bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct sampling of orujo oil for determining residual hexane by using a chemsensor
Authors: Peña F. , Cárdenas S. , Gallego M. , Valcárcel M. 
Published: November 2006

AbstractHexane is used to extract edible oils from oleaginous seeds. The detection of hexane in orujo oil is mandatory, as its presence in the final product may negatively affect human health. Headspace‐GC is the technique of choice for determining residual solvent in foods. In the present work, a new instrument based on the headspace principle and mass spectrometric detection without chromatographic separation, ChemSensor, is proposed for the direct screening of orujo oil to determine residual hexane. This instrument provided an overall response, corresponding to the volatiles profile, including that of hexane, which could not be directly discriminated. By selecting them/zvalues corresponding ton‐hexane (major component of commercial hexane), the selectivity of the method was good enough to determine residual hexane in the range of 2.0–65 μg mL−1(corresponding to 2.3–75.6 mg of hexane per kg of oil) with high precision. The detection limit achieved (0.7 mg per kg of oil) was lower than the maximum residual limit established by the European Union (5 mg per kg of oil). Two multivariate techniques, partial least squares and principal components regression (PCR), were compared with univariate regression; PCR provided the best results.
Lipid class separation by HPLC combined with GC FA analysis: Comparison of seed lipid compositions from different Brassica napus L. varieties
Authors: Beermann Christopher , Green Angelika , Möbius Michael , Schmitt Joachim J. , Boehm Günther 
Published: November 2006

AbstractA reliable HPLC method was established to evaluate the lipid composition of useful plants modified by breeding techniques. This study focused on the polar lipid distribution and polar lipid FA compositions of four rapeseed varieties. Structure and quantity of the distinct lipid classes were compared by HPLC using ELSD followed by a GC FA analysis. A baseline separation of 14 lipid classes could be achieved within one step by using an eluent gradient of hexane, tert‐methylbutyl ether, isopropanol, acetonitrile, chloroform, triethylamine, acetic acid, and water supplemented with ammonium sulfate with a polyvinyl alcohol column. After automatic fractionation, the FA compositions of the distinct lipid classes were characterized by a subsequent complementary GC FA analysis through direct acetylchloride methylation. The rape varieties analyzed showed diversity in polar lipid content and distribution, dominated by PC, PE, PI, monoglycosyldiacylglycerols, and phytosterols. Extensive variations were detected in FA within the lipid classes of rape varieties with predominantly oleic acid, linoleic acid, and α‐linolenic acid observed followed by palmitic acid and gondoic acid. Oleic acid was mainly connected to PC and linoleic acid to PE, whereas α‐linolenic acid and γ‐linolenic acid were predominantly linked to PI in all varieties.
Antioxidative properties and enzymatic synthesis of ascorbyl FA esters
Authors: Viklund Fredrik , Alander Jari , Hult Karl 
Published: November 2006

AbstractEfficient synthesis of unsaturated FA esters of ascorbic acid is possible with only a small excess of one of the reactants in t‐amyl alcohol using Candida antarctica lipase as biocatalyst. Using free acids, we obtained yields that were comparable to yields reached using vinyl‐activated acyl donors (71, 80, and 86% yields of esters with FA excesses of 1∶1, 1∶1.5, and 1∶2, respectively). As very low water activity is needed to achieve sufficiently high yields of product, molecular sieves were used to improve the ascorbyl ester yields. Ascorbyl oleate is more amorphous and has a much lower m.p. and lower enthalpy of fusion than ascorbyl palmitate. This leads to a higher solubility of ascorbyl oleate in oil, resulting in an increased antioxidant effect compared to that of the palmitate. In an accelerated storage test using deodorized rapeseed oil, samples incubated with ascorbyl palmitate showed noticeable oxidation after 1 wk of storage, whereas samples incubated with ascorbyl oleate displayed negligible oxidation for 9 and 4 wk at 30 and 40°C, respectively.
Effect of γ‐tocopherol on formation of nonvolatile lipid degradation products during frying of potato chips in triolein
Authors: Neff W. E. , Warner K. , Eller F. 
Published: November 2006

AbstractFormation of undesirable odors and flavors during food processing operations is an important problem for the food industry. To determine the effect of γ‐tocopherol on these negative attributes of fried food, we fried potato chips in triolein with 0, 100, or 400 ppm γ‐tocopherol. Triolein extracted from potato chips was sampled for residual γ‐tocopherol and nonvolatile degradation products after the chips were aged. RP‐HPLC coupled to atmospheric pressure chemical ionization MS and size‐exclusion chromatography was used to analyze, samples for degradation products in the triolein absorbed in potato chips as well as the fryer, triolein. MS results showed that γ‐tocopherol reduced the production of nonvolatile degradation products in the triolein absorbed by the potato chips and in the triolein in the fryer. Fryer oil samples and extracted potato chip oils with 400 ppm γ‐tocopherol had a significantly lower production of degradation compounds than did samples with 100 ppm γ‐tocopherol. Both fryer oils and potato chips containing 100 ppm γ‐tocopherol had significantly fewer nonvolatile degradation products than did the samples without γ‐tocopherol. These nonvolatile compounds are known precursors of negative odors and flavor compounds produced during the frying and aging of foods.
A rapid method for the analysis of hydrogenated fats by GC with IR detection
Authors: Mjøs Svein Are , Pettersen Jan 
Published: November 2006

AbstractA rapid method for analysis of trans and cis FA in hydrogenated fats has been developed. The method is based on a single anlaysis by CG with IR detection. Multivariate partial least squares regression is applied on the IR spectra to predict the number of cis and trans double bonds. For each chain length the method provides information about the amount of the saturated FA, the amount of trans monoenes, the amount of cis monoenes, the amount of PUFA, and the average number of cis and trans double bonds in PUFA. The method has been validated by summing the values to a total trans value and total unsaturation. These sum values were compared with total trans unsaturation, as determined by AOCS method Cd 14‐95, and iodine value, as determined by AOCS Cd 1d‐92.
Production of structured TAG rich in 1,3‐capryloyl‐2‐arachidonoyl glycerol from Mortierella single‐cell oil
Authors: Nagao Toshihiro , Kawashima Akiko , Sumida Motoo , Watanabe Yomi , Akimoto Kengo , Fukami Harukazu , Sugihara Akio , Shimada Yuji 
Published: November 2006

AbstractTwo oils containing a large amount of 2‐arachidonoyl‐TAG were selected to produce structured TAG rich in 1,3‐capryloyl‐2‐arachidonoyl glycerol (CAC). An oil (TGA58F oil) was prepared by fermentation of Mortierella alpina, in which the 2‐arachidonyoyl‐TAG content was 67 mol%. Another oil (TGA55E oil) was prepared by selective hydrolysis of a commercially available oil (TGA40 oil) with Candida rugosa lipase. The 2‐arachidonoyl‐TAG content in the latter was 68 mol%. Acidolysis of the two oils with caprylic acid (CA) using immobilized Rhizopus oryzae lipase showed that TGA55E oil was more suitable than TGA58F oil for the production of structured TAG containing a higher concentration of CAC. Hence, a continuous‐flow acidolysis of TGA55E oil was performed using a column (18×125 mm) packed with 10 g immobilized R. oryzae lipase. When a mixture of TGA55E oil/CA (1∶2, w/w) was fed at 35°C into the fixed‐bed reactor at a flow rate of 4.0 mL (3.6 g)/h, the degree of acidolysis initially reached 53%, and still achieved 48% even after continuous operation for 90 d. The reaction mixture that flowed from the reactor contained small amounts of partial acylglycerols and tricaprylin in addition to FFA. Molecular distillation was used for purification of the structured TAG, and removed not only FFA but also part of the partial acylglycerols and tricaprylin, resulting in an increase in the CAC content in acylglycerols from 44.0 to 45.8 mol%. These results showed that a process composed of selective hydrolysis, acidolysis, and molecular distillation is effective for the production of CAC‐rich structured TAG.
Reaction selectivity of Burkholderia cepacia (PS‐30) lipase as influenced by monoacylation of sn‐glycerol
Authors: Fu Xun , Parkin Kirk L. 
Published: November 2006

AbstractReaction selectivities were determined in multicompetitive reactions mediated by Burkholderia cepacia lipase (Amano PS‐30) at a water activity of 0.19 in hexane. Saturated FA (C4–C18 even chain) and oleic acid (C18∶1) were reacted with a single alcohol, glycerol, α‐or β‐MAG, containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate. Similar odrinal patterns of FA selectivity, with C8, C10, and C16 preferred over others, were generally observed for incorporation of FA into specific acylglycerol (AG) pools of the 24 specific cases evaluated. The three exceptions were enrichment of C14 and C18 in the MAG pool with α‐C16‐MAG, substrate, and a general suppression of >C8 incorporation into the TAG pool for reactions with α‐C10‐ and α‐C16‐MAG. PS‐30 lipase selectivity toward MAG was in descending order: α/β‐C4‐MAG>β‐C10‐MAG>β‐C16‐MAG>α/β‐C18∶1‐MAG>α‐C10‐MAG>α‐C16‐MAG. Selectivity in channeling CX of the original CX‐MAG substrates into higher AG species was in descending order: α‐C10‐MAG∼α‐C16‐MAG>α‐C18∶1‐MAG>β‐C10‐MAG∼β‐C16‐MAG∼β‐C18∶1‐MAG >α/β‐C4‐MAG. Generally, MAG were better acyl donors than FA for esterification reactions leading to DAG formation. These observations are relevant to the design of biocatalytic processes intended to yield specifically structured TAG.
Genomic regions governing soybean seed nitrogen accumulation
Authors: Panthee D. R. , Pantalone V. R. , Sams C. E. , Saxton A. M. , West D. R. , Rayford W. E. 
Published: November 2006

AbstractNitrogen accumulation in the form of seed protein takes place in soybean [Glycine max (L.) Merr.] during the reproductive stages of development. The purpose of this study was to relate genotypic differences in seed nitrogen accumulation with genomic regions controlling nitrogen accumulation in soybean during R5, R6, and R7 growth stages. A population of 101 F6∶8 recombinant inbred lines (RIL) developed from a cross of N87‐984‐16×TN93‐99 was utilized. The RIL were grown at the University of Tennessee, Knoxville Experiment Station, in a randomized complete block design with three replications in 2002. Seed nitrogen was determined from pod samples harvested at the R5, R6, and R7 growth stages. A significant (P<0.05) difference among genotypes was found for nitrogen accumulation at all three growth stages. Single‐factor ANOVA revealed that quantitative trait loci (QTL) governing nitrogen accumulation in soybean seed were distributed in the linkage groups A2, B2, D1a, D1b, E, G, and M. Phenotypic variation explained by an individual QTL ranged from 5 to 11.6%. These QTL may provide useful marker‐assisted selection opportunities for soybean protein improvement.
Novel natural antioxidant for stabilization of edible oil: The ajowan (Carum copticum) extract case
Authors: Bera D. , Lahiri D. , Nag A. 
Published: November 2006

AbstractAn inexpensive, natural antioxidant was developed for stabilizing flaxseed and bahera oils, which are readily available and consumed in large quantities for their EFA in India, Asia, and also parts of the Western world. With the incorporation of soluble ajowan (Carum copticum) extract, as ajowan powder, into the oils, their oxidation could be prevented. After storage of the oils for a year in the presence of antioxidant, the ordor, taste, and chemical properties of the oil were the same.
Processing vegetable oils using nonporous denser polymeric composite membranes
Authors: Subramanian R. , Nakajima M. , Raghavarao K. S. M. S. , Kimura T. 
Published: November 2006

AbstractMembrane processing offers several advantages over conventional processes for edible oil refining. In recent years, processing solvent‐extracted, screw‐pressed, and used frying oils using nonporous denser polymeric composite membranes without pretreatment and addition of chemicals has been extensively investigated. In the present review, results obtained with real and model systems have been summarized and a comprehensive explanation is provided on the mechanism of rejection and differential permeation of oil constituents. Phospholipid‐TG and pigment‐TG systems are construed as conventional solute‐solvent systems, and tocopherol‐TG and FFA‐TG systems are treated as liquid mixtures exhibiting differential permeability. Dense membrane theory appears more applicable than the reverse osmosis theory in qualitatively explaining the differential permeability of liquid constituents of the oil. Membrane processing of oils appears to have the potential to be a one‐step process, especially for screw‐pressed oils, in producing a premium‐quality product. However, the development of suitable membranes that enable higher fluxes is necessary for industrial adoption of this technology.
Thermal properties and adhesion strength of modified soybean storage proteins
Authors: Mo Xiaoqun , Sun Xiuzhi , Wang Donghai 
Published: November 2006

AbstractSoy proteins have shown great potential for adhesive and resin applications. This investigation characterized the thermal and adhesive properties of the major soy protein components conglycinin (7S) and glycinin (11S) after chemical modification. These globulins were extracted from defatted soy flour, then modified with either sodium hydroxide, sodium dodecyl sulfate (SDS), or urea. Modified 7S, 11S, and mixtures of 7S and 11S at varying ratios were evaluated for gluing strength with cherry veneer plywood and for thermal denaturation using DSC. Adhesive strength and water resistance were significantly improved for all proteins modified with sodium hydroxide. Gluing strength and water resistance were improved for SDS‐ and ureamodified proteins containing greater portions of 7S globulins. The opposite behavior was observed for proteins containing large amounts of 11S globulins. DSC results showed that the temperatures of denaturation (Td) decreased for the proteins modified with sodium hydroxide or urea, whereas the Td values of proteins modified with SDS were similar to the unmodified proteins. These results suggested that, at the concentrations studied, sodium hydroxide or urea could denature soybean protein more effectively than SDS, resulting in lower protein thermal stability. Soybean proteins with high ratios of 11S had more ordered structures, as evidenced by the high enthalpy values of protein denaturation observed in DSC measurements.
Method for analysis of TAG formed by reaction of fish oil with hydrogenated soybean oil
Authors: López‐Hernández Arnoldo , Torres Carlos F. , Garcia Hugo S. , Hill Charles G. 
Published: November 2006

AbstractAn HPLC method was developed for analysis of the TAG formed during interesterification of a fish oil rich in DHA residues and of a fully hydrogenated soybean oil. TAG species were separated using a three‐phase (acetone/acetonitrile/chloroform) solvent system. Peak identities were assigned on the basis of a multiple linear regression analysis by using factors such as carbon number, number of double bonds, and number of PUFA in the molecule as predictors for TAG retention time. Good agreement between experimental and predicted retention times was observed when the effect of the PUFA was separated in the regression model from that of the monounsaturated FA. In addition, the new method permits one to determine tristearin at concentrations up to 3 mg/mL without encountering the problem of partial retention of this TAG in the column that was observed when chloroform is not incorporated in the mobile phase.
Photo‐oxidation of lipids impregnated on the surface of dried seaweed (Porphyra yezoensis Ueda). Hydroperoxide distribution
Authors: Pan Xiangqing , Ushio Hideki , Ohshima Toshiaki 
Published: November 2006

AbstractThe distribution of hydroperoxide isomers generated by photo‐oxidation of natural lipids impregnated on the surface of dried seaweed previously exposed to visible light and without added photosensitizer were studied. The surface of dried seaweed was impregnated with linoleic acid methyl ester, and the sample was divided into two parts. One part was exposed to light from a 100‐W tungsten bulb (4500 lux) in a low‐temperature room (5°C). The other part was kept in the dark as a control. Positional isomers of the hydroperoxides generated from the impregnated linoleic acid methyl ester were separated individually by HPLC and further identified by MS. The dried seaweed kept in the dark contained four hydroperoxide isomers, namely, 13‐hydroperoxy‐cis‐9, trans‐11‐octadecadienoate, 13‐hydroperoxy‐trans‐9, trans‐11‐octadecadienoate, 9‐hydroperoxy‐trans‐10,cis‐12‐octadecadienoate, and 9‐hydroperoxy‐trans‐10, trans‐12‐octadecadienoate. For the dried seaweed exposed to light, the oxidized lipids contained not only the same four isomers, but also 12‐hydroperoxy‐cis‐9, trans‐13‐octadecadienoate and 10‐hydroperoxy‐trans‐8,cis‐12‐octadecadienoate. When fresh seaweed was dried in the sunlight, the formation of 12‐cis,trans‐ and 10‐cis,trans‐hydroperoxides of naturally occurring methyl linoleate was verified. Dried seaweed was then impregnated with eicosapentaenoic acid ethyl ester and exposed to light. Light exposure also generated certain hydroperoxide isomers attributable to singlet oxygen oxidation, namely, 6‐hydroperoxy‐trans‐4,cis‐8, cis‐11,cis‐14,cis‐17‐ethyl and 17‐hydroperoxy‐cis‐5,cis‐8,cis‐11, cis‐14,trans‐18‐ethyl eicosapentaenoate. When dried sea‐weed without any impregnated lipids was exposed to the light for 24 h in a cold room (5°C), characteristic isomers, including both the 20‐carbon FA isomers 6‐OOH and 17‐OOH as well as the 18‐carbon FA isomers 10‐OOH and 12‐OOH, were detected in the light‐exposed sample but were not found in the control. These results clearly show that singlet oxygen oxidation of lipids occurred in the seaweed exposed to light. We concluded that this lipid oxidation was catalyzed by chlorophyll as a photosensitizer in seaweed.
Liquid‐phase theoretical antioxidant activity trend of some cinnamic acid antioxidants
Authors: Lithoxoidou Alexandra T. , Bakalbassis Evangelos G. 
Published: November 2006

AbstractThe trend in antioxidant activity of four cinnamic acid antioxidants, derived on the basis of their liquid‐phase phenolic O H bond dissociation enthalpies, is determined theoretically, with the aid of the polarizable continuum model at the density functional theory level. Three solvents, differing in their hydrogen‐bonding ability and polarity—n‐heptane, acetonitrile, and ethanol—were used to model different environmental situations. The trends in solution‐phase antioxidant activity appeared different in each solvent; still, the theoretical antioxidant activity trend derived in n‐heptane was in excellent agreement with the experimental one in the lipid systems and the gas‐phase system. Different ortho substituents show notably different solvent effects. These results could lead to the determination of reliable antioxidant activity trends in real‐solution environments of interest in food or biological science frameworks.
Utilization of olive‐residue oil in the formulation of lubricating calcium greases
Authors: Chtourou Manef , Trabelsi Mahmoud , Frikha Mohamed Hédi 
Published: November 2006

AbstractCalcium greases were manufactured from olive‐residue oil in a closed reactor by substituting olive‐residue oil for animal tallow. The results of the performance tests applied to the obtained greases showed that their physicochemical and mechanical characteristics are comparable to those of calcium grease manufactured industrially by using animal tallow. The substitution of part of the animal tallow with olive‐residue oil increased the thermal and mechanical stability of the grease. Olive‐residue oil could constitute, alone or in combination with animal tallow, a raw material in the formulation of lubricating calcium grease.
Emulsifying properties and surface behavior of native and denatured whey soy proteins in comparison with other proteins. Creaming stability of oil‐in‐water emulsions
Authors: Palazolo Gonzalo G. , Sorgentini Delia A. , Wagner Jorge R. 
Published: November 2006

AbstractIn this work a comparative study of emulsifying and surface behaviors of native whey soy proteins (NWSP) and denatured whey soy proteins (DWSP) with those of native soy isolates, denatured soy isolates (DSI), and sodium caseinate was done. These samples showed different molecular mass distributions in gel filtration profiles. Dissociation and soluble high‐M.W. species in DWSP and DSI were observed. Lower interfacial and surface pressure values were obtained with native samples. Thermal treatment and salt addition enhanced tensioactivity in all fractions. Backscattering measurements of all oil‐in‐water emulsions, which exhibited a trimodal size distribution of droplets, showed the existence of a negative correlation with the median diameter of droplets. Greater droplet sizes were observed with NaCl addition. The NWSP emulsion had the lowest stability against creaming. Denaturation of this sample increased stability and favored air incorporation in emulsions. Destabilization depends not only on median droplet size but also on floc formation and structure. NaCl addition negatively affected the creaming stability only in emulsions formulated with soy isolates. The use of denaturation to enhance the surface and emulsifying properties of whey soy proteins would allow their use in food emulsions.
Production of linolenic acid in yeast cells expressing an omega‐3 desaturase from tung (Aleurites fordii)
Authors: Dyer John M. , Chapital Dorselyn C. , Kuan Jui‐Chang W. , Shepherd Hurley S. , Tang Fuqiang , Pepperman Armand B. 
Published: November 2006

AbstractTung oil is an industrial drying oil containing ca. 90% PUFA. We previously reported on enzymes required for the synthesis of linoleic (6% of FA) and eleostearic (80%) acids and here describe the cloning and functional analysis of an omega‐3 FA desaturase (FAD3) required for the synthesis of linolenic acid (1%). The tung FAD3 cDNA was identified by screening a tung seed cDNA library using the polymerase chain reaction and degenerate primers encoding conserved regions of the FAD3 enzyme family. Expression of this cDNA in yeast cells, cultured in the presence of linoleic acid, resulted in the synthesis and accumulation of linolenic acid, which accounted for up to 18% w/w of total cellular FA. Tung FAD3 activity was significantly affected by cultivation temperature, with the greatest amount of linolenic acid accumulating in yeast cells grown at 15°C. The amount of linolenic acid synthesized in yeast cells by tung FAD3 is ca. 10‐fold higher than that observed by expression of a rapeseed (Brassica napus) FAD3 in yeast, suggesting that tung FAD3 might be useful for biotechnological production of omega‐3 FA in transgenic organisms.