Oxidation of soybean lipids catalyzed by lipoxidase was prevented by heat treatment of soybean meats, which were then ground to give a full‐fat soy flour free of rancid odor and flavors. Our previous studies showed that lipids in cracked, dehulled, soybeans rapidly oxidized after the lipoxidase system was activated by increasing moisture content to 20%. A series of experiments are reported in which various heat treatments were evaluated for effectiveness of lipoxidase deactivation. Dry heat to 212 F, steaming, or both, deactivated lipoxidase to give flours that had low values of peroxide, conjugated diene and free fatty acid and had good flavors after 2 years’ storage. Wet heat alone was also an effective treatment, whereas wet heat preceded by dry heat at 180 F gave poor flavor stability after 2 years. Gas liquid chromatography studies gave evidence that the rapid formation of volatiles in full‐fat soy flours was catalyzed by an enzyme system. A 10 member taste panel was able to detect significant flavor and odor differences between oxidized and nonoxidized samples.

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A processing method for preparing full-fat soybean flours for human consumption by a new extrusion-cooking method was developed. Biological evaluations were made of samples produced experimentally by this method to determine the best conditions for preparing a product of maximum nutritive value and stability. Twelve processed full-fat soybean flours, prepared under different conditions, were evaluated by means of chemical analyses, biological assays, available lysine content, organoleptic and bacteriological test s~ and oxidative stability storage tests. Flour of high nutritive value and good stability can be prepared by preheating unextraeted soybean flakes or grits to 200-212F, premixing and adding sparge steam at 212F to adjust moisture content to 18-21%, extruding for 1-1.5 rain with final extrusion temp reaching 250-290F, cooling, drying and grinding. Clinical testing of the flour with infants up to 12 months of age has begun in two Far Eastern countries on a fairly extensive scale,

A method is reported for removingepi‐progoitrin, the major glucosinolate, from crambe seed meal. Defatted meal was cooked and water extracted or treated with soda ash and then water extracted. Although soda ash aided destruction and removal of glucosinolate factors, there was a 28% reduction in total lysine. In animal feeding tests designed to reflect differences due to toxic factors, soda ash treated and water extracted meals gave the best results. No toxicity was apparent in rats and chicks fed these meals in nutritionally adequate diets. The rat diet included 30% crambe meal for 90 days; the chick diet, 20% crambe meal for 4 weeks. Pathological examinations in both series showed no organ damage.

A vapor‐type desolventizer was developed previously at this laboratory to recover hexane and concentrated alcohols from soybean mares. The work reported in this paper extends the application of this unit to the recovery of dilute alcohols. Soybean protein meals washed with aqueous alcohols are debittered to yield a better flavored product with a significant increase in protein content. The protein of defatted meal was increased from about 50 to 70 or 75% by washing with methanol, ethanol, or isopropyl alcohol in a concentration range of 50舑70%. System modifications and critical variables were investigated so as to minimize residual alcohol and to yield a free‐flowing homogeneous product. Residual alcohol in the desolventized flakes was 0.25舑1.0%. Facility of removal followed the order舒methanol, isopropyl alcohol, and ethanol. Two‐stage flash desolventization as well as the use of the more dilute alcohols resulted in lower residual alcohol content of the desolventized product. After a minimum value for residual alcohol in the flakes is reached, further removal is difficult. However, water continues to be removed so that the alcohol water ratio becomes higher with an increased vaporization force as with increased temperature. It is postulated that the alcohol is held by adsorption or hydrogen bonding. The desolventized products analyzed: protein 72舑77%; Nitrogen Solubility Index 4舑16; water absorption values 328舑410%. The products were light‐colored, granular, and free flowing. The soybean flakes extracted with methanol exhibited the best flavor.