bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface and pore structure of deoiled acid‐and heat‐treated spent bleaching clays
Authors: Ng K. F. , Nair N. K. , Liew K. Y. , Noor Ahmad M.
Published: May 2007

Samples of spent bleaching clay were deoiled by hexane, methanol, hexane‐methanol, and supercritical CO2 extractions. The deoiled clays were regenerated by acid and heat treatments. Nitrogen adsorption isotherms for these samples are type IV with hysteresis loops corresponding to type H3, indicating slit‐shaped pores. Used deoiled and dried samples have smaller surface areas and pore volumes than unused clay. The surface areas and pore volumes increased after heat treatment. Acidified heat‐treated deoiled samples have smaller surface areas and greater pore volumes than unused clay, except for the methanol‐deoiled sample. Thus, heat and acid treatments removed substances adsorbed in the pores that were not removed by solvents or CO2 extraction. This was confirmed from the ratios of the cumulative surface area/BET surface area, as well as analysis of the pore size distributions, which indicated an increase in mesopores with radii of between 25 and 100 Å. The t‐plots showed that smaller pores with sizes between 7 and 25 Å, present originally in the unused clays, were closed by heat treatment. These pores were absent in the deoiled and the heat‐treated samples except for the heat‐treated sample that was deoiled by hexane followed by methanol. Smaller pores, accompanied by an increase in surface area, were also observed for all deoiled samples after acid and heat treatments.
Membrane degumming of crude soybean and rapeseed oils
Authors: Subramanian R. , Nakajima M.
Published: May 2007

Membrane separation in edible oil processing is a potential area for energy savings. However, technical and operating‐cost‐related barriers have impeded the successful application of membrane separation in food processing. Studies were undertaken with soybean and rapeseed oils in a magnetically stirred flat‐membrane batch cell with two types of composite polymeric membranes at 3 MPa pressure and at a constant temperature of 40°C. The membranes were NTGS‐1100 and NTGS‐2100, and used silicon as the active layer and polysulfone and polyimide as support layers, respectively. The membrane selectively rejected phospholipids, the content being less than 240 mg/kg in the permeate without any pretreatment or dilution of crude oil with organic solvent. Long‐term studies up to 97 days with soybean oil at two different pressures, 2 and 3 MPa, showed that the rejection of phosphatides was above 96% in most permeates. The permeate flux remained nearly constant but must be improved.
Enrichment of γ‐linolenic acid from borage oil via lipase‐catalyzed reactions
Authors: Huang Fang‐Cheng , Ju Yi‐Hsu , Huang Cheng‐Wei
Published: May 2007

Three lipase‐catalyzed reactions were utilized to enrich γ‐linolenic acid in borage oil: (i) selective hydrolysis in isooctane by Candida rugosa lipase immobilized on microporous polypropylene, (ii) selective esterification of free fatty acid from saponified borage oil and n‐butanol by Lipozyme IM‐20, and (iii) acidolysis of the products of the previous two reactions, that is, unhydrolyzed acylglycerols and unesterified free fatty acid. In the selective hydrolysis, γ‐linolenic acid content could be raised from 23.6 mol% in borage oil to 51.7% in the unhydrolyzed acylglycerols. On the other hand, γ‐linolenic acid content in free fatty acid could be increased to 87% after selective esterification. Products with 65% γ‐linolenic acid in their acylglycerols were obtained by means of the acidolysis reaction.
A new approach to genetic alteration of soybean protein composition and quality
Authors: Kwanyuen Prachuab , Pantalone Vincent R. , Burton Joseph W. , Wilson Richard F.
Published: May 2007

Although soybeans produce high‐quality meal, modern animal and fish production systems often require synthetic essential amino acid supplements to fortify feed rations. However, biotechnology may enable development of soybeans with naturally adequate levels of certain essential amino acids for advanced feed formulations. One approach involves genetic manipulation of glycinin (11S) and β‐conglycinin (7S) contents, the principal components of soybean storage proteins. Because 11S contains more cysteine and methionine than 7S protein, a higher 11S:7S ratio could lead to beneficial changes in the nutritional quality of soybean meal. Although genotypic variation for 11S:7S may be low among soybean [Glycine max (L.) Merr.] germplasm, ratios ranging from 1.7–4.9 were observed among accessions of the wild ancestor of cultivated soybean (Glycine soja Sieb, and Zucc.). Thus, wild soybean germplasm was evaluated as a potential source of genes that govern protein synthesis that may have been lost during the domestication of G. max. Change in the amount of 11S protein accounts for a significant portion of the genotypic variation in protein concentration and composition among wild soybeans. Strong positive correlation exists between the 11S:7S ratio and methionine or cysteine concentration of total protein. Moderate positive associations were found for threonine or tyrosine. A moderate negative correlation was found between lysine and 11S:7S. No association was found for leucine and phenylalanine or for total essential amino acid concentration. Based on these data, G. soja may contain a different complement of genes that influence expression of 11S and 7S proteins than G. max germplasm. Thus, through interspecific hybridization, wild soybeans may be a useful genetic resource for the further improvement of protein quality in cultivated soybeans.
Triacylglycerol composition and structure in genetically modified sunflower and soybean oils
Authors: Reske Johanna , Siebrecht Jodi , Hazebroek Jan
Published: May 2007

Changes in composition were examined in oils extracted from genetically modified sunflower and soybean seeds. Improvements were made to the analytical methods to accomplish these analyses successfully. Triacylglycerols (TAG) were separated on two 300 mm × 3.9 mm 4µ Novapak C18 high‐performance liquid chromatography (HPLC) columns and detected with a Varex MKIII evaporative light‐scattering detector. Peaks were identified by coelution with known standards or by determining fatty acid composition of eluted TAG by capillary gas chromatography (GC). Stereospecific analysis (fatty acid position) was accomplished by partially hydrolyzing TAG with ethyl magnesium bromide and immediately derivatizing the resulting diacylglycerols (DAG) with (S)‐(+)‐1‐(1‐naphthyl)ethyl isocyanate. The derivatized sn‐1,2‐DAG were completely resolved from the sn‐2,3‐DAG on two 25 mm × 4.6 mm 3 µ silica HPLC columns. The columns were chilled to −20°C to obtain baseline resolution of collected peaks. The distribution of fatty acids on each position of the glycerol backbone was derived from the fatty acid compositions of the two DAG groups and the unhydrolyzed oil. Results for the sn‐2 position were verified by hydrolyzing oils with porcine pancreatic lipase, isolating the resulting sn‐2 monoacylglycerols by TLC, and determining the fatty acid compositions by GC. Results demonstrated that alterations in the total fatty acid composition of these seed oils are determined by the concentration of TAG species that contain at least one of the modified acyl groups. As expected, no differences were found in TAG with fatty acid quantities unaffected by the specific mutation. In lieu of direct metabolic or enzymatic assay evidence, the authors’ positional data are nevertheless consistent with TAG biosynthesis in these lines being driven by the mass action of available acyl groups and not by altered specificity of the acyltransferases, the compounds responsible for incorporating fatty acids into TAG.
Large‐scale synthesis of methyl cis‐9, trans‐11‐octadecadienoate from methyl ricinoleate
Authors: Berdeaux O. , Christie W. W. , Gunstone F. D. , Sebedio J. ‐L.
Published: May 2007

The conjugated linoleic acid methyl cis‐9,trans‐11‐octadecadienoate has been prepared on a large scale from methyl ricinoleate. Methyl ricinoleate was purified from castor esters by a partition method. It was converted to the mesylate, which was reacted with a base (1,8‐diazabicyclo[5,4,0]‐undec‐7‐ene) to give a product that contained 66% of the desired ester. Two urea crystallizations produced a product containing 83% methyl cis‐9,trans‐11‐octadecadienoate, the identity of which was confirmed by gas chromatography linked to mass spectrometry and by Fourier transform infrared spectroscopy. The remaining impurities were methyl cis‐9,cis‐11‐ and cis‐9‐,trans‐12‐octadecadienoate.
Inhibition of soybean oil oxidation by extracts of dry beans (Phaseolus vulgaris)
Authors: Ganthavorn Chutima , Hughes Joe S.
Published: May 2007

Polyphenolic compounds were extracted from pinto, kidney, white (Great Northern), pink, and black beans by hot methanol extraction and added to soybean oil. Oil oxidation was assayed by thiobarbituric acid‐reactive substances (TBARS). All bean polyphenolics extracts exhibited similar antioxidant capacity in delaying the onset of iron‐catalyzed oxidation better than butylated hydroxyanisole (BHA), propyl gallate (PG), and ascorbic acid. Bean polyphenolic compounds were stable after heating to 50°C and maintained their antioxidant potential after 3 mon at 4°C. Bean extracts effectively inhibited iron‐catalyzed oxidation of soybean oil, probably by chelating metal ions, because no antioxidant effect was observed when soybean oil was oxidized without an iron catalyst.
Analogous salicylic acid affinity regions in serum albumin and soybean β‐Conglycinin
Authors: Rothfus John A. , Wolf Walter J.
Published: May 2007

The known structures of human serum albumin and its binding sites for salicylic acid (SA) were used as a model for examining the amino acid sequence of soybean β‐conglycinin to determine whether a plant protein might share structural similarities with albumin relative to the binding of SA, Molecular mechanics energy calculations for computed nonionized and ionized interactions in vacuo identified the two major SA affinity regions in human serum albumin and a single analogous region in the α‐subunit of soybean β‐conglycinin. SA interactions with 21‐residue segments from both proteins suggest redundant binding sites with multiple degrees of affinity. Highaffinity segments incorporate hydrophobic amino acids with combinations or multiple residues of histidine, tryptophan, lysine, or arginine in keeping with a preference of SA for homopolymers of these acids over other homopolypeptides. Residue spacing also seems important. High affinity is associated with but not imparted by genetic similarity. Profiles from β‐sheet conformations simplify identification of analogous segments.
Influence of concentration and temperature on the flow behavior of oil‐in‐water emulsions stabilized by sucrose palmitate
Authors: Partal P. , Guerrero A. , Berjano M. , Gallegos C.
Published: May 2007

To study the influence that concentration and temperature exert on the viscous behavior of emulsions stabilized by a sucrose ester (SE) of high hydrophilic‐lipophilic balance (HLB), flow curves and droplet size distributions were determined. Flow curves of presheared emulsions always exhibited a shear‐thinning behavior at intermediate shear rates, a tendency to a limiting viscosity at high shear rates, and a metastable region at low rates. This behavior can be fitted to a Carreau model. Both SE and oil concentrations increase emulsion viscosity as a result of a more structured system with a lower droplet size and polydispersity. An increase in temperature usually leads to a decrease in emulsion viscosity. However, at high oil concentration, coalescence and phase separation take place at low temperature. On the other hand, at high temperature, droplet bursting due to shear forces, leading to an increase in viscosity, may result. Despite the strong structural breakdown caused by steady shear, master flow curves may be obtained by using superposition methods.
Thermal and structural properties of sn‐1,3‐dipalmitoyl‐2‐oleoylglycerol and sn‐1,3‐dioleoyl‐2‐palmitoylglycerol binary mixtures examined with synchrotron radiation X‐ray diffraction
Authors: Minato A. , Ueno S. , Yano J. , Smith K. , Seto H. , Amemiya Y. , Sato K.
Published: May 2007

Thermodynamic and polymorphic behavior of POP (sn‐1,3‐dipalmitoyl‐2‐oleoylglycerol) and OPO (sn‐1,3‐dioleoyl‐2‐palmitoylglycerol) binary mixtures was examined using differential scanning calorimetry and conventional and synchrotron radiation X‐ray diffraction. A molecular compound, βC, was formed at the 1:1 (w/w) concentration ratio of POP and OPO, giving rise to two monotectic phases of POP/compound and compound/OPO in juxtaposition. βC has a long‐spacing value of 4.2 nm with a double chainlength structure and the melting point of 31.9°C. A structural model of the POP‐OPO compound is proposed, involving the separation of palmitoyl and oleoyl chain leaflets in the double chainlength structure. In the polymorphic occurrence of the POP‐OPO mixtures, the POP fraction transformed from α to β′ with no passage through γ, then transformed to β. The presence of OPO in POP promoted the β′‐β transformation of POP during the melt‐mediated crystallization.
Survey of the fatty acid composition of peanut (arachis hypogaea) germplasm and characterization of their epoxy and eicosenoic acids
Authors: Hammond Earl G. , Duvick Daniel , Wang Tong , Dodo Hortense , Pittman R. N.
Published: May 2007

Peanut (Arachis hypogaea) plant introductions (732) were analyzed for fatty acid composition. Palmitate varied from 8.2 to 15.1%, stearate 1.1 to 7.2%, oleate 31.5 to 60.2%, linoleate 19.9 to 45.4%, arachidate 0.8 to 3.2%, eicosenoate 0.6 to 2.6%, behenate 1.8 to 5.4%, and lignocerate 0.5 to 2.5%. The eicosenoate was shown to be cis‐11‐eicosenoate. In addition, epoxy fatty acids were found in many plant introductions in percentages ranging as high as 2.5%. These were tentatively identified as chiefly 9,10‐epoxy stearate and coronarate with smaller amounts of vernolate. The percentage of palmitate was shown to be correlated positively with linoleate and negatively with oleate, eicosenoate, and lignocerate. Stearate was highly correlated with arachidate and negatively with eicosenoate and lignocerate. Oleate and linoleate, the two major fatty acids, were negatively correlated. Arachidate was negatively correlated with eicosenoate, and eicosenoate was positively correlated with lignocerate. Behenate and lignocerate were positively correlated. Epoxy esters were positively correlated with palmitate and negatively with oleate. Segregation of the plant introductions by axis flower, growth habit, and pod types showed significant differences that reflected the same fatty acid groupings revealed by the correlations.
The removal of pesticide residues from wool wax by solvent extraction
Authors: Jones F. William
Published: May 2007

A range of suitable solvents for the removal of dieldrin and diazinon residues from wool wax by solvent‐solvent extraction was evaluated. Extraction of a 10% solution of wool wax in hexane with N,N‐dimethylformamide was shown to be the most effective. These solvents were then used to meanure the partition coefficients of 36 organochlorine, organophosphorus, and pyrethroid pesticides that have the potential to be found in wool wax. Repeated batchwise extraction of a raw wool wax, which had been spiked to produce typical pesticide residue levels, yielded a high‐quality wax in which all pesticide residues had been reduced to below detectable levels. The treated wool wax was lighter in color with a lower acid number and a lower free alcohol content and had excellent water absorption characteristics. All detergents associated with the recovery of wool wax from an aqueous scour were also removed.
Removal of pesticides from wool wax by continuous countercurrent dual‐solvent extraction
Authors: Jones F. William
Published: May 2007

Pesticide residues in raw wool wax were removed to below detectable levels by continuous countercurrent extraction with hexane and N,N‐dimethylformamide (DMF) in a pilot‐scale mixer‐settler contactor. The disengagement of the phases in the settling compartments was promoted by the addition of a small amount of formic acid (3% vol/vol) to the DMF‐rich feed. Empirical equations were developed to predict the effect on the pesticide partition coefficients of the wool wax concentration, the presence of small amounts of water, ethanol, and/or isopropanol in the solvents, and the temperature used in the contactor. These empirical equations were included in equations that describe the concentration of the pesticides in the different stages of the contactor and were used to develop a spreadsheet model that accurately predicted the mixer‐settler’s performance. The raffinate wool wax produced by this process after conventional neutralization met all BP and USP specifications for pharmaceutical lanolin.
Microfiltration and stabilization of egg yolk phospholipid emulsions by a microporous glass membrane
Authors: Mine Yoshinori , Shimizu Masaaki , Nakashima Tadao
Published: May 2007

A microporous glass membrane with a narrow‐range pore size was applied for the microfiltration of egg yolk phospholipid emulsions. The oil‐in‐water and water‐in‐oil emulsions were successfully filtered using the membrane without any coalescence of oil droplets or the breakdown of the emulsions. The filtrated oil‐in‐water emulsion was stable for at least 6 wk when stored at 5°C. The results obtained suggest that the technique would be valuable for the precise filtration of emulsions for food uses as well as intravenous fat and/or drug carrier emulsions, and offer the stabilization of the emulsions.
Evolution of phenolic compounds in virgin olive oil during storage
Authors: Cinquanta Luciano , Esti Marco , Notte Ennio La
Published: May 2007

Phenolic compounds are of fundamental importance to the shelf life of virgin olive oils because of their antioxidative properties. In this paper, the evolution of simple and complex olive oil phenols during 18 mon of storage is studied by high‐performance liquid chromatography (HPLC) analysis. The olive oils under examination were from various olive cultivars, harvested in two sectors in the same region at different stages of ripeness. The findings indicate that it is not the variety but rather the ripeness of the olives and the soil and climate that influence the phenol composition of virgin olive oil. In addition, a positive correlation was found between the age of the oils and the tyrosol to total phenols ratio. Lastly, gas chromatography‐mass spectrometry analysis confirmed that the unidentified peaks detected by HPLC were of a phenolic nature.
An infrared spectroscopy study of lipid adsorption from hexane onto an acid‐activated bleaching clay
Authors: Adhikari C. , Proctor A. , Blyholder G. D.
Published: May 2007

The mode of adsorption of oleic acid (OA) (0.05 M), triglyceride (TG) (0.05 M) and phosphatidylcholine (PC) (0.5 mM) from hexane solution onto 0.5 g of an acid‐activated bleaching clay was investigated using diffuse reflectance Fourier transform infrared spectroscopy. OA was mostly weakly adsorbed by bound water, with some OA adsorbed to silanol sites through carboxyl carbonyl groups. TG was hydrogen‐ bonded to surface silanol groups through ester carbonyl groups. The CH2 stretches indicated that TG was oriented perpendicular or at an angle to the surface. PC phosphate groups were bound by the surface moisture with little interaction with silanol groups. The adsorption mechanism of these lipids contrasts with the adsorption of carotenoid and chlorophyll under the same conditions. These pigments are bound by chemisorption, with catalytic modification often occurring before adsorption.
Separation and identification of triximenynin from Santalum spicatum R. Br.
Authors: Liu Yandi D. , Longmore Robert B. , Boddy Michael R. , Fox John E. D.
Published: May 2007

Seed lipids of Western Australian sandalwood (Santalum spicatum) were separated using preparative thin‐layer chromatography. The oil contains about 49% oleic acid and about 40% ximenynic acid. The individual triacylglycerol bands were characterized by high‐performance liquid chromatography and gas chromatography. The oil consisted of three major triglycerides: triximenynoyl‐glycerol (triximenynin), an oleoyl‐diximenynoyl‐glycerol, and a dioleoylximenynoyl‐glycerol, as demonstrated by gas chromatography with mass selective detection.
The analysis of sterol degradation products to detect vegetable fats in chocolate
Authors: Crews C. , Calvet‐Sarrett R. , Brereton P.
Published: May 2007

A method for the detection of hydrocarbon sterol degradation products (sterenes) has been adapted for the analysis of noncocoa butter vegetable fats in chocolate. The method involves solvent extraction of the fat separation of the sterene fraction, and analysis of individual sterenes with mass spectrometric detection. The sterene composition of refined noncocoa vegetable fats was determined in samples of cocoa butter, and retail chocolates. The presence of known sterenes was confirmed for all of the refined vegetable fats and for a single sample of cocoa butter, the processing history of which was not known. Detection of vegetable fat added to chocolate at the 5% level was demonstrated. Sterenes were detected only in chocolates labeled as containing vegetable fats. This technique has potential use as a screening method for the detection, but not quantification, of refined vegetable fat in chocolate.
Characterization of edible oils and lard by fourier transform infrared spectroscopy. Relationships between composition and frequency of concrete bands in the fingerprint region
Authors: Guillén M. D. , Cabo N.
Published: May 2007

Fourteen samples of edible oils and lard have been studied by means of Fourier transform infrared spectroscopy. The spectra were recorded from a film of pure oil or lard between two discs of KBr. The bands of the spectra were assigned to different functional group vibrations. The frequencies of some bands have constant values, independent of the nature of the sample. However, frequencies of other bands, some of them in the fingerprint region, depend greatly on the sample composition. Equations obtained from frequency of these bands and composition data are valuable to predict the proportions of saturated, monounsaturated and polyunsaturated acyl groups in oils and lard.
Characterization of α‐ and γ‐linolenic acid oils by reversed‐phase high‐performance liquid chromatography‐atmospheric pressure chemical ionization mass spectrometry
Authors: Laakso Päivi
Published: May 2007

Triacylglycerols of oils rich in α‐ and/or γ‐linolenic acids were analyzed by reversed‐phase high‐performance liquid chromatography (HPLC) coupled with atmospheric pressure chemical ionization mass spectrometry [(APCI)MS]. The (APCI)MS spectra of most triacylglycerols exhibited [M + H]+ and [M ‐ RCOO]+ ions, which defined the molecular weight and the molecular association of fatty acyl residues, respectively. Reversed‐phase HPLC resulted in, at least, partial separation of triacylglycerols containing α‐ and/or γ‐linolenic acid moieties. Molecules containing α‐linolenic acid residues exhibited a relatively weaker retention by the stationary phase than the corresponding molecules containing γ‐linolenic acid residues. Good separation of triacylglycerols of cloudberry seed oil, evening primrose oil, borage oil, and black‐currant seed oil was achieved. The molecular species identification of separated components was based on the (APCI)MS data as well as on the elution properties of triacylglycerols on reversed‐phase HPLC. This study demonstrated the efficiency of HPLC‐(APCI)MS in determining the molecular species compositions of triacylglycerols in complex natural mixtures. Good quality mass spectra could be extracted even from minor chromatographic peaks representing 0.2% or less of the total triacylglycerols.
Antioxidant activity of green teas in different lipid systems
Authors: Frankel Edwin N. , Huang Shu‐Wen , Aeschbach Robert
Published: May 2007

Different commercial green teas from Japan, China, and India, were compared in different lipid systems. Green teas were active antioxidants in bulk corn oil oxidized at 50°C but were prooxidant in the corresponding oil‐in‐water emulsions. Green teas also were active antioxidants in soybean lecithin liposomes oxidized at 37°C in the presence of cupric acetate as catalyst. At 50°C, however, three of the samples of green tea were active antioxidants in the absence of copper catalyst, and two samples showed prooxidant activity in the presence of copper catalyst. The marked variation in activity among green tea samples may be due partly to differences in their relative partition between phases in different lipid systems. The improved antioxidant activity observed for green teas in lecithin liposomes compared to corn oil emulsions can be explained by the greater affinity of the polar tea catechin gallates for the polar surface of the lecithin bilayers, thus affording better protection against oxidation. Liposomes may thus be appropriate lipid models to evaluate antioxidants for foods containing phospholipids.
Frying quality and oxidative stability of high‐oleic corn oils
Authors: Warner K. , Knowlton S.
Published: May 2007

To determine the frying stability of corn oils that are genetically modified to contain 65% oleic acid, high‐oleic corn oil was evaluated in room odor tests and by total polar compound analysis. Flavor characteristics of french‐fried potatoes, prepared in the oil, were also evaluated by trained analytical sensory panelists. In comparison to normal corn oil, hydrogenated corn oil and high‐oleic (80 and 90%) sunflower oils, high‐oleic corn oil had significantly (P<0.05) lower total polar compound levels after 20 h of oil heating and frying at 190°C than the other oils. Fried‐food flavor intensity was significantly higher in the normal corn oil during the early portion of the frying schedule than in any of the high‐oleic or hydrogenated oils; however, after 17.5 h of frying, the potatoes fried in normal corn oil had the lowest intensity of fried‐food flavor. Corn oil also had the highest intensities of off‐odors, including acrid and burnt, in room odor tests. High‐oleic corn oil also was evaluated as a salad oil for flavor characteristics and oxidative stability. Results showed that dry‐milled high‐oleic corn oil had good initial flavor quality and was significantly (P<0.05) more stable than dry‐milled normal corn oil after oven storage tests at 60°C, as evaluated by flavor scores and peroxide values. Although the high‐oleic corn oil had significantly (P<0.05) better flavor and oxidative stability than corn oil after aging at 60°C, even more pronounced effects were found in high‐temperature frying tests, suggesting the advantages of high‐oleic corn oil compared to normal or hydrogenated corn oils.
A kinetic study on the autoxidation of sunflowerseed oil
Authors: Topallar Hüseyin , Bayrak Yüksel , Işcan Mehmet
Published: May 2007

Unhydrogenated and hydrogenated sunflowerseed oils were exposed to the autoxidation process by sunlight under atmospheric conditions. Experiments were carried out in equal‐sized glass, PET (polyethylene terephthalate) polymer, and metal (covered by tin) containers. The reaction time was 30 d, and the reaction course was observed by determining weight changes and peroxide values (PV) of the oil samples at the same time within 2‐d intervals. The logarithm of the PV was plotted against time, and straight lines were obtained from the 4th or 6th d. The autoxidation reaction constants were obtained for each oil in each container. When comparing the reaction constants, the unhydrogenated oils autoxidize easily, and the autoxidation reaction occurs faster in sunlight in glass than in the PET polymer container and much faster than in the darkness of the metal container.
Oxidative stability and nuclear magnetic resonance analyses of linoleic acid encapsulated in cyclodextrins
Authors: Reichenbach Wendy A. , Min David B.
Published: May 2007

The effects of α‐ and β‐cyclodextrin (CD) on the oxidative stability of linoleic acid (LA) at 35°C were studied by measuring headspace oxygen depletion in airtight 35‐mL serum bottles. LA was encapsulated in α‐CD or β‐CD in an aqueous solution during homogenization at 8000 rpm for 1 min and then dried under vacuum for 60 h at room temperature. Headspace oxygen was measured by thermal conductivity gas chromatography. The rate of oxygen depletion for the control, which contained LA only, was 93.8 µmole/L·h. The rates of oxygen depletion for LA, encapsulated at a 1:1 mole ratio (mole CD/moles LA) in α‐CD and β‐CD, were 13.8 and 111 µmoles/L·h, respectively. When LA was encapsulated in α‐CD and β‐CD at a 2:1 mole ratio (moles CD/moles LA), the rates of oxygen depletion were 0.573 and 53.9 µmoles/L·h, respectively. Although α‐CD protected LA from reaction with oxygen at both ratios, the rate of oxygen depletion by LA encapsulated in β‐CD at a 1:1 mole ratio was not statistically different from the control. β‐CD protected LA from reaction with oxygen at a 2:1 mole ratio. 1H nuclear magnetic resonance spectra of the complexes formed from 1:1 mole ratios of LA and CD indicated that LA was encapsulated in α‐CD or β‐CD.
13C nuclear magnetic resonance spectral confirmation of Δ6‐and Δ7‐trans‐18:1 fatty acid methyl ester positional isomers
Authors: Mazzola E. P. , McMahon J. B. , McDonald R. E. , Yurawecz M. P. , Sehat N. , Mossoba M. M.
Published: May 2007

Trans octadecenoic acid methyl ester isomers were obtained from a partially hydrognated soybean oil and isolated by silver‐ion high‐performance liquid chromatography. Recently, the double‐bond positions for nine individual trans octadecenoic acid positional isomers (Δ8 through Δ16) were confirmed by gas chromatography‐electron ionization mass spectrometry after derivatization to 2‐alkenyl‐4,4‐dimethyloxazoline. In this communication, the presence of two additional trans‐18:1 fatty acid methyl ester positional isomers (Δ6 and Δ7) in the same mixture is confirmed by 13C nuclear magnetic resonance spectroscopy. The identity of the Δ5‐trans‐18:1 fatty acid methyl ester positional isomer is inferred.
Practical limitations in determining vegetable oil acid values by a novel pH‐metric method
Authors: Berezin O. Yu , Tur’yan Ya I. , Kogan L. , Kuselman I. , Shenhar A.
Published: May 2007

A novel pH‐metric method is described for the determination of acid values (AV) in vegetable oils without titration. The method is based on a reagent containing triethanolamine, isopropanol, and water to which an oil sample is added before measuring pH. Oil samples with AV in the range 0.006–0.107 mg KOH/g oil were prepared from commercial soybean oil by treatment with a strong‐base anion exchanger in OH− form and addition of oleic acid. Compared to the standard titrimetric method, significantly greater AV were obtained at less then 0.02 mg KOH/g oil. This was due to the influence of triethanolamine hydrolysis on the acid‐base equilibrium in the mixture “oil‐reagent.” Thus, the AV 0.02 mg KOH/g oil is accepted as the limit of quantitation. Because refined oils usually have AV of 0.05 mg KOH/g oil or more, this method should be suitable for practical oil analyses.
Explorative spectrometric evaluations of frying oil deterioration
Authors: Engelsen Søren Balling
Published: May 2007

The potential of spectroscopy as a reliable and fast method for determining the deterioration of frying oils was investigated. Daily oil samples were collected from a commercial Chinese spring roll plant. The plant was operated one shift, 5 d a week, then cleaned and restarted with fresh oil every 4 wk. Each oil sample was analyzed by 11 chemical/physical methods and fluorescence, near infrared/visible (NIR/VIS), Fourier transform infrared (FT‐IR) and FT‐Raman spectroscopic procedures. The results were evaluated and compared by principal‐component analysis and partial least squares regression. Most chemical/physical and all spectroscopic methods detected the deterioration during the first half of the frying cycle. Thereafter, an equilibrium occurred between deterioration processes and replenishment with new oil. At equilibrium, the correlation between frying time and the various methods was nonlinear. FT‐IR with the attenuated total reflectance sampling technique was the most direct and accurate method of monitoring gross changes in the frying oil. Fluorescence was the technique that provided the best models for anisidine value, oligomers, iodine value, and vitamin E. NIR/VIS spectroscopy proved to be a good general‐purpose technique. The study demonstrated that spectroscopic sensors have the potential to replace titration and chromatographic procedures, and can be used in combination with chemometric data analysis to optimize deep‐frying operations.
Thermoxidation of substrate models and their behavior during hydrolysis by porcine pancreatic lipase
Authors: Arroyo Ruth , Sánchez‐Muniz Francisco J. , Cuesta Carmen , Sinisterra José V. , Sánchez‐Montero José M.
Published: May 2007

The behavior of thermoxidized triacylglycerols during hydrolysis catalyzed by porcine pancreatic lipase was evaluated using nonpolar triacylglycerols isolated from palm olein (NPTPO), triolein, and sn‐1,3 diolein substrates. Substrates were thermoxidized at 180°C for 1 to 4 h. Owing to formation of polymers and dimers of triacylglycerols, the molecular weight of the thermoxidized substrates increased. After 1 h heating, the concentration of polymers and dimers was similar for the sn‐1‐3 diolein and triolein samples but higher in NPTPO samples. Conjugated double bonds were formed in all samples, and α,β‐unsaturated carbonyl compounds developed through allylic oxidations. These caused increased ultraviolet absorbance at 232 nm. The hydrolysis of heated and unheated samples by the lipase can be described by a Michaelian equation. The enzyme showed a higher apparent Vmax and KMwith heated sn‐1,3 diolein and triolein than with their unheated counterparts. This was due to the generation of polar compounds which acted as emulsifiers and which favored the formation of an oil/water microemulsion. This behavior was not observed in NPTPO, where heating decreased the apparent Vmax and KMover the first 2 h. Later, a tendency to increase these values was observed. The results could be explained by a balance between concentration of surfactants and of natural emulsifiers in the thermoxidized samples.
Supercritical fluid extraction of lipids from deep‐fried food products
Authors: Devineni N. , Mallikarjunan P. , Chinnan M. S. , Phillips R. D.
Published: May 2007

A supercritical fluid extraction (SFE) method is described for extracting lipids from fried‐food samples. Response surface analysis was used to study the effects of variables, including pressure, temperature, flow rate, and modifier (methanol) on lipid extraction by SFE. The analysis of variance for the response variables indicated that the models developed were satisfactory with coefficients of determination of 0.95 and 0.92 for chicken nuggets and potato fries, respectively. The models predicted that increasing the pressure increased the percentage lipid extracted for both chicken nuggets and potato fries. In addition, the pressure by temperature interactions were significant for chicken nuggets and potato fries. Slight differences in fatty acid composition were observed between SFE and the Goldfisch method. The SF extracts contained traces of C12:0, C20:0, and C24:0 in chicken nuggets and C14:1, C18:3, C22:0, and C23:0 in potato fries, respectively, which are not found in the Goldfisch extracts. The optimal conditions for extraction are: 53 MPa, 150°C, 4 mL/min, and 10% modifier for chicken nuggets and 53 MPa, 150°C, 3 mL/min, and 0% modifier for potato fries. To duplicate the results of exhaustive Goldfisch extraction with petroleum ether, SFE conditions of 44 MPa, 80°C, 3 mL/min, and 0% modifier were used to produce similar results for both chicken nuggets and potato fries.
Anchovy oil thermal polymerization kinetics
Authors: Guner F. Seniha
Published: May 2007

The thermal polymerization reaction kinetics of anchovy oil was investigated with and without catalyst. In order to make a comparison, linseed oil was included in the study. Reactions were carried out 260, 270, and 280°C, and a kinetic model was determined for each case. The reactions for linseed oil with and without catalyst at all temperatures followed the first‐order kinetics. In the case of anchovy oil, the best‐fitted straight line is obtained by plotting viscosity values against time, and the reaction proceeds in two stages at 280°C without catalyst. The use of catalyst lowered the temperature to 270°C for the appearance of two different rates. Additionally, some mathematical equations were derived between iodine value, refractive index, viscosity, and reaction time.
Antioxidant activity and active sites of phospholipids as antioxidants
Authors: Saito Hiroaki , Ishihara Kenji
Published: May 2007

Various compounds, representative of the major functional groups in phospholipids, phosphatidylethanolamine and phosphatidylcholine, were tested for antioxidant activity (AA) in a sardine oil system to determine the relationship between molecular structure and the AA of these compounds. AA was found to be attributable not only to the side‐chain amino groups but also to the cooperative effect of the hydroxy group in the side chain. Choline and ethanolamine, side‐chain moieties of phospholipids, strongly inhibited increases in peroxide values in a sardine oil mixture during storage; however, phosphatidic acid derivatives and glycerol, also major functional groups of phospholipids, did not show AA. Choline and ethanolamine have hydroxy amines as functional groups; therefore, several model reagents that contained amines and alcohols were assayed to compare the activity of the amino group with that of the hydroxy group. All basic alkylamines examined had AA as decomposers of hydroperoxides. The intramolecular hydroxy group in these amines complemented AA of the amino group. Only intramolecular alcohol, which can donate a proton, showed strong synergistic activity with AAof the basic amines, while protected groups, such as methyl ether and phosphate ester, did not show this effect.
Blending process optimization into special fat formulation by neural networks
Authors: Block J. M. , Barrera‐Arellano D. , Figueiredo M. F. , Gomide F. A. C.
Published: May 2007

Computer programs are used to manage, supervise, and operate production lines of oil, margarine, butter, and mayonnaise in the fats and oils industry. Automation allows for lower‐cost and better‐quality products. The present paper shows a multilayer perceptron‐type, second‐generation neural network that was built based on a desirable product solid profile and was designed to formulate fats from three ingredients (one refined oil and two hydrogenated soybean‐based stocks). This network operates with three sequential decision levels, technical, availability and costs, to furnish up to nine possible formulations for the desired product. Upgrading verification was accomplished by soliciting to the formulation network all 63 products used in the upgrading (the answers were evaluated by a panel of experts and considered satisfactory) and 17 commercial products. It was possible to formulate more than 50% of the products in the network with only the three bases available. The results demonstrate the possibility of using neural networks as an alternative to the automation process for the special fats formulation process.
Enzymatic hydrolysis in conjunction with conventional pretreatments to soybean for enhanced oil availability and recovery
Authors: Shankar Devesh , Agrawal Y. C. , Sarkar B. C. , Singh B. P. N.
Published: May 2007

Enzymatic hydrolysis of oilseeds prior to extraction has recently been shown to enhance the extractable oil in oilseeds and its recovery. This paper presents the results of optimizing the combination of enzymatic hydrolysis with one or more conventional pretreatments to soybean and of optimizing the hydrolysis parameters as they determine the mechanical extractability as well as the solvent extractability. Enzymatic hydrolysis in conjunction with flaking (dehulling inherent) and steam conditioning offered statistically the best pretreament combination for soybean at a 5% level of significance, enhancing the extractable oil content by about 4.8% of moisture‐free sample. The optimal hydrolysis parameter values based on response surface analysis were: hydrolysis moisture content 23.22% wet basis, enzyme concentration 11.99 vol/wt, and incubation period 13.79 h. Over 99% of the total extractable oil released after hydrolysis was extractable within 16 h on a Soxhlet extractor.
Soy hull carbon as adsorbents of crude soy oil components: Effect of carbonization time
Authors: Proctor A. , Gnanasambandam Ravin
Published: May 2007

Studies were conducted to evaluate the performance of soy hull carbon adsorbents as affected by carbonization time. Carbonization was done by heating soy hulls to 400°C for up to 30 min. Increased carbonization time resulted in elevated surface pH and titratable alkalinity. The effectiveness of adsorbents in binding minor soy oil components was studied. Free fatty acids content was decreased 70% with adsorbents carbonized for 30 min. Peroxides were adsorbed, but increasing carbonization time did not alter absorption by carbons. A similar trend was observed with the adsorption of total phospholipids. The residual lutein content of crude soy oil was not affected by the adsorbents. X‐ray diffraction studies showed that carbonization at 400°C converted the polysaccharide‐based structure of soy hull to an amorphous, highly disorganized, random structure. Increase in carbonization time resulted in broadening of the diffraction pattern between 5 and 25° 2ϑ. Infrared spectra of soy carbon samples revealed presence of asymmetric C‐H stretch, symmetric C‐H bends, and C=O groups. The intensities of these spectra decreased with time of carbonization.
Triacylglycerols responsible for the onset of nucleation during clouding of palm olein
Authors: Sulaiman Mohd Zaki , Sulaiman Nik Meriam , Kanagaratnam Sivaruby
Published: May 2007

This paper discusses the results of an investigation to identify triacylglycerols that induce clouding of refined bleached deodorized (RBD) palm olein, which occurred within 24 h after fractionation. The experiments were conducted in a jacketed glass vessel in which the liquid sample was cooled from 70 to 23°C at a predetermined rate. Clouding began at around 28.5°C. The presence of three different types of saturated triglycerides, namely tripalmitin, dipalmitoyl‐myristoylglycerol and dipalmitoyl‐stearoyl‐rac‐glycerol, is critical in the formation of nuclei and thus clouding of the RBD palm olein. This conclusion is based on the significant increase in the relative concentration of these components in the nuclei as compared to the mother oil.
Physical properties of liquid edible oils
Authors: Coupland John N. , McClements D. Julian
Published: May 2007

Literature values of density, viscosity, adiabatic expansion coefficient, thermal conductivity, specific heat (constant pressure), ultrasonic velocity, and ultrasonic attenuation coefficient are compiled for a range of food oils and water at 20°C, and a series of empirical equations are suggested to calculate the temperature dependency of these parameters. The importance of these data to the application of ultrasonic particle‐sizing instruments to food emulsions is discussed.
Differential scanning calorimetry of water buffalo and cow milk fat in mozzarella cheese
Authors: Tunick Michael H. , Malin Edyth L.
Published: May 2007

The thermal profiles of the fat in mozzarella cheeses made from cow milk (CM) and water buffalo milk (WBM) were obtained by differential scanning calorimetry (DSC). The DSC curves of mozzarella cheese made from WBM were distinguishable from those of CM. The curves resembled those of the corresponding milk fats and could be divided into low‐, medium‐, and high‐temperature melting regions. The valley in the curve between the low‐ and medium‐temperature melting regions was at 10.8°C in WBM cheese and below 10°C in CM cheese. In the WBM cheese, the area of the low‐melting region was larger than the area of the medium‐temperature melting region, but the two areas were equal in the CM cheeses. Mixtures of the two cheeses exhibited temperature and area values between those of the pure cheeses. Milk‐fat mixtures showed similar behavior. The contrasting DSC melting profiles provide a way of distinguishing between the two mozzarella cheese types and for detecting mixtures of the two fats in mozzarella cheese.
Odor and flavor contribution of 2‐pentyl pyridine to soy protein isolates
Authors: Boatright W. L. , Crum A. D.
Published: May 2007

Total lipid extracts from two commercial soy protein isolates (SPI) were subjected to analyses by gas chromatography/olfaction by using capillary columns with stationary phases of three different polarities. With Kovats indices to identify the location of the odorous compounds on chromatograms produced with the same lipid extracts by gas chromatography/mass spectroscopy, the corresponding mass spectra of clearly distinguishable odors were examined. Compounds, tentatively identified by their mass spectra, were confirmed by retention times (on all three stationary phases), odor intensity, and odor description when compared with standards. Major odorous compounds identified included 2‐methyl butyric acid methyl ester, hexanal, butyric acid, and 2‐pentyl pyridine. Subsequent sensory analyses demonstrated that the mean levels of 2‐pentyl pyridine found in two SPI (0.28 and 1.01 ppm), combined with its repulsive flavor profile (throat‐catching and grassy in water) and extremely low flavor threshold level (0.000012 ppm), make it a major contributor to the undesirable flavor of SPI. Its mean contents in SPI were 23,333 and 84,167 times greater, respectively, than its flavor threshold. The level of hexanal was 112 and 201 times, respectively, above its flavor threshold, and the level of 2‐pentyl furan in each SPI was 433 and 592 times, respectively, above its flavor threshold, which indicates that these two compounds make relatively minor contributions to the flavor of SPI.
Bishomopinolenic (7,11,14–20:3) acid in pinaceae seed oils
Authors: Wolff Robert L. , Christie William W. , Coakley David
Published: May 2007

Bishomopinolenic (7,11,14–20:3; BHP) acid has been identified in a sample of pine (Pinus contorta) seed oil by gas‐liquid chromatography‐mass spectrometry of its 4,4‐dimethyloxazoline and picolinyl ester derivatives. Neither 20:3n‐6 nor 18:3n‐6 acids could be detected. The distribution of BHP acid in the seed oils of four conifer families has been established. It only occurred in Pinaceae (Pinus, Abies, Cedrus, Tsuga, Pseudotsuga, Larix, and Picea; 72 species analyzed), where it could reach 0.7% of total fatty acids. It could not be detected in Taxaceae (Taxus baccata), Cupressaceae (Juniperus communis), or Taxodiaceae (Sciadopytis verticillata) seed lipids. It is assumed that BHP acid is the elongation product of pinolenic (5,9,12–18:3) acid, and that, at most, 3% of pinolenic acid is elongated to BHP acid. Consequently, the Δ5‐desaturation would not necessarily be a final step in the biosynthesis of unsaturated polymethylene‐interrupted fatty acids in Pinaceae seeds. Moreover, conifer seeds appear devoid of the Δ6‐desaturase.