At present corn is graded organoleptically into “normal” and various “off‐odor” categories. The possibility of classifying corn odor on the basis of gas chromatographic patterns of headspace volatiles was studied using 60 samples of corn and statistical step‐wise discriminant and regression analyses. Three options for subdividing the patterns into variables and several transformations for quantitation of peak areas were explored. To obtain optimum odor classification, five to seven gas chromatographic features were necessary. When applied to additional samples, classification at an error probability P < 0.05 (above 95% confidence level) was obtained for some statistical models. Thus, an objective system is feasible for classification of grain odor.

No abstract

Two commercial cottonseed meals, a direct solvent-extracted meal and a screw-pressed meal, were subjected to successive solvent-extraction procedures by using an acetone/hexane/water azeotrope to reduce their cyclopropenoid fatty acid content. The two original commercial meals, as well as a double-and triple-extracted portion, were then incorporated at 20 wt % levels in the rations of laying hens. A negative control containing 25% soybean meal and a positive control containing 2 % refined cottonseed oil of known CPA content were also employed. During a fourweek feeding period the eggs were collected during the third and fourth week and stored at 35F for periods of three and six months. Overall egg quality and the fatty acid distribution of the extracted yolk lipids were determined after the three-and six-month storage period.

Chemical inactivation of cyclopropenoid fatty acids in commercial cottonseed meals was explored with three classes of compounds : anhydrous gases, organic acids and sulfhydryl compounds. Of the reagents screened, sulfur dioxide reduced the cyclopropenoid content by over 90% while free cottonseed fatty acids and thioglycollic acid reduced the cyclopropenoid fatty acid content by over 30%. Large batches of the above three selected meals, as well as a control commercial screw-pressed meal, were then incorporated at 20 wt % levels in the rations of laying hens. A negative control containing 25% soybean meal and a positive control containing a 2% refined cottonseed oil of known CPA content were also employed. During a four-week feeding period, eggs were collected during the third and fourth week and stored at 35 F for periods of 3 and 6 months. Overall egg quality and the fatty acid distribution of the yolk lipids were determined after the 3 and 6 months' storage periods.

A rapid analytical procedure for determining the residual cyclopropenoid fatty acids (CPA) in cottonseed meal has been developed. The procedure involves room‐temperature extraction of crude CPA‐containing lipids with a hexane‐water‐acetone azeotrope solvent, followed by a benzenemethanol wash. The crude lipids are then converted to methyl esters by methanolysis with sodium methoxide. Extraction with petroleum ether, followed by washing with aqueous acetone, results in a substance which is free from interfering materials. The purified methyl esters are then analyzed for CPA by a spectrophotometric modification of the Halphen reaction.