1960) in volves absorption of cresol red during a shaking process of a specific grind on soybean meal and will evaluate overheated as well as underheated soybean meal. Attempts have been made to determine if the (mg cresol red absorbed per g meal) reported was the lowest safe level. Unheated soybean meal samples averaged 2.55. Genetically uniform day old chicks fed heated soybean meal sample testing 3.3 averaged 61.9 g at one week compared with 68.3g for soybean meal testing 3.6. Poults fed the same meals averaged 129g and 138g respectively at one week. In both tests at two weeks these differences had decreased to only 266 vs 271. Effects on pancreas Weights were not significant except with raw soybean meals.

International Mycotoxin Check Sample Program. Part I. Report on the Performance of Participating Laboratories

Three aflatoxin-contaminated samples, raw peanut meal, finished peanut butter, and white corn meal, were analyzed by 139 laboratories in 34 countries. Sufficient data were obtained to permit a statistical comparison of the performance of laboratories using the BF, CB, and Pons methods and those using high performance liquid chromatography for quantification. A raw peanut meal sample showed no significant differences among means for laboratories using the four methods, and a white corn meal sample showed only one such significant difference; however, a finished peanut butter sample containing less than 10 μg total aflatoxins/kg showed 10 significant differences among means for laboratories using the 4 methods considered

Gas-Liquid Chromatographic Determination of Selenium in Biological Materials, Using 4-Bromo- and 4-Chloro-1,2-Diaminobenzene as Derivatizing Reagents

A method is described for the gas-liquid chromatographic determination of traces of selenium in marine biological materials. The method is based on the reaction of Se(IV) with bromo- and chloro-substituted 1,2-diaminobenzenes. The benzoselenadiazoles so formed are sensitive to electron capture detection. The sample is digested in a nitric-perchloric acid mixture and selenium is reduced to the IV oxidation state. Different aliquots of the digest solution are reacted with either 4-bromo- or 4-chloro-l,2-diaminobenzene to quantitatively form the corresponding 2,1,3-benzoseIenadiazole. Recovery of added selenite to a fish meal sample was 95% for the bromo derivative and 101% for the chloro derivative. Different portions of a well mixed fish meal sample were analyzed in independent laboratories by the fluorometric method and by atomic absorption spectrophotometry (hydride generation). The following mean values (μg/g) were found: present method 1.89, fluorometric method 1.91, atomic absorption method 2.1. The lower limit of detection for the method described was 13 ng, using the bromo derivative, and 27 ng, using the chloro derivative.