Functional properties of low-fat soy flour produced by an extrusion-expelling system

Low-fat soy flour (LFSF) obtained by extrusion-expelling processing was investigated for functional properties. Flours with the following various levels of protein dispersibility indexes (PDI) and residual oil (RO) contents were investigated: “high” 67±4/10.4±1, “mid” 42±3/7.4±2, and “low” 14±5/6.5±0. The solubility of all three LFSF was minimal at pH 4.0 and increased at more alkaline and acidic pH levels. Water-holding capacity (WHC) increased with a decrease in PDI and RO content, whereas fat-binding capacity (FBC) decreased. Foaming stability increased as PDI and RO increased, with significant differences between all LFSF samples. Emulsification capacity (EC) was measured at three pH levels (5.5, 6.7, and 8.0). At each pH level, the “low” samples showed the least EC compared to the “mid” and “high” samples, with no significan difference between the “mid” and “high” samples at pH 6.7 and 8.0. Emulsification stability and activity decreased from low LFSF to high LFSF. This study showed that in general low LFSF was less functional than the other flours tested and there was no significant difference in the functionality of mid- and high-LFSF samples.     

Kinetic characteristics of extraction of the polymer component from a porous composite material

In a polychronic model of washing of LDPE out of a synthetic leather (SL) base with a selective solvent, the “kinetic nonequivalence” parameter of the polymer gel particles is the reflection of the characteristics of the material's pore structure and is not a function of the thermodynamic quality of the extractant. A decrease in the thermodynamic quality of the extractant is accompanied by an increase in the “strength” of the LDPE gel formed in the pores of the SL base. In extraction of LDPE from a SL base according to the mechanism of “capillary flow of gel,” the gel should be moved over the pores of the material in a sufficiently efficient regime of “hydrodynamic entrainment” by the stream of extractant. Translated fromKhimicheskie Volokna, No. 2, pp. 36–39, March–April, 2000.     

Synthesis of PCL-b-PVAc block copolymers by combination of click chemistry, ROP, and RAFT polymerizations

Abstract  

The synthesis of new poly(ε-caprolactone)(PCL)-b-poly(vinyl acetate)(PVAc) block copolymers was investigated using different combinations of click chemistry, reversible addition-fragmentation transfer (RAFT), and ring opening polymerization (ROP) techniques. Two approaches, “coupling” and “macroinitiator” routes were studied. For the coupling approach, a chain transfer agent comprising an azide function was synthesized and used as initiator for the VAc polymerization. PCL containing an alkyne termination was obtained from a bifunctional initiator bearing an alkyne function and an hydroxyl group. These two functionalized precursors, PVAc and PCL, were coupled by a 1,3 cyclo addition reaction “click chemistry” in order to obtain the corresponding block copolymer. For the macroinitiator approach, PCL-b-PVAc block copolymers were synthesized using a two-step procedure: at first, a PCL macroinitiator with a xanthate end group was prepared by coordinated anionic polymerization of ε-caprolactone; then, the RAFT polymerization of VAc was initiated from the PCL, for the preparation of PCL-b-PVAc block copolymers. Whatever the method used, no detectable quantities of unreacted PVAc or PCL were observed. ¹H NMR and size exclusion chromatography analyses indicated successful synthesis of the block copolymers with well-defined structures.     

13C nuclear magnetic resonance spectroscopic analysis of the triacylglycerol composition of some margarines

The triacylglycerol fraction of three samples of margarine, namely “Flora” (Holland), “Kaliakra” (Bulgaria), and “Corona” (Holland), were studied by¹³C nuclear magnetic resonance spectroscopy. By examining the various carbon chemical shifts of the saturated and unsaturated carbon nuclei, “Flora” margarine was shown to contain a mixture of hydrogenated and unhydrogenated vegetable oils. This technique allowed all major acyl groups (saturated, oleate, linoleate, and linolenate) and minor acyl components [different positional isomers of long-chain (E)- and (Z)-monoenoic moieties, arising as by-products during catalytic hydrogenation] to be identified. The amount of each fatty acid present in the margarine was also estimated from the relative intensities of the corresponding signals. “Kaliakra” margarine consisted of a blend of unhydrogenated natural fats and oils that contained saturated fatty acids, oleate, and linoleate. There were no signs in the spectrum of “Kaliakra” of any (E)-isomers, nor signals associated with positional unsaturated acyl groups (other than oleate and linoleate). The sample of “Corona” margarine consisted of a mixture of hydrogenated and unhydrogenated vegetable oils and butter (1.3%). The presence of butter in this sample was identified by the characteristic carbon shifts of the C-1 to C-4 carbon atoms of butyrate. The distribution of the fatty acids on the glycerol “backbone” also was estimated by this technique.     

Degumming and refining practices in the U.S.

The “state of the art” of degumming and refining crude vegetable oils in the U.S. is discussed with reference to (a) production volumes and significant quality characteristics of oils processed; (b) processes and equipment for degumming, refining, and waterwashing the oils, illustrated by diagrams and flow charts; and (c) key process controls and analytical testing requirements for each unit operation.     

A simple and precise method for the routine determination of platelet-activating factor in blood and urine

A simple and precise method is described for the measurement of platelet-activating factor (PAF) in blood and urine. The method involves the isolation of PAF from blood samples by two successive steps. In the first step, blood proteins are precipitated with ethanol and the “free” PAF, i.e. the PAF which is extractable with ethanol, is recovered. In the second step, “bound” PAF, i.e., PAF not extractable with ethanol, is extracted from the protein precipitate with chloroform/methanol/water. The extraction of PAF from urine samples requires only the ethanol extraction step. “Free” and “bound” PAF are then each fractionated by silicic acid column chromatography, and the methanol/water eluent containing PAF is then further fractionated by high-performance liquid chromatography using an isocratic solvent system of acetonitrile/methanol/water. PAF is then quantitated by measuring its ability to induce platelet aggregation in an aggregometer. Application of the method to blood and urine samples from twenty-three healthy volunteers revealed PAF levels in blood of 140–480 pg/mL (630–254.4 pg “free” PAF/mL and 64–225.6 pg “bound” PAF/mL), and of 1.2–4.0 pg PAF/mL in urine. The method overcomes various technical problems and was shown to be very precise. It should prove useful for monitoring PAF levels in various disease conditions.     

The mass spectra of the 4,4-dimethyloxazoline derivatives of the methoxymethyl olefins of malvalic and sterculic acids

A new approach to the gas chromatographymass spectrometry analysis of cyclopropenoid fatty acids is described. The method is based on the “on-site”-modification of the cyclopropenoid ring with AgNO₃-saturated methanol to the methoxymethyl olefin and a subsequent “remote-site”-derivatization of the carboxyl group to its 4,4-dimethyloxazoline. The mass spectra of the isomeric reaction products obtained from malvalic and sterculic acid were found to be useful for locating the original cyclopropenoid ring in the fatty acid chain.     

Assignment of 13C NMR chemical shift and microstructure of copolymers of 2-chloroethyl vinyl ether-maleic anhydride and n-butyl vinyl ether-maleic anhydride

Summary The chemical shift in the ¹³C NMR spectra of copolymers of 2-chloroethyl vinyl ether (CEVE) and maleic anhydride (MA), and of n-butyl vinyl ether (BVE) and MA is assigned. It is found that both copolymers are made of completely alternating monomer unit sequences and that the proportion of cis linkage configuration at the cyclic MA units is 45 % and 47 % in the CEVE-MA copolymer and in the BVE-MA copolymer, respectively. Depending on the relative orientation of the cyclic anhydride group, quasi “isotactic” and quasi “syndiotactic” tacticity are considered, with quasi “syndiotactic” diads shielding the vinyl ether carbons more effectively. Received: 19 April 1999/Accepted: 17 June 1999     

Biokinetics of dietaryRRR-α-tocopherol in the male guinea pig at three dietary levels of vitamin C and two levels of vitamin E. Evidence that vitamin C does not “spare” vitamin Ein vivo

The net rates of uptake of “new” and loss of “old”2R,4′ R,8′ R-α-tocopherol (RRR-α-TOH, which is natural vitamin E) have been measured in the blood and in nine tissues of male guinea pigs over an eight week period by feeding diets containing deuterium-labelled α-tocopheryl acetate (d ₆-RRR-α-TOAc). There was an initial two week “lead-in” period during which 24 animals [the “high” vitamin E (HE) group] received diets containing 36 mg of unlabelled (d ₀)RRR-α-TOAc and 250 mg of ascorbic acid per kg diet, while another 24 animals [the “low” vitamin E (LE) group] received diets containing 5 mgd ₀-RRR-α-TOAc and 250 mg ascorbic acid per kg diet. The HE group was then tivided into three equal subgroups, which were fed diets containing 36 mgd ₆-RRR-α-TOAc and 5000 mg [the “high” vitamin C (HEHC) subgroup], 250 mg [the “normal” vitamin C (HENC) subgroup] and 50 mg [the “low” vitamin C (HELC) subgroup] ascorbic acid per kg diet. One animal from each group was sacrificed each week and the blood and tissues were analyzed ford ₀- andd ₆-RRR-α-TOH by gas chromatography-mass spectrometry. The LE group was similarly divided into three equal subgroups with animals receiving diets containing 5 mgd ₆-RRR-α-TOAc and 5,000 mg (LEHC), 250 mg (LENC) and 50 mg (LELC) ascorbic acid per kg diet with a similar protocol being followed for sacrifice and analyses. In the HE group the totald ₀-+d ₆-)RRR-α-TOH concentrations in blood and tissues remained essentially constant over the eight week experiment, whereas in the LE group the totalRRR-α-TOH concentrations declined noticeably (except in the brain, an organ with a particularly slow turnover of vitamin E). There were no significant differences in the concentrations of “old”d ₀-RRR-α-TOH nor in the concentrations of “new”d ₆-RRR-α-TOH found in any tissue at a particular time between the HEHC, HENC and HELC subgroups, nor between the LEHC, LENC and LELC subgroups. We conclude that the long-postulated “spring” action of vitamin C on vitamin E, which is well documentedin vitro, is of negligible importancein vivo in guinea pigs that are not oxidatively stressed in comparison with the normal metabolic processes which consume vitamin E (e.g., by oxidizing it irreversibly) or elminate it from the body. This is true both for guinea pigs with an adequate, well-maintained vitamin E status and for guinea pigs which are receiving insufficient vitamin E to maintain their body stores. The biokinetics of vitamin E uptake and loss in the HE guinea pigs are compared with analogous data for rats reported previously (Lipids 22, 163–172, 1987). For most guinea pig tissues the uptake of vitamin E under “steadystate” conditions was faster than for the comparable rat tissues. However, the brain was an exception with the turnover of vitamin E occurring at only one-third of the rate for the rat. NRCC Publication No. 30775.     

Towards paired and coupled electrode reactions for clean organic microreactor electrosyntheses

Electrosynthesis offers a powerful tool for the formation of anion and cation radical intermediates and for driving clean synthetic reactions without the need for additional chemical reagents. Recent advances in microfluidic reactor technologies triggered an opportunity for new microflow electrolysis reactions to be developed for novel and clean electrosynthetic processes. Naturally, two electrodes, anode and cathode, are required in all electrochemical processes and combining the two electrode processes into one “paired” reaction allows waste to be minimised. By decreasing the inter-electrode gap “paired” reactions may be further “coupled” by overlapping diffusion layers. The concept of “coupling” electrode processes is new and in some cases coupled processes in micro-flow cells are possible even in the absence of intentionally added electrolyte. The charged intermediates in the inter-electrode gap act as electrolyte and processes become “self-supported”. Hardly any examples of “coupled” paired electrochemical processes are known to date and both “paired” and “coupled” processes are reviewed here. Coupled electrode processes remain a challenge. In future “pairing” and “coupling” electrode processes into more complex reaction sequences will be the key to novel and clean flow-through microreactor processes and to novel chemistry.     

Functional analysis of gas chromatographic data for C-4 through C-18:2 fatty acids

The problem of finding a functional relationship between concentration and output data from GC has been considered for a series of fatty acids (FA). The concentrations used are relative values, i.e., the actual concentration of a FA divided by that for an internal standard. The GC output used is relative peak areas, i.e., the integrated chromatogram area of the FA divided by that for the internal standard. Five functions have been investigated, each in reasonable accord with the concept of relative response factors being constant for a homologous series of compounds. We conclude that one of the five, C_j = aA _j ^b , is clearly superior and recommend its use in agreement with a literature report for different compound types (5). In the equation above, “C” and “A” are the relative concentrations and areas, respectively, and “a” and “b” are fitting constants determined from the data by least-squares minimization. We found it was impossible to deal with a matrix of 10 acids and 9 concentrations in a manner that would reproduce the data within the experimental uncertainty (6%), and we concluded that an acid-by-acid analysis was preferable.     

Binding of gossypol under conditions of complete rupture of the pigment glands

Summary The “free” gossypol of cooked cottonseed meats is composed of gossypol and of “gossypol-like pigments,” which are soluble in 70% aqueous acetone. The “gossypol-like pigments” may account for 30 to 100% of the “free” gossypol as determined by the A.O.C.S. method. Thorough comminution, followed by prolonged cooking, results in reduction of all the pigments in cotton-seed meats. “Free” gossypol is not completely eliminated, but the gossypol level, as determined by the benzene transfer method, may be reduced to zero. “Gossypol-like pigments” are converted into gossypol by the action of hot aqueous hydrochloric acid. Good agreement is observed between the data for “total” gossypol, as determined through the use of the A.O.C.S. oxalic acid method and through the use of hot aniline. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Intraspecific Variation in Plant Defense Alters Effects of Root Herbivores on Leaf Chemistry and Aboveground Herbivore Damage

Root herbivores can indirectly affect aboveground herbivores by altering the food quality of the plant. However, it is largely unknown whether plant genotypes differ in their response to root herbivores, leading to variable defensive phenotypes. In this study, we investigated whether root-feeding insect larvae (Agriotes sp. larvae, wireworms) induce different responses in Plantago lanceolata plants from lines selected for low and high levels of iridoid glycosides (IG). In the absence of wireworms, plants of the “high-IG line” contained approximately twofold higher levels of total IG and threefold higher levels of catalpol (one of the IG) in leaves than plants from the “low-IG line,” whereas both lines had similar levels of IG in roots. In response to wireworms, roots of plants from both lines showed increased concentrations of catalpol. Leaves of “low-IG line” plants increased catalpol concentrations in response to wireworms, whereas catalpol concentrations of leaves of “high-IG line” plants decreased. In contrast, glucose concentrations in roots of “low-IG” plants decreased, while they increased in “high-IG” plants after feeding by wireworms. The leaf volatile profile differed between the lines, but was not affected by root herbivores. In the field, leaf damage by herbivores was higher in wireworm-induced compared to noninduced “low-IG” plants and lower in wireworm-induced compared to noninduced “high-IG” plants, despite induction of catalpol in leaves of the “low-IG” plants and reduction in “high-IG” plants. This pattern might arise if damage is caused mainly by specialist herbivores for which catalpol may act as feeding stimulant rather than as deterrent. The present study documents for the first time that intraspecific variation in plant defense affects the outcome of plant-mediated interactions between root and shoot herbivores.     

Effect of heating process on the formation of nanoparticles of elastin model polypeptide, (GVGVP)251, by gamma-ray crosslinking

Nanoparticles were prepared by the thermosensitive aggregation of the elastin model polypeptide, (GVGVP)₂₅₁, and gamma-ray crosslinking. Three different heating processes, “slow heating,” “fast heating,” and “heat shock,” were used for the aggregation of the peptide, followed by gamma-ray crosslinking. Only the “heat shock” process successfully yielded stable nanoparticles with diameters of less than ca. 150 nm and a narrow size distribution. Circular dichroism (CD) spectrometry showed that this polypeptide formed a type-II β-turn structure when the temperature was increased to above the cloudy point in the case of the “heat shock” process; suggesting that this structure might contribute to stable nanoparticle formation by gamma-rays. CD spectrometry also suggested that this structure would be affected during the formation of stable crosslinked particles.     

Worksoftening of margarine and shortening

Margarine and butter have a certain yield value which is mainly determined by the fact that the fat crystals do not move in respect of each other but are fixed in a tridimensional network. The permanent network greatly contributes to the total hardness (60–80%). This contribution can be determined by kneading the sample isothermally and by measuring the hardness before and after kneading. The decrease in hardness is called the “structural hardness” and the relative decrease the “worksoftening.” These values give a certain impression of the plasticity of the product at a certain hardness, while the Spreadability Index, which can be calculated from the structural hardness and the worksoftening, is a good measure for spreadability.     

Development of porous permeable ceramic material and filtering element technology for candle-shaped filter equipment

Areduction in manufacture expenditure for a production unit, and also preparation of metals and alloys in pure and ultra-pure form may be achieved using newly created filtering elements made of porous permeable ceramic materials with a pore size controlled from “micro” to “nano”. Methodology is presented for creating filtering elements made of porous permeable ceramic based on a concentrate of disthene-sillimanite for candle-shaped filtering elements. Translated from Novye Ogneupory, No. 1, pp. 23 – 27, January 2009.     

Note on acetone-soluble material in cottonseed meals

Summary In connection with a study of methods of eliminating traces of “free” gossypol from cottonseed meals a procedure for isolation of gossypol from the 70% acetone extracts of the meals by transfer to benzene solution has ben developed. A procedure is also given for quantitative determination of the isolated gossypol. Analysis of four samples of cooked cottonseed meats and meal by the method showed that in each instance substances other than gossypol are measured by the A.O.C.S. method for “free” gossypol in meals containing low concentrations of residual “free” gossypol. This procedure promises to provide another analytical tool for the study of residual material in processed cottonseed meal that causes egg discoloration when fed to laying hens. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

Feature

Control of oilseed processing for best quality and yield requires attention to many details, starting at the seed unloading station and continuing through to the loading of products. Present trading rules encourage practices that degrade oil and meal. Better cleaning would pay handsomely in quality products. The continuous mechanical screw-press process and the solvent extraction process have many common problems which involve quality and yield control. Time, temperature, and moisture are the variable involved in all the unit processes that comprise oilseed milling. These unit processes and some recent developments in low-temperature processing are described. Oilseed milling is still “rough terrain” with regard to automation, but labor costs as a percentage of total processing costs are relatively low in large-capacity plants. Presented at the AOCS Short Course, “Processing Quality Control of Fats and Oils,” East Lansing, Mich., Aug. 29—Sept. 1, 1966.     

Insights into surface reactivity: formic acid oxidation on Cu(110) studied using STM and a molecular beam reactor

Using a combination of STM and molecular beam reactor data we summarise some important features of a model reaction (formic acid oxidation on Cu(110)) which is of general significance to surface reactivity and to catalysis. Three such features are highlighted here. The first concerns the role of weakly held species (possibly physisorbed) in surface reactions. These species, although of very short lifetime on the surface, can, nevertheless, diffuse over long distances to “find” a sparse distribution of active sites. Thus a very low coverage of oxygen on the surface of Cu(110) increases the sticking probability of all the formic acid molecules which strike the surface to high value (0.82), even though the clean surface is relatively unreactive. The important concept here is the “diffusion circle” or “collection zone” which represents the area of surface visited by the molecule in its short sojourn in the weakly held state. The second theme concerns the concept of the “flexible surface”. We show that the involvement of surface atoms in reactions directs the structure and reactivity for a particular reaction. For formic acid oxidation the liberation of Cu atoms during the removal of oxygen as water leads to gross restructuring of the surface and can lead to “compression” of one reactant (the oxygen in this case) into a lower area, higher local coverage, unreactive state (the c(6×2) oxygen structure). Thirdly, and finally, it is proposed that, for many surface reactions, the surface acts in an analogous way to a solvent, supporting a “dissolved” (highly mobile and fluxional) phase of intermediates at low coverage, which crystallise out above a critical coverage (the 2D “solubility limit”). This revised version was published online in July 2006 with corrections to the Cover Date.     

Physicochemical aspects of texturization: Fiber formation from globular proteins

The modification of proteins to produce fibrous or “fiber-like” textured products is a subject of unique importance and interest. Unfortunately, very little is known about the physicochemical properties of texturized “fibers”, the mechanisms that produce them, or the forces that hold the protein molecules in a given structure. This paper deals with the following topics: (a) methods for characterizing the physico-chemical properties of textured protein products; (b) the structures of naturally occurring fibrous proteins and synthetic polypeptides as possible models for texturized “fibers”; (c) the current understanding of the mechanisms and the forces required to form and stabilize fibrous protein structures; and (d) a brief and generalized survey of the presently available “fiber” forming processes.