The observation in the early 1940s that the quantum efficiency of photosynthesis in a diatom was almost the same whether incident light was absorbed by chlorophyll a or by fucoxanthol sparked subsequent investigations of the variety of chloroplast pigments and in a diversity of photosynthetic organisms. Subsequent fluorimetric measurements provided the first relevant observation on the existence of excitation energy transfer in photosynthesis. These and some other experiments prior to the classical work of Arnold and Oppenheimer [(1950) J Gen Physiol 33: 423–435] and of Duysens [(1952) Doctoral thesis, State University of Utrecht, the Netherlands] are reviewed here.

A laboratory-scale, high-pressure, continuous reactor was used to partially hydrogenate soybean oil with copper catalysts. Effects of pressure on the kinetics of the reaction were studied by conducting experiments in a central composite design. The interaction of pressure (75\s-200 psig) with the other independent variables of temperature (155\s-255 C) and copper concentration (0.15\s-1.85%) was evaluated. Dependent variables studied were linolenate selectivity and formation of trans isomers and conjugated dienes. in addition, effects of pressure up to 500 psig, use of experimental and commercial copper catalysts and comparison of continuous with high-pressure batch rections were investigated. Linolenate selectivity (8\s-10) and trans-isomer formation were not significantly affected by any of the independent variables. Conjugated dienes were eliminated as products of the reaction when pressure was above 200 psig. Experimental copper-silica catalyst gave a 1.6-fold increase in reaction rate over commercial copper catalysts.

Three analyses were automated to monitor a laboratory continuous hydrogenator. Attenuated total reflectance infrared was used to followtrans isomer formation, refractive index for iodine value change and gas liquid chromatography for fatty acid composition. The instant response of the infrared spectrometer was confirmed by the later responses of the refractometer and gas chromatograph. All 3 operations were used to follow the progress of batch, continuous or semicontinuous hydrogenation.

In the early 1940s, soybean oil was considered neither a good industrial paint oil nor a good edible oil. The history of soybean oil is a story of progress from a minor, little-known, problem oil to a major source of edible oil proudly labeled on premium products in the 1980s. It is also a story of cooperative government research and industrial implementation of research findings. After 3-1/2 decades, soybean oil, “the number one problem of the soybean industry,” has become the source of choice for edible oil products in the U.S., moreover, increasing outlets appear to be assured in the world markets of the future.

Journal of the American Oil Chemists' SocietyVolume 58, Issue 3Part1 p. 208-209 Processing—Summary of Discussion Session IIB H. J. Dutton, H. J. Dutton Northern Regional Research Center, Agricultural Research, Science and Education Administration, USDA, 61604 Peoria, ILSearch for more papers by this author H. J. Dutton, H. J. Dutton Northern Regional Research Center, Agricultural Research, Science and Education Administration, USDA, 61604 Peoria, ILSearch for more papers by this author First published: 01 March 1981 https://doi.org/10.1007/BF02582342Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume58, Issue3Part1March 1981Pages 208-209 RelatedInformation

Journal of the American Oil Chemists' SocietyVolume 58, Issue 3Part2 p. 292-293 Soya Oil—Summary Of Discussion Session III B H. J. Dutton, H. J. Dutton Northern Regional Research Center, Agricultural Research, Science and Education Administration, USDA, 61604 Peoria, ILSearch for more papers by this author H. J. Dutton, H. J. Dutton Northern Regional Research Center, Agricultural Research, Science and Education Administration, USDA, 61604 Peoria, ILSearch for more papers by this author First published: 01 March 1981 https://doi.org/10.1007/BF02582361AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume58, Issue3Part2March 1981Pages 292-293 RelatedInformation

An automatic system for transesterification of fats and oils was developed and coupled with an auto-injector type gas chromato-graph. Using a timer sequencer, electronic valving for sample and reactant solution introduction and appropriate pumps and a real-time computer, the system permits programmed monitoring of vegetable oil for fatty acid composition. The system can be used with batch or continuous reactors to determine the progress of composition modification and in processing streams to confirm uniformity of incoming stocks or finished products.

Triglycerides containing cis- and trans-12-octadecenoic acid (12c-18:1 and 12t-18:1) and cis-9-octadecenoic acid (9c-18:1) labeled with deuterium were fed to 2 young adult male subjects. These fatty isomers each contained a different number of deuterium lables, which allowed mass spectrometric analysis to distinguish among them after they were fed as a mixture. This approach results in a direct comparison of the absorption and distribution of these 3 monenoic acids into blood plasma and lipoprotein lipids. Plasma lipid data indicated that all phospholipid fractions selectively incorporate 12c-18:1 and 12t-18:1 in preference to 9c-18:1. Discrimination against 12c-18:1 and 12t-18:1 compared to 9c-18:1 was found in the plasma neutral lipids, with a strong discrimination against 12t-18:1 incorporation into the cholesteryl ester fraction. Considerable reduction in the percentage of linoleic and arachidonic acid was observed when 12-18:1 isomers were incorporated in plasma triglyceride, phosphatidylcholine and spingomyelin samples. Chylomicron lipid analyses indicated that all isomers were well absorbed. Variation was observed in the relative distribution of 12c-18:1, 12t-18:1 and 9c-18:1 between the very low density, low density and high density lipoprotein lipid classes. No desaturation of 12c-18:1 to linoleic acid was detected.

Mixtures of specifically deuterated triolein and trielaidin were fed to three subjects, and the incorporation of these labeled fats into human plasma, erythrocyte, and platelet neutral lipids was followed by gas chromatography-mass spectrometry analysis. Plasma triglycerides selectively incorporated 10% more oleic acid than elaidic acid. Plasma cholesterol ester samples contained three times more oleic acid than elaidic acid. Plasma free fatty acid fractions also contained about 25% more elaidic acid than oleic acid. Low levels of deuterated fatty acids were found in the platelet neutral lipids. These samples followed the same general selectivities observed in the plasma samples. Results from analysis of erythrocyte neutral lipids were inconsistent. Erythrocytes from one subject contained high levels of deuterated fat in the triglyceride fraction, whereas erythrocytes from a second subject contained very low levels of deuterated fat. Uptake of elaidic acid by blood lipids confirms selectivities and distribution patterns previously reported in animal and in vitro studies. Effect of the number and position of the deuterium atoms on fatty acid metabolism is evaluated by feeding three differently labeled deuterated elaidic acids and two differently labeled deuterated oleic acids as paired mixtures. A 28% deuterium isotope effect due to deuterium on the fatty acid double bond was observed in the cholesteryl ester samples when oleic-9,10-d2 acid was fed against oleic-8,8,13,13,14,14-d6 acid. No evidence for a similar isotope effect was found for deuterated fatty acid incorporation into triglycerides and free fatty acid fractions.

The description of catalysts in terms of the rates of reactions they promote is now feasible. Several procedures have been published in the literature for determining selectivity of hydrogenation catalysts, particularly as ratios of reaction rates. The present contribution reviews these procedures, tests their performance with sample data, and compares their merits.

The objective of this study was to follow the uptake and distribution of oleic and elaidic acids into human erythrocytes, platelets, and plasma phospholipids. The use of dual and triple labeling methodology permitted a precise comparison of elaidic and oleic acid utilization. Elaidic acid (EI) was selectively concentrated in all the plasma phospholipids except for lysophosphatidylcholine. Three times more elaidic than oleic acid (Ol) accumulated in the 1-acyl position of phosphatidylcholine, as determined by hydrolysis with phospholipase A2. Rapid incorporation and removal of elaidate were observed for all samples. These results support the concept that enzymes responsible for acylation of phospholipids are sensitive to double bond configuration and the physical properties of the fatty acid moieties. Labeled fatty acid levels in red cell and platelet phospholipids were much lower than for plasma phospholipids, indicating a relatively slow rate for the in vivo incorporation of fatty acids into blood cell membrane phospholipids. No isotope effect was found when oleic acid labeled with deuterium on the double bond was used.

Data required for modeling and simulation of continuous hydrogenation kinetics have been obtained in an isothernal, cocurrent flow-type reactor. A preheated suspension of catalyst in oil, mixed with hydrogen, is passed cocurrently through 10 m length of 0.12 cm ID Teflon tubing at flow rates varying from 1.5 to 4.5 ml/min, gas flow rates from 100 to 700 ml/min, and temperatures from 150 to 190 C. The hydrogenations are run using nickel catalyst at outlet pressures of one atmosphere. Samples are removed at equal intervals along the length of the reactor and analyzed by gas chromatography. The kinetics of the continuous reactor are satisfactorily modeled by the simple scheme Ln→Lo→01→S using first order kinetics. Reaction rates, calculated by a digital computer, are shown to be related to temperature by the Arrhenius equation.trans Content and degree of hydrogenation are increased with temperature are decreased as oil flow increases. Hydrogen flow rate has little or no effect over the range studied.

Selective hydrogenation of soybean oil with copper catalyst at 50 psig or less is characterized as a relatively slow reaction requiring higher catalyst concentrations than the less selective but rapid nickel-catalyzed reactions used in most commercial practice. Hydrogenations of soybean oil have been performed which included a high-pressure scan (500, 1000, and 3000 psig), at selected temperatures (110, 130, 150, and 170 C), and at specific catalyst concentrations (0.05, 0.1, 0.2, and 0.4% copper). Selectivities, relative reaction rates, and geometric and positional isomerization have been determined as an evaluation of the effects of high pressure on the kinetics of the reaction. The experimental results indicate that an appropriate selection of pressure, temperature, and catalyst concentration can permit: (a) a significant increase in the rate of reaction while retaining the high linolenic acid selectivity of copper catalysts, (b) use of lower concentrations of copper catalyst while maintaining the higher reaction rate, and (c) elimination of conjugated diene as a measureable product in the hydrogenated oil.

Mixtures of dienoic fatty acids such as occur in edible hydrogenated fat products cannot be analyzed by current methodology. A method of ozonization, reduction to alcohol fragments by sodium borohydride, gas chromatographic analysis for alcohol, alcohol ester, and internal dialcohol fragments, and computer resolution of a matrix of linear simultaneous equations, is described that gives the analysis of the diene isomers.

Ternary and binary gradient systems have been developed for the high-performance liquid chromatographic analysis of complex pigment distributions typical of natural samples. Improved chromatographic resolution reveals significantly more pigment components in extracts from a sediment (Priest Pot, Cumbria, UK), a microbial mat (les Salines de la Trinital, South Catalonia, Spain) and a culture (C. phaeobacteroides) including novel bacteriochlorophyll derivatives. The methods developed are directly suited to LC–MS analysis and the automated acquisition of MS/MS data for pigments.