bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient esterification of sorbitan oleate by lipase in a solvent‐free system
Authors: Xu Yan , Wang Dong , Mu Xiao Qing , Ni Yong Quan
Published: November 2006

The lipase‐catalyzed esterification of sorbitan with oleic acid in a solvent‐free system to form sorbitan oleate (commercial name Span80) was studied as a feasible approach aimed at meeting the demand for sugar alcohol‐based surfactants. Screened results obtained from enzymatic synthesis of sorbitan oleate indicated that Novozym 435 had its highest catalytic activity in a solvent‐free system. The introduction of a reduced‐pressure system increased the production of sorbitan oleate to a maximum of 95% of theoretical, obtained from 0.2 mol sorbitan, 0.1 mol oleic acid, and 2.0 g lipase (6 wt% of sorbitan) in a solvent‐free reaction mixture at optimal reaction conditions. Results obtained from lipase‐catalyzed batch esterification reactions showed that more than 90% conversion of sorbitan oleate was maintained after 10 batches of esterification reactions, indicating excellent enzyme stability. Subsequent analysis by HPLC indicated that the product of enzyme‐catalyzed esterification by the immobilized lipase contained a significantly greater amount of monoester (about 80%) compared to the composition obtained by chemical synthesis (about 50%).
Roasting effects on the distribution of tocopherols and phospholipids within each structural part and section of soybeans
Authors: Yoshida Hiromi , Matsuda Kyoko , Hirakawa Yuki , Mizushina Yoshiyuki
Published: November 2006

To clarify the effects of microwave roasting on the distribution of tocopherols and FA of phospholipids within soybeans, whole soybeans (Glycine max) were treated by microwave and further evaluted as compared to a raw sample. Tocopherol homologs, measured using HPLC, and phospholipid profiles, quantified with GC, were determined in the seed coat, the embryonic axis, and selections of cotyledons separated from three cultivars. The tocopherols were predominantly detected in the axis, followed by the cotyledons, and then very little in the coat. As much as 25% of the individual tocopherols originally present in the coat were lost at 12 min of roasting, whereas <25% was lost in the cotyledons and the axis after 20 min of roasting. The greatest rate of phospholipid loss (P<0.05) was observed in PE, followed by PC and PI, and their changing patterns were more pronounced in the coat than in the cotyledons or the axis. Thus, tocopherol content and phospholipid profiles change with microwave roasting according to tissue.
The antioxidant effect of natural substances on lipids during irradiation of chicken legs
Authors: Mahrour A. , Caillet S. , Nketsia‐Tabiri J. , Lacroix M.
Published: November 2006

Entire fresh chicken legs were subjected to three pretreatments (packaged in air; packaged under vacuum; or marinated in natural plant extracts and packaged in air) followed by irradiation (0, 3, or 5 kGy). The control and irradiated chicken legs were stored at 4°C and analyzed for FA composition and sensory quality at predetermined intervals. Irradiation dose had a significant (P<‐0.01) effect on FA derived from phospholipid but less than on FA derived from a neutral lipid. In general, levels of unsaturated FA decreased as the radiation dose increased; however, for marinated chicken legs irradiated with 5 kGy, levels of linoleic acid (C18∶2) and arachidonic acid (C20∶4) derived from the phospholipid fraction were significanlty (P≤0.05) higher than those irradiated in air or under vacuum. The concentration of FA also decreased significantly (P≤0.05) as storage time increased. For chicken legs packaged in air or marinated and then packaged in air, significant (P≤0.01) inverse correlations existed between high‐carbon‐number PUFA and lower‐carbon‐number (≤17) saturated FA; this relationship was not apparent in samples irradiated under vacuum. A processing combination of marinating and vacuum packaging might better control lipid oxidation and degradation in irradiated chicken. Panelists found no significant difference (P>0.05) in the flavor and oder intensity of cooked irradiated chicken legs and their nonirradiated equivalents.
Friction properties of vegetable oils
Authors: Biresaw G. , Adhvaryu A. , Erhan S. Z.
Published: November 2006

Vegetable oils are a renewable and an environmentally friendly alternative to petroleum‐based oils in lubrication and other important application areas. Vegetable oils fall into two broad chemical categories: triesters (or TG) and monoesters. Most vegetable oils are triesters of glycerol with FA, whose characteristics are dependent on the chemistry and composition of the FA residues. A small percentage of vegetable oils are monoesters of long‐chain FA and fatty alcohols of varying chemistries. In this work, the free energy of adsorption (ΔGads) of safflower (SA), high‐oleic safflower (HOSA), and jojoba (JO), methyl oleate (MO), and methyl palmitate (MP) on steel were investigated. SA and HOSA are TG of vegetable oils with FA residues of radically different degrees of unsaturation. JO is a monoester vegetable oil. ΔGads is one of the major factors affecting the boundary friction properties of lubricant ingredients. ΔGads was found to increase in the order: HOSA≤SA<JO<MO≤MP. The results are consistent with the degree of functionality and other chemical properties of the oils studied.
Characterization of sacha inchi (Plukenetia volubilis L.) oil by FTIR spectroscopy and 1H NMR. Comparison with linseed oil
Authors: Guillén María D. , Ruiz Ainhoa , Cabo Nerea , Chirinos Rosana , Pascual Gloria
Published: November 2006

Three oil samples obtained from sacha inchi (Plukenetia volubilis L.) seeds were studied by means of FTIR and 1H NMR. Frequency data of the most significant bands of the IR spectrum of this oil are given. These data show that sacha inchi oil has a high degree of unsaturation. The same fact is deduced from the ratio between the absorbance of the bands due to the stretching vibrations of the cis olefinic CH double bonds at 3010.5 cm−1 and to the methylene symmetrical stretching vibrations at 2855.1 cm−1. The proportions of monounsaturated, polyunsaturated, and saturated acyl groups were predicted from the frequency of some IR bands, and these were in satisfactory agreement with the values obtained through FAME generation and their quantification by GC. Likewise, simple observation of the 1H NMR spectra provided a great deal of information about sacha inchi oil, with regard not only to the relative proportions of the different acyl groups but also to their nature. Thus, the presence of γ‐linolenic acyl groups was discounted. Furthermore, the area of some 1H NMR signals was used to determine the proportion of saturated and mono‐, di‐, and triunsaturated acyl groups, which also were in satisfactory agreement with the values obtained by classical methods. IR and 1H NMR determinations take very little time in comparison with classical methods and do not require chemical manipulation or transformation of the sample. A comparison was also made between the compositions of sacha inchi and linseed oil. Both oils are important sources of the healthful n−3 linolenic acyl groups, and sacha inchi also contains high proportions of the n−6 linoleic acyl groups.
Side‐chain autoxidation of stigmasterol and analysis of a mixture of phytosterol oxidation products by chromatographic and spectroscopic methods
Authors: Johnsson Lars , Andersson Rolf E. , Dutta Paresh C.
Published: November 2006

Although the structure of phytosterols is closely related to cholesterol, there is a gap in knowledge concerning the formation and occurrence of oxidation products from phytosterols. The main objective of this study was to isolate and characterize some side‐chain oxidation products formed after autoxidation of stigmasterol. Another objective was to highlight the difficulties in the analysis of phytosterol and a mixture of their oxidation products by GC. Pure stigmasterol was oxidized at 120°C for 72 h in an air‐ventilated oven. Preparative TLC separated the oxidation products, and the products were characterized with GC‐MS and NMR. In addition to the common ring‐structure oxidation compounds, three semipolar oxidation products—24‐ethylcholest‐5,22‐dien‐3β,25‐diol, 24‐ethylcholest‐5,22‐dien‐3β,24‐diol, and 24‐ethyl‐5,22‐choladien‐3β‐ol‐24‐one—were characterized for the first time by TLC, GC‐MS, and NMR. Moreover, the results of the analysis of a large number of oxidation products from sitosterol, campesterol, and stigmasterol by capillary column GC indicated that further efforts and optimization are required in this area.
Trans FA in sunflower oil at different steps of refining
Authors: Tasan Murat , Demirci Mehmet
Published: November 2006

The contents of total trans FA of sunflower oils at different stages of refining processes were determined by capillary GLC. The contents of 18∶1, 18∶2, and 18∶3 trans acids were 0.22±0.03, 2.31±0.23, and 0.03±0.01%, respectively, in physically refined sunflower oils, and 0.05±0.01, 0.69±0.26, and 0.02±0.01%, respectively, in chemically refined sunflower oils. The total trans FA contents drastically increased at the end of the physical refining process. The total trans FA contents of chemically refined sunflower oils were <1%. Because of the high temperature applied in the last stage of physical refining, the content of total trans FA was higher than in chemically refined sunflower oils. The last‐stage conditions should be carefully evaluated to reduce the formation of trans FA during physical refining.
CLA production from ricinoleic acid by lactic acid bacteria
Authors: Ando Akinori , Ogawa Jun , Kishino Shigenobu , Shimizu Sakayu
Published: November 2006

The ability to produce CLA from ricinoleic acid is widely distributed in lactic acid bacteria. Washed cells of Lactobacillus plantarum JCM 1551 were selected as a potential catalyst for CLA production from ricinoleic acid. Cells cultivated in medium supplemented with a mixture of α‐linolenic acid and linoleic acid showed enhanced CLA productivity. Under optimal reaction conditions, with the free acid form of ricinoleic acid as the substrate and washed cells of L. plantarum as the catalyst, 2.4 mg/mL CLA was produced from 3.4 mg/mL ricinoleic acid in 90 h, with a molar yield with respect to ricinoleic acid of 71%. The CLA produced, which was obtained in the FFA form, consisted of a mixture of two CLA isomers, cis‐9,trans‐11‐octadecadienoic acid (21% of total CLA) and trans‐9,trans‐11‐octadecadienoic acid (79% of total CLA), and accounted for 72% of the total FA obtained.
Production of MAG of CLA in a solvent‐free system at low temperature with Candida rugosa lipase
Authors: Watanabe Yomi , Yamauchi‐Sato Yoshie , Nagao Toshihiro , Yamamoto Takaya , Tsutsumi Kentaro , Sugihara Akio , Shimada Yuji
Published: November 2006

We attempted to produce MAG of CLA through lipase‐catalyzed esterification of a FFA mixture containing CLA (referred to as FFA‐CLA) with glycerol. Screening of lipases showed that MAG‐CLA was produced efficiently at 5°C with Penicillium camembertii, Rhizopus oryzae, and Candida rugosa lipases. Among them, C. rugosa lipase was selected because the lipase is widely used as a catalyst for oils and fats processing. The reaction was conducted with agitation of a 300‐g mixture of FFA‐CLA/glycerol (1∶5, mol/mol), a 200‐U/g mixture of C. rugosa lipase, and 2% water. When the reaction was conducted at 30°C, the esterification scarcely proceeded, owing to inhibition of the reaction by glycerol. But the reaction at 5°C eliminated the inhibition and produced MAG efficiently: The degree of esterification reached 93.8% after 58 h, and MAG content in the reaction mixture was 88.4 wt%. To reduce the reaction time, the reactor was connected with a vacuum pump after 24 h, and the reaction was continued with dehydration at 5 mm Hg. The degree of esterification reached 94.7% after 24 h of dehydration (48 h in total), and MAG content increased to 93.0 wt%. Candida rugosa lipase acted a little more strongly on cis‐9, trans‐11 CLA than on trans‐10,cis‐12 CLA, but the contents of the two isomers in MAG obtained from a 48‐h reaction were the same as the contents in FFA‐CLA.
Concentrating PUFA from mackerel processing waste
Authors: Zuta Charles P. , Simpson Ben K. , Chan Hing Man , Phillips Leroy
Published: November 2006

Mackerel processing waste comprising skins, viscera, and muscle tissue was evaluated for concentrating PUFA by urea complexation. Fish oil was extracted using either chloroform/methanol (2∶1, vol/vol) or hexane/isopropanol (3∶2, vol/vol). The yield of oil, as well as iodine, peroxide, and acid values, was determined for fresh fish oil extracts, and oil samples were storel at −70°C in the presence of 100 ppm α‐tocopherol. PUFA concentrates were prepared from saponified fish oil. The mean oil yields were 9.18±2.3, 9.2%±2.4, and 38.1±3% for viscera, muscle, and skin, respectively. The mean baseline iodine value was 134±5, which increased to 296±7 after urea complexation. It was possible to concentrate PUFA from mackerel processing waste. The type of tissue used did not affect the amount of PUFA concentrated. Mackerel skin was most desirable because of its high oil content.
Development of a flow injection chemiluminescent assay for the quantification of lipid hydroperoxides
Authors: Bunting John P. , Gray David A.
Published: November 2006

An automated flow injection chemiluminescence (FICL) system for measuring lipid hydroperoxide (LOOH) concentrations in oils was developed. Initially, a crude oil‐in‐water emulsion (formed by mixing solvent‐diluted oil with the aqueous‐based CL compound, luminol, and the catalyst for the reaction, cytochrome c) was tested. The assay was rapid (60 samples per hour), reproducible (CV no greater than 10%,n=3) and had a low sample requirement (1 mg of oil) because of its high sensitivity (0.5 nmol LOOH). CL intensity was influenced by the amount and type of oil under analysis. Owing to these factors, quantitative data were attainable only with a uniform oil concentration and with a calibrant derived from an oil equivalent to that under analysis. This method yielded quantitative data in good agreement with an iodometric titration assay for LOOH (r=0.9204). A refinement of the first method consisted of replacing the luminol and cytochrome c CL compounds with lucigenin, resulting in an assay insensitive to α‐tocopherol. A monophasic reaction solution was devised to remove the effect of turbidity; however, the CL signal was still influenced by oil type. Therefore, quantitative data were still attainable only when the same type of oil was used for calibration.
Synthesis of 1,3‐dicapryloyl‐2‐docosahexaenoylglycerol by a combination of nonselective and sn‐1,3‐selective lipase reactions
Authors: Negishi Satoshi , Arai Yuri , Arimoto Shin , Tsuchiya Kinya , Takahashi Isamu
Published: November 2006

A two‐step consecutive synthetic method for the production of symmetrical, structured lipids by a combination of nonselective and sn‐1,3 regioselective ester exchange reactions was investigated. In the first step, TAG with unspecifically substituted DHA were obtained by reacting tricapryloylglycerol (CCC) with ethyl docosahexanoate (EtDHA) using the lipase QLM (from Alcaligenes sp.), followed by removing the ethyl ester and CCC by molecular distillation. In the second step, sn‐1,3 regioselective ester exchange was achieved by reacting the resulting TAG with ethyl caprylate (EtC) using the immobilized lipase Novozyme 435 (Candida antarctica lipase), followed by distillation of the ethyl ester and CCC to give sn‐1,3‐dicapryloyl‐sn‐2‐docosahexaenoylglycerol (CDC). The acylglycerol composition of CDC was analyzed by GLC, which showed that the content of dicapryloyl‐docosahexaenoylglycerols (2CD) in the product was 76.4%, and that the ratio of CDC to sn‐1,2‐dicapryloyl‐sn‐3‐docosahexaenoylglycerol contained in 2CD was 82.7∶17.3 (%). The distillates CCC, EtDHA, and EtC could be recycled repeatedly to produce CDC as the substrate for the consecutive ester exchange reaction. In addition, separation of CCC and EtDHA was unnecessary for reuse. The present method is considered to meet the requirements for industrial utilization, in which simplicity in scaleup, high yields, compact reaction system, and minimal formation of by‐products are important factors.
Microwave‐assisted catalytic transfer hydrogenation of safflower oil
Authors: Prabhavathi Devi B. L. A. , Karuna M. S. L. , Narasimha Rao K. , Saiprasad P. S. , Prasad R. B. N.
Published: November 2006

Catalytic transfer hydrogenation (CTH) of safflower oil was studied using aqueous ammonium formate as hydrogen donor and palladium on carbon as catalyst in a closed vessel under controlled microwave irradiation conditions. The method offered good selectivity in complete reduction of linoleic acid to monounsaturated acid with a slight increase in stearic acid compared to other reported catalytic transfer hydrogenation methods. Selectivity was achieved by using microwave‐assisted CTH without employing an emulsifier or high ratios of water to oil.
Antioxidant activity of phenolic compounds in 2,2′‐azobis (2‐amidinopropane) dihydrochloride (AAPH)‐induced oxidation: Synergistic and antagonistic effects
Authors: Peyrat‐Maillard M. N. , Cuvelier M. E. , Berset C.
Published: November 2006

Interactions between phenolic antioxidants in binary systems were determined by adding two antioxidants simultaneously in equimolar proportions to an aqueous dispersion of linoleic acid that was then subjected to 2,2′‐azobis (2‐amidinopropane) dihydrochloride‐induced oxidation and by evaluating the protective effect of the antioxidant mixture. The antioxidant power of the mixture was then compared with the expected antioxidant activity calculated by the sum of efficiencies of each compound separately, relative to their proportions in the mixture. If it was higher, a synergy was pointed out whereas a lower value was representative of an antagonism. Thus, synergistic effects were observed between rosmarinic acid and quercetin, or rosmarinic acid and caffeic acid, whereas antagonistic effects were obtained with the following mixtures: α‐tocopherol/caffeic acid; α‐tocopherol/rosmarinic acid; (+)‐catechin/caffeic acid; and caffeic acid/quercetin. These mixture effects are partly explained by regeneration mechanisms between antioxidants, depending on the chemical structure of molecules and on the possible formation of stable intermolecular complexes.
Dependence of oil stability index of fatty compounds on their structure and concentration and presence of metals
Authors: Knothe Gerhard , Dunn Robert O.
Published: November 2006

During storage and use, vegetable oil‐derived industrial products such as biodiesel and biodegradable lubricants can be subjected to conditions that promote oxidation of their unsaturated components. The materials arising during oxidation and subsequent degradation can seriously impair the quality and performance of such products. Therefore, oxidative stability is a significant issue facing these vegetable oil‐derived products, and enhanced understanding of the influence of various components of vegetable oils and storage parameters is necessary. In this work, the oil stability index (OSI) was used for assessing oxidation of monoalkyl esters of FA by varying several parameters. Neat fatty compounds and prepared mixtures thereof were studied for assessing the influence of compound structure and concentration. Small amounts of more highly unsaturated compounds had a disproportionately strong effect on oxidative stability. The recently developed concept of bis‐allylic equivalents correlated more closely than the iodine value with the OSI times of mixtures of fatty esters. The OSI times of free acids were shorter than those of the corresponding alkyl esters. The presence of copper, iron, and nickel also reduced oxidative stability, but their effect was less than the presence of more highly unsaturated fatty compounds. Of these metals, copper had the strongest catalytic effect on OSI time. OSI may be an alternative to long‐term storage tests for determining the influence of extraneous materials such as metals on oxidative stability.
Screw pressing of whole and dehulled flaxseed for organic oil
Authors: Zheng Yun‐ling , Wiesenborn Dennis P. , Tostenson Kristi , Kangas Nancy
Published: November 2006

Flaxseed oil, a rich source of dietary n−3 FA, is commonly obtained by cold pressing whole seed. Furthermore, flaxseed hulls are emerging as a valuable lignan‐rich product for functional food use; therefore, the pressing characteristics of dehulled seed need to be understood. Screw press performance was measured for pressing of whole and dehulled flaxseed. When whole Omega flaxseed was pressed through a 6‐mm choke, an inverse relationship between seed moisture content (6.1–11.6% range) and oil recovery (70.1–85.7%) was observed. However, peak oil recovery from pressing dehulled Omega flaxseed of 72.0% was found at 10.5% moisture content in the moisture content range of 7.7–11.2%. Although oil recovery from dehulled Omega flaxseed was lower than from whole Omega flaxseed, the weight of oil produced from dehulled Omega flaxseed per unit time was higher. The dependence of capacity on moisture content was less evident with the 6‐mm choke than with the 8‐mm choke. An inverse relationship between moisture content of whole flaxseed and oil and meal temperature was observed. The oil and meal temperatures from pressing dehulled flaxseed were significantly lower than those from whole flaxseed. Therefore, pressing dehulled flaxseed appears to offer advantages in organic flaxseed oil production.
Use of phenylselenyl chloride in the preparation of methyl 11‐phenylseleno‐10‐acetamido‐ and ethyl phenylselenoethoxy fatty alkanoates
Authors: Ahmad Shabana , Rauf Abdul
Published: November 2006

Reaction of methyl 10‐undecenoate (I) with phenylselenyl chloride in acetonitrile furnished methyl 11‐phenylseleno‐10‐acetamido‐undecanoate (II) as a major product, and a similar reaction of I with phenylselenyl chloride in absolute ethanol gave ethyl 11‐phenylseleno‐10‐ethoxy‐undecanoate (III) as a sole product. A similar reaction of methyl octadec‐cis‐9‐enoate (IV; oleate) with phenylselenyl chloride in absolute ethanol was conducted and resulted in the formation of ethyl 10(9)‐phenylseleno‐9(10)‐ethoxy‐octadecanoate (V).
Influence of soybean protein isolates‐phosphatidycholine interaction on the stability on oil‐in‐water emulsions
Authors: Scuriatti M. P. , Tomás M. C. , Wagner J. R.
Published: November 2006

Soybean protein isolates and phospholipids present specific surface properties with synergistic or antagonistic effects on emulsion stability. Oil‐in‐water emulsions (25∶75 w/w) were prepared using native and denatured soybean isolates (NSI and DSI, respectively) with the addition of phosphatidylcholine (PC) (protein/PC ratio 100∶1 to 10∶1). The effect of ionic strength was also studied by adding sodium chloride (0–100 mM) to the aqueous phase. Analysis of NSI/PC and DSI/PC emulsions showed that the creaming rate diminished upon addition of PC, with the creamed phase showing more stability than those of the control systems. In DSI/PC systems, the coalescence process was partially controlled, as evidenced by a decrease in the size of oil droplets. Both systems were altered by the presence of sodium chloride, with an increase in the creaming rate attributable to flocculation and the coalescence of droplets. Under these conditions, DSI/PC emulsions exhibited a stronger protein‐phospholipid interaction than those of NSI/PC.
Genotype and growing location effects on phytosterols in canola oil
Authors: Hamama Anwar A. , Bhardwaj Harbans L. , Starner David E.
Published: November 2006

There is little information available about phytosterols in canola (Brassica napa L.) oil and the effects of genotype and growing locations from Virginia and the mid‐Atlantic region of the United States, a potential area for the establishment of domestic production to provide edible oil. Our objectives were to characterize the phytosterols, phospholipids, unsaponifiable matter, and FA in oil from Virginia‐grown canola. Among 11 canola genotypes grown at two locations during 1995–1996 significant variations existed for oil content and FA profiles, but not for contents of phospholipids, unsaponifiable matter, total phytosterols, campesterol, stigmasterol, and β‐sitosterol, Total phytosterol content in the oil of Virginia‐grown canola varied from 0.7 to 0.9% with a mean of 0.8%. This concentration compared favorably with oil from Canadian canola, which typically contains 0.5 to 1.1% total phytosterols. The mean contents of brassicasterol, campesterol, stigmasterol, β‐sitosterol, Δ5‐avenasterol, and Δ7‐stigmatenol as percentages of total phytosterols in Virginia‐grown canola were: 9.7, 32.0, 0.6, 49.3, 4.99, and 3.5%, respectively. Growing location did not affect phytosterols in Virginia‐grown canola oil but had significant effects on contents of phospholipids, and saturated (myristic, stearic, and arachidic) and unsaturated (palmitoleic, linoleic, linolenic, eicosenoic, and erucic) FA.
Molecular exchange in thermal equilibrium between dissolved and crystalline tripalmitin by NMR
Authors: Löfborg Negin , Smith Paul , Furó Istvan , Bergenståhl Björn
Published: November 2006

An NMR technique to measure exchange kinetics at thermal equilibrium in dispersions of moderately soluble crystalline material is presented. By monitoring the exchange of molecules between pools in solid and dissolved form, one can characterize the surface specific exchange rate. Illustrative experiments were performed in a model system with β‐type crystals of tripalmitin as the solid phase and tripalmitin, a fraction of it deuterated, dissolved in a medium‐chain TG oil as the liquid phase. The concentration of deuterated tripalmitin in the solvent was followed by 2H NMR after the crystals, which initially lack deuterated tripalmitin, were immersed in the liquid. The variation of the 2H concentration in the solvent provided the surface specific exchange rate. No systematic errors, due to the slight difference in properties of the deuterated tripalmitin compared to hydrogenated tripalmitin, were observed. The methodology worked well between crystal concentrations of 2 and 4 wt%.
Multivariate determination of cloud point in palm oil using partial least squares and principal component regression based on FTIR spectroscopy
Authors: Setiowaty G. , Che Man Y. B.
Published: November 2006

A rapid FTIR spectroscopic method was developed for quantitative determination of the cloud point (CP) in palm oil samples. Calibration samples were prepared by blending randomized amounts of palm olein and palm stearin to produce a wide range of CP values ranging between 8.3 and 47.9°C. Both partial least squares (PLS) and principal component regression (PCR) calibration models for predicting CP were developed by using the FTIR spectral regions from 3000 to 2800 and 1800 to 1600 cm−1. The prediction capabilities of these calibration models were evaluated by comparing their standard errors of prediction (SEP) in an independent prediction set consisting of 14 palm oil samples. The optimal model based on PLS in the spectral range 1800‐1600 cm−1 produced lower SEP values (2.03°C) than those found with the PCR (2.31°C) method. FTIR in conjunction with PLS and PCR models was found to be a useful analytical tool for simple and rapid quantitative determination of CP in palm oil.
Shear and longitudinal ultrasonic measurements of solid fat dispersions
Authors: Saggin Raffaella , Coupland John N.
Published: November 2006

Dispersions of coating fat in corn oil (2.5–12.5 wt%) were prepared following two different protocols: Type A dispersions had an average crystal size of 30–36 μm, whereas type B dispersions were less than 1 μm. In both dispersions the fat crystals were aggregated into larger structures (up to 80 μm). The longitudinal ultrasonic properties (i.e., velocity, attenuation, and reflectance) were linearly related to the solid fat content, but only attenuation was sensitive to the different microstructures. The velocity and reflectance measurements were modeled using the Urick equation. Shear ultrasonic reflectance and oscillatory viscometry were used to measure the dynamic viscosity of all dispersions. According to both methods, type B samples were always more viscous than type A at a similar solids content. The correlation between the two techniques was good (r2>0.99), but the numeric agreement was different for both systems.
Reaction selectivity of rhizomucor miehei 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 Rhizomucor miehei (RM) lipase at 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, or α‐or β‐MAG containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate. Similar patterns of broad FA selectivity toward C8–C18 FA were generally observed for esterification into specific acylglycerol (AG) pools with the different α/β‐CX‐MAG cosubstrates. Exceptions were enrichment of C18 in the MAG pool with α‐C16‐MAG substrate, and a general suppression of C4/C6 FA reactivity and a specific discrimination toward >C8 FA incorporation into the TAG pool, both for reactions with α‐C10‐ and α‐C16‐MAG. RM lipase selectivity toward MAG was in descending order: β‐C18∶1‐MAG>α/β‐C4‐MAG∼β‐C10‐MAG∼β‐C16‐MAG>α‐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>β‐C10‐MAGβ‐C16‐MAG>α‐C18∶1‐MAG>β‐C18∶1‐MAG∼ α/β‐C4‐MAG. Aside from their characteristic FA selectivity, Burkholderia cepacia (PS‐30) and RM lipases behaved similarly in terms of MAG selectivity as well as a general conservation of FA selectivity throughout the sequential steps of TAG assembly from FA and glycerol for processes designed to yield specifically structured TAG.
Characterization of soybean protein isolates The effect of calcium presence
Authors: Scilingo A. A. , Añón M. C.
Published: November 2006

Results of a study of the effect of calcium addition on polypeptide composition, hydrophobicity, sulfhydryl content, thermal stability, enthalpy of denaturation, and water solubility of soybean protein isolates suggest that the addition of small amounts of calcium (1.23–5.0 mg/g protein) induced the formation of α, α′ soluble aggregates, whereas large amounts (5.0–9.73 mg/g protein) induced the selective insolubilization of the glycinin fraction. The addition of this ion also produced thermal stabilization of the soybean proteins, mainly the glycinin fraction, and increased the enthalpy of denaturation. A decrease in the surface hydrophobicity of proteins with increasing calcium content was also observed. The results obtained suggested the existence of specific calcium‐soy protein interactions, especially with the glycinin fraction.
Evaluation of virgin olive oil bitterness by quantification of secoiridoid derivatives
Authors: Mateos Raquel , Cert Arturo , Pérez‐Camino M. Carmen , García José M.
Published: November 2006

The bitterness of the main compounds identified in the phenolic extract of virgin olive (Olea europaea L.) oils has been sensory‐tested. The aldehydic form of oleuropein aglycone (AOA) was responsible for this attribute. Correlations between the sensory bitterness and concentrations of secoiridoid derivatives, analyzed separately or in different combinations, were obtained for olive oils from different olive varieties. The best correlation obtained corresponds to AOA content (r=0.96; P=1.83×10−17) in the concentration range of 0.03 to 0.5 mmol/kg. AOA concentrations ≥0.5 mmol/kg produce sensory saturation of this attribute. The correlation with AOA concentration was better than that with the absorbance of the phenolic extract at 225 nm. Therefore, the equation obtained allows the evaluation of the bitterness in virgin olive oils by HPLC analysis of the phenolic extract using detection at 280 nm.
Application of phospholipids extracted from bovine milk to the reconstitution of cream using butter oil
Authors: Miura Susumu , Tanaka Miyako , Suzuki Asuka , Sato Kaoru
Published: November 2006

Phospholipid (PL) extracted from bovine milk was tested for its emulsifying properties in conjunction with the reconstitution of cream using butter oil. PL from bovine milk dispersed in the oil phase was found to stabilize the cream, whereas PL extracted from soybean oil was found to solidify the cream. Different PL species purified from bovine milk PL were tested for their emulsifying properties. PC from bovine milk dispersed in butter oil was shown to stabilize the cream, whereas PE and sphingomyelin had no such effects. PC from soybean oil also was found to have emulsifying abilities. It was suggested that PC stabilized the reconstituted cream, regardless of its origin.
GC‐MS method for characterization and quantification of sitostanol oxidation products
Authors: Soupas Laura , Juntunen Laura , Säynäjoki Suvi , Lampi Anna‐Maija , Piironen Vieno
Published: November 2006

A new GC‐MS method for characterization and quantification of phytosterol oxidation products was developed. Applicability of this method was tested by characterizing sitostanol oxides formed in bulk and then quantifying selected oxides in purified rapeseed oil and tripalmitin matrices in which the complex matrix made oxide analysis difficult. In bulk, nine different sitostanol oxides were characterized, including epimers of 7‐ and 15‐hydroxysitostanol and 6‐ and 7‐ketositostanol. In both lipid matrices, the amounts of sitostanol oxides generated in thermo‐oxidation were very low. According to statistical analyses, depending on the oxide, the GC‐MS results were the same or slightly higher than those quantified by the more common GC‐FID method. Thus, GC‐MS provides a powerful alternative for characterization and quantification of phytostanol oxides found in low amounts in complex matrices and is a promising method for future phytosterol oxide studies.
Recovery of phytosterols from sunflower oil deodorizer distillates
Authors: Moreira Eduardo A. , Baltanás Miguel A.
Published: November 2006

Phytosterols are usually recovered by crystallization from the deodorizer distillate (DD) of vegetable oils. In this work, the impact of the principal process variables (viz., solvents and cosolvents, cooling rate, crystallization temperature, and ripening time) on the quality and yield of the recovered phytosterols was studied by using a sunflower oil DD “enriched” (i.e., preconcentrated) via transesterification with ethanol (EDD) as a feedstock and commercial hexane as solvent (S), with S/EDD mass ratios of 3 to 5. Water (0 to 4.5 wt%) and ethanol (0 to 10 wt%) were used as cosovents, with crystallization temperatures between 0 and −20°C and crystallization times from 4 to 96 h. The cooling rate was either −20°C/h or “brisk chilling” from 40 to −5°C. The nature and composition of the EDD solvent and cosolvent composite arose as the most important process variable, strongly influencing both the percentage of sterol yield and the purity of the crystals, as well as their filterability and washability. Water‐saturated hexane sufficed to give good crystallization, yet the beneficial effect of adding water as the single cosolvent was enhanced by adding small and precise amounts of ethanol. A recovery of sterols as high as 84% (with 36% purity) was achieved by using a single‐stage batch crystallization of the S/EDD mixture (S/EDD=mass ratio 4).
Evolution of the oxidation process in olive oil triacylglycerol under accelerated storage conditions (40–60°C)
Authors: Gómez‐Alonso S. , Salvador M. D. , Fregapane G.
Published: November 2006

This paper presents an analysis of oxidation in olive oil TAG at different temperatures within a range of 40–60°C in darkness, as measured by the rate of formation of hydroperoxides, their decomposition products, and sensory and chemical flavor deterioration. At 60°C, the oxidation process was relatively fast, and all the indexes of the extent of oxidation behaved in a very similar way. The behaviors of the rate of formation of conjugated dienes (measured as the K232), of oxidized TAG (determined by HPLC), and of carbonyl compounds (measured as anisidine value) were very similar to that of the PV. The induction periods (IP) of the four indexes were less than 36 h. Nevertheless, the IP for K270 and the sum of oxidized TAG dimers and polymers were 5 d. At 50 and 40°C, the rate of formation of secondary oxidation products was lower. Residual linolenic acid or PUFA as determined by GC showed correlation coefficients higher than 0.999 with the Totox index at all of the assayed temperatures. The rancid recognition threshold corresponded to lower values of the oxidation indexes at lower temperature. Moreover, at all assayed temperatures, the rancidity threshold apparently coincided with the IP for the kinetics of 2,4‐decadienal formation.
Effects of antioxidants and humidity on the oxidative stability of microencapsulated fish oil
Authors: Baik M. ‐Y. , Suhendro E. L. , Nawar W. W. , McClements D. J. , Decker E. A. , Chinachoti P.
Published: November 2006

The effects of various antioxidants and RH on the oxidative stability of microencapsulated fish oil powder were investigated using PV and thiobarbituric acid tests. The micorencapsulation process provided high encapsulation efficiency (≥88% of extractable fish oil). Without antioxidants, the encapsulated fat was 10 times more stable against oxidation than the surface fat, as determined by PV. α‐Tocopherol, which is a lipophilic antioxidant, showed a greater antioxidative effect in both surface and encapsulated fats than ascorbyl palmitate, which is an amphiphilic antioxidant. According to TBARS values, the longest lag period was observed at 0% RH. Addition of >200 ppm α‐tocopherol in a 10–30% RH range prolonged the oxidative stability of the microencapsulated fish oil powder.
Phospholipids from palm‐pressed fiber
Authors: Choo Yuen May , Bong Siow Ching , Ma Ah Ngan , Chuah Cheng Hock
Published: November 2006

Palm‐pressed fiber, a by‐product of palm oil milling, was extracted successively with hexane and 95% ethanol; the ethanol extracts yielded 46,800 ppm of phospholipids. The phospholipid composition, as analyzed by HPLC coupled with an ELSD, was found to be predominantly PC, PE, phosphatidylglycerol, and PA; as expected, the FA were more unsaturated than the TAG. Palm‐pressed fiber is estimated to be able to provide 21,645 tonnes of palm lecithin based on the present total world production of fresh fruit bunches and thus be an alternative source of lecithin, which is normally obtained from soybeans.
Adsorption of FFA in crude catfish oil onto chitosan, activated carbon, and activated earth: A kinetics study
Authors: Sathivel Subramaniam , Prinyawiwatkul Witoon
Published: November 2006

The feasibility of using chitosan, activated carbon, and activated earth to remove FFA from crude catfish visceral oil, and the adsorption kinetics of the procedure were evaluated. The effect of adsorbents on water activity and the 18∶3 and 22∶6 content of crude catfish visceral oil was also studied. The initial adsorption kinetic coefficients of FFA (mL g−1 min−1) were 0.1, 0.07, and 0.03 for chitosan, activated carbon, and activated earth, respectively. The external film mass‐transfer coefficient (0.001 mL s−1) was similar for the three adsorbents. The adsorption capacity of FFA at saturation (mg g−1) was 71.2 for chitosan, 65.5 for activated carbon, and 57.0 for activated earth. The intraparticular diffusion coefficients (mg mL−1 min−0.05) were 0.14, 0.12, and 0.09 for chitosan, activated carbon, and activated earth, respectively. Water activity of the crude oil decreased with increased contact time of the adsorbents. Results indicated that chitosan was a better adsorbent than activated carbon and activated earth for FFA removal from crude catfish visceral oil.
Photo‐oxidation of lipids impregnated on the surface of dried seaweed (Porphyra yezoensis Ueda). Characterization of volatiles
Authors: Pan Xiangqing , Ushio Hideki , Ohshima Toshiaki
Published: November 2006

Volatiles generated by the photo‐oxidation of lipids applied to the surface of dried seaweed (Porphyra yezoensis Ueda) previously exposed to visible light were studied. The surface of dried seaweed was impregnated with eicosapentaenoic acid (EPA) ethyl ester or linoleic acid (LA) methyl ester. The sample was then divided into two parts, and each part was sealed in a 50‐mL crimp‐top vial with a PTFE silicone‐lined cap. One vial was exposed to light from a 100‐W tungsten bulb (6000 lux) in an oven at 45°C. The other vial was covered with aluminum foil to shield the seaweed from light and kept in the oven as a control. Volatile compounds in the headspace of the vials were collected by a solid‐phase microextraction technique and analyzed by GC‐FID and GC‐MS. The numbers of peaks as well as the peak areas of volatiles in the light‐exposed sample were much greater than those in the control in GC profiles obtained in the same oxidation period. The peak areas of volatiles changed with the prolongation of oxidation time, and the formation rates were different between volatiles. Approximately 28 volatiles were identified in the control kept in the dark as well as in the light‐exposed sample impregnated with EPA ethyl ester. The relative amounts of propanal, 2‐propenal, 1‐penten‐3‐one, 1‐penten‐3‐ol, 2‐butenal, heptanoic acid, and 2‐pentenal in the headspace of the light‐exposed vials were significantly higher than those in the control, whereas the relative amounts of 3,5‐octadien‐2‐one, ethyl butyrate, and 2,4‐heptadienal in the control were significantly higher than those in the headspace of the light‐exposed vial. Approximately 35 volatiles were identified from the dried seaweed impregnated with LA methyl ester. The relative amounts of hexanal, 2‐heptenal, 2‐octenal, octanoic acid methyl ester, and hexanoic acid in the headspace of the light‐exposed vial were significantly higher than those in the control, and the relative amounts of 2‐decenal, 2,4‐nonadienal, and 2,4‐decadienal in the control were significantly higher than those in the headspace of the light‐exposed vial. We proposed the formation mechanisms of some volatiles to be the well‐accepted homolytic‐heterolytic cleavage of hydroperoxides that were generated by oxidation of the unsaturated lipids.
Refunctionalization of extruded‐expelled soybean meals
Authors: Wang H. , Johnson L. A.
Published: November 2006

Soybean meals produced by extruding‐expelling (FF) have poor functional properties due to heat denaturation of the proteins, which limits their utilization in foods. Hydrothermal cooking (HTC), a treatment in which steam (150°C) and high shear are applied to a slurry of soybean meal, was used to refunctionalize EE protein meals. Two EE samples with protein dispersibility indexes (PDI) of 35 and 60 were used, along with solvent‐extracted white flakes and full‐fat whole soy meal as controls. Two HTC methods were explored: One method used a treatment temperature of 154°C and seven different residence times, controlled by varying the holding tube length; the other involved flashing the treated slurry directly into the atmosphere without any back‐pressure regulation or holding. Effects of residence time on functional properties of the samples were investigated. The maximum effect of HTC conducted with the use of holding tubes (with‐holding‐tube HTC) was also compared with that of flash‐out HTC. Solid dispersibility, protein dispersibility, and emulsification capacity of both EE meals were significantly improved by both types of HTC treatments. The flash‐out HTC showed more benefits than the with‐holding‐tube HTC in refunctionalizing heat‐denatured EE protein. For example, the solid dispersibility, protein dispersibility, and emulsification capacity of EE meal with PDI of 35 were improved 2.0, 4.4, and 2.1 times, respectively, by flash‐out HTC treatment. Therefore, the HTC refunctionalization was proved effective in partially restoring the functional properties of the heat‐denatured soy proteins.
Hybrid Hibiscus seed oil compositions
Authors: Holser R. A. , Bost G.
Published: November 2006

The seeds of cultivated Hibiscus spp. were extracted with supercritical carbon dioxide, and the resulting extracts were analyzed to identify the major TG components as the corresponding FAME. The seed oils were composed predominantly of oleic and linoleic FA (69.6–83.4%) with lesser amounts of palmitic acid (14.8–27.0%). Minor amounts of C14, C18, and C20 saturated FA were also detected. The oil content of the seeds was determined to be between 11.8 and 22.1 wt% for hybrid varieties and between 8.9 and 29.5 wt% for the native species from which the hybrid varieties were developed. The protein content of the defatted seed meal averaged 20% for the hybrid varieties. The composition of the extracted hibiscus seed oils suggests potential edible applications.
Effect of growing area on pigment and phenolic fractions of virgin olive oils of the arbequina variety in Spain
Authors: Criado M. Nieves , Morelló J. Ramón , Motilva M. José , Romero M. Paz
Published: November 2006

The purpose of this investigation was to study differences in the chlorophyll, carotenoid, and phenolic fractions of virgin olive oils from the Arbequina variety cultivated in different olive growing areas of Spain. Virgin olive oil from Lleida was less heavily pigmented, and these oils showed more negative values for the ordinate a* (of the CIELAB colorimetric system). Pheophytin a was the major chlorophyll pigment, and lutein was the major component of the carotenoid fraction in all oils analyzed. The chlorophyll a concentration in virgin olive oils from Lleida was 700 μg kg−1, but was 175 μg kg−1 in oils from Jaén, and 200 μg kg−1 in oils from Tarragona. Finally, the chlorophyll a/chlorophyll b ratio was 9 in oils from Lleida and around 0.6 in the other two Arbequina olive oils. In relation to the phenolic fraction, the hydroxytyrosol and tyrosol contents were significantly higher in olive oils from Jaén (grown at higher altitude and precipitation rates). The secoiridoid derivatives showed a significantly higher concentration in olive oils from Tarragona, probably due to the low altitude where they grow, and finally the ratio of (dialdehydic form of elenolic acid linked to tyrosol)/lignans had a value of 1.4 in olive oils from Lleida, whereas this value was around 0.7 in the other Arbequina olive oils.
γ‐Linolenic acid from caryophyllaceae seed oil
Authors: Guil‐Guerrero J. L. , López‐Martínez J. C. , Navarro‐Juárez R. , García‐Maroto F. , Campra‐Madrid P.
Published: November 2006

Seeds from 50 species belonging to the family Caryophyllaceae, subfamilies Alsinoideae, Silenoideae, and Spergulaceae, were surveyed in a search for new sources of γ‐linolenic acid (GLA) having low levels of other interfering PUFA and therefore appropriate for GLA purification. It was detected mainly in Alsinoideae species, with a maximum of 15.6% of total FA in Minuartia laricifolia subsp. ophiolitica. Different amounts of stearidonic acid (18∶4n−3) were present in the Alsinoideae species, ranging from undetectable levels in seven species to 3.30% of total FA in Stellaria media. An ANOVA showed a taxonomical correlation between GLA percentages and the genus/subfamily within this family.