bluuebunny/crossref_metadata_2025 huggingface dataset:
Dehulling crambe seed for improved oil extraction and meal quality
Authors: Reuber M. A. , Johnson L. A. , Watkins L. R.
Published: November 2006

Crambe seed had low bulk density (328 kg/m3) due to thick hulls (0.23 mm), which made up 21.2% of the seed weight. The mean seed diameter was 2.7 mm (SD±0.2 mm); the thousand‐grain‐weight was 6.2 g. Dehulling improves oil extraction efficiency and facilitates the marketing of high‐protein meal (>40% protein). The effectiveness of roller milling/aspirating and the effectiveness of impact milling/aspirating on dehulling crambe seed were studied and compared by analyzing the meat and hull fractions for oil and protein contents and calculating material balances. Roller milling was more effective than impact milling. The optimal roller mill gap was 7/64 in. (0.28 cm), and the optimal impact mill speed was 2,400 rpm generating 44.7 m/s tangential speed. The optimal aspiration airflow was 1,970 ft3/min (55.7 m3/min). Roller milling/aspirating was projected to produce 46% protein meal at 12% moisture and 1% residual oil (typical of solvent extraction) or 42% protein meal at 12% moisture and 6% residual oil (typical of screw pressing most other oilseeds). Hand‐dissected hulls contained 10.4% moisture, and 1.2% oil and 8.8% protein on a dry basis, whereas the meats contained 8.8% moisture, and 47.6% oil and 31.6% protein on a dry basis. Optimal roller milling/aspirating produced hulls with 8.1% oil and 11.4% protein and meats with 42.6% oil and 30.5% protein on a dry basis.
Degumming of crude soybean oil by ultrafiltration using polymeric membranes
Authors: Pagliero C. , Ochoa N. , Marchese J. , Mattea M.
Published: November 2006

In this study, the ability of two ultrafiltration polymeric membranes to perform the degumming of a crude soybean oil/hexane mixture is tested. The performance of both membranes is defined in terms of their permeation flux, permeate color, and rejection of phospholipids. One of the membranes was synthesized in our laboratories from polyvinylidenefluoride (PVDF); the other one is a commercially available membrane made of polyimide. The degumming experiments were done in a stirred dead‐end ultrafiltration cell pressurized with N2. Results show that tested membranes are suitable for removing phospholipids from the crude oil/hexane miscella in the range of temperature and transmembrane pressure utilized in this work. Both membranes have high selectivity regarding phospholipids and produce a moderate reduction in permeate color. The PVDF membrane gives permeate fluxes up to threefold larger than those obtained with polyimide membrane at the same operational conditions, making the former more suitable for use at industrial scale.
Lipase‐catalyzed synthesis of unsaturated acyl l‐ascorbates and their ability to suppress the autoxidation of polyunsaturated fatty acids
Authors: Watanabe Yoshiyuki , Adachi Shuji , Nakanishi Kazuhiro , Matsuno Ryuichi
Published: November 2006

l‐Ascorbic acid and various polyunsaturated fatty acids (PUFA) were condensed at 55°C by the immobilized lipase Chirazyme l‐2 in dry acetone to produce the unsaturated acyl ascorbates. The PUFA moieties of the products were much more resistant to autoxidation at 65°C and nearly 0% relative humidity than the corresponding unmodified PUFA. The effects of the molar ratio of ascorbic acid or linoleoyl ascorbate to linoleic acid on the autoxidation of linoleic acid were examined. The autoxidation of linoleic acid was effectively suppressed at molar ratios greater than or equal to 0.2 when either ascorbic acid or linoleoyl ascorbate was mixed with linoleic acid. The addition of lauroyl ascorbate, synthesized through the enzyme‐catalyzed condensation of ascorbic acid and lauric acid in acetone, to docosahexaenoic acid also significantly suppressed the autoxidation of docosahexaenoic acid at molar ratios of ≥0.2.
FTIR spectroscopic determination of soap in refined vegetable oils
Authors: Mirghani M. E. S. , Che Man Y. B. , Jinap S. , Baharin B. S. , Bakar J.
Published: November 2006

A new analytical method was developed for the determination of soap in palm and groundnut oils by FTIR spectroscopy. Soap from 0 to 80 mg/kg oil was produced in situ in the oils by adding sodium hydroxide. The FTIR spectroscopy was with a sodium chloride transmission cell, and the partial least‐squares statistical method was used to calibrate a model for each oil. The accuracy of the method was comparable to that of AOCS Method Cc17‐95, with coefficients of determination (R2) of 0.98 and 0.98 for both palm and groundnut oils. The standard errors of calibration were 1.84 and 1.36 for the two oils, respectively. The calibration models were cross‐validated, and the R2 of cross‐validation and standard errors of cross validation were computed. The standard deviation of the difference for repeatability of the FTIR method was better than that for the chemical method used for determining soap in palm and groundnut oils. With its speed and ease of data manipulation by computer software, FTIR spectroscopy is a possible alternative to the standard wet chemical methods for rapid (2 min) and accurate routine determination of soap in chemically refined vegetable oils.
Biosynthetic pathway of diepoxy bicyclic FA from linoleic acid by Clavibacter sp. ALA2
Authors: Iwasaki Yugo , Brown Wanda , Hou Ching T.
Published: November 2006

The biosynthetic pathway of two bicyclic FA, 12∶17, 13∶17‐diepoxy‐9(Z)‐octadecenoic acid (DEOA) and 7‐hydroxy‐12∶17, 13∶17‐diepoxy‐9(Z)‐octadecenoic acid (hDEOA), by Clavibacter sp. ALA2 was investigated. When cultivated with linoleic acid as a substrate, the strain produced 12,13,17‐trihydroxy‐9(Z)‐octadecenoic acid (THOA), DEOA, and hDEOA as well as other FA. To clarify the synthetic route to these bicyclic FA, the strain was cultivated with purified THOA as a starting substrate. THOA was consumed almost completely by the strain with sequential generation of DEOA and hDEOA. Moreover, the strain produced hDEOA when cultivated with purified DEOA. Therefore, it was confirmed that THOA was a precursor of these bicyclic FA and that hDEOA was generated from DEOA. Based on our previously reported result that linoleic acid is first converted to 12,13‐dihydroxy‐9(Z)‐octadecenoic acid (DHOA) and the present results, the overall biosynthetic pathway for the diepoxy bicyclic FA from linoleic acid was postulated as: linoleic acid→DHOA→THOA→DEOA→hDEOA.
Determination of partially hydrogenated terphenyls‐based thermal heating fluid in vegetable oils by HPLC with fluorescence detection
Authors: Moh M. H. , Tang T. S. , Tan G. H.
Published: November 2006

An HPLC method for the determination of partially hydrogenated terphenyls‐based thermal heating fluid, Therminol 66™, in various vegetable oils is described. Direct analysis of palm olein showed that the 3‐ and 4‐cyclohexylbiphenyl peaks of the Therminol 66™ used in quantitative analysis co‐eluted with other fluorescent peaks present naturally in the oil. However, those interfering peaks were readily removed after saponification of palm olein. The concentrations of the 3‐ and 4‐cyclohexylbiphenyls of Therminol 66™ were monitored by fluorescence detection at 257 (excitation) and 320 nm (emission). The calibration graph obtained by using the peak areas of the 3‐ and 4‐cyclohexylbiphenyls against the concentrations of Therminol 66™ was linear, with a correlation coefficient of 0.994. The limit of quantitation, using spiked palm olein, was as low as 0.2 μg/g. The coefficients of variation obtained from the intra‐ and interday studies obtained by using three spiked concentrations (0.2, 0.5, and 1.0 μg/g) were 1.76–6.43 and 3.77–10.4%, respectively. The mean recovery value obtained from sunflower, soybean, and canola oils was more than 88.7%.
Comparison of ultrasonic and pulsed NMR techniques for determination of solid fat content
Authors: Singh Anand Pal , McClements D. J. , Marangoni A. G.
Published: November 2006

In this work an ultrasonic velocity technique was compared to direct pulsed NMR (pNMR) spectroscopy for the determination of the solid fat content (SFC) of anhydrous milk fat (AMF), cocoa butter (CB), and blends of AMF and CB with canola oil (CO) in the range 100 to 70% (w/w). In situ measurements of ultrasonic velocity were carried out during cooling (50–5°C) and heating (5–50°C) of the fat samples, and SFC values were calculated. The SFC were also determined simultaneously by pNMR. Peak melting temperatures determined by DSC were used as an indicator of the polymorphic state of the different fats and fat blends. Estimates of SFC obtained using pNMR and ultrasonic velocimetry did not agree. Our results suggested that ultrasonic velocity was highly dependent on the polymorphic state of the solid fat. Ultrasonic velocity in fat that contained crystals in a more stable polymorphic form was consistently higher than in fat that contained crystals in a less stable polymorphic modification. A high attenuation of the signal was observed in milkfat and CB at lower temperatures, particularly after sitting for 24 h. This high attenuation could be a product of scattering by crystallites or by microscopic air pockets formed upon solidification of the material, or it could be due to high ultrasonic absorption associated with phase transitions. This research highlights some of the problems associated with applying ultrasonics to the determination of SFC.
Determination of FA composition and total trans FA of Turkish margarines by capillary GLC
Authors: Arici Muhammet , Tasan Murat , Gecgel Umit , Ozsoy Semra
Published: November 2006

In this research, FA composition and total trans FA contents of 16 different brands of margarine (8 hard‐type and 8 soft‐type) sold in Turkey were determined by capillary GLC method. According to the results, the contents of saturated FA, monounsaturated FA, and PUFA were within the ranges of 23.9–32.3, 44.0–61.9, and 14.2–24.1%, respectively, in hard‐type margarines, and 27.0–39.9, 21.0–40.9, and 32.0–53.7%, respectively, in soft‐type margarines. Hard‐type margarines contained total trans FA concentrations of 20.1–34.3%, whereas soft‐type margarines contained less than 8.9% total trans FA. C18∶1trans acid content was within the range of 18.5–29.8% in hard‐type margarines, and it was significantly higher than the range in soft margarines (0.7–8.1%). C18∶1trans acid was the major trans FA in all margarines, and C18∶3trans acid concentrations were less than 0.2%.
Lipase‐catalyzed acidolysis of menhaden oil with CLA: Optimization by factorial design
Authors: Torres Carlos F. , Barrios Ernesto , Hill Charles G.
Published: November 2006

Menhaden oil was interesterified with CLA in a packed‐bed reactor containing an immobilized lipase from Mucor miehei (L9) as the biocatalyst. Process optimization was studied using a sequence of 22×3 factorial designs involving the mole ratio of reactants, the reaction temperature, and the space‐time of the reactor as experimental parameters. Three different responses—percentage of incorporation of CLA, level of n−3 residues remaining, and conversion of CLA—were considered as objective functions. The parameters studied showed opposite effects for incorporation of CLA and the retention level of n−3 residues. A desirability function was constructed to describe a desirable balance of the conflicting response variables. Optimal conditions correspond to a molar ratio of CLA to fish oil of 0.8 to 1, a temperature of 60°C, and a space‐time of 5 h.
Use of NIR spectroscopy for estimation of FA composition of soy flour
Authors: Sato Tetsuo , Takahashi Masakazu , Matsunaga Ryoichi
Published: November 2006

The feasibility of NIR spectroscopy for the determination of FA composition in soy flour was examined. NIR spectra were obtained for a small amount of soybean powder (about 8 mg) in a modified single‐grain cup using an NIR instrument by scanning the wavelengths from 1100 to 2500 nm at 2‐nm intervals. The relationship between the NIR spectral patterns of soybean powder and the FA compositions was examined: As the linoleic acid ratio increased, the NIR absorbance at 1708 nm, where the linoleic acid moiety has an absorption band, became stronger downward in the second‐derivative NIR spectra. The correlation coefficients between the standardized NIR readings at 1708 nm and the linoleic acid ratio or the oleic acid ratio in the FA composition of soy flour were −0.853 and 0.877, respectively. A rough estimation of the linoleic acid moiety or oleic acid moiety in soy flour could be successfully carried out with even a very small amount of soy flour according to the NIR spectral pattern due to the wavelength assignments of moieties.
Plackett‐burman design for determining the preference of Rhizomucor miehei lipase for FA in acidolysis reactions with coconut oil
Authors: Rao Reena , Divakar S. , Lokesh Belur R.
Published: November 2006

The preference of lipase (EC 3.1.1.3) from Rhizomucor miehei in the incorporation of 11 FA, ranging from C10∶0 to C22∶6, into coconut oil TAG during acidolysis was studied by applying the Plackett‐Burman experimental design. Enzymatic acidolysis reactions were carried out in hexane at 37°C for 48 h with coconut oil (0.1 M) and a mixture of 11 FA at a TAG to FA molar ratio of 1∶1. Lipase was used at the 5 wt% level. The incorporation of FA into coconut oil TAG was determined by GC. The lipase showed preference for long‐chain saturated FA for incorporation into coconut oil TAG. The FA with 18 carbon atoms showed a high incorporation rate (18∶1>18∶1>18∶3). The lipase showed the least preference for the incorporation of 12∶0, which occurs in maximal concentration (46%), whereas the most preferred FA, 18∶0, occurs at a very low concentration (<2%) in coconut oil. The overall preference of lipase for the incorporation of different FA into coconut oil TAG was 18∶0>18∶2, 22∶0>18∶1, 18∶3, 14∶0, 20∶4, 22∶6>16∶0>12∶0≫10∶0.
Enantiomeric composition of filbertone in hazelnuts and hazelnut oils from different geographical origins
Authors: Ruiz del Castillo M. L. , Gómez Caballero E. , Blanch G. P. , Herraiz M.
Published: November 2006

The potential of enantiomeric analysis of (E)‐5‐methyl‐hept‐2‐en‐4‐one (filbertone) for authenticity control of oils is evaluated for a selection of both hazelnuts and hazelnut oils from different geographical origins. The analytical method proposed involves the enantioselective GC analysis of the fraction resulting from the preseparation with HPLC of either a hazelnut extract or a hazelnut oil. The obtained results demonstrate that the proposed procedure avoids the partial or total racemization of filbertone and thus allows the reliable determination of its enantiomeric composition. Moreover, the enantiomeric ratio of filbertone is not affected by the cold pressing process of hazelnut oil production and was found to be nearly constant for oils obtained from unroasted hazelnuts of different geographical origins.
Pinacol rearrangement of jojoba bis‐epoxide
Authors: Zeltser Inna , Shani Arnon
Published: November 2006

Jojoba bis‐epoxide (1.6 mmol) undergoes pinacol rearrangement upon reaction with the iodide ion (60 mmol) under slightly acidic conditions, via an iodohydrin as an intermediate, to yield bis‐ketojojoba in high yield (92%) after 25 h reflux in THF; no hydroxy derivatives were detected. Since the nucleophilic opening of the epoxide ring is statistically equal on both sides, the rearranged product may have the two carbonyl groups on either side of the original carbon atoms of the two epoxide rings, both completely opened. MS of the rearranged products reveals that the ring opening is approximately equal on both sides of the epoxide ring. Other nucleophiles, such as acetate and amine, open the ring sluggishly without rearrangement.
Prevention of metallic corrosion by lauric hydrazide and its salts under vapor phase conditions
Authors: Quraishi M. A. , Bhardwaj V. , Rawat J.
Published: November 2006

Six organic volatile corrosion inhibitors (VCI) were synthesized using lauric hydrazide with various acids such as cinnamic acid, succinic acid, nitrobenzoic acid, phthalic acid, and maleic acid and evaluated as corrosion inhibitors of mild steel, copper, brass, zinc, and aluminum by weight loss and potentiodynamic polarization methods. All the investigated VCI exhibited good inhibition efficiency for all the metals tested. The inhibition efficiency of all compounds increased as the inhibitor concentration increased. Lauric hydrazide cinnamate showed the best results among all compounds studied. In addition, all inhibitors showed anodic behavior. Adsorption studies demonstrated that all the investigated compounds followed Temkin's adsorption isotherm.
LC‐electrospray ionization and LC‐FABMS study of flavonoid glycosides extracted from peanut meal
Authors: Singleton J. A. , Stikeleather L. F. , Sanford J. H.
Published: November 2006

HPLC, HPLC‐electrospray ionization (LC‐ESI), and LC‐FABMS were used to characterize flavonoid glycosides in the methanol extract from peanut meal. Five isoflavones, diadzin, glycitin, genistin, daidzein, and genistein, were separated by HPLC and characterized by comparison with known standards using ESI‐MS. The flavonoid methylquercetin (rhamnetin) was present in the methanol extract from peanuts and identified by ESI‐MS. Four other flavonoids, two quercetin diglycosides, one quercetin monoglucoside, and isorhamnetin glucoside, were found to be present in the methanol extract based on their reversed‐phase elution pattern, mass ions, and fragment ions using flow‐FABMS.
Characterization of the TAG of peanut oil by electrospray LC‐MS‐MS
Authors: Dorschel Craig A.
Published: November 2006

A study of processed peanut oil was undertaken to assess the utility of HPLC combined with tandem MS to obtain data easily regarding the number of TAG of fats and oils and their FA composition. Mass chromatograms and spectra corresponding to only TAG of a single M.W. were obtained for the full range of TAG in the sample. Analysis of the mass spectra allowed the identification of more than 160 TAG in the sample by their FA composition. In addition, it was possible to estimate relative abundances of the TAG and suggest the position of the FA on glycerol for a limited number of cases. This technique greatly simplifies the task of assigning FA to coeluting TAG and facilitates identification of TAG present in trace quantities in mixtures, with possible application in circumstances where such trace TAG could be significant markers. Results are quickly obtained without extensive sample preparation or prefractionation of the sample.
Fast quality screening of vegetable oils by HPLC‐thermal lens spectrometric detection
Authors: Luterotti Svjetlana , Franko Mladen , Bicanic Dane
Published: November 2006

Isocratic reversed‐phase HPLC with thermal lens spectrometric (TLS) detection enabled identification of linseed, olive, sesame, and wheat germ vegetable oils to control the authenticity of the oils based on characteristic carotenoid/carotene profiles. Four characteristic regions of carotenoids (i.e., lutein, xanthophyll, carotene, and lycopene) have been identified in each type of oil. The concentrations of total β‐carotene (BC) and α‐carotene (AC), together with trans‐to cis‐isomers of β‐carotene (TBC/CBC) and BC/AC ratios were shown to be reliable and useful indices for fast screening of oils for nutritional quality. The oil TBC/CBC ratio and the BC concentration (in μg/mL) should meet the following numerical criteria: linseed (≽2∶1, ≽1.7), olive (≽3∶1, ≽0.4), sesame (≽1∶1, ≽0.1), and wheat germ oil (≽1∶1, ≽1.7). Based on the above criteria, unsatisfactory olive oils differed significantly from the consumable ones. Likewise, the concentration of AC in consumable wheat germ and sesame oil should not be lower than 0.6 and 0.02 μg/mL, respectively. The AC level in safflower oil should not be higher than 0.04 μg/mL. The BC/AC ratios exceeding 3∶1, 6∶1, and 8∶1 should be used as an additional quality requirement for consumable wheat germ, sesame, and safflower oil, respectively.
Formation of 4‐hydroxynonenal, a toxic aldehyde, in soybean oil at frying temperature
Authors: Seppanen C. M. , Saari Csallany A.
Published: November 2006

The formation of 4‐hydroxy‐2‐trans‐nonenal (HNE), a mutagenic and cytotoxic product of the peroxidation of linoleic acid, was monitored in soybean oil that was heated at 185°C for 2, 4, 6, 8, and 10 h. Unheated soybean oil contained no HNE and a relatively low concentration of polar lipophilic secondary oxidation products (aldehydes and related carbonyl compounds), measured as 2,4‐dinitrophenylhydrazine derivatives by HPLC. An increase in the concentration of both HNE and total lipophilic polar oxidation products was observed with increased exposure to frying temperature. A considerable concentration of HNE had already formed at 2 h and the concentration continued to increase at 4 and 6 h of heating. After 6 h the concentration of HNE decreased, possibly due to degradation of the aldehyde with further exposure to high temperature. The loss of endogenous tocopherols was also monitored in the heated oil, and the tocopherol concentration decreased as the secondary lipid oxidation products increased.
Fat bloom formation and characterization in milk chocolate observed by atomic force microscopy
Authors: Hodge S. M. , Rousseau D.
Published: November 2006

The surface microstructure and polymorphic behavior of milk chocolate subjected to multiple thermal cycles between 20 and 32, 33, or 34°C were examined using atomic force microscopy (AFM) and powder X‐ray diffraction (XRD). The surface of unbloomed milk chocolate was smooth (surface roughness of 278 nm) and consisted of small, evenly distributed crystals. XRD results indicated the presence of mostly form V crystals and little or no form VI crystals. Cycling between 20 and 32°C resulted in little bloom formation and change in polymorphic behavior. Gradual bloom formation occurred as a result of cycling between 20 and 33°C, and was accompanied by the nascence of form VI crystals. Surface roughness increased gradually from 417 nm after one cycle to 476 and 521 nm after two and three cycles, respectively. Extensive bloom arose from cycling between 20 and 34°C. Surface roughness increased from 373 nm after one cycle to 603 and 736 nm after two and three cycles, respectively. This heavily bloomed chocolate consisted of jutting crystals and large raised, yet smooth areas that were haphazardly located within the chocolate matrix. In summary, a new perspective on the development of surface bloom due to thermal cycling is provided.
Preparative‐scale supercritical fluid extraction/supercritical fluid chromatography of corn bran
Authors: Taylor Scott L. , King Jerry W.
Published: November 2006

A preparative‐scale supercritical fluid extraction/supercritical fluid chromatography (SFE/SFC) procedure has been developed for the removal of oil from corn bran to obtain fractions enriched with free sterols and ferulate‐phytosterol esters (FPE). Operational parameters from an analytical‐scale supercritical fluid fractionation technique were translated to and optimized on a home‐built, preparatory‐scale SFE/SFC apparatus. SFE was performed at 34.5 MPa and 40°C using supercritical carbon dioxide. These conditions did not result in exhaustive extraction of the corn bran, but yielded about 96% of the available oil. SFC was conducted in three steps, followed by reconditioning of the sorbent bed. Preparative‐scale SFE/SFC of corn bran produced a fraction enriched greater than fourfold in free sterols and 10‐fold in FPE, suggesting that such a scheme could be used industrially to produce a functional food ingredient.
TAG composition and solid fat content of palm oil, sunflower oil, and palm kernel olein belends before and after chemical interesterification
Authors: Noor Lida H. M. D. , Sundram K. , Siew W. L. , Aminah A. , Mamot S.
Published: November 2006

Modification of the characteristics of palm oil (PO), sunflower oil, and plam kernel olein (PKOo) according to conventional three‐component mixture designs was undertaken by a combination of blending and chemical interesterification (CIE) techniques. TAG composition and solid fat content (SFC) profile of the starting blends were analyzed and compared with those of the interesterified blends. Upon CIE, extensive rearrangement of FA among TAG was evident. Concentrations of several TAG were increased, some were decreased, and several new TAG were formed. The resulting changes in TAG profile were reflected in the SFC of the blends. The SFC values of the chemically interesterified blends, except binary blends of PO/PKOo, revealed that they were softer than their respective starting blends. SFC data also indicated that eutectic interaction occurred between PO and PKOo in the starting blends and that this interaction was diminished after CIE.
Kinetics of the hydroformylation of soybean oil by ligand‐modified homogeneous rhodium catalysis
Authors: Kandanarachchi Pramod , Guo Andrew , Demydov Dmytro , Petrovic Zoran
Published: November 2006

The kinetics and mechanism of the hydroformylation of soybean oil by homogeneous ligand‐modified rhodium catalysts were investigated at 70–130°C and 4000–11,000 kPa. The effects of reaction rates on systematic variations in reaction parameters were evaluated in order to develop an industrial process to convert vegetable oils to polyaldehydes. The activation energies in the presence of triphenylphosphine (Ph3P) (61.1±0.8 kJ/mol) (mean±SD) and triphenyl phosphite [(PhO)3P] (77.4±5.0 kJ/mol) were determined. The catalyst was deactivated at temperatures higher than 100°C. An evaluation of the effects of the reaction parameters on initial rates yielded the rate laws for Ph3P {rate=k [olefin][Rh(CO)2Acac]1.1 [Ph3P]−0.5 (pH2+pCO)1.4, where Rh(CO)2Acac is (acetylacetonato)dicarbonylrhodium (I)} and (PhO)3P {rate=[olefin] [Rh(CO)2Acac]1.2 [(PhO)3P]−0.8 (pH2+pCO)0.9 at total pressures lower than 7000 kPa, and rate =[olefin] [Rh(CO)2Acac]1.2 [(PhO)3P]−0.8(pH2+pCO)1.7 at total pressures higher than 7000 kPa}.
FA selectivity of lipases in acyl‐transfer reactions with acetate esters of polyols in organic media
Authors: Lee Chen‐Hsien , Parkin Kirk L.
Published: November 2006

FA reaction selectivity of Burkholderia cepacia, Rhizomucor miehei, and Candida antarctica fraction B lipases was compared between acyl‐transfer and esterification reactions. Multicompetitive reaction mixtures containing a series of n‐chain FA (a C4–C18 series; and a C18∶x series, where X=0‐3 double bonds) and a single acetate ester co‐substrate [triacetin, 1,2‐propanediol (1,2‐PD)diacetate, and 1,3‐PD diacetate] were studied in tert‐butyl methyl ether at an aw of 0.69. For B. cepacia lipase, FA optima for C8, C16, and C18∶2 were observed in all reactions with 1.0‐ to 5.9‐fold differences in FA selectivity. For R. miehei lipase, an optimum for C8 FA was observed in all reactions with 1.2‐ to 6.7‐fold differences in FA selectivity. For C. antarctica lipase, FA optima for C8/C10 were observed in all reactions with 1.0‐ to 2.8‐fold differences in FA selectivity. FA selectivities were broadly modulated upon changing from free polyol to acetate ester co‐substrates for B. cepacia and R miehei lipases, whereas FA selectivity modulations were more specific upon this change in reaction configuration for C. antarctica B lipase. For all lipases, reactivity toward unsaturated C18∶x FA was enhanced in acyl‐transfer relative to esterification reactions with these polyol co‐substrates.
Partial purification of nigella sativa L. Seed lipase and its application in hydrolytic reactions. Enrichment of γ‐linolenic acid from borage oil
Authors: Tuter Melek , Aksoy H. Ayşe , Ustun Guldem , Riva Sergio , Secundo Francesco , ipekler Serhat
Published: November 2006

Selective hydrolysis of borage (Borago officinalis L.) oil was catalyzed by two lipase preparations of Nigella sativa L. seeds at 40°C in a mixture of borage oil, water, and hexane. Ammonium sulfate‐precipitated lipase (Nigella PL) and lipase partially purified by DEAE‐ion exchange chromatography (Nigella CPL) exhibited a negative specificity toward γ‐linolenic acid (GLA). Best results were obtained in the experiments conducted with 330 U/g oil of Nigella PL and 200 U/g oil of nigella CPL. When 330 U/g oil of Nigella PL was used, after 8 h the GLA level rose from 21.9% in the starting oil to 29.6 and 41.8% in TAG and DAG fractions of the product mixtures, respectively (1.5‐fold enrichment of GLA in the total unhydrolyzed acylglycerol fraction). At 200 U/g oil enzyme concentration of Nigella CPL, after 77 h maximum GLA enrichment was observed in the DAG fraction. The GLA content of the DAG increased to 34.6%, corresponding to almost 1.6‐fold enrichment. The relative inability of Nigella sativa lipase(s) to hydrolyze γ‐linolenoyl moieties of TAG can be used for the enrichment of this acid in the unhydrolyzed acylglycerol fractions of GLA‐containing oils.
Oil‐free protein isolates from full‐fat, dehulled mustard flour by microfiltration
Authors: Dendukuri Dhananjay , Diosady Levente L.
Published: November 2006

New microfiltration (MF)‐based aqueous processes for the extraction of oil‐free protein isolates from full‐fat, dehulled mustard flour have been developed. The processes used hydrophilic MF membranes to separate oil and protein. The most successful processing sequence consisted of alkaline extraction of oil and protein from the flour at pH 11, centrifugation to remove undissolved solids, and an initial microfiltration step to separate oil and dissolved protein. This was followed by proteolytic enzyme treatment of the retentate and a second‐stage MF step to recover further protein. The proteolytic enzyme treatment was designed to break aggregated proteins into smaller fractions to permit their passage through the MF membrane. The permeates from the two microfiltration steps were ultrafiltered to concentrate the protein and remove antinutritional compounds and highly fragmented peptides. With this process, 60% of the protein originally in the flour was separated from the oil phase. Approximately 40% of the protein present in the flour was recovered in the form of two oil‐free protein isolates—a soluble protein isolate containing 91% protein and a precipitated protein isolate containing 100% protein. The process proves the potential of MF as an effective method of extracting oil‐free protein isolates from oilseeds without the use of organic solvents.
Oxidation of FA with alkene of alkyne functionalities studied with chemiluminescence and real‐time IR spectroscopy
Authors: Samuelsson Johan , Johansson Mats
Published: November 2006

The oxidation of well‐defined FA derivatives has been studied with real‐time IR (RTIR) and chemiluminescence (CL) techniques. Both methyl esters and model oils based on different FA have been studied to reveal the effect of functionality. The FA used were linoleic and crepenynic acid, the latter with an alkyne functionality. The purpose was to reveal how structural differences affect the oxidation and how this is monitored with CL and RTIR. Both model oils had longer oxidation induction times than the corresponding methyl esters, as seen by both IR and CL. Generally, the induction times measured with IR were shorter than those determined by CL, but the rate of oxidation did not seem to differ much between the model oils and the corresponding methyl esters. The results also imply that the higher functionality of the model oils gives a greater possibility of intramolecular addition reactions instead of chain scission during oxidation, making the model oils emit fewer low‐M.W. volatiles than the methyl esters. There is also a difference between methyl crepenynate and methyl linoleate, in that the alkyne functionality seems to enhance the possibility of chain scission instead of addition reactions. The results presented imply that the CL signal can be used to monitor the oxidation and the formation of volatile compounds from a FA structure. By combining the CL measurements with RTIR data, information about the oxidation reactions can be obtained, giving a greater understanding of what reactions are occurring during oxidation and how they are related to each other.
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

Hexane 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

A 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

Efficient 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

Formation 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

A 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

Two 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

Reaction 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

Nitrogen 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

An 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

Membrane 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

Soy 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

An 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.