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An almost complete dehulling (hull residue lower than 3%) of sunflower seeds, before oil extraction, reduces to a minimum both the transfer of pigments from hulls to the flour and the content of fiber in the finished product. In this paper some results of our work on the dehulling of high-oil seeds with an air-jet impact huller are presented. The effectiveness of dehulling has been evaluated as a function of characteristics of the seed (variety, moisture and so forth) and of operative parameters (impact velocity, etc.). The optical analysis of the impact of the seeds on the target was made by means of high-speed cinematography (about 8000 frames/see) to have a better view of the phenomenon and to measure the parameters of energy involved. The use of proper seed monentum, which is a function of the characteristic of the seed, can allow selective hull breaking with minimum kernel breakage. Almost complete hull-free kernels from high-oil sunflower seeds were obtained by means of a continuous dehuller-separator pilot plant.

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Removal of gossypol from cottonseed meal and fermentable sugars from soybean meal by butanol-HCl solution was tested. Acidic butanol treatment yields low gossypol cottonseed protein concentrates and low oligosaccharides soy protein concentrates, respectively. This procedure does not appreciably alter proteins, as it is shown by the comparison of electrophoretic patterns of albumins and globulins extracted from meal and corresponding protein concentrates.

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Horse liver alcohol dehydrogenase was reacted with glyoxal at different pH values ranging from 6.0 to 9.0. At pH 9.0 the enzyme undergoes a rapid activation over the first minutes of reaction, followed by a decline of activity, which reaches 10 "/, of that of the native enzyme. Chemical analysis of the inactivated enzyme after sodium borohydride reduction shows that 11 arginine and 11 lysine residues per mole are modified.At pH 7.7 the enzyme activity increases during the first hour of the reaction with glyoxal and then decreases slowly. Chemical analysis shows that 4 arginine and 3 lysine residues per mole are modified in the enzyme at the maximum of activation.At pH 7.0 the enzyme undergoes a 4-fold activation. Chemical analysis shows that in this activated enzyme 3 lysine and no arginine residues per mole have been modified.Steady-state kinetic analysis suggests that the activated enzyme is not subjected to substrate inhibition and that its Michaelis constant for ethanol is three times larger than that of the native enzyme. The possible role of arginine and lysine residues in the catalytic function of liver alcohol dehydrogenase is discussed.

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