bluuebunny/crossref_metadata_2025 huggingface dataset:
The speed of sound and isentropic bulk modulus of biodiesel at 21°C from atmospheric pressure to 35 MPa
Authors: Tat Mustafa E. , Van Gerpen Jon H. , Soylu Seref , Canakci Mustafa , Monyem Abdul , Wormley Samuel
Published: November 2006

Biodiesel, an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils and animal fats, can be used in existing diesel engines without modification. However, property changes associated with the differences in chemical structure between biodiesel and petroleumbased diesel fuel may change the engine's injection timing. These injection timing changes can change the exhaust emissions and performance from the optimized settings chosen by the engine manufacturer. This study presents the results of measurements of the speed of sound and the isentropic bulk modulus for methyl and ethyl esters of fatty acids from soybean oil and compares them with No. 1 and No. 2 diesel fuel. Data are presented at 21±1°C and for pressures from atmospheric to 34.74 MPa. The results indicate that the speed of sound and bulk modulus of the monoesters of soybean oil are higher than those for diesel fuel and these can cause changes in the fuel injection timing of diesel engines. Linear equations were used to fit the data as a function of pressure, and the correlation constants are given.
Characterization of semisolid fats and edible oils by Fourier transform infrared photoacoustic spectroscopy
Authors: Yang Hong , Irudayaraj Joseph
Published: November 2006

The potential of Fourier transform infrared photoacoustic spectroscopy (FTIR‐PAS) for the analysis of semisolid fat and edible oil was demonstrated with butter, soybean oil, and lard as representative materials. Results of Fourier transform infrared attenuated total reflectance (FTIR‐ATR) spectroscopy analysis was compared with FTIR‐PAS results. The PAS technique is simple and requires no sample preparation unlike ATR. Optimal PAS instrumental parameters for obtaining quality spectra are a scanning speed of 5 kHz, number of scans of 256 scans/sample, and a resolution of 4 cm−1. The PAS spectra of soybean oil and lard are similar because they have similar functional groups. Results for soybean oil compare well with those available in the literature. The ATR spectra of butter were better than those from its PAS counterpart. Functional groups corresponding to vibration mode and intensity are provided for soybean oil and lard.
Crystallization kinetics of palm stearin in blends with sesame seed oil
Authors: Toro‐Vazquez J. F. , Briceño‐Montelongo M. , Dibildox‐Alvarado E. , Charó‐Alonso M. , Reyes‐Hernández J.
Published: November 2006

This study investigates the crystallization kinetics of palm stearin (PS), a palm oil fraction, in blends with sesame seed oil. The results indicate that the crystallization behavior of PS in sesame oil is mainly associated with the crystallization of tripalmitin. Therefore, crystallization of blends of 26, 42, 60, and 80% (wt/vol) PS in sesame oil was described by equations developed for simpler systems (e.g., Fisher and Turnbull equation). The isothermal crystallization, melting profile, and fitting of the kinetics of nucleation to the Fisher and Turnbull equation showed that the 26, 42, and 60% PS/sesame oil blends crystallized mainly in the β1′ polymorph state. In contrast, the 80% blend crystallized in two different polymorph states (i.e., β1′ at T≼307.6 K and β1 at T≽308.2 K). The data indicated that, in spite of the higher concentration of PS in the 80% PS/sesame oil system, crystallization in the β1 state required more free energy for nucleation (δGc) than β1′ crystallization in the 26, 42, and 60% PS/sesame oil. At the low cooling rate used (1 K/min) it was observed that, for a particular PS blend, the higher the effective supercooling the higher the viscosity of the oil phase and the smaller the induction time of crystallization (Ti). Additionally, the β1′ crystals from PS, developed at the highest effective supercooling investigated, were smaller than the β1 crystals obtained at lower effective supercooling.
Hydrogenation of soybean oil triglycerides: Effect of pressure on selectivity
Authors: List G. R. , Neff W. E. , Holliday R. L. , King J. W. , Holser R.
Published: November 2006

Soybean oil contains five triglycerides that account for over 70% of the total. These include LLL, LLO, LLP, LOO, and LOP and their isomers (where L=linoleic, O=oleic, P=palmitic). High‐performance liquid chromatographic analysis of samples taken during a typical hydrogenation run in which the iodine value (IV) was reduced from 130 to about 70 showed that the linoleate‐containing triglycerides were reduced at a much faster rate than the linolenate‐containing triglycerides. Results clearly show that hydrogenation proceeds through definite pathways rather than by random saturation of fatty acids within the triglyceride molecules. Pressure has a significant effect on the course of hydrogenation. At higher pressures (500 psi), the reaction is truly nonselective, since di‐and trisaturated glycerides are formed at about 70 IV, whereas at 50 psi, the reaction becomes selective. At higher pressures, fat functionality and solid fat result primarily from di‐and trisaturated fatt acid triglycerides as well as trans fatty acid triglycerides. At lower pressures, functionality results from trans acid triglyceride formation. Although the reactivity of linoleate containing triglycerides followed the pattern 6 double bonds>5 double bonds>4 double bonds, other factors may be important. For example, LLP is reactive and undergoes hydrogenation, while LLS remains unchanged. Triolein, which constitutes less than 3% of the total triglyceride in natural soybean oil, is a significant product of hydrogenation, which suggests that LLL and LLO are reduced directly while adsorbed on the catalyst surface.
Simple, high‐efficiency synthesis of fatty acid methyl esters from soapstock
Authors: Haas Michael J. , Bloomer Scott , Scott Karen
Published: November 2006

We report a simple method that efficiently esterifies the fatty acids in soapstock, an inexpensive, lipid‐rich by‐product of edible oil production. The process involves (i) alkaline hydrolysis of all lipid‐linked fatty acid ester bonds and (ii) acid‐catalyzed esterification of the resulting fatty acid sodium salts. Step (i) completely saponified all glycerides and phosphoglycerides in the soapstock. Following water removal, the resulting free fatty acid sodium salts were rapidly and quantitatively converted to fatty acid methyl esters (FAME) by incubation with methanol and sulfuric acid at 35°C and ambient pressure. Minimum molar reactant ratios for full esterification were fatty acids/methanol/sulfuric acid of 1∶30∶5. The esterification reaction was substantially complete within 10 min and was not inhibited by residual water contents up to ca. 10% in the saponified soapstock. The product FAME contained >99% fatty acid esters, 0% triglycerides, <0.05% diglycerides, <0.1% monoglycerides, and <0.8% free fatty acids. Free fatty acid levels were further reduced by washing with dilute sodium hydroxide. Free and total glycerol were <0.01 and <0.015%, respectively. The water content was <0.04%. These values meet the current specifications for biodiesel, a renewable substitute for petroleum‐derived diesel fuel. The identities and proportions of fatty acid esters in the FAME reflected the fatty acid content of soybean lipids. Solids formed during the reaction contained 69.1% ash and 0.8% protein. Their sodium content indicated that sodium sulfate was the prime inorganic component. Carbohydrate was the predominant organic constituent of the solid.
Partially hydrolyzed rapeseed protein isolates with improved functional properties
Authors: Vioque Javier , Sánchez‐Vioque Raul , Clemente Alfonso , Pedroche Josto , Millán Francisco
Published: November 2006

Limited rapeseed protein hydrolysates ranging from 3.1 to 7.7% hydrolysis were produced from isoelectric‐precipitated protein isolate. Water absorption, oil absorption, whippability, foam capacity and stability, emulsifying activity, and emulsion stability of the hydrolysates were determined. All protein hydrolysates showed better functional properties than the original protein isolate. Foam and emulsion stability decreased as the degree of hydrolysis increased. The hydrolysate with the lowest degree of hydrolysis showed the best functional properties. These improved functional properties make rapeseed protein hydrolysates a useful product to be used in foods such as breads, cakes, ice creams, meat products, desserts, and salad dressings.
Analysis of triacylglyceride hydroperoxides in vegetable oils by nonaqueous reversed‐phase high‐performance liquid chromatography with ultraviolet detection
Authors: Bauer‐Plank Christina , Steenhorst‐Slikkerveer Lisette
Published: November 2006

Triacylglyceride hydroperoxides (HPO‐TAG), the primary autoxidation products of triacylglycerides (TAG), have been analyzed in polyunsaturated vegetable oils by means of nonaqueous reversed‐phase high‐performance liquid chromatography (HPLC) with ultraviolet detection. Using a retention time model based on equivalent carbon numbers, mono‐ and bishydroperoxy TAG and hydroxy TAG could be identified. The correlation between the peroxide value (POV) determined by iodometric titration and quantitative HPLC results for HPO‐TAG was established for sunflower oil samples with POV between 0.5 and 50 meq/kg. The recovery of HPO‐TAG in the HPLC procedure was found to be close to 100% in the POV range of 4 to 71 meq/kg. Absolute quantitative results for HPO‐TAG in sunflower oil samples could not be obtained accurately, as molar extinction coefficients of HPO‐TAG occurring in natural oils deviate from those of available HPO‐TAG reference compounds.
Monitoring a progressing transesterification reaction by fiber‐optic near infrared spectroscopy with correlation to 1H nuclear magnetic resonance spectroscopy
Authors: Knothe Gerhard
Published: November 2006

Biodiesel is a promising alternative diesel fuel obtained from vegetable oils, animal fats, or waste oils by transesterifying the oil or fat with an alcohol such as methanol. In an extension of previous work, fiber‐optic near infrared spectroscopy was used to quantitatively monitor the transesterification reaction (6‐L scale) of a vegetable oil (soybean oil) to methyl soyate. The results were correlated with 1H nuclear magnetic resonance spectroscopy. The method described here can be applied to the transesterification of other vegetable oils.
Regioselective analysis of the fatty acid composition of triacylglycerols with conventional high‐performance liquid chromatography
Authors: Arcos Jose A. , Garcia Hugo S. , Hill Charles G.
Published: November 2006

A new method for regioselective analysis of triacyglycerols via conventional high‐performance liquid chromatography (HPLC) has been developed. The method is simple and avoids the time‐consuming purification processes normally characteristics of regioselective analyses. The procedure utilizes an sn‐1,3‐specific lipase from Rhizopus arrhizus to deacylate the fatty acid residues located at the sn‐1 and sn‐3 positions of triacylglycerols. The fatty acid residues esterified at the sn‐2 position are determined by subtraction of the results of the sn‐1,3 analysis from an overall composition analysis based on complete saponification of the original sample. The fatty acid mixtures are converted to p‐bromophenacyl esters and analyzed using conventional HPLC techniques. The analytical procedure has been verified using a standard structured triacylglycerol. The analytical results for three edible vegetable oils are compared with those obtained via the method proposed by P.J. Williams and co‐workers.
Lipase‐catalyzed synthesis of ferulate esters
Authors: Compton David L. , Laszlo Joseph A. , Berhow Mark A.
Published: November 2006

Four commercially available esterases were screened for their ability to esterify ferulic acid (4‐hydroxy‐3‐methoxy cinnamate). Novozym® 435 was found to be the only one of those screened to convert ferulic acid to ethyl and octyl ferulate at 20 and 14% yields, respectively. The highest percentage conversion was obtained using a 1∶1 mole ratio of alcohol to ferulic acid in stirred batch reactions in anhydrous 2‐methyl‐2‐propanol at 60°C using one equivalent (wt/wt based on ferulic acid) of Novozym 435. Increased water content and a higher alcohol/ethyl ferulate ratio had adverse effects on the lipase‐catalyzed esterification. The Novozym 435 activity was tested in less polar solvents (anhydrous toluene and hexane) by monitoring the alcoholysis of ethyl ferulate with 1‐octanol, which resulted in a 50% yield of octyl ferulate. The alcoholysis was improved to 83% by applying a 16 mm Hg vacuum for 5 min every 24 h to remove the ethanol co‐product. The optimal alcoholysis parameters were applied to the alcoholysis of ethyl ferulate with monoolein and the transesterification with triolein. The transesterification of ethyl ferulate with triolein in anhydrous toluene produced a combined 44% yield of ferulyl monoolein and ferulyl diolein, a 20% greater yield than that obtained for alcoholysis using monoolein. The highest yield, 77%, of ferulyl monoolein and ferulyl diolein was achieved using a threefold excess of neat triolein. The lipase‐catalyzed transesterification of ethyl ferulate with triolein appears to be a technically feasible route to ferulyl‐substituted acylglycerols, which are potentially useful sunscreen ingredients.
The study of epoxidized rapeseed oil used as a potential biodegradable lubricant
Authors: Wu Xuedong , Zhang Xingang , Yang Shengrong , Chen Haigang , Wang Dapu
Published: November 2006

The application of epoxidized rapeseed oil as a biodegradable lubricant is described. The epoxidation treatment has no adverse effect on the biodegradability of the base stock. Epoxidized rapeseed oil has superior oxidative stability compared to rapeseed oil based on the results of both oven tests and rotary oxygen bomb tests. Moreover, the oxidative stability can be dramatically promoted by the addition of a package of antioxidants. The epoxidized rapeseed oil has better friction‐reducing and extreme pressure abilities according to tribological investigations. Formation of a tribopolymerization film is proposed as explanation of the tribological performance of epoxidized rapeseed oil.
Physical refining of coconut oil: Effect of crude oil quality and deodorization conditions on neutral oil loss
Authors: Petrauskaitè V. , De Greyt W. F. , Kellens M. J.
Published: November 2006

In the present study, neutral oil loss (distillative and mechanical carry‐over) during physical refining of coconut oil was quantified. Neutral oil loss seems to depend on both the crude oil quality and the process conditions during deodorization. The distillation of volatile glyceridic components (monoand diglycerides), originally present in the crude oil, was confirmed as the major cause for the neutral oil loss. The amount of these volatile components in crude coconut oils cannot be derived as such from the initial free fatty acid content. A lower deodorization pressure with less sparge steam resulted in a larger neutral oil loss than a higher pressure with more steam. A “deodorizability” test on a laboratory scale under standardized conditions (temperature=230°C, pressure=3 mbar, time=60 min, sparge steam=1%), to evaluate crude oil quality and to obtain a more accurate prediction of the expected neutral oil loss and free fatty acid content in the fatty acid distillate, is described.
A new method for free fatty acid reduction in frying oil using silicate films produced from rice hull ash
Authors: Kalapathy U. , Proctor A.
Published: November 2006

Sodium silicate films were produced from rice hull ash silica, and their application in reducing free fatty acid (FFA) in frying oil was investigated. Sodium hydroxide concentration of these films was 32, 28, 24, and 20% with silica concentration of 45, 50, 55, and 60%, respectively. Moisture contents of these films were 20–23%. Adsorption performance of the films was investigated in frying oil at 80°C for 10–40 min. FFA content gradually decreased with treatment time for all films. There were no significant differences in FFA content among films for treatments up to 30 min. Treatment with 45 and 50% silica films for 40 min led to significantly larger reduction in FFA compared to treatment with 60% silica film. Differences between the FFA content of oil treated for 40 min with 55% silica and the FFA content of oils treated with other silica films were insignificant. FFA content of oil decreased from 0.8 to 0.55, 0.55, 0.57, and 0.59% after 40 min treatment with 45, 50, 55, and 60% silica film, respectively. Peroxide values (PV) of treated oils slightly increased from 48 to about 60 meq/kg for films with 45, 50, and 55% silica. Treatment with 60% silica led to a decrease in PV values to 42 meq/kg. Soap content of oil increased from 51 to over 100 ppm as a result of silicate film treatment.
Characterization of italian olive oils based on analytical and nuclear magnetic resonance determinations
Authors: Sacco Antonio , Brescia Maria Antonietta , Liuzzi Vitantonio , Reniero Fabiano , Guillou Glaude , Ghelli Stefano , van der Meer Pieter
Published: November 2006

Analytical measurements and proton nuclear magnetic resonance (1H NMR) spectra of phenolic extracts were performed on a set of italian extra‐virgin olive oils from different cultivars and geographical locations of Apulia region. Multivariate statistical analysis (principal component analysis, hierarchical clustering analysis, and discriminant analysis) was applied separately to analytical and NMR data. Analytical parameters, in particular fatty acid compositions, permit the discrimination of olive variety, while 1H NMR data of phenolic extracts permit a classification according to the geographical origin of the samples.
Constituents of Amomum tsao‐ko and their radical scavenging and antioxidant activities
Authors: Martin Teresita S. , Kikuzaki Hiroe , Hisamoto Masashi , Nakatani Nobuji
Published: November 2006

Constituents of the fruit of Amomum tsao‐ko were investigated following a preliminary screening of the antioxidant activity of several extracts of the fruit of this plant that showed that the dichloromethane extract and the ethyl acetatesoluble and water‐soluble fractions of the 70% aqueous acetone extract had higher activity than α‐tocopherol and butylated hydroxytoluene (BHT). Eleven compounds were isolated from the ethyl acetate‐soluble fraction, and their structures were elucidated as (+)‐hannokinol (1), meso‐hannokinol (2), (+)‐epicatechin (3), (−)‐catechin (4), β‐sitosterol (5), β‐sitosterol 3‐O‐glucoside (6), 2,6‐dimethoxyphenol (7), protocatechualdehyde (8), protocatechuic acid (9), vanillic acid (10), and p‐hydroxybenzoic acid (11) based on mass and various nuclear magnetic resonance (NMR) spectroscopic techniques. This is the first isolation of epicatechin and catechin from the genus Amomum. The radical scavenging activity of the isolated compounds was evaluated using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and colorimetric and electron spin resonance (ESR) analyses. The antioxidant activity of the compounds was also determined based on the oxidative stability index (OSI). The catechins and catechol derivatives showed strong activities in both the DPPH radical scavenging activity and antioxidant activity assays.
Adhesive properties of soy proteins modified by sodium dodecyl sulfate and sodium dodecylbenzene sulfonate
Authors: Huang Weining , Sun Xiuzhi
Published: November 2006

A study was conducted on adhesive and water‐resistance properties of soy protein isolates modified by sodium dodecyl sulfate (SDS) (0.5, 1, and 3%) and sodium dodecylbenzene sulfonate (SDBS) (0.5, 1, and 3%) and applied on walnut, cherry, and pine plywoods. Soy proteins modified by 0.5 and 1% SDS showed greater shear strengths than did unmodified protein. One percent SDS modification had the highest shear strength within each wood type tested. Soy proteins modified with 0.5 and 1% SDBS also showed greater shear strengths than did the unmodified protein. The 1% SDBS‐modified soy protein had the highest shear strength in all wood samples tested. Compared to the unmodified protein, the modified proteins also exhibited higher shear strengths after incubation with two cycles of alternating relative humidity and zero delamination rate and higher remaining shear strengths after three cycles of water soaking and drying. These results indicate that soy proteins modified with SDS and SDBS have enhanced water resistance as well as adhesive strength. Possible mechanisms for the effects of SDS and SDBS also are discussed.
Synthetic antioxidants in edible oils by square‐wave voltammetry on ultramicroelectrodes
Authors: Ceballos Claudio , Fernández Héctor
Published: November 2006

Square wave voltammetry (SWV) on carbon disk ultramicroelectrodes (UME) was used to determine antioxidants tert‐butylhydroxyanisole (BHA) and tert‐butylhydroxytoluene (BHT) in vegetable oils. Direct determinations were accomplished in benzene/ethanol/H2SO4 solutions or in acetonitrile (ACN) after an extractive procedure. Much better recovery percentages were obtained in ACN extracts. By comparing with high‐performance liquid chromatography (HPLC) results, BHA has a slightly lower recovery percentage by the SWV technique on ACN extracts. On the other hand, BHT shows a greater recovery percentage using the methodology proposed here. The analysis time through SWV is less than an hour for a duplicated analysis while the HPLC technique needs a greater time, besides the overnight stored time required by the current methodology. The present work tends to show that SWV on carbon disk UME allows sensitive, reproducible, and faster determination of BHA, BHT, or antioxidant mixtures in oil‐solvent solutions or after a simple extractive procedure with the advantage of a higher recovery percentage. This validates the methodology as an analytical alternative for antioxidant quantification.
Ultrafiltration of partially hydrolyzed rice bran protein to recover value‐added products
Authors: Hamada Jamel S.
Published: November 2006

Rice brans were treated with a protease together with a disulfide bond‐breaking agent (Na2SO3) to achieve a 2–4% peptide bond hydrolysis (DH). Ultrafiltration (UF) with 3 kDa molecular weight cut‐off (MWCO) membrane led to substantial loss of feed protein due to permeation. Using 1 kDa MWCO membrane increased protein yields, but it was not effective in purifying the protein hydrolysates despite the increase in membrane area and operating time. The efficiency of this UF process can be improved using a larger MWCO membrane (e.g., 2 kDa MWCO), which may facilitate complete removal of phytate. Based on disparity of molecular sizes, use of phytase may also increase purity of protein retentates and allow the recovery of functional inositol phosphates in permeates. The presence of Na2SO3 during proteolysis to 2% DH of preheated bran (100°C, 10 min) repaired the damage caused by preheat treatment by increasing protein recovery but increased the concentration of small peptides in hydrolysates, i.e., <1 kDa, particularly for highly aggregated proteins. Heat treatment is necessary to stabilize rice bran, but the sulfite treatment may be avoided to increase UF yield and purity of protein retentates and allow higher DH values for hydrolysis of stabilized brans. Accordingly, this UF process can be an efficient method for recovering high‐value components from rice bran, an underutilized rice milling co‐product, for many industrial applications.
Industrial production of dihomo‐γ‐linolenic acid by a Δ5 desaturase‐defective mutant of Mortierella alpina 1S‐4 Fungus
Authors: Kawashima Hiroshi , Akimoto Kengo , Higashiyama Kenichi , Fujikawa Shigeaki , Shimizu Sakayu
Published: November 2006

Dihomo‐γ‐linolenic acid (DGLA)‐containing oil (triacylglycerol) was produced by the fungus Mortierella alpina S14, which is a Δ5 desaturase‐defective mutant of the arachidonic acid‐producing strain 1S‐4. Using soy flour as the nitrogen source, S14 produced 8.1 g DGLA/L of culture medium in a 50‐L jar fermenter. Shifting the cultivation temperature from 26 to 28°C resulted in reduction of the percentage of DGLA in total fatty acids. Under optimal conditions in a 10‐kL industrial fermenter, DGLA production reached 7.0 g/L (percentage of DGLA, 43.9%) at day 12 of cultivation. The other fatty acids were palmitic (18.2%), stearic (7.9%), oleic (7.5%), linoleic (4.4%), γ‐linolenic (3.2%), arachidonic (0.4%), and lignoceric (7.7%) acids.
Effect of processing conditions on physical properties of a milk fat model system: Rheology
Authors: Herrera M. L. , Hartel R. W.
Published: November 2006

The effect of processing conditions on rheological behavior of three blends of 30, 40, and 50% of high‐melting fraction [melting point measured as Mettler dropping point (MDP)=47.5°C] in low‐melting fraction (MDP=16.5°C) of milk fat was studied. The effects of cooling and agitation rates, crystallization temperature, chemical composition of the blends, and time of storage on complex, storage and loss moduli were investigated by dynamic mechanical analysis (DMA). Compression tests were performed on samples using frequency values within the linear viscoelastic range (1 to 10 Hz). Loss modulus was, on average, 10 times lower than elastic modulus and was generally not affected by processing conditions. Samples showed a more solid‐like behavior that was better described by storage modulus. Storage modulus varied with all processing conditions used in this study, and even for the same solid fat content, different rheological properties were found. Storage and complex modulus increased with temperature of crystallization (25 to 30°C), even though solid fat contents of samples measured after 24 h at 10°C were the same. Moduli were higher for samples crystallized at slow cooling rate, decreased with agitation rate, and were lower for the 30–70% blend at all processing conditions used. Storage moduli also increased with storage time. Shear storage modulus was calculated from the DMA experimental data, and the results were in agreement with the values reported in literature for butter systems. Fractal dimensions calculated for these systems showed a significant decrease as agitation rate increased in agreement with the softening effect reported for working of butter.
Effect of processing conditions on physical properties of a milk fat model system: Microstructure
Authors: Herrera M. L. , Hartel R. W.
Published: November 2006

The effect of processing conditions on the microstructure of three blends of 30, 40, and 50% high‐melting fraction [Mettler dropping point (MDP)=47.5°C] in the lowmelting fraction (MDP=16.5°C) of milk fat was studied. The effect of cooling and agitation rates, crystallization temperature, chemical composition of the blends, and storage time on crystalline microstructure (number, size, distribution, etc.) was investigated by confocal laser scanning microscopy (CLSM). To improve resolution, a mix of Nile blue and Nile red dyes was dissolved in the melted samples in proportions that did not modify the nucleation kinetics. Samples were then crystallized by cooling (0.2 or 5.5°C/min) to crystallization temperature (25, 27.5, and 30°C). After 2 h at crystallization temperature, a slurry was placed on a microscope slide and samples were stored 24 h at 10°C. During this period, more material crystallized. Slowly crystallized samples (0.2°C/min) formed different structures from rapidly crystallized samples (5.3°C/min). Crystals were sometimes diffuse and hard to distinguish from the liquid. Samples were darker as a result of this solid‐mass distribution. However, rapidly crystallized samples had well‐defined crystals and seemed to be separated by a distinct liquid phase. These crystals were not in touch with each other as was the case for slowly crystallized samples. Higher agitation rates led to smaller crystal size due to enhanced nucleation. Larger crystals were formed when crystallization occurred at higher temperatures. Storage time resulted in an increase of crystal size. Larger crystal size and structures with more evident links had a more elastic behavior with higher elastic modulusE’.
Protein concentrate and adhesives from meat and bone meal
Authors: Park Sang K. , Bae D. H. , Hettiarachchy N. S.
Published: November 2006

Defatted meat and bone meal (MBM) was prepared by the removal of extractable fat with isopropyl alcohol. Proteins in the defatted MBM were extracted with 0–4% NaCl concentrations with 0.05% CaCl2 or 0.05% MgCl2 at pH 5.5–6.6 for 1 h at 50°C and precipitated at pH 4.0–4.5. By using the salt extraction procedure, MBM protein concentrate (MBMPC) (32 g) was obtained from defatted MBM (100 g). Recovery of protein was dependent on the extraction temperature employed; recovery values ranged from 33.2 to 51.4%. At 4% NaCl concentration, MgCl2 increased protein solubility by 30%, compared to the control. The adhesiveness of MBMPC at various pH values ranging from 5.0 to 9.0 was investigated. At pH 6.0–8.0, adhesiveness of MBMPC showed the highest value (78.2 kg). The adhesiveness increased linearly as the MBMPC concentration increased up to 20% with respect to temperature for MBMPC adhesiveness, the greatest adhesiveness was in the range of 70 to 90°C. Improved adhesiveness and water resistance were observed with 0.05% glutaraldehyde treatment.
Antioxidative characteristics of oils in ground pork‐fat patties cooked with soy sauce
Authors: Chiou R. Y. ‐Y. , Ku K. ‐L. , Lai Y. ‐S. , Chang L. ‐G.
Published: November 2006

Ground pork‐fat patties were cooked alone (control), with NaCl solution, with NaCl solution containing sucrose, with fermented soybean broth, with fermented black soybean broth, and with commercial soy sauce products at 125°C for 2 h. The top‐layer oils were then stored at 60°C for periodical determinations of conjugated diene hydroperoxide (CDHP) contents. The fermented broth‐cooked and soy sauce‐cooked oils were stable against CDHP formation during storage. This supports the customary impression that soy sauce‐cooked pork is stable against oxidative rancidity. Analysis of the fatty acid compositions showed the presence of linoleic, linolenic, and arachidonic acids, which are susceptible to oxidation. When the fermented brothcooked oils were extracted with methanol, concentrated, and introduced to the control oils for storage, an estimated antioxidative potency close to that of 2 ppm butylated hydroxyanisole was observed. In comparing free amino acid compositions of the fermented soybean and black soybean broths before and after cooking the ground pork‐fat patties, threonine, serine, glutamic acid, alanine, isoleucine, leucine, tryptophan, and tyrosine contents tecreased while proline, valine, histidine, and arginine contents increased.
Establishment of a model substrate oil for antioxidant activity assessment by oil stability index method
Authors: Nakatani Nobuji , Tachibana Yukari , Kikuzaki Hiroe
Published: November 2006

A model substrate oil using methyl linoleate was established for the determination of the antioxidant activity by Oil Stability Index (OSI) method. OSI values for methyl linoleate with different concentrations (5–100%) in silicone oil were measured at different temperatures (70–120°C). As the temperature increased, the OSI value decreased in each concentration of methyl linoleate. Optimal temperature and concentration of antioxidants, α‐tocopherol, and butylated hydroxytoluene on OSI values for 10% methyl linoleate model oil was measured at 90, 100, 110, and 120°C. The logarithmic relationship between temperature and OSI using model substrate oil was similar to that of soybean oil. Furthermore, application of some spice extracts to this model oil system was carried out to give results thhat compared well with those available in the literature. Thus, the procedure using methyl linoleate‐silicone oil as a model substrate oil is available for evaluating the antioxidant activity by the OSI method.
Characterization and oxidative stability of enzymatically produced fish and canola oil‐based structured lipids
Authors: Akoh Casimir C. , Moussata Charment O.
Published: November 2006

Two‐kilogram quantities of structured lipids (SL) of menhaden fish and canola oils containing caprylic acids (8∶0) were produced in a laboratory‐scale packed‐bed bioreactor by acidolysis catalyzed by an immobilized lipase, Lipozyme IM, from Rhizomucor miehei. SL were characterized and their oxidative stabilities investigated. The SL contained 29.5% 8∶0 for fish oil and 40.15 for canola oil. Polyunsaturated fatty acids (PUFA) of fish oil remained unchanged after the modification while PUFA of canola oil were reduced from 29.6 to 21.2%. Monoenes, especially 18∶1n−9, were completely replaced by 8∶0 in fish oil and reduced from 61.9 to 34.7% in canola oil. Downstream processing of enzymatically produced SL led to loss in natural total tocopherol contents of the fish and canola oils. The effects of antioxidants such as α‐tocopherol (TOC), tert‐butylhydroxyquinone (TBHQ), and combinations thereof on the oxidative stability of SL were investigated. SL were analyzed for oxidative stability index, peroxide value, conjugated diene content, free fatty acid content, iodine value, saponification number, and thiobarbituric acid value. Iodine value of unmodified fish oil (154.71) was reduced to 144.10 and that of canola oil (114.49) to 97.27 after modification. The SN increased from 183.72 to 242.63 for fish oil and from 172.50 to 227.90 for canola oil. TBHQ exhibited better antioxidant effects than TOC. A combination of TBHQ/TOC also proved to be an effective antioxidant for SL. We suggest the addition of antioxidants to enzymatically produced and purified SL.
Modifications of butter stearin by blending and interesterification for better utilization in edible fat products
Authors: Pal P. K. , Bhattacharyya D. K. , Ghosh S.
Published: November 2006

This work primarily aims to further modify the stearin fractions, obtained from anhydrous milk fat, after fractionation by dry process and by solvent process using isopropanol, for extending their scope of utilization in edible fat products. Butter stearin fractions, on blending with liquid oils like sunflower oil and soybean oil in different proportions, offer nutritionally important fat products with enriched content of essential fatty acids like C18∶2 and C18∶3. The butter stearin fraction from isopropanol fractionation, when interesterified with individual liquid oils by Mucor miehei lipase as a catalyst, yields fat products having desirable properties in making melange spread fat products with reasonable content of polyunsaturated fatty acids and almost zero trans fatty acid content.
Adhesion properties of soy protein with fiber cardboard
Authors: Zhong Zhikai , Susan Sun X. , Fang Xiaohua , Ratto Jo A.
Published: November 2006

Adhesion properties of soy protein isolate (SPI) on fiber cardboard and effects of press conditions, pre‐pressing drying time, and protein concentrations on gluing strength were investigated. Shear strength increased as press time, press pressure, and/or press temperature increased. The effect of temperature on shear strength became more significant at high press pressure. The shear strength of the SPI adhesive on fiber cardboard decreased by 12–25% after water soaking. Shear strength increased as pre‐pressing drying time increased and reached its maximal value at about 10 min. An SPI/water ratio of 12∶100 (w/w) gave the highest gluing strength. The specimens showed complete cohesive failure (fiber cardboard failure) except for soaked specimens pressed at low press temperature, low pressure, and short press time. Specimens pressed at 25°C and 2 MPa for 5 min with pre‐pressing drying time of 10 min and an SPI/water ratio of 12∶100 (w/w) had T‐peel strength and tensile bonding strength of 1.15 N/mm and 0.62 MPa, respectively, without water soaking, and 1.11 N/mm and 0.24 MPa, respectively, with water soaking.
Lipase‐catalyzed synthesis of triolein‐based sunscreens in supercritical CO2
Authors: Compton David L. , King Jerry W.
Published: November 2006

Novozym® 435‐catalyzed transesterification of ethyl 4‐hydroxy‐3‐methoxy cinnamate (ethyl ferulate, EF) with triolein to form the ultraviolet (UV)‐absorbing lipids monoferuloylmonooleoyl‐glycerol (FMO) and feruloyl‐dioleoyl‐glycerol (FDO) has been conducted using supercritical CO2 (SC−CO2) batch reactions. The alcoholysis of 0.1 M EF with 0.1 M 1‐octanol in SC−CO2 to form octyl ferulate was used as a model reaction to optimize pressure and temperature conditions. Conditions ranging from 45 to 80°C and 10.3 to 34.5 MPa (1,500 to 5,000 psi) were tested with a maximal conversion of 53% of the EF being achieved at 13.8 MPa (2,000 psi) and 80°C after 24 h. These optimized conditions applied to the transesterification of EF with triolein effected a combined FMO and FDO yield of 69%. Triolein exhibits higher solubilities in SC−CO2 at higher pressures; therefore, the transesterification was performed at 80°C over a range of pressures from 13.8 to 34.5 MPa (2,000 to 5,000 psi). Results showed that a maximal yield of 74% of FMO and FDO was reached at 80°C and 24.1 MPa (3,500 psi) after 48 h. Compared to the FMO and FDO synthesis conducted neat or in toluene, the synthesis of the UV‐absorbing lipids in SC−CO2 affords higher yields within a shorter amount of time. Therefore, the transesterification of EF with triolein in a SC−CO2 batch reaction is a viable route to UV‐absorbing lipids that could be used as active ingredients in sunscreen formulations.
Enzymatic esterification of (−)‐menthol with fatty acids in solvent by a commercial lipase from Candida rugosa
Authors: Babali Banu , Aksoy H. Ay§e , Tüter Melek , Ustun Guldem
Published: November 2006

Esterification of (−)‐menthol with fatty acids in isooctane was successfully catalyzed using a commercial lipase, Lipase AY “Amano” 30 from Candida rugosa in original powder form. The esterification reactions were performed to elucidate the effects of temperature, enzyme load, molar ratio of (−)‐menthol/fatty acid, and fatty acid type, keeping the (−)‐menthol concentration at 200 mM. At the optimal conditions for (−)‐menthol esterification, determined at a (−)‐menthol/lauric acid molar ratio of 1∶1 and 35°C [1.5 g enzyme/g (−)‐menthol, 0.1 g molecular sieves], the molar conversion of (−)‐menthol after 48 h reached 93%. After 24h, the lowest and the highest molar conversions of fatty acids at 2∶1 molar ratio were obtained with myristic acid (71%) and margaric acid (98%), respectively. After 48 h, the molar conversions of lauric acid at molar ratios 2∶1, 1∶1, and 1∶2 were 98, 93, and 49%, respectively.
Solubility of the diarrheic shellfish toxin okadaic acid in supercritical CO2
Authors: González J. C. , Vieytes M. R. , Vieites J. M. , Botana L. M.
Published: November 2006

The solubility of okadaic acid (OA) in supercritical CO2 was measured using a flow‐type apparatus with sequential sampling during dynamic nonrecirculating experiments at saturation conditions. Methanol and water were used as solvent modifiers of CO2. Collected OA was measured by high‐performance liquid chromatography with fluorimetric detection after derivatization with 1‐bromoacetylpyrene to obtain the labeled ester of the toxin. Solubility results were obtained with methanol concentrations ranging from 0 to 8.5% volume in the CO2 density range of 0.495 to 0.913 g/mL at 40, 60, and 73°C. Measured solubility of OA ranged from 0 to 15×10−6 mol/L, increasing with methanol concentration and fluid density and diminishing with temperature. Experiments with water‐modified CO2 up to 0.3% volume (near saturation) were done at 60°C; solubilities of OA up to 5×10−6 mol/L were measured. This is the first approach to handle the liposoluble diarrheic shellfish toxins with supercritical CO2. The study, with pure OA, provides useful information regarding the effects of pressure, temperature, and addition of modifiers on its solubility. Obtained results show that the toxin can be solubilized in this media and potential applications are suggested and being currently investigated.
Comparison of different methods for the determination of the oil content in oilseeds
Authors: Matthäus Bertrand , Brühl Ludger
Published: November 2006

The investigation and assessment of the oil content of oilseeds are important criteria, especially for the oil milling trade. Standard methods for the determination of the oil content of oilseeds are very time consuming, with extraction periods of 4 to 8 h. Three different oilseeds—rapeseed, sunflower, and soybean—are extracted by supercritical fluid extraction (SFE), accelerated solvent extraction, microwave‐assisted extraction, solid fluid vortex extraction, and Soxtherm, and the results are compared with the result of the German Fat Science Society (DGF) standard method B‐I 5 (87). Besides, the extracts are analyzed regarding the content of tocopherols as a parameter for mild extraction conditions and the content of diglycerides and free fatty acids as parameters for the content of more polar lipids. The results of the determination of the oil content under optimal conditions are comparable with the results of the DGF standard method B‐I 5 (87). There are no significant differences between the different methods. The content of tocopherols is dependent upon the extraction method and the type of oilseed. The highest content is obtained by SFE. The content of diglycerides and free fatty acids varied according to the oilseed.
Composition and activity of commercial triacylglycerol acylhydrolase preparations
Authors: Bjurlin Marc A. , Bloomer Scott , Haas Michael J.
Published: November 2006

Commercial lipase preparations were surveyed to determine gross composition, amounts of nonprotein impurities, and esterolytic and lipolytic activities. Most of the 34 commercial lipase preparations contained more than 80% non‐proteinaceous material, with salt and carbohydrate being the most abundant materials. The tributyrin hydrolase activity of these commercial lipase preparations was determined and expressed as lipase/esterase forestomach units (LFU). Tributyrin hydrolase activity ranged from negligible (5.3 LFU/g) to very high (>1000,000 LFU/g). Aspergillus and Penicillium preparations were low in tributyrin hydrolase activity. Candida rugosa preparations were intermediate in activity. Preparations of porcine pancreas, Rhizomucor, Pseudomonas, and Rhizopus lipases exhibited a broad range of levels of activity. No relation between protein content and tributyrin hydrolase activity was observed. Isoelectric focusing of the proteins present in the preparations demonstrated the presence of between 2 and 27 isophoretically discrete bands in the isoelectric range of 3 to 9. Although there were many similarities of distribution of protein isoelectric points within genera and spcies, the preparations generally displayed unique patterns of isophoretically discrete protein bands. Lipase zymography demonstrated the presence of 0 to 7 isophoretically discrete lipase activities in each preparation, spanning the entire range of isoelectric points surveyed.
Specificity of papaya lipase in esterification of aliphatic alcohols a comparison with microbial lipases
Authors: Gandhi Neena N. , Mukherjee Kumar D.
Published: November 2006

Straight‐chain saturated C4 to C18 alcohols and unsaturated C18 alcohols such as cis‐9‐octadecenyl (oleyl) cis‐6‐octadecenyl (petroselinyl), cis‐9, cis‐12‐octadecadienyl (linoleyl), all‐cis‐9,12,15‐octadecatrienyl (α‐linolenyl), and all‐cis‐6,9,12‐octadecatrienyl (γ‐linolenyl) alcohols, were esterified with caprylic acid using papaya (Carica papaya) latex lipase (CPL) and immobilized lipase from Candida antarctica (Lipase B, Novozym, NOV) and Rhizomucor miehei (Lipozyme, LIP) as biocatalysts. With CPL, highest activity was found for octyl and decyl caprylate syntheses, whereas both NOV and LIP showed a broad chain‐length specificity toward the alcohol substrates. CPL strongly discriminated against all C18 alcohols studied, relative to n‐hexanol, whereas the microbial lipases accepted the C18 alcohols as substrates nearly as well as n‐hexanol. Both petroselinyl and γ‐linolenyl alcohol were very well accepted as substrates by NOV as well as LIP, although the corresponding fatty acids, i.e., petroselinic and γ‐linolenic acid, are strongly discriminated against by several microbial and plant lipases, including LIP and CPL.
Effects of fat crystallization on the behavior of proteins and lipids at oil droplet surfaces
Authors: Sugimoto Taisuke , Mori Tomohiko , Mano Jun ichi , Mutoh Taka‐Aki , Shiinoki Yasuhiko , Matsumura Yasuki
Published: November 2006

The effects of fat crystallization induced by thermal treatment on the rheological properties of creams and physical phenomena at the oil droplet surfaces were investigated. Creams A or B were prepared from commercial proprietary fats A or B (vegetable oils with different triaclyglycerol composition) and aqueous solution containing proteins. Thermal treatment of the creams at the “critical temperatures” (temperatures inducing a small percentage of solid fats in the oil droplets) caused a rapid increase of solid fat contents in the following cooling process. The thermal treatment of cream B at the “critical temperature” caused an increase of viscosity of the cream and an increase of protein surface coverage during the subsequent cooling process. These results suggest that the oil droplet aggregation induced by the thermal treatment at the “critical temperature” and the subsequent cooling occurred via further adsorption of proteins. Electron spin resonance measurement demonstrated the dramatic reduction of fluidity of triacylglycerol molecules at the oil droplet surface in cream B during the cooling process after thermal treatment at temperatures below “critical”. Based on these results, we speculated on the mechanism for the destabilization of thermally treated creams during the cooling process.
Chemical binding of jojoba liquid wax to polyethylene
Authors: Shevachman M. , Belfer S. , Binman S. , Shani A.
Published: November 2006

Jojoba wax was chemically bonded to polyethylene—in film or hollow fiber form—via a stable sulfonamide bond. The jojoba‐bonded polyethylene was obtained by binding allyl amino jojoba derivatives to chlorosulfonated polyethylene. The amount of jojoba added to the polymer ranged from 9 to 98% (w/w), depending onthe reaction conditions. Swelling of the polymer in the reaction solvent was the major factor affecting the efficacy of the chemical binding of the jojoba amino groups to the chlorosulfonyl entities of the polymer. The double‐bond regions in the bound jojoba wax were preserved, i.e., they were shown to be reactive in a bromination reaction. These modified membranes can find application in separation processes, such as metal ion separation and pervaporation.
Emulsifying and foaming properties of native and chemically modified peptides from the 2S and 12S proteins of rapeseed (Brassica napus L.)
Authors: Malabat Christophe , nchez‐Vioque Ra I S , Rabiller Claude , Gu guen Jacques
Published: November 2006

The 2S and 12S proteins of rapeseed were isolated and subsequently hydrolyzed by pepsin or a combination of pepsin plus trypsin. The resulting hydrolysates had a 15% degree of hydrolysis and were purified by gel filtration chromatography in order to obtain homogeneous peptide fractions. Three major fractions, having an average peptide chain length of 7.5–11 amino acids, were recovered. Purified peptide fractions were acylated with butyric anhydride and sulfamidated with p‐toluenesulfonyl chloride. The degree of modification was always higher than 90%. Emulsifying and foaming properties of native and chemically modified peptides were studied and compared to those of sodium dodecyl sulfate (SDS) as standard. A peptide fraction from the 15% hydrolysis of the 12S protein exhibited the best foaming properties. After sulfamidation, this peptide fraction showed a foam formation similar to that of SDS. Whereas the attachment of toluene groups generally improved the surface properties, the incorporation of an aliphatic chain of four atoms of carbon was detrimental in most of the cases. On the other hand, none of the native or hydrophobized peptide fractions was able to form a stable emulsion.