bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure indices in FA chemistry. How relevant is the iodine value?
Authors: Knothe Gerhard 
Published: November 2006

AbstractMost common analytical methods in FA chemistry can be categorized as yielding either structure or quality indices. Quality indices often describe components in fats and oils arising from processing, storage, and naturally occurring, nonfatty materials. Common structure indices are the iodine value (IV), the saponification value, and the hydroxyl value. Although modern analytical methods yield more detailed and reliable information, structure indices are still widely used. The IV, which indicates total unsaturation, has even been included in some standards for industrial products such as biodiesel. However, the IV index is too general to allow the correlation of physical and chemical properties with FA composition. The IV is treated in a theoretical fashion regarding biodiesel‐ and oxidative stability‐related issues. That the concept of IV as a structure index is unsatisfactory is shown by the development of a quaternary composition diagram (QCD). The QCD demonstrates the derivation of a specific IV from varying FA compositions. Improved correlations are possible among the structure indices. Alternative indices for the IV are developed. Possible alternatives are the allylic position equivalent (APE) and the bisallylic position equivalent (BAPE) which better relate structure and amount of common component FA in vegetable oils to observed properties. The APE and BAPE indices are based on the number of reactive positions in oxidation.
Camelina oil and its unusual cholesterol content
Authors: Shukla V. K. S. , Dutta P. C. , Artz W. E. 
Published: November 2006

AbstractThe oil in Camelina sativa L. Crantz has a combined linolenic and linoleic acid content that is greater than 50% and a relatively low saturated FA content (∼10%). Although the FA composition has been reported, no information is available on the sterol composition of camelina oil. The derivatized plant sterols were separated and quantified with capillary GC and their identity confirmed with GC‐MS. The refined camelina oil sample contained approximately 0.54 wt% unsaponifiables, and over 80% of the unsaponifiables were desmethylsterols. Perhaps the most unusual characteristic of camelina oil is its relatively high content of cholesterol, particularly for a vegetable oil, since it contains several times the cholesterol found in other “high‐cholesterol” vegetable oils. Camelina oil also contains relatively large amounts of another unusual sterol, brassicasterol. The major sterols identified in the camelina oil included cholesterol (188 ppm), brassicasterol (133 ppm), campesterol (893 ppm), stigmasterol (103 ppm), sitosterol (1,884 ppm), and Δ5‐avenasterol (393 ppm).
Validation of the oxygen radical absorbance capacity (ORAC) parameter as a new index of quality and stability of virgin olive oil
Authors: Ninfali Paolino , Bacchiocca Mara , Biagiotti Enrica , Servili Maurizio , Montedoro Gianfrancesco 
Published: November 2006

AbstractThe induction period (IP), determined using accelerated methods such as the Rancimat test, is a parameter that has been used to predict the shelf life of virgin olive oil. The oxygen radical absorbance capacity (ORAC) has recently been proposed as a quality index of virgin olive oil because it measures the efficiency of phenolic compounds in the protection against peroxyl radicals. This study aims to investigate relationships between the ORAC and IP values and proposes ORAC as a new parameter of virgin olive oil stability. The concentrations of phenolics, o‐diphenols, tocopherol, β‐carotene, lutein, and ORAC and IP values were determined in 33 virgin olive oils. Regression analyses showed that both ORAC and IP values correlate with total phenols and o‐diphenols with highly significant indices, whereas the correlations of both ORAC and IP with tocopherols, β‐carotene, and lutein were not significant. The ORAC values correlate with the IP values with low but significant indices (R=0.42; P<0.02). The results confirm the key role of phenolic compounds in accounting for the shelf life of virgin olive oil and suggest that the ORAC parameter may be used as a new index of quality and stability.
Riboflavin‐photosensitized singlet oxygen oxidation product of vitamin D2
Authors: King Joan M. , Min David B. 
Published: November 2006

AbstractThe riboflavin‐photosensitized singlet oxygen oxidation of vitamin D2 in a model system of 12% water and 88% acetone was studied to understand the possible oxidation of fortified vitamin D in milk. Only the samples containing vitamin D2 and riboflavin under light storage showed two new peaks in the HPLC chromatogram, indicating that singlet oxygen oxidation of vitamin D2 had occurred. UV analysis indicated that a new compound was formed from the reaction of the triene of vitamin D2 with oxygen. The mass spectrum showed that one of the two compounds had a molecular ion at m/z=412, which was an increase of the mass of vitamin D2 by the mass of exactly one oxygen. The IR spectrum suggested the presence of a hydroxyl group and no carbonyl group in the product. The combned information from UV, MS, and FTIR spectra and the chemical mechanisms of singlet oxygen oxidation of vitamin D2 indicated that a 5,6‐epoxide of vitamin D2 was formed from vitamin D2 in the presence of riboflavin under light.
Characterizing cocoa butter seed crystals by the oil‐in‐water emulsion crystallization method
Authors: Hindle Scott A. , Povey Malcolm J. W. , Smith Kevin W. 
Published: November 2006

AbstractUnambiguous quantitative evidence for the catalytic action of seed crystals in cocoa butter is presented. We used an ultrasound velocity technique to determine the isothermal growth of solid fat content in cocoa butter oil‐in‐water emulsions, in which the probability of finding a seed crystal in any one droplet was around 0.37 at 14.2°C. The upper limit for the size of seed crystals in West African cocoa butter was around 0.09 μm, the Gibbs free energy for nucleation was 0.11 mj m−2, and the concentration of seed crystals was in the range of 1016to 1017m−3. X‐ray diffraction measurements showed that emulsified cocoa butter crystallizes in the α polymorph and does not appear to transform to the β′ form within the first 25 min of crystallization. Primary nucleation events in cocoa butter emulsions are accounted for by seed crystals. Collision‐mediated nucleation, a secondary nucleation mechanism, in which solid droplets (containing seed crystals) catalyze nucleation in liquid droplets, is shown to account for subsequent crystallization. This secondary nucleation mechanism is enhanced by stirring.
Characterization of olive oil classes using a Chemsensor and pattern recognition techniques
Authors: Peña F. , Cárdenas S. , Gallego M. , Valcárcel M. 
Published: November 2006

AbstractClassification is an important component of food quality assurance, as methods to guarantee authenticity of food products are widely demanded by food producers, processors, consumers, and regulatory bodies. The objective of this work was to develop a rapid classification method in order to discriminate virgin olive oil, olive oil, and „orujo” olive oil, the prices of which differ dramatically in the market on a ccount of the high quality level of the former. For these purposes, new ChemSensor equipment that combines a headspace autosampler with a mass‐selective detector and Pirouette data evaluation software was used. To take into account the large number of samples analyzed (50 samples repeated 10 times), as well as the wide interval ofm/zratios scanned (41–170), chemometric approaches were necessary. Cluster analysis, principal component analysis, K‐nearest neighbors, and soft independent modeling of class analogy (SIMCA) were applied to model the different oil classes. The results indicated good classification and prediction abilities, with SIMCA affording the best results (viz. 97% specificity).
Monitoring milk fat fractionation: Effect of agitation, temperature, and residence time on physical properties
Authors: Vanhoutte Bert , Dewettinck Koen , Vanlerberghe Brecht , Huyghebaert André 
Published: November 2006

AbstractWith the use of two central composite designs, the effects of agitation rate, fractionation temperature, and residence time on the thermal properties of the stearin and olein milk fat fractions were investigated. The main function of agitation during fat fractionation was suspending the crystal aggregates and enhancing the heat transfer. For the experimental conditions described here, crystal aggregation did not seem to be affected by agitation. The effect of fractionation temperature on the physical properties of the olein fraction was very significant. Triangle diagrams were shown to be a useful tool for monitoring and designing fractionation processes. They illustrate that oleins with similar melting properties can be produced over a range of yields of stearin, which is important from an industrial point of view. Crystallizer residence time, which influences production costs, clearly affects both stearin yield and olein melting properties. For any fractionation temperature, stearin fractions with virtually identical melting properties and yields can be obtained over a range of olein melting properties. Manipulation of both the fractionation temperature and residence time allows the fractionation process to be adapted to meet changing market demands for fractions with different melting properties.
Comparison of a low‐linolenic and a partially hydrogenated soybean oil using pan‐fried hash browns
Authors: Soheili Kambiz C. , Tippayawat Preeyanooch , Artz William E. 
Published: November 2006

AbstractHash browns (HB) were fried (Teflon‐coated pan, ∼180°C) with low‐linolenic acid (LL‐SBO) and creamy partially hydrogenated soybean oils (PH‐SBO). High‐performance size‐exclusion chromatography of the oil extracted before heating indicated a relatively low polymer content (LL‐SBO, 3.8%; PH‐SBO, 1.6%), although the oil remaining in the pan after frying had a much greater polymer content (38.8%, LL‐SBO; 17.5%, PH‐SBO). The percentage of altered TAG in the LL‐SBO sample (extracted from HB) was 34.4% after frying, whereas the PH‐SBO had 33.2% altered TAG (as determined by supercritical fluid chromatography). In the LL‐SBO pan‐fried HB samples (not the extracted oil), 2‐pentanone, hexanal, 2‐hexenal, trans‐2‐heptenal, 2‐pentylfuran, and trans‐2‐octenal were found, whereas the major volatile compounds in the HB fried with PH‐SBO included hexanal, trans‐2‐hexenal, and trans‐2‐heptenal. Hexanal was the most abundant volatile compound in both HB samples (LL‐SBO, 2.7 ppm; PH‐SBO, 0.3 ppm). There were significant differences in the polymer content, hexanal content, p‐anisidine values, and Foodoil sensor readings between LL‐SBO and PH‐SBO (P<0.05). The PH‐SBO sample was more stable than the LL‐SBO sample. Moreover, the LL‐SBO oil sample in the pan after frying had the greater increase in polymer content.
Composition and sensory qualities of minimum‐refined soybean oils
Authors: Wang Xi , Wang Tong , Johnson Lawrence A. 
Published: November 2006

AbstractCommodity (normal) and high‐oleic soybean oils extracted by extrusion‐expelling (E‐E) were minimally processed using water degumming and adsorptive deacidification to produce edible oil. Degummed and deacidified oils were deodorized at 150°C for 1 h by purging with N2, CO2, or steam. They were also conventionally deodorized for quality comparisons. Generally, the oxidative stability of the properly gas‐purged commodity oils was better than that of the conventionally deodorized oils. Total tocopherols, FFA contents, and colors of the deodorized oils were not significantly different among the treatments. Sensory analysis of the oils showed that the toasty/nutty flavors of the gas‐purged oils, especially for the degummed oils, were more intense than those of the conventionally deodorized oils. The beany flavors of gas‐purged oils were not significantly different from those of conventionally deodorized oils, although the flavor intensities tended to be slightly higher in gas‐purged oils. The overall flavor intensities of the gas‐purged oils were similar to those of conventionally deodorized oils. Therefore, E‐E soybean oil has the potential to be minimally refined to produce edible oil with good compositional and sensory qualities.
Particle size effects on supercritical CO2 extraction of oil‐containing seeds
Authors: del Valle José M. , Uquiche Edgar L. 
Published: November 2006

AbstractRosehip seeds were milled, sieved, and extracted with 26.3 g/g substrate/h of supercritical carbon dioxide (CO2) at 40°C and 300 bar. The extraction kinetics were characterized by an initial solubility‐controlled period (8.78 g oil/kg CO2 at 40°C and 300 bar), followed by a transition period to a final mass transfer‐controlled process. The integral yield of oil approached an asymptotic value that was dependent on the particle size of the substrate: 57.1 g oil/kg dry oil‐free substrate (large particles), 171.0 g/kg (medium‐size particles), or 391.5 g/kg (small particles). Based on gravimetric determinations and microscopic analysis, our size‐classification process segregated seed parts having different oil contents. Particles ≥0.85 mm were mainly composed of tough, lignified testa fragments devoid of oil, whereas particles ≤0.425 mm contained mostly brittle, oil‐rich germ fragments. The segregation of seed in fractions with different oil contents may be a common occurrence in supercritical extraction experiments, especially for seeds with thick and/or hard testa and small germ, whose fractions can be separated by sieving.
FA and unsaponifiable composition of five Amazonian palm kernel oils
Authors: Bereau Didier , Benjelloun‐Mlayah Bouchra , Banoub Joseph , Bravo René 
Published: November 2006

AbstractThe kernel oils of five different palm species native to the Amazon basin and French Guyana were studied. Those studied were Acrocomia lasiospatha Wall., Astrocaryum vulgare C. Mart., Bactris gasipaes H.B.K., Elaeis oleifera (Kunth) Cortés, and Maximiliana maripa Drude. Lauric and myristic acids were found in all of the oils. Analysis of the unsaponifiable contents, especially the sterol and triterpene alcohol determinations, revealed the preponderance of sitosterol and the presence of two triterpene alcohols (cycloartenol and 24‐methylenecycloartanol). Antioxidant (vitamin E) levels were present in small amounts, with the levels being more similar to olive than to palm oil.
Tocopherols in sea buckthorn (Hippophaë rhamnoides L.) berry oil
Authors: Zadernowski R. , Naczk M. , Amarowicz R. 
Published: November 2006

AbstractThe free tocopherol content in whole berries of six sea buckthorn cultivars grown in northeastern Poland and Belorussia was determined with HPLC. The total free tocopherol content in oil from whole berries was 101.4–128.3 mg/100 g of oil. α‐Tocopherol was the predominant tocopherol of sea buckthorn berries, and only traces of γ‐tocopherol were detected in the oil. α‐ and δ‐Tocopherols constituted 62.5–67.9% and 32.1–37.5% of total tocopherol, respectively. The total free tocopherol content in oil of sea buckthorn cv. Nadbaltycka increased during maturation from 40.4 to 109.8 mg/100 g of oil. Green berries contained a marked amount of γ‐tocopherol, but its content rapidly declined to traces when the color of berries turned from green to olive‐yellow.
Chemical composition and antioxidant activity of extracts from Daphne gnidium L.
Authors: Deiana M. , Rosa A. , Casu V. , Cottiglia F. , Bonsignore L. , Dessì M. A. 
Published: November 2006

AbstractMembers of the Daphne genus have been of interest owing to their excellent medicinal value. In this work, we describe the results of phytochemical analysis and the antioxidant activity of the methanol extracts from leaves and stems of D. gnidium L. grown wild in Sardinia, Italy. Four coumarins (daphnetin, daphnin, acetylumbelliferon, and daphnoretin), nine flavonoids (apigenin, luteolin, quercetin, orientin, isoorientin, luteolin 7‐O‐glucoside, apigenin 7‐O‐glucoside, genkwanin, and 5‐O‐β‐d‐primeverosyl genkwanine), and α‐tocopherol were isolated. We investigated the ability of the two extracts and five pure compounds (daphnetin, daphnoretin, apigenin, luteolin, and α‐tocopherol) to protect linoleic acid against free radical attack in simple in vitro systems by autoxidation and iron‐ or EDTA‐mediated oxidation. Pure compounds were the most active antioxidants. During autoxidation, daphnetin, luteolin, and α‐tocopherol were effective at a molar ratio of 1∶1600, 1∶2500, and 1∶2000, respectively. Daphnoretin was active only at high concentrations. During the iron‐catalyzed oxidation of linoleic acid, all the materials tested showed activity in the following order: luteolin>daphnetin>α‐tocopherol >leaf extract>stem extract>daphnoretin. Apigenin was not active in any of the experimental systems used.
Production of FAME from acid oil, a by‐product of vegetable oil refining
Authors: Haas Michael J. , Michalski Paul J. , Runyon Stan , Nunez Alberto , Scott Karen M. 
Published: November 2006

AbstractSimple alkyl FA esters have numerous uses, including serving as biodiesel, a fuel for compression ignition (diesel) engines. The use of acid‐catalyzed esterification for the synthesis of FAME from acid oil, a by‐product of edible vegetable oil refining that is produced from soapstock, was investigated. Soybean acid oil contained 59.3 wt% FFA, 28.0 wt% TAG, 4.4 wt% DAG, and less than 1% MAG. Maximum esterification occurred at 65°C and 26 h reaction at a molar ratio of total FA/methanol/sulfuric acid of 1∶15∶1.5. Residual unreacted species under these conditions, as a fraction of their content in unesterified acid oil, were FFA, 6.6%; TAG, 5.8%; and DAG, 2.6%. This corresponds to estimated concentrations of FFA, 3.2%; TAG, 1.3%; and DAG, 0.2%, on a mass basis, in the ester product. In an alternative approach, the acylglycerol species in soapstock were saponified prior to acidulation. High‐acid (HA) acid oil made from this saponified soapstock had an FFA content of 96.2 wt% and no detectable TAG, DAG, or MAG. Optimal esterification conditions for HA acid oil at 65°C were a mole ratio of FFA/methanol/acid of 1∶1.8∶0.17, and 14 h incubation. FAME recovery under these conditions was 89% of theoretical, and the residual unesterified FFA content was approximately 20 mg/g. This was reduced to 3.5 mg/g, below the maximum FFA level allowed for biodiesel, by washing with NaCl, NaHCO3, and Ca(OH)2 solutions. Alternatively, by subjecting the unwashed ester layer to a second esterification, the FFA level was reduced to less than 2 mg/g. The acid value of this material exceeded the maximum allowed for biodiesel, but was reduced to an acceptable value by a brief wash with 0.5 N NaOH.
Structural characterization of triacylglycerols using electrospray ionization‐MSn ion‐trap MS
Authors: Marzilli Lisa A. , Fay Laurent B. , Dionisi Fabiola , Vouros Paul 
Published: November 2006

AbstractStructural analysis of mixtures of TAG requires the determination of the M.W. of each compound, the characterization of the structure(s) of the individual FA substituents, and identification of the relative disposition of the acyl groups on the glycerol backbone (regiospecificity). In this study we demonstrated that ion‐trap MS in combination with electrospray ionization provides an easy and detailed characterization of the TAG structure. We showed that electrospray mass spectra are characterized by intense molecular ion adducts and that the acyl group disposition on the TAG backbone can be determined on the basis of relatively well‐defined quantitative differences of fragment ions produced from MS2 data. Moreover, additional spectral data can be generated by MS3 experiments on moieties containing individual acyl ion fragments. When hyphenated with chromatographic separations ion‐trap electrospray MS might become a routine and powerful way to analyze TAG mixtures.
Detection of olive oil adulteration using principal component analysis applied on total and regio FA content
Authors: Dourtoglou V. G. , Dourtoglou Th. , Antonopoulos A. , Stefanou E. , Lalas S. , Poulos C. 
Published: November 2006

AbstractPrincipal component analysis (PCA) has been used to establish a new method for the detection of olive oil adulteration. The data set, composed of values obtained from the determination of the mole percentage of total FA and their regiospecific distribution in positions 1 and 3 in TG of oils (pure or mixtures) by GC analysis, was subjected to PCA. 3‐D scatter plots showed clearly that it is possible to distinguish the pure oils from the mixtures. Moreover it is possible to discriminate the different types of seed oil used for the adulteration.
TAG composition of ewe's milk fat. Detection of foreign fats
Authors: Goudjil Hanane , Fontecha Javier , Fraga Ma Jesús , Juárez Manuela 
Published: November 2006

AbstractThe TAG composition of 45 samples of ewe's milk, collected throughout the year from five Spanish breeds, was analyzed according to their carbon number by using short capillary column GC. The TAG content had a bimodal distribution with maxima at C38 (12.8%) and C52 (8.4%). The TAG composition did not vary significantly with respect to the time of year of sampling but was affected by the breed. Multiple regression equations based on TAG content are proposed to detect foreign fats in ewe's milk fat. Analysis of known mixtures of lard, palm oil, and cow's milk fat with ewe's milk fat have experimentally confirmed the accuracy of the equations.
Physical analyses of gel‐like behavior of binary mixtures of high‐ and low‐melting fats
Authors: Higaki K. , Sasakura Y. , Koyano T. , Hachiya I. , Sato K. 
Published: November 2006

AbstractGel‐like fat mixtures of high‐melting (HM) and low‐melting (LM) fats were formed by means of rapid cooling and subsequent heating. No “non‐fat” ingredients such as emulsifiers, water, or waxes were added to the mixtures. The gel‐like fats having solid fat content (SFC) values below 2.0 wt% formed crystal networks of HM‐fats that entrapped the liquid oil fraction of LM‐fats. In a search for optimal fat combinations exhibiting gel‐like behavior, fully hydrogenated rapeseed oil with a high amount of behenic acid (FHR‐B), fully hydrogenated rapeseed oil with a high amount of stearic acid (FHR‐S), tristearoylglycerol (SSS), triarachidonoyl‐glycerol (AAA), and tribehenoylglycerol (BBB) were examined as the HM‐fats. For LM‐fats, sal fat olein (SFO), cocoa butter (CB), palm super olein (PSO), and olive oil were examined. The following results were obtained: (i) the gel‐like behavior was observed in mixtures of FHR‐B/SFO and FHR‐B/CB with initial concentrations of FHR‐B of 1.5–4.0 wt%. (ii) Rapid cooling to Tc (crystallization temperature) from 70°C and subsequent heating to Tf (final temperature) were necessary to reveal the gel‐like behavior, whereas simple cooling without a cooling/heating procedure did not form the gel‐like fat mixture. (iii) Optimal values of Tc and Tf were related to the m.p. of the LM‐fat and HM‐fat, respectively. (iv) Temperature variations of SFC as well as X‐ray diffraction spectra showed that the melt‐mediated transformation from α to β of the HM‐fat crystals was a prerequisite to reveal the gel‐like behavior. Consequently, the fat mixture revealing the gel‐like behavior might be called β‐fat gel.
Purification of FAME by rice hull ash adsorption
Authors: Özgül‐Yücel Sevil , Türkay Selma 
Published: November 2006

AbstractRice hull ash (RHA) and silica gel were used for purification of FAME by adsorption of FFA at atmospheric conditions. Studies demonstrated that silica gel is a better adsorbent than RHA in purifying FAME. However, both adsorbents were effective in reducing FFA levels from FAME extracts. The FFA adsorption efficiency increased with high FAME concentration and high adsorbent dosage. But FAME adsorption also increased with larger doses of adsorbent. The adsorption isotherms of FFA were determined with both adsorbents. FFA adsorption displayed Freundlich‐type isotherms.