bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transesterification of phytosterol and edible oil by lipase powder at high temperature
Authors: Negishi Satoshi , Hidaka Ichiro , Takahashi Isamu , Kunita Shigeru 
Published: November 2006

AbstractPhytosterol, which is hardly soluble in edible oil, was solubilized at a high concentration by converting it to FA esters by lipase‐catalyzed transesterification at temperatures higher than 100°C using powdered Lipase QLM (Meito Sangyo Co., Ltd., Nagoya, Japan). Transesterification was conducted, in sunflower oil containing 10% phytosterol, without adding water or solvent, at 100°C. The conversion rate was 97.1% after 7 h of reaction. The effect of temperature on the conversion rate was also examined. Maximum enzyme activity occurred in the 100–120°C range, and 20% of the maximum activity was retained even at 130°C. When the lipase was recovered by filtration and recycled for repeated reactions at 90°C, the half‐life of lipase activity was 260 h. Thus, edible oils with nutritional value could be produced by blending the phytosterol‐containing sunflower oil into other edible oils.
Separation of EPA and DHA in fish oil by lipase‐catalyzed esterification with glycerol
Authors: Halldorsson Arnar , Kristinsson Bjorn , Glynn Caroline , Haraldsson Gudmundur G. 
Published: November 2006

AbstractThe objective of this study was to investigate the use of lipases as catalysts for separating EPA and DHA in fish oil by kinetic resolution based on their FA selectivity. Esterification of FFA from various types of fish oils with glycerol by immobilized Rhizomucor miehei lipase under water‐deficient, solvent‐free conditions resulted in a highly efficient separation of EPA and DHA. Reactions were conducted at 40°C with a 10% dosage of the lipase preparation under vacuum to remove the coproduced water, thus rapidly shifting the reaction toward the products. The bulk of the FA, together with EPA, were converted into acylglycerols, whereas DHA remained in the residual FFA. As an example, when FFA from tuna oil comprising 5% EPA and 25% DHA were esterified with glycerol, 90% conversion into acylglycerols was obtained after 48 h. The residual FFA contained 78% DHA and only 3% EPA, in 79% DHA recovery. EPA recovery in the acylglycerol fraction was 91%. The type of fish oil and extent of conversion were highly important parameters in controlling the degree of concentration.
Chemometric classification of olive cultivars based on compositional data of oils
Authors: Brescia Maria Antonietta , Alviti Giovanna , Liuzzi Vitantonio , Sacco Antonio 
Published: November 2006

AbstractEuropean Union regulations provide important guidelines for maintaining the Protected Designation of Origin (PDO) of olive oil and other foods. This includes characterization of foods based on variety (cultivar) and geographical origin, as this may be used as a criterion for determining authenticity and quality. Therefore, analytical method standards need to be established to ensure these criteria. This study describes how cultivar differences can be established between Italian oils, obtained from single varieties, based on acid, sterol, and TAG differences determined by chemometrics. TAG and FA composition provided the best basis for differentiation of olive oils among cultivars. The results were compared with those obtained using 13C NMR analysis, and a similar differentiation between oils of different cultivars was achieved. 13C NMR provides useful information on the acyl composition and on the positional distribution of the glycerol moiety and can be used for classification of cultivars based on oil composition. Furthermore, the advantages of this technique come from the rapidity with which information can be obtained and from the very simple preparation procedure required for analysis.
Dispersed phase destabilization in table spreads
Authors: Rousseau D. , Zilnik L. , Khan R. , Hodge S. 
Published: November 2006

AbstractCommercially available butter, regular‐fat margarine, and a fat‐reduced margarine (38% fat w/w) were stored between 10 and 35°C for up to 4 d to elaborate on the relationship between droplet size and solid fat content (SFC) that exists in these spreads. At 10°C, the mean volume‐weighted droplet size for butter was 4.22±0.40 μm followed by margarine (6.22±0.10 μm) and fat‐reduced margarine (12.62±0.28 μm). At higher temperatures, as a result of decreasing SFC, the mean droplet size increased as did the droplet size distribution, leading to eventual coalescence and destabilization in all spreads. In butter, the critical SFC was ∼9%, whereas in margarine notable coalescence occurred at ∼5% SFC. The fat‐reduced margarine destabilized at lower temperatures than the other spreads (∼20°C vs. ∼30°C), at an SFC of ∼6.5%. In these spreads, two different mechanisms influenced dispersed phase stability: (i) steric stabilization against coalescence via fat crystals located at the droplet interface, known as Pickering stabilization, and (ii) stabilization against droplet sedimentation (and droplet encounters) due to the presence of the fat crystal network.
Cholesterol oxidation in some processed fish products
Authors: Pickova Jana , Dutta Paresh C. 
Published: November 2006

AbstractNumerous foods of animal origin are reported to contain considerable levels of cholesterol oxidation products (COP); however, very few reports are available on fish products. Levels of COP were assessed in samples of fish roe, fish oil, and fish meal. Among the fish roe samples, the smoked cod roe had the highest amount of COP, 93 μg/g lipids. Refined and bleached menhaden oil had 8 μg/g, and two experimental alkali‐refined, bleached, and deodorized herring fish oil samples contained similar amounts of COP. The range of total COP in the three fish meal samples ranged from 50 to 78 μg/g fish meal. Generally, processed fish roe contained high amounts of COP compared with refined fish oils, which had very low amounts of COP. Fish meal samples had very high amounts of COP.
Do antioxidants improve the oxidative stability of oil‐in‐water emulsions?
Authors: Cuvelier Marie‐Elisabeth , Lagunes‐Galvez Laura , Berset Claudette 
Published: November 2006

AbstractOil‐in‐water emulsions were prepared with 30% stripped sunflower oil, stabilized by 20 g/L BSA and homogenized under high pressure to obtain a mean droplet size near 0.5 μm. The emulsions were shown to be physically stable during storage in a shaker at 47°C for 5 d. Such a medium was suitable to test the efficiency of different types of antioxidants. Oxidation of control emulsions appeared rapidly without a lag phase, and the contents of conjugated dienes and hexanal reached a plateau after around 20 h. In the presence of EDTA, the oxidation was strongly inhibited, suggesting that some metallic ions present in the oil or the protein solution act as inducers. Ascorbic acid and ascorbyl palmitate were inactive. Isoeugenol was found to be a powerful antioxidant, better than eugenol, α‐tocopherol, and Trolox.
Stability of spray‐dried encapsulated carotenoid pigments from rosa mosqueta (Rosa rubiginosa) oleoresin
Authors: Robert P. , Carlsson R. M. , Romero N. , Masson L. 
Published: November 2006

AbstractOleoresin of rosa mosqueta (Rosa rubiginosa) was encapsulated with starch or gelatin by spray‐drying. Stability of the powders was studied at 25, 40, and 55°C in the dark. Degradation of trans‐rubixanthin, trans‐lycopene, and trans‐β‐carotene followed a pseudo‐first‐order kinetic model for both encapsulating agents. The gelatin matrix provided a greater protective effect over the main carotenoid pigments, as shown by the lower degradation rate constants and the longer half‐life values at 21°C. In contrast, the carotenoid pigments showed the same degradation rate in starch, but trans‐β‐carotene was more stable in gelatin. The kinetic compensation effect obtained according to the calculated thermodynamic parameters suggests that the carotenoids are degraded by the same mechanism.
Electrochemical hydrogenation of canola oil using a hydrogen transfer agent
Authors: Mondal Kanchan , Lalvani Shashi B. 
Published: November 2006

AbstractA novel low‐temperature process for the electrochemical hydrogenation of canola oil is described. An emulsion of oil and water containing formic acid and a nickel hydrogenation catalyst, placed in the cathode compartment of an electrolysis cell and subjected to an electrical current, underwent hydrogenation at temperatures as low as 45°C. At these low temperatures of hydrogenation, the trans FA content of the hydrogenated canola oil was very low as compared with that of the edible oils hydrogenated by commercial processes using high temperature and high partial pressure of hydrogen gas. Because of its adverse health effects, a high trans FA content in edbile oils is viewed as undesirable. In addition to the commercially available nickel supported on silica, amorphous nickelphosphorus alloys supported on a variety of substrates were also used. Amorphous alloys are generally very corrosion resistant because of the absence of grain boundaries. A mechanism for hydrogenation using the hydrogen transfer agent of formic acid and its continuous regeneration at the cathode was evoked to explain the experimental data.
Adsorption isotherms in bleaching hazelnut oil
Authors: Bayrak Yuksel 
Published: November 2006

AbstractAdsorption isotherms in bleaching hazelnut oil were determined to investigate the applicability of the Langmuir and Freundlich equations and to elucidate the adsorption characteristics of oil on bentonite EY‐09 (Bensan Co. Ltd., Edirne, Turkey). The degree of bleaching was monitored spectrophotometrically. Absorbance measurements were carried out to investigate the adsorption force of clay during bleaching of hazelnut oil with 0.3, 0.5, 0.7, and 0.9 wt% clay at 50, 60, 70, 80, and 90°C. Bentonite EY‐09 was used as the bleaching clay (adsorbent). Plots of log(x/m) vs. log Xe (for the Freundlich isotherm) and Xe/(x/m) vs. Xe (for the Langmuir isomtherm) were made (where x is the amount of pigment removed per unit mass of the adsorbent, m, and Xe is the equilibrium concentration of the pigment). The Freundlich constants were found to increase with temperature for a given oil/bleaching agent ratio, showing the formation of more active sites on the adsorbent with a rise in temperature. Since the heat evolved during adsorption (0.32–1.03 kJ mol−1) was less than 20 kJ mol−1, the forces between the adsorbent and adsorbate appeared to be van der Waals forces. This type of adsorption is defined as physical or van der Waals adsorption. The results obtained show good agreement with the Freundlich isotherm, indicating that the adsorption of the pigment from the oil proceeds by monolayer formation on the surface of the adsorbent.
Simulation modeling of the phase behavior of palm oil‐supercritical carbon dioxide
Authors: Lim C. S. , Manan Z. A. , Sarmidi M. R. 
Published: November 2006

AbstractThe phase behavior of crude palm oil (CPO) with supercritical CO2 was successfully modeled in an Aspen Plus® 10.2.1 commercial simulator (Aspen Technology Inc., Cambridge, MA) using the Redlich‐Kwong‐Aspen (RKA) equation of state thermodynamic model. The modeling procedure involved estimating pure component vapor pressures and critical properties and computing a regression of phase equilibrium behavior. The interaction parameters for the RKA model were obtained from the regression of experimental phase equilibrium data for a binary system of palm oil components‐supercritical CO2 available in the literature. The distribution coefficients and solubilities of palm oil components obtained from this simulation showed good agreement with experimental data obtained from the literature. The model provides an efficient and cost‐effective alternative for the preliminary design and optimization of a supercritical fluid extraction process involving a complex CPO‐supercritical CO2 system.
NIR reflectance spectroscopic analysis of the FA composition in sesame (Sesamum indicum L.) seeds
Authors: Sato Tetsuo , Maw Aye Aye , Katsuta Masumi 
Published: November 2006

AbstractThe feasibility of using NIR reflectance spectroscopy to estimate the FA composition of sesame seed (Sesamum indicum L.) samples from the National Institute of Crop Science of Japan and from Myanmar was examined. Multiple linear‐regression analyses of NIR sepctral data and chemical data for whole seeds were carried out to develop calibration equations for predicting the proportion of each of the four major FA in sesame seeds from the total FA composition. The SE of prediction (SEP) was 0.616% for palmitic acid, 0.348% for stearic acid, 1.051% for oleic acid, and 0.826% for linoleic acid. This NIR method provides a simple, rapid, and nondestructive means of estimating the FA composition of sesame seeds for breeding selection, regardless of the color of the sesame seed coats. However, the proportions of palmitic and stearic acids could not be reliably measured because their SEP were almost as great as the SD of their concentrations in the set of prediction samples. The relationship between NIR spectral patterns and the FA composition of sesame seeds also was examined. The correlation coefficient calculated for the standardized second‐derivative NIR spectral readings at 1708 nm and the percentages of linoleic acid was −0.830. A rough estimate of the proportion of linoleic acid in the total FA composition of sesame seeds could be obtained even with single sesame seeds, except for those with a black coat, based on NIR spectral pattern analysis using the wavelength assignments of linoleic acid.
Production of cocoa butter‐like fats by the lipase‐catalyzed interesterification of palm oil and hydrogenated soybean oil
Authors: Abigor Roland D. , Marmer William N. , Foglia Thomas A. , Jones Kerby C. , DiCiccio Robert J. , Ashby Richard , Uadia Patrick O. 
Published: November 2006

AbstractCocoa butter‐like fats were prepared from refined, bleached, and deodorized palm oil (RBD‐PO) and fully hydrogenated soybean oil (HSO) by enzymatic interesterification at various weight ratios of substrates. The cocoa butter‐like fats were isolated from the crude interesterification mixture by fractional crystallization from acetone. Analysis of these fat products by RP‐HPLC in combination with ELSD or MS detection showed that their TAG distributions were similar to that of cocoa butter but that they also contained MAG and DAG, which were removed by silica chromatography. The optimal weight ratio of RBD‐PO to HSO found to produce a fat product containing the major TAG component of cocoa butter, namely, 1(3)‐palmitoyl‐3(1)‐stearoyl‐2‐monoolein (POS), was 1.6∶1. The m.p. of this purified product as determined by DSC was comparable to the m.p. of cocoa butter, and its yield was 45% based on the weight of the original substrates.
Lipase‐catalyzed incorporation of n−3 PUFA into palm oil
Authors: Fajardo A. Ramírez , Akoh Casimir C. , Lai O. M. 
Published: November 2006

AbstractTwo immobilized lipases, IM60 from Rhizomucor miehei and QLM from Alcaligenes sp., were used as biocatalysts for the modification of the FA composition of palm oil by incorporating n−3 PUFA. Acidolysis and interesterification reactions were conducted with hexane as organic solvent, and the products were analyzed by using GLC. After a 24‐h incubation in hexane, there was an average incorporation of 20.8% EPA and 15.6% DHA into palm oil, respectively, while the percentages of palmitic and oleic acids in palm oil decreased by 28.8 and 11.8%, respectively. Higher EPA and DHA incorporation was obtained when EPAX (fish oil concentrate high in n−3 PUFA) was used in the ethyl ester form (interesterification reaction) than in the free acid form (acidolysis) in the presence of Lipozyme (IM60 lipase. Lipase QLM was found to discriminate against EPA, and it showed slightly better catalytic activity for DHA in the free acid form than in the ethyl ester form. Generally, as the mole ratio of the acyl donor to TAG increased, the percentage incorporation of EPA and DHA increased; however, reactions catalyzed by Lipozyme IM60 did not show increases in the incorporation beyond a TAG/EPAX mole ratio of 3. When limitations due to mass transfer were not a factor, an increase in the reactant amount also gave an increase in the percentage incorporation of the n−3 PUFA. Palm oil containing EPA and DHA was successfully produced and may be beneficial in certain food and nutritional applications.
A computational study of the structure‐activity relationships of some p‐hydroxybenzoic acid antioxidants
Authors: Vafiadis Anastasios P. , Bakalbassis Evangelos G. 
Published: November 2006

AbstractEquilibrium structures of all derivatized systems of p‐hydroxybenzoic acid, 3,4‐dihydroxybenzoic acid, 3‐methoxy‐4‐hydroxybenzoic acid, and 3,5‐dimethoxy‐4‐hydroxybenzoic acid and calculated structural and energetic molecular descriptors were determined at the B3LYP/6‐31+G(d) density functional theoretical level in an attempt to study their structure‐activity relationships (SAR). The theoretical antioxidant activity trend, derived in terms of hydrogen‐donating capacity against radicals in lipid systems, is in excellent agreement with the experimental one. The lower antioxidant activity of benzoates, experimentally found relative to the homologous cinnamates, could be due to (i) their lower spin delocalization, (ii) their higher calculated heats of formation values in forming radicals (ΔHOF), and (iii) the much stronger electron‐withdrawing effect of the‐COOH group than‐CH=CHCOOH. The low calculated dipole moment values of the global minimum structures of the antioxidants could facilitate their solubilities in nonpolar solvents, hence the ease of hydrogen abstraction. However, highest occupied molecular orbital (HOMO) eigenvalues can neither predict antioxidant activity nor differentiate the same activity between two series of structurally related compounds. Again, density functional theory calculations provide a good molecular descriptor, ΔHOF, to correlate with the antioxidant activity in molecules showing similar structural characteristics.
Multivariate sensory characteristics of low and ultra‐low linolenic soybean oils displayed as faces
Authors: Su Caiping , Gupta Monoj , White Pamela 
Published: November 2006

AbstractThe effects of linolenic acid (18∶3) concentration, combined with IBHQ addition, temperature, and storage time, on the flavor stability of soybean oils (SBO) were evaluated. A descriptive panel was trained to evaluate the overall oil quality and the intensity of individual flavors of SBO during 12 mon of storage under fluorescent light at both 21 and 32°C. Chernoff faces were used to achieve a simplified and integrated interpretation of the multivariate sensory data and to facilitate the interpretation of the vast amount of the data. In early storage, SBO with low 18∶3 (2.2% 18∶3, LLSBO) showed better flavor stability than did SBO with ultra‐low 18∶3 (1.0% 18∶3, ULSBO). This trend disappeared during storage. During 10‐ to 12‐mon storage, a painty flavor became predominant in all oils, which may have made it difficult for panelists to detect differences in treatment effect on flavor characteristics of SBO. During early storage, oils with TBHQ addition had poorer overall oil quality and stronger beany, painty, and fishy flavors than did oils without TBHQ addition. This trend disappeared as storage time progressed to 10 mon. Oils storedat 32°C had poorer overall oil quality and stronger painty, fishy, and beany flavors than did oils stored at 21°C starting from 2‐mon storage.
Extracting long‐chain fatty acids from a fermentation medium
Authors: Lalman Jerald A. , Bagley David M. 
Published: November 2006

AbstractSeveral solvents were evaluated for extracting free long‐chain FA (LCFA) from a fermentation medium. Chloroform, chloroform/methanol (1∶1), hexane, and hexane/methyl tert‐butyl ether (MTBE) (1∶1) were evaluated as alternative extraction solvents. Parameters considered for optimizing LCFA recoveries included pH and ionic strength. Maximal LCFA recoveries were obtained by adding 2 mL of the hexane/MTBE (1∶1) solvent mixture, 80 μL of 50% H2SO4, and 0.05 g NaCl to 1 mL of the aqueous sample and mixing for 15 min at 200 rpm. This method quantified saturated LCFA [capric acid (C10∶0) to stearic acid (C18∶0)] and unsaturated LCFA with 18 carbons [linoleic acid (C18∶2) and oleic acid (C18∶1)] with a 98 to 100% recovery. Caproic (C6∶0) and caprylic (C8∶0) acids were characterized by 27 and 76% recoveries, respectively.
Fatty acid composition and oxidation of lipids in Korean catfish
Authors: Hwang K. T. , Kim J. E. , Kang S. G. , Jung S. T. , Park H. J. , Weller C. L. 
Published: November 2006

AbstractThis study determined the lipid content and FA composition of muscle and a mixture of muscle and viscera from Korean catfish as well as lipid oxidation and hydrolysis. Lipid content and FA compositions in Korean catfish, which were purchased every month or two during September 1999–July 2000, were analyzed. Lipid oxidation and hydrolysis were determined as PV, thiobarbituric acid value, and FFA in the muscle and the mixture during storage at 2°C for 12 d and −14°C for 9 wk. Lipid contents of the muscle and the mixture were 3.2 (w/w) and 5.4%, respectively. Oleic acid was the most abundant FA in the catfish lipids, constituting 28.0% (w/w) of total FA in the muscle and 25.6% in the mixture, followed by palmitic acid and linoleic acid, amounting to 20.2 and 12.2%, respectively, in the muscle and 20.2 and 12.5% in the mixture. EPA and DHA were 3.2 and 6.8%, respectively, in the muscle and 3.5 and 8.1% in the mixture. Seasonal variation in lipid contents and FA composition was minimal in catfish. Lipids in minced catfish oxidized and hydrolyzed readily at 2°C. Inclusion of viscera into the muscle increased lipid oxidation and hydrolysis. Frozen storage at −14°C and addition of ascorbic acid both reduced lipid oxidation. Frozen storage retarded lipid hydrolysis in catfish.
Fatty acid (FA) composition and contents of trans unsaturated FA in hydrogenated vegetable oils and blended fats from Pakistan
Authors: Bhanger Muhammad Iqbal , Anwar Farooq 
Published: November 2006

AbstractThis study presents the FA composition and trans FA (TFA) contents of different hydrogenated vegetable oils and blended fats marketed in Pakistan. Thirty‐four vanaspati (vegetable ghee), 11 shortenings, and 11 margarines were analyzed. The contents of saturated FA, cis monounsaturated FA, and cis PUFA were in the following ranges: vanaspati 27.8–49.5, 22.2–27.5, 9.3–13.1%; vegetable shortenings 37.1–55.5, 15.8–36.0, 2.7–7.0%; and margarines 44.2–55.8, 21.7–39.9, 2.9–20.5%, respectively. Results showed significantly higher amounts of TFA in vanaspati samples, from 14.2 to 34.3%. Shortenings contained TFA proportions of 7.3–31.7%. The contents of TFA in hard‐type margarines were in the range of 1.6–23.1%, whereas soft margarines contained less than 4.1% TFA.
Immobilized lipase‐catalyzed ethanolysis of sunflower oil
Authors: Yesiloglu Yesim 
Published: November 2006

AbstractThe ethanolysis of sunflower oil catalyzed by an immobilized 1,3‐specific porcine pancreatic lipase in a medium composed solely of substrates was investigated. The effects of the oil/ethanol molar ratio, temperature, amount of added water, and amount of enzyme used [respectively, 1∶3, 45°C, 0% (vol/vol), and 0.5 g of lipase, i.e., 10% w/w of total substrate]. To investigate the reusability of the lipase, the four‐step ethanolysis process was repeated by transferring the immobilized lipase to a substrate mixture. As a result, the percentage of conversion after the first usage decreased markedly.