Composition of the carbonyl compounds of extraction cottonseed meal
SummaryOn the basis of a quantitative analysis of the volatile carbonyl compounds present in acetone-treated meal it has been shown that they contain a total of about 11 compounds, the main ones of which are acetone and mesityl oxide.It has been established that the moist heat treatment of extraction meal does not lead to the complete elimination of these compounds, and under severe conditions it actually leads to an increase in the amount of carbonyl compounds through degradation of, mainly, the fatty fraction of the meal.The amount of assimilable lysine in the meal decreases simultaneously.
Determination of residual solvent in oilseed meals and flours: III. Isopropanol
A relatively simple volatilization procedure is described for the determination of residual isopropanol in oilseed meals and flours. A 1 g sample is placed in a 100 ml serum bottle, 200 µl of distilled water containing 0.075 mg of ethanol is added and the bottle is sealed with a rubber stopper and heated at 110 C for 1 hr. A 2 ml aliquot of the headspace gas is analyzed by gas chromatography using the added ethanol as an internal standard. Values determined by this procedure for three cottonseed, two peanut and two fish meals or flours which had been processed with isopropanol, ranged from 10 to 12,000 ppm and were of the same order of magnitude as values determined by a modification of the Todd azeotropic distillation procedure. Advantages of the volatilization over the azeotropic distillation procedure are that less operator and gas chromatograph time are required per analysis.
Determination of residual solvent in oilseed meals and flours: I. Dimethyl formamide extraction procedure
A procedure is described for determination of residual acetone and hexane in cottonseed and soybean meals and flours by extraction of the residual solvent with dimethyl formamide (DMF)-water (95∶5) followed by gas liquid chromatography analysis of the DMF extracts. A representative group of samples was analyzed both by this procedure and one employing iso-octane as extractant. In all cases where residual solvent was found, the amount was markedly greater when aqueous DMF was the extracting solvent.