Water, in its subcritical state, can be used as both a solvent and reactant for the hydrolysis of triglycerides. In this study, soybean, linseed, and coconut oils were successfully and reproducibly hydrolyzed to free fatty acids with water at a density of 0.7 g/mL and temperatures of 260−280 °C. Under these conditions the reaction proceeds quickly, with conversion of greater than 97% after 15−20 min. Some geometric isomerization of the linolenic acids was observed at reaction temperatures as low as 250 °C. Reactions carried out at higher temperatures and pressures, up to the critical point of water, produced either/or degradation, pyrolysis, and polymerization, of the oils and resultant fatty acids.

No abstract

Full-fat soyflakes are readily extracted with supercritical carbon dioxide (SC-CO 2 ) at pressures of 3,000-10,000 psig and 50 C. Under these conditions, SC-CO 2 has the density of a liquid and the diffusivity of a gas. Therefore, equilibrium solubility is readily achieved in a short-path batch extractor which permits high gas flow rates. Soybean oil extracted with SC-CO 2 is lighter in color and contains less iron and about one-tenth the phosphorus of hexane-extracted crude oil from the same beans. The lower phosphorus content is reflected in a chromatographic refining loss of 0.6% compared to 1.9% for hexane crude. Refined oils from hexane and SC-CO 2 extraction had equivalent odor and flavor scores initially and after 4 days' storage at 60 C. Carbon dioxide, an ideal solvent for extraction of food products, is tow-cost and readily available from fermentat-ion processes and could free over 20 million gallons of costly hexane per year for essential energy uses.

Liquid vegetable oils (VO), including cottonseed, peanut, soybean, corn, and canola, were randomly interesterified with completely hydrogenated soybean or cottonseed hardstocks (vegetable oil trisaturate; VOTS) in ratios of four parts VO and one part VOTS. Analysis of the reaction products by high-performance liquid chromatography showed that at 70°C and vigorous agitation, with 0.5% sodium methoxide catalyst, the reactions were complete after 15 min. Solid-fat index (SFI) measurements made at 50, 70, 80, 92, and 104°F, along with drop melting points, indicated that the interesterified fats possess plasticity curves in the range of commercial soft tub margarine oils prepared by blending hydrogenated stocks. Shortening basestocks were prepared by randomly interesterifying palm or soybean oil with VOTS in ratios of 1 :I or 3:1 or 4:1, respectively. Blending of the interesterified basestocks with additional liquid VO yielded products having SFt curves very similar to commercial all purpose-type shortening oils made by blending hydrogenated stocks. Other studies show that fluid-type shortening oils can be prepared through blending of interesterified basestocks with liquid VO. Xray diffraction studies showed that the desirable [3' crystal structure is achieved through interesterification and blending. JAOCS 72, 379-382 (1995).