bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical hydrogenation of edible oils in a solid polymer electrolyte reactor. Sensory and compositional characteristics of low Trans soybean oils
Authors: Warner K. , Neff W. E. , List G. R. , Pintauro Peter
Published: November 2006

Soybean oils were hydrogenated either electrochemically with Pd at 50 or 60°C to iodine values (IV) of 104 and 90 or commercially with Ni to iodine values of 94 and 68. To determine the composition and sensory characteristics, oils were evaluated for triacylglycerol (TAG) structure, stereospecific analysis, fatty acids, solid fat index, and odor attributes in room odor tests. Trans fatty acid contents were 17 and 43.5% for the commercially hydrogenated oils and 9.8% for both electrochemically hydrogenated products. Compositional analysis of the oils showed higher levels of stearic and linoleic acids in the electrochemically hydrogenated oils and higher oleic acid levels in the chemically hydrogenated products. TAG analysis confirmed these findings. Monoenes were the predominant species in the commercial oils, whereas dienes and saturates were predominant components of the electrochemically processed samples. Free fatty acid values and peroxide values were low in electrochemically hydrogenated oils, indicating no problems from hydrolysis or oxidation during hydrogenation. The solid fat index profile of a 15∶85 blend of electrochemically hydrogenated soybean oil (IV=90) with a liquid soybean oil was equivalent to that of a commercial stick margarine. In room odor evaluations of oils heated at frying temperature (190°C), chemically hydrogenated soybean oils showed strong intensities of an undesirable characteristic hydrogenation aroma (waxy, sweet, flowery, fruity, and/or crayon‐like odors). However, the electrochemically hydrogenated samples showed only weak intensities of this odor, indicating that the hydrogenation aroma/flavor would be much less detectable in foods fried in the electrochemically hydrogenated soybean oils than in chemically hydrogenated soybean oils. Electrochemical hydrogenation produced deodorized oils with lower levels of trans fatty acids, compositions suitable for margarines, and lower intensity levels of off‐odors, including hydrogenation aroma, when heated to 190°C than did commercially hydrogenated oil.
Cyclic fatty acid monomers and thermoxidative alteration compounds formed during frying of frozen foods in extra virgin olive oil
Authors: Romero A. , Cuesta C. , Snchez‐Muniz F. J.
Published: November 2006

The measurement of polar content and specific polar compound distribution was used to evaluate the alteration of an extra virgin olive oil (EVO) used 20 times to fry frozen foods employing two methods of frying (with or without oil replenishment during frying). In addition, cyclic fatty acid monomers (CFAM) were quantified and identified throughout the 20 frying operations. Total polar content and specific polar compounds increased in the used oil (with or without replenishment). Nevertheless, frequent replenishment (FR) permits a higher number of fryings because of a dilution effect that helps maintain lower amounts of polar and specific alteration compounds than when null replenishment (NR) was used. CFAM were absent in the unused EVO, but appeared in the oil bath as a consequence of oil heating. The total CFAM concentration was higher when the oil was used with the NR method. Cyclopentyl fatty acids were more abundant than cyclohexyl ones. The data suggested that the FR frying is more appropriate to maintain the quality of the oil during frozen food frying.
Effect of processing conditions on crystallization kinetics of a milk fat model system
Authors: Herrera M. L. , Hartel R. W.
Published: November 2006

Crystallization behavior of three blends of 30, 40, and 50% of high‐melting fraction (MDP=47.5°C) in low‐melting fraction (MDP=16.5°C) of milk fat was studied under dynamic conditions in laboratory scale. The effect of cooling and agitation rates, crystallization temperature, and chemical composition of the blends on the morphology, crystal size distribution, crystal thermal behavior, polymorphism, and crystalline chemical composition was investigated by light microscopy, differential scanning calorimetry (DSC), X‐ray diffraction (XRD) and gas chromatography (GC). Different nucleation and growth behavior were found for different cooling rates. At slow cooling rate, larger crystals were formed, whereas at fast cooling rate, smaller crystals appeared together. Slowly crystallized samples had a broader distribution of crystal size. Crystallization temperatures had a similar effect as cooling rate. At higher crystallization temperatures, larger crystals and a broader crystal size distribution were found. Agitation rate had a marked effect on crystal size. Higher agitation rates lead to smaller crystal size. Cooling rate was the most influential parameter in crystal thermal behavior and composition. Slowly crystallized samples showed a broader melting diagram and an enrichment of long‐chain triacylglycerols. Crystallization behavior was more related to processing conditions than to chemical composition of blends.
Use of thermostable Fusarium heterosporum lipase for production of structured lipid containing oleic and palmitic acids in organic solvent‐free system
Authors: Nagao Toshihiro , Shimada Yuji , Sugihara Akio , Murata Aoi , Komemushi Sadao , Tominaga Yoshio
Published: November 2006

A newly developed 1,3‐positionally specific thermostable lipase from Fusarium heterosporum (named R275A lipase) was immobilized on Dowex WBA for the production of structured lipid by acidolysis of tripalmitin (PPP) with oleic acid (OA). The immobilized catalyst was fully activated by pretreatment at 50°C in a PPP/OA mixture containing 2% water. The pretreatment caused concomitant hydrolysis, but the hydrolysis was repressed using a substrate without water in the subsequent reactions. The optimal reaction conditions were determined as follows: A mixture of PPP/OA (1∶2, w/w) and 8% immobilized lipase catalyst was incubated at 50°C for 24 h with shaking at 130 oscillations/min. The acidolysis reached 50% under these conditions, and the contents of triolein, 1,3‐dioleoyl‐2‐palmitoyl‐glycerol, 1(3),2‐dioleoyl‐3(1)‐palmitoyl‐glycerol, 1(3),2‐palmitoyl‐3(1)‐oleoyl‐glycerol, 1,3‐dipalmitoyl‐2‐oleoyl‐glycerol, and PPP in the reaction mixture were 8, 36, 4, 28, 1, and 6 mol%, respectively. The stabilities of immobilized R275A lipase catalyst and two immobilized catalysts containing Rhizopus delemar or Rhizomucor miehei lipases were compared under the conditions mentioned above, with the catalysts being transferred to fresh substrate every 24 h. The half‐life of the R275A lipase catalyst was 370 d, which was significantly longer than those of Rhizopus and Rhizomucor lipase catalysts.
Enzymatic synthesis of low‐calorie structured lipids in a solvent‐free system
Authors: Yang Taek Ho , Jang Young , Han Jeong Jun , Rhee Joon Shick
Published: November 2006

For the synthesis of low‐calorie structured lipids (LCSL), transesterification between triacetin and stearic acid using immobilized lipase in a solvent‐free system was investigated. Stearic acid, a long‐chain saturated fatty acid, was incorporated mainly into the sn‐1 and/or sn‐3 positions of triacetin by lipase‐catalyzed reaction. Three types of reactor systems (open, closed, and vacuum) were studied for the production of LCSL. The effects of various reaction variables such as water activity of substrates and lipase, molar ratio of substrates, stirring speed and reaction temperature were investigated. In the vacuum reactor system, a certain amount of water was added periodically to maintain the optimal water content of the reaction system. When a suitable amount of water (0.65 wt% of substrates) was added at every 1 h into the vacuum reactor system, more than 88% LCSL was obtained within 4 h using Chirazyme® L‐2.
Fractionation of menhaden oil and partially hydrogenated menhaden oil: Characterization of triacylglycerol fractions
Authors: Lee Ki‐Teak , Foglia Thomas A.
Published: November 2006

Menhaden oil (MO) and partially hydrogenated menhaden oil (PHMO) were dry‐fractionated and solvent‐fractionated from acetone. After conversion to fatty acid methyl esters, the compositional distribution of saturated, monounsaturated, trans, and n−3 polyunsaturated fatty acids (PUFA) in the isolated fractions was determined by gas chromatography. Acetone fractionation of MO at −38°C significantly increased the n−3 PUFA content in the liquid fractions over that of starting MO (P<0.05). For PHMO, liquid fractions obtained by low‐temperature crystallization (−38, −18, and 0°C) from acetone showed significant increases (P<0.05) in monounsaturated fatty acid (MUFA) content over that of the starting PHMO. For selected MUFA‐enriched fractions, reversed‐phase high‐performance liquid chromatography (HPLC) was used to separate, isolate, and characterize the major triacylglycerol (TAG) molecular species present. Thermal crystallization patterns for these fractions also were determined by differential scanning calorimetry (DSC). The results demonstrated that under the appropriate conditions it is possible to dry‐fractionate or solvent‐fractionate MO and PHMO into various solid and liquid fractions that are enriched in either saturated, monounsaturated, polyunsaturated, or the n−3 classes of fatty acids. Moreover, characterization of these TAG fractions by reversed‐phase HPLC gives insight into the compositional nature of the TAG that are concentrated into the various fractions produced by these fractionation processes. Finally, the DSC crystallization patterns for the fractions in conjunction with their fatty acid compositional data allow for the optimization of the fractionation schemes developed in this study. This information allows for the production of specific TAG fractions from MO and PHMO that are potentially useful as functional lipid products.
A laboratory study of the bleaching process in stigmasta‐3,5‐diene concentration in olive oils
Authors: Bonveh J. Serra , Torrent M. Solvia , Coll F. Ventura
Published: November 2006

The bleaching effect was simulated in pilot plant by measuring the influence of temperature (40, 50, 60, 70, 80, and 90°C), time (5, 10, 15, 20, 25, and 30 min), and concentration of solid adsorbent [1.5 and 8% (w/w) of Tonsil supreme NFF] on stigmasta‐3,5‐diene (STIG) obtained by dehydration of steroidal compounds. Conditions were chosen to simulate those used in industrial operations. The presence of refined oils in extra virgin olive oil can be detected by these newly formed steroid hydrocarbons. Experimental results indicated that STIG did not exceed an imposed limit of 0.15 mg/kg in extra virgin olive oil, when oils were bleached with 1.5% earth at temperatures ≤80°C for 30 min in admixed to oils sold as virgin. A large proportion of the adulterations were not detectable by the official methods. Color determinations (CIE‐1931) chromatic coordinates) were replicated on a refined oil and in admixed extra virgin olive oil. Color of olive oil was not significantly affected by mixing with refined oil (≤20%).
Deactivation and coke formation on palladium and platinum catalysts in vegetable oil hydrogenation
Authors: Edvardsson Jonas , Rautanen Petri , Littorin Anders , Larsson Mikael
Published: November 2006

Deactivation of palladium and platinum catalysts due to coke formation was studied during hydrogenation of methyl esters of sunflower oil. The supported metal catalysts were prepared by impregnating γ‐alumina with either palladium or platinum salts, and by impregnating α‐alumina with palladium salt. The catalysts were reused for several batch experiments. The Pd/γ‐Al2O3 catalyst lost more than 50% of its initial activity after four batch experiments, while the other catalysts did not deactivate. Samples of used catalysts were cleaned from remaining oil by repeated extractions with methanol, and the amount of coke formed on the catalysts was studied by temperature‐programmed oxidation. The deactivation of the catalyst is a function of both the metal and the support. The amount of coke increased on the Pd/γ‐Al2O3 catalyst with repeated use, but the amount of coke remained approximately constant for the Pt/γ‐Al2O3 catalyst. Virtually no coke was detected on the Pd/α‐Al2O3 catalyst. The formation of coke on Pd/α‐Al2O3 may be slower than on the Pd/γ‐Al2O3 owing to the carrier's smaller surface area and less acidic character. The absence of deactivation for the Pt/γ‐Al2O3 catalyst may be explained by slower formation of coke precursors on platinum compared to palladium.
Lipid and γ‐linolenic acid accumulation in strains of zygomycetes growing on glucose
Authors: Kavadia A. , Komaitis M. , Chevalot I. , Blanchard F. , Marc I. , Aggelis G.
Published: November 2006

Strains of Zygomycetes, belonging to the genera Zygorhynchus, Mortierella, Rhizopus, Mucor, and Cunninghamella, when cultivated on glucose produced significant quantities of γ‐linolenic acid (GLA). After exhaustion of the nitrogen source from the culture medium, all strains accumulated cellular lipids in concentrations ranging from 10 to 28% (oil/dry mycelium). However, in some strains after the depletion of the carbon source (glucose) from the culture medium, a reconsumption of the accumulated oil and synthesis of fat‐free cell material was observed. Accumulation of large amounts of oil in the mycelium resulted in the production of oil with low GLA content. Rhizopus stolonifer strain LGAM (9)1, and Cunninghamella sp. strain LGAM (9)2 produced more than 30 mg GLA/g of dry cellular mass. Cunninghamella sp. accumulated 28.1% oil/dry cellular mass, which contained 11.9% GLA. The production of GLA was 260 mg/L of culture medium.
Improvement of the phase‐transfer catalysis method for synthesis of glycidyl ether
Authors: Kang Ho‐Cheol , Lee Byung Min , Yoon Jungho , Yoon Minjoong
Published: November 2006

A convenient procedure for the synthesis of aliphatic alkylglycidyl ether has been studied. It has been found that the improved preparation of the alkylglycidyl ether can be achieved by using fatty alcohol such as octanol and octadecanol with epichlorohydrin in the presence of phase‐transfer catalyst (PTC) such as 1‐alkyloxypropan‐2‐ol‐3‐trimethyl ammonium methylsulfate, 1‐alkyloxypropan‐2‐ol‐3‐methyldiethanolammonium methylsulfate, alkyloxy‐2‐hydroxypropyldimethylamine and alkyloxy‐2‐hydroxypropyldiethanolamine, tetrabutylammonium bromide, etc. without water and other organic solvents. This method, carried out in solid phase/organic phase (reactants and product themselves), has the following merits: (i) producing the solid by‐products such as sodium chloride and sodium hydroxide which are easily removed by simple filtration, (ii) saving the amount of reactants used such as sodium chloride and phase‐transfer catalyst, and (iii) increasing the yields of glycidyl ethers. The yields of octylglycidyl ether and octadecylglycidyl ether are 92.0 and 91.7%, respectively. The amount of sodium hydroxide used can be saved by from 1.5 to 0.7 molar ratio with respect to octanol in comparison with those in the conventional method using PTC.
Preparation of sharp‐melting hard palm midfraction and its use as hard butter in chocolate
Authors: Hashimoto Satsuki , Nezu Toru , Arakawa Hiroshi , Ito Tomonori , Maruzeni Shoji
Published: November 2006

Preparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is obtained by multistep fractionation of palm oil involving dry fractionation (DF) and/or solvent fractionation (SF), usually using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3‐disaturated triacylglycerols tend to selectively crystallize more than nonsymmetrical 1,2‐ or 2,3‐disaturated triacylglycerols, making it suitable for obtaining the solid midfraction. Unfortunately, triacylglycerols are very soluble in hexane, and temperatures at least 15 degrees lower than those required for acetone must be used for equivalent crystal yields. On the other hand, DF is a less expensive and safer process. Thus, multistep fractionation combining DF and SF using acetone was developed to achieve sufficient removal of high‐melting components, and further enrichment of 1,3‐dipalmitoyl‐2‐oleoylglycerol and the hard PMF was obtained by triple‐step fractionation of palm olein or double‐step fractionation of soft PMF. Compared to conventional hard PMF, this hard PMF had a steeper melting curve and better snapping and sharp‐melting qualities when used in chocolate. Heat resistance of the hard PMF chocolate was similar to the conventional hard PMF chocolate, and its bloom resistance could be improved by adding polyglycerol fatty acid esters.
Cooking indices to predict screw‐press performance for crambe seed
Authors: Wiesenborn Dennis , Doddapaneni Rajeev , Tostenson Kristi , Kangas Nancy
Published: November 2006

Screw presses offer one means for extracting oil from crambe seed. Crambe seed was steam‐cooked at 80 to 112°C for 5 to 20 min, dried to 6% (wet basis), and screw‐pressed. Meal residual oil decreased with increased cooking time and temperature to a minimum at 10 to 15 min and 100°C (8.5 to 8.9% oil vs. 11 to 12% in uncooked or lightly cooked seed). More intense cooking increased residual oil to a high of 16% at 20 min and 112°C. The degree of cooking was quantified using indices based on light absorbance at 280 nm (A280 index, a measure of soluble protein) and myrosinase activity for aqueous seed extracts. Regression analysis showed that oil recovery, meal residual oil, and the A280 index were significantly correlated with cooking time and temperature. A plot of residual oil vs. the A280 index showed that this index helps discriminate between under‐, over‐, and optimally cooked seed. The myrosinase index helped identify undercooked samples but was unable to identify overcooked samples. The optimal A280 index values from this bench‐scale study may not be the same in full‐scale processes, but this approach can be adapted for tuning such processes.
Effects of ultrasonic irradiation on crystallization behavior of tripalmitoylglycerol and cocoa butter
Authors: Higaki Kaoru , Ueno Satoru , Koyano Tetsuo , Sato Kiyotaka
Published: November 2006

Effects of application of ultrasonic power (20 kHz, 100 W) on the crystallization behavior of tripalmitoylglycerol (PPP) and cocoa butter have been examined in terms of rate of nucleation and polymorphic control. High‐purity PPP (>99%) and low‐purity PPP (>80%) samples were employed to mimic real fat systems, which usually have higher concentrations of minor components in addition to the main component. For both the high‐purity and low‐purity PPP, the application of ultrasonic power accelerated the rate of nucleation as measured by induction time for the occurrence of crystals and by the number of crystals nucleated. As for the polymorphic influences, the nucleation of both the β′ and β forms was accelerated by the ultrasound, yet the β′ form nucleation was more accelerated when the low‐purity PPP samples were employed. As for cocoa butter, sonication for a short period accelerated the crystallization of Form V. The present results indicate that ultrasound irradiation is an efficient tool for controlling polymorphic crystallization of fats.
Ketonization of fatty methyl esters over Sn−Ce−Rh−O catalyst
Authors: Klimkiewicz Roman , Teterycz Helena , Grabowska Hanna , Morawski Ireneusz , Syper Ludwik , Licznerski Benedykt W.
Published: November 2006

A mixture of methyl esters of fatty acids obtained by transterification of nonerucic rape oil was ketonized. The starting material, diluted with methanol, was converted at atmospheric pressure over a catalyst that contained Sn, Ce, and Rh oxides in a molar ratio of 90:9:1. At a temperature of 385°C ketones were obtained with a total yield of 63% at the 96% conversion of starting material. The reported experiments prove that catalysts other than iron that are active in ketonization of primary alcohols can be successfully used in ketonization of esters of fatty acids. The kind of diluent used plays a crucial role in the conversion.
Enzymatic synthesis of high‐purity structured lipids with caprylic acid at 1,3‐positions and polyunsaturated fatty acid at 2‐position
Authors: Kawashima Akiko , Shimada Yuji , Yamamoto Miwa , Sugihara Akio , Nagao Toshihiro , Komemushi Sadao , Tominaga Yoshio
Published: November 2006

We attempted to synthesize high‐purity structured triacylglycerols (TAG) with caprylic acid (CA) at the 1,3‐positions and a polyunsaturated fatty acid (PUFA) at the 2‐position by a two‐step enzymatic method. The first step was synthesis of TAG of PUFA (TriP), and the second step was acidolysis of TriP with CA. Candida antarctica lipase was effective for the first reaction. When a reaction medium of PUFA/glycerol (3∶1, mol/mol) and 5% immobilized Candida lipase was mixed for 24 h at 40°C and 15 mm Hg, syntheses of TAG of γ‐linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic acids reached 89, 89, 88, and 83%, respectively. In these reactions, the lipase could be used for at least 10 cycles without significant loss of activity. In the second step, the resulting trieicosapentaenoin was acidolyzed at 30°C for 48h with 15 mol parts CA using 7% of immobilized Rhizopus delemar lipase. The CA content in the acylglycerol fraction reached 40 mol%. To increase the content further, the acylglycerols were extracted from the reaction mixture with n‐hexane and were allowed to react again with CA under conditions similar to those of the first acidolysis. After three successive acidolysis reactions, the CA content reached 66 mol%. The content of dicapryloyl‐eicosapentaenoyl‐glycerol reached 86 wt% of acylglycerols, and the ratio of 1,3‐dicapryloyl‐2‐eicosapentaenoyl‐glycerol to 1(3),2‐dicapryloyl‐3(1)‐eicosapentaenoyl‐glycerol was 98∶2 (w/w). In this reaction, the lipase could be used for at least 20 cycles without significant loss of activity. Repeated acidolysis of the other TriP with CA under similar conditions synthesized 1,3‐dicapryloyl‐2‐γ‐linolenoyl‐glycerol, 1,3‐dicapryloyl‐2‐arachidonoyl‐glycerol, and 1,3‐dicapryloyl‐2‐docosahexaenoyl‐glycerol in yields of 58, 87, and 19 wt%, respectively.
Nutritional and potential disease prevention properties of carotenoids
Authors: Basu Hemendra N. , Vecchio Anthony J. Del , Flider Frank , Orthoeter Frank T.
Published: November 2006

Epidemiological studies have shown that people who consume diets with a high content of vegetables have a reduced risk of degenerative diseases such as specific cancers, cardiovascular disease, age‐related macular degenerative disease (AMD), and cataracts. There is no convincing evidence that the protective role of vegetables against cancer and cardiovascular disease is due to carotenoids. However, there is a strong possibility that lutein and zeaxanthin present in food materials may prevent AMD and cataract formation. Increased use of cooked tomato products also has been shown to reduce prostate cancer risk as a result of increased bioavailability of cis‐lycopene. One of the most important biochemical mechanisms underlying the cancer‐preventive activity of carottenoids is the stimulation of intercellular gap junction communications. β‐Carotene, canthaxanthin, and lutein are efficient inducers of intercellular gap junction communication, whereas α‐carotene and lycopene are less active.
Fatty acid profiles from forty‐nine plant species that are potential new sources of γ‐linolenic acid
Authors: Guil‐Guerrero J. L. , García Maroto F. F. , Giménez Giménez A.
Published: November 2006

Forty‐nine plant species from Spain, belonging to the Boraginaceae, Scrophulariaceae, Onagraceae, and Ranunculaceae families, were surveyed in a search of new sources of γ‐linolenic acid (18∶3ω6, GLA). Fatty acid profiles from seeds, stems, roots, flowers and leaves were determined. GLA was detected mainly in seed and root tissues. High GLA amounts were found in seeds of Boraginaceae species, with a maximum of 20.25% of total fatty acids in Myosotis nemorosa. Within the Scrophulariaceae the highest GLA content (10.17%) was found in Scrophularia sciophila. Variable amounts of stearidonic acid, (18∶4ω3, SDA) were present in Boraginaceae species, ranging from 0.08% of total seed fatty acids in Anchusa azurea to 21.06% in Echium asperrimum. SDA was also very abundant in all organs of Asperugo procumbens. A multivariate analysis was performed using our results and those reported for other plant species belonging to the same families in order to investigate a possible correlation between the fatty acid profile and the genera within these families.
The antioxidant properties of lycopene concentrate extracted from tomato paste
Authors: Wenli Yu , Yaping Zhao , Zhen Xue , Hui Jin , Dapu Wang
Published: November 2006

Lycopene concentrate (LC) containing 50 wt% lycopene was extracted from tomato paste. The antioxidant properties of LC were evaluated by means of chemiluminescence in four models. The four models were superoxide anions generated from pyrogallol autoxidation, hydroxyl radicals from Fenton reaction, singlet oxygens from OH−−NaClO−H2O2, and lipid peroxidation from 2,2′‐azobis(2‐amidinopropane)dihydrochloride‐induced γ‐linolenic acid. LC was an effective scavenger toward superoxide anions, hydroxyl radicals, and singlet oxygens, and also it could effectively reduce lipid peroxidation. The 50% efficient concentrations (EC50) toward superoxide anions, hydroxyl radicals, lipid peroxidation and singlet oxygen were 0.75, 0.05, 0.1, and 1 mg/mL, respectively. In addition, changes of antioxidant behaviors with time were investigated. The time requirements of LC for effectively scavenging superoxide anions, hydroxyl radicals, and inhibiting lipid peroxidation were not higher than 6, 6, and 18 s, respectively.
Purification of specific structured lipids by distillation: Effects on acyl migration
Authors: Xu Xuebing , Skands Anja , Adler‐Nissen Jens
Published: November 2006

The cause and effects of acyl migration during the purification of specific structured lipids by distillation were studied in a conventional batch deodorizer with stripping steam. The mixture of specific structured lipids produced by lipase‐catalyzed acidolysis between rapeseed oil and capric acid contained a large amount of free fatty acids and a small amount of partial acylglycerols besides triacylglycerols. Therefore, the effect of steam, free fatty acids, diacylglycerols, and monoacyl‐glycerols on acyl migration was studied in a palm oil midfraction model. The results showed that all these factors influenced the rate of acyl migration, and their combinations made the effect more severe. However, diacylglycerols were found to be the main reason for acyl migration. In the distillation of the specific structured lipid product mixture, distillation temperature and time were the main factors to determine the degree of acyl migration and the extent of separation of free fatty acids. The results indicate that more efficient separation technology should be used to improve the quality of the purified structured lipids. In order to reduce the distillation temperature, vacuum should be made as low as possible with more effective pumps. To reduce the distillation time, thin‐film principle in a packed column should be used, or other more efficient distillation techniques such as molecular distillation or short‐path distillation should be exploited.
Inhibitory effect of 1,3‐diglycerides during adsorption of β‐carotene onto attapulgite and sepiolite
Authors: Boki Keito , Sakamoto Naomitsu , Minami Kazuo
Published: November 2006

The adsorption isotherms of β‐carotene on attapulgite and sepiolite were measured in the presence of 1,3‐diglyceride in n‐hexane to elucidate the relative inhibitory power of the diglycerides, hydroxyl group, carbon number, and double bond for adsorption bleaching. The adsorption mode of β‐carotene was the Langmuir type. The inhibition of β‐carotene adsorption may be caused by the polarity of diglycerides and the formation of diglyceride micelles. The relative inhibitory power of 1,3‐diolein, 1,3‐distearin, and 1,3‐dipalmitin toward β‐carotene adsorption was 1.49, 1.40, and 0.99, respectively. Therefore, the relative inhibitory power due to the hydroxyl group and increase in the carbon atom of the fatty acid in glyceride was 0.41–0.49.
Two‐step enzymatic synthesis of docosahexaenoic acid‐rich symmetrically structured triacylglycerols via 2‐monoacylglycerols
Authors: Irimescu Roxana , Furihata Kiyomi , Hata Kazuhiko , Iwasaki Yugo , Yamane Tsuneo
Published: November 2006

Symmetrically structured triacylglycerols (TG) rich in docosahexaenoic acid (DHA) with caprylic acid (CA) at the outer positions were synthesized enzymatically form bonito oil in a two‐step process: (i) ethanolysis of bonito oil TG to 2‐monoacylglycerols (2‐MG) and fatty acid ethyl esters, and (ii) reesterification of 2‐MG with ethyl caprylate. Ethanolysis catalyzed by immobilized Candida antarctica lipase (Novozym 435) yielded 92.5% 2‐MG with 43.5% DHA content in 2 h. The 2‐MG formed were reesterified with ethyl caprylate by immobilized Rhizomucor miehei lipase (Lipozyme IM) to give structured TG with 44.9% DHA content [based on fatty acid composition with caprylic acid (CA) excluded] in 1 h. The final structured lipids comprised 85.3% TG with two CA residues and one original fatty acid residue, 13% TG with one CA residue and two original fatty acid residues, and 1.7% tricaprylolglycerol (weight percent). The amount of TG with two CA residues and one C22 residue (22∶6=DHA, 22∶5, and 22∶4) was 51 wt%. The 1,3‐dicapryloyl‐2‐docosahexaenoylglycerol to 1,2(2,3)‐dicapryloyl‐3 (1)‐docosahexaenoylglycerol ratio (based on high‐performance liquid chromatography peak area percentages) was greater than 50∶1. The recovery of TG as structured lipids after silica gel column purification was approximately 71%. Ethyl esters and 2‐MG formed at 2 h of ethanolysis could be used to determine the positional distribution of fatty acids in the intial TG owing to the high 1,3‐regiospecificity of Novozym 435 and the reduced acyl migration in the system.
Molecular‐weight distributions of degradation products in selected frying oils
Authors: Abidi S. L. , Warner K.
Published: November 2006

Polar isolates of frying oils used for frying French fries, potato chips, or French fries/tortilla chips were analyzed for nonvolatile components by high‐performance size‐exclusion chromatography (HPSEC) with viscometric (VIS)/refractometric (RI) detection. The degradation products were separated on three mixed‐bed polystyrene/divinylbenzene columns with tetrahydrofuran as eluent. Dual VIS/RI detection of the column effluent enabled simultaneous determination of analyte molecular weights (MW) and concentrations. MW of individual components were calculated from viscosity data with the use of a universal calibration technique. HPSEC of polar samples obtained from different oilseed lines yielded triglyceride‐derived products in which the corresponding nonvolatile components had variable MW and compositions. Elevated levels of high‐MW components were correlated with the extent of frying oil degradation to serve as indicators for frying oil stability. MW/concentration profiles of degradation products varied notably with frying times. The distribution patterns of degradation products were markedly affected by other frying conditions and oil varieties and therefore served as fingerprint properties of specific oils. High‐oleic sunflower oil (HOSUN) (used for frying French fries) appeared to be more stable than cottonseed oil: at 30 h, the concentrations of the highest MW components were 0.63 vs. 0.89 mg/100 mg oil. HOSUN (used for frying French fries/tortilla chips) tended to be more stable than sunflower oil (SUN), as the most abundant (at 30 h, 3.99 vs. 4.34 mg/100 mg oil) species were components 4 (MW=1385) and 3 (MW=2055) for HOSUN and SUN, respectively. High‐oleic soybean oil (HOSBO) was notably more stable than soybean oil: at 40 h, the concentrations of the highest MW (2980 vs. 6315) components were 0.21 vs. 4.51 mg/100 mg oil.
Rejection of carotenoids in oil systems by a nonporous polymeric composite membrane
Authors: Subramanian R. , Nabetani H. , Nakajima M. , Ichikawa S. , Kimura T. , Maekawa T.
Published: November 2006

Ealier studies by the authors on crude vegetable oils showed that color compounds are reduced to the extent of 74–80% during membrane processing. In the present study, attempts were made to understand the rejection mechanism of carotenoids using real and model oil systems. In case of model systems consisting of refined high‐oleic sunflower (HOSF) oil, lecithin and β‐carotene, the rejection of carotenes was low (11–20%). This could be explained based on the differences between the model and real systems as well as on the solution‐diffusion mechanism controlling the material transport across the membrane. This study revealed that β‐carotene did not have affinity for the phospholipid reverse micells present in the oil. Xanthophylls, the major carotenoids present in the crude soybean oil, were rejected to the extent of 60% in the model system (HOSF oil and lutein). High‐performance liquid chromatographic analysis of crude oil revealed that there were few other xanthophylls, which are more polar than lutein. These unidentified xanthophylls would be rejected to a much greater extent by the hydrophobic membrane. The extent of color reduction would depend on the actual composition of xanthophylls present in the crude oil and their relative polarity.
Refining normal and genetically enhanced soybean oils obtained by various extraction methods
Authors: Wang Tong , Johnson Lawrence A.
Published: November 2006

Four different extraction methods, extrusion‐expelling, conventional flaking‐solvent extraction, expander‐solvent extraction, and screw pressing, were used to separate oil and meal of a commodity soybean. The quality and refining characteristics of oils obtained by these methods were evaluated, and the effects of extraction method on oil quality were determined. The screw‐pressed oil was more oxidized and hydrolyzed than the oils from the other extraction methods. The extruded‐expelled oil had oxidative status similar to the solvent‐extracted oils, although it contained the lowest amount of tocopherols. Five genetically enhanced soybeans were also processed by extrusion‐expelling and solvent extraction methods, and differences in refining of these oils were examined. Overall, extruded‐expelled oils were significantly different from the solvent‐extracted oils in that they contained less tocopherols and were more oxidized than the solvent‐extracted oils during refining. The differences between oils from the two extraction methods were magnified owing to the inclusion in the experiment of oils with modified compositions. The more unsaturated oils underwent significantly more oxidative degradation during refining than did the more saturated ones.
A rapid high‐performance liquid chromatographic method for the determination of sinapine and sinapic acid in canola seed and meal
Authors: Cai R. , Arntfield S. D.
Published: November 2006

A high‐performance liquid chromatographic (HPLC) method has been developed to separate sinapine and sinapic acid from other phenolics in canola seed and meal in a single run. The separation was achieved with a reverse‐phase C18 column. Owing to the higher recovery of phenolics and ease of use, refluxing with 100% methanol for 20 min was selected as the extraction method for HPLC analysis and determination of total phenolics using Folin‐Ciocalteu reagent. A 10‐min isocratic/linear/concave gradient and a 15‐min isocratic/linear gradient were selected as the best gradients for the separation of these phenolic compounds. Peak identities for sinapine and sinapic acid were verified with ion exchange separation followed by HPLC analysis. The method was calibrated using sinapine bisulfate and sinapic acid standards; correlation coefficients (R2) for the calibration curves were 0.997 and 0.999 for sinapine bisulfate and sinapic acid, respectively. The extinction coefficient of sinapine was determined to be 1.16 times that of sinapic acid at the detector wavelength (330 nm). Applying this method to routine canola phenolic analyses can greatly reduce the cost by simplifying the procedures and reducing the time required for each determination.
Detection of lard and randomized lard as adulterants in refined‐bleached‐deodorized palm oil by differential scanning calorimetry
Authors: Marikkar J. M. N. , Lai O. M. , Ghazali H. M. , Che Man Y. B.
Published: November 2006

A study was conducted to assess the use of differential scanning calorimetry (DSC) for detecting the presence of lard/randomized lard as adulterants in refined‐bleached‐deodorized (RBD) palm oil. Lard extracted from the adipose tissues of pig was chemically interesterified using sodium methoxide as catalyst. DSC thermal profiles of both genuine lard and randomized lard were compared with those of other common animal fats such as beef tallow, mutton tallow, and chicken fat. Lard and randomized lard were then blended with RBD palm oil in two series, in proportions ranging from 0.2 to 20%, and DSC analyses were obtained. The DSC cooling profiles of adulterated RBD palm oil samples showed an adulteration peak corresponding to lard/randomized lard in the low‐temperature region. This peak was confirmed as an indicator of the presence of lard in RBD palm oil since similar experiments carried out using other common animal fats such as mutton tallow, beef tallow, and chicken fat showed that the lard adulteration peak could be distinctly identified. Using this method, a detection limit of 1% lard/randomized lard was reached (P<0.0001).
Multivariate calibration of fourier transform infrared spectra for determining thiobarbituric acid‐reactive substance content in palm oil
Authors: Mirghani M. E. S. , Che Man Y. B. , Jinap S. , Baharin B. S. , Bakar J.
Published: November 2006

Fourier transform infrared (FTIR) spectra of palm oil samples between 2900 and 2800 cm−1 and 1800 and 1600 cm−1 were used to compare different multivariate calibration techniques for quantitative determination of their thiobarbituric acid‐reactive substance (TBARS) content. Fifty spectra (in duplicate) of palm oil with TBARS values between 0 and 0.25 were used to calibrate models based on partial least squares (PLS) and principal components regression (PCR) analyses with different baselines. The methods were compared for the number of factors, coefficients of determination (R2), and accuracy of estimation. The standard errors of prediction (SEP) were calculated to compare their predictive ability. The calibrated models generated three to eight factors, R2 of 0.9414 to 0.9803, standard error of estimation (SEE) of 0.0063 to 0.0680, and SEP of 1.20 to 6.67.
A rapid spectrophotometric method for the determination of peroxide value in food lipids with high carotenoid content
Authors: Hornero‐Méndez Dámaso , Pérez‐Gálvez Antonio , Mínguez‐Mosquera Ma Isabel
Published: November 2006

A rapid and sensitive ultraviolet‐visible spectrophotometric method for determination of peroxide value (PV) in foods with high carotenoid content (e.g., paprika oleoresin, paprika powder, red palm oil) has been developed. The proposed protocol [modified International Dairy Federation (IDF) method] was established from the IDF Fe(II)‐oxidation‐based spectrophotometric method, and the main one of the introduced modifications consisted of a clean‐up extraction step of pigments before determining the PV by complexing Fe(III) ions with thiocyanate. Fe(II) oxidation time, reaction medium, and Fe(III)‐thiocyanate complex formation time were optimized. The modified IDF method was compared with and was validated by iodometric AOAC official method with a good correlation (R2=0.957) between data obtained by both analytical methods. The high sensitivity of the method allows the use of only about 0.010–0.015 g of sample, with a detection limit of 0.044 mequiv peroxide/kg of sample. Therefore, an improved spectrophotometric method for assessing PV in food lipids with high carotenoid content is now available and can be applied to any kind of sample, independent of oil and pigment content.
Transesterification of rapeseed oil in the presence of basic zeolites and related solid catalysts
Authors: Leclercq Elisabeth , Finiels Annie , Moreau Claude
Published: November 2006

The transesterification of rapeseed oil with methanol was performed by reflux of methanol over cesium‐exchanged NaX faujasites, mixed magnesium‐aluminum oxides, magnesium oxide, and barium hydroxide for different methanol‐to‐oil ratios. Over cesium‐exchanged NaX faujasites and mixed magnesium‐aluminum oxides, a long reaction time and a high methanol‐to‐oil ratio are required to achieve both high oil conversion and high yields in methyl esters. However, over a 300 m2/g magnesium oxide, methanol‐to‐oil ratios and reaction times are significantly reduced to obtain both high oil conversion and high yield in the methyl esters, particularly when the hydroxide precursor is calcined at 823 K. Finally, preliminary results with other basic solids such as barium hydroxide have shown a very high activity and a very high yield in esters. This catalyst is particularly effective since, for a methanol‐to‐oil ratio of 6, at reflux of methanol and after a reaction time of only 1 h, the oil conversion is about 80% with a nearly quantitative ester molar fraction.
Effect of roasting oil composition on the stability of roasted high‐oleic peanuts
Authors: Bolton G. E. , Sanders T. H.
Published: November 2006

Off‐flavor due to lipid degradation is an important factor in the shelf life of peanut products. The use of recently developed peanuts with high‐oleic acid/linoleic acid (O/L) ratio has the potential to significantly extend the shelf life of roasted peanuts. To determine the full potential for shelf‐life improvement of oil‐roasted high‐O/L peanuts, a study was conducted to examine the effects of roasting high‐O/L peanuts (O/L=30) in high‐O/L (O/L=23.2) or conventional (O/L=1.5) peanut oil. Peanuts were roasted at 177°C to Hunter L values of 49±1. Roasted peanuts were stored at 30°C for 20 wk. Samples were taken at regular intervals to determine PV, oxidative stability index (OSI), moisture content, and water activity. The O/L ratio of high‐O/L roasted peanuts was 27.9 vs. 13.6 for the conventional oil‐roasted peanuts. After 20 wk of storage, PV of conventional oil‐roasted peanuts was 10.8 compared to 5.3 for the high‐O/L‐roasted peanuts. OSI values were 88.5 and 52.4 immediately after roasting for the high‐O/L‐roasted vs. conventional oil‐roasted peanuts. OSI for both decreased, but differences remained similar throughout the storage period. Shelf life of high‐O/L peanuts decreased when roasted in conventional O/L‐peanut oil vs. high‐O/L peanut oil.
The effect of steam treating waste cooking oil on the yield of methyl ester
Authors: Supple B. , Howard‐Hildige R. , Gonzalez‐Gomez Esther , Leahy J. J.
Published: November 2006

The effect of steam injection and sedimentation treatment of waste cooking oil on the quality of TG, to be used as a raw material for the production of biodiesel, was investigated. The effect of steam treatment was evaluated in terms of a number of physical and chemical characteristics. Significant decreases in the moisture, FFA, and PV, as well as increased energy value, were observed. GC analysis of the treated materials demonstrated little change in either the overall composition of the oils or the iodine value. The decreases in moisture from 1.4 to 0.4% and in FFA from 6.27 to 4.28% were found to correlate strongly with an increase in yield of ester from 67.5 to 83.5%.
Inhibition of lipid peroxidation and nonlipid oxidative damage by carnosine
Authors: Yen Wen‐Jye , Chang Lee‐Wen , Lee Chia‐Pu , Duh Pin‐Der
Published: November 2006

The antioxidant effects of carnosine on lipids and nonlipids, including liposomes, carbohydrates, and proteins, were investigated. Carnosine exhibited a remarkable antioxidant effect in liposome and deoxyribose model systems. Carnosine at high amounts (50 mg/mL) was effective in protecting protein against oxidation. The correlation coefficients between reducing ability and the inhibition of liposome, albumin, and deoxyribose oxidation were r=0.92, 0.83, and 0.41, respectively. Carnosine exhibited metal‐binding ability and scavenging ability for hydroxyl radicals generated by photolysis of H2O2 with UV light. The correlation coefficients between hydroxyl radical scavenging and the inhibitory effect on deoxyribose, liposome, and albumin oxidative damage were r=0.97, 0.60, and 0.29, respectively. These properties may explain how carnosine protects lipids and non‐lipids against oxidative damage.
Effect of DAG on milk fat TAG crystallization
Authors: Wright Amanda J. , Marangoni Alejandro G.
Published: November 2006

The effect of milk fat and standard DAG on the crystallization behavior of milk fat TAG (MF‐TAG) was investigated. When milk fat DAG were added to MF‐TAG at the 0.1 wt% level, crystallization was delayed. Racemic purity was shown to be an important factor in the ability of DAG to influence TAG crystallization. Only sn‐1,2 isomers of blends of MF‐TAG with 0.1 wt% of the racemic mixtures of dipalmitin and diolein increased the activation free energy barrier to MF‐TAG nucleation (ΔGc) and delayed the subsequent crystallization process by increasing the crystallization induction time (τSFC) determined from solid fat content‐time measurements. Although crystallization kinetics were affected, the properties of the resulting network structures remained unchanged upon addition of milk fat minor components at the 0.1 wt% level
Isothermal crystallization kinetics of refined palm oil
Authors: Chen C. W. , Lai O. M. , Ghazali H. M. , Chong C. L.
Published: November 2006

The induction times for the crystallization, under isothermal conditions, of refined, bleached, and deodorized palm oil from the melt were studied by viscometry. At temperatures below 295 K, the crystallization of palm oil was observed to occur in a two‐stage process. This two‐stage process was caused by the fractionation of palm oil, most probably into the stearin and olein fractions. At temperatures higher than 295 K, only a single‐stage crystallization process was observed. As seen under polarized light microscopy, spherical crystals were initially formed from the first fraction at temperatures from 287 to 293 K. The diameters of these spherical crystals decreased as the temperature increased. After that, needle‐shaped crystals were formed from the second fraction and continued to grow from the surface of these spherical crystals until the spherical crystals were fully enclosed, i.e., the cocrystallization of two polymorphs was observed. At temperatures higher than 293 K, the needle‐shaped crystals formed from a mixture of the two fractions were found to be the only polymorphs developed with the onset of crystallization. X‐ray diffraction results showed that for temperatures below 295 K, the spherical crystals formed from the first fraction were in α form, whereas the needle‐like crystals that nucleated later from the second fraction were in β′ form. β′ crystals were the only polymorphs formed for temperatures above 295 K. The results obtained were in good agreement with the discontinuity observed in the induction time vs. temperature curve. Activation free energies for nucleation were calculated according to the Fisher‐Turnbull equation for the various polymorphic forms. Viscometry was observed to be a sensitive method for characterizing the overall crystallization process. This technique is suitable for induction time studies of palm oil crystallization, especially at lower temperatures and with viscous oil.
Trans FA and solid fat contents of margarines marketed in Turkey
Authors: Tekin Aziz , Cizmeci Melih , Karabacak Hulya , Kayahan Muammer
Published: November 2006

Trans FA (TFA), solid fat contents (SFC), and slip melting points of 12 different tub and stick margarines marketed in Turkey were examined in this study. No trans isomers were found in four margarines, which suggests they were formulated from interesterified or blended fats and oils. The products with no TFA generally had more short‐chain saturated FA, which suggests coconut oil‐based oil components. TFA content of the other 10 products varied from 7.7 to 37.8%. Compared to the products formulated in North America, Turkish margarines contain more TFA and have higher SFC.