bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of monodisperse water‐in‐oil‐in‐water emulsions using microfluidization and straight‐through microchannel emulsification
Authors: Kobayashi Isao , Lou Xuefang , Mukataka Sukekuni , Nakajima Mitsutoshi 
Published: November 2006

AbstractWater‐in‐soybean oil‐in‐water (W/O/W) emulsions with an internal water phase content of 10–30% (vol/vol) were prepared by a two‐step emulsification method using microfluidization and straight‐through microchannel (MC) emulsification. A straight‐through MC is a silicon array of micrometer‐sized through‐holes running through the plate. Microfluidization produced water‐in‐oil (W/O) emulsions with submicron water droplets of 0.15–0.26 μm in average diameter (dav,w/o) and 42–53% in CV (CVw/o) using tetraglycerin monolaurate condensed ricinoleic acid esters (TGCR) and polyglycerin polycondensed ricinoleic acid esters (PGPR) as surfactants dissolved in the oil phase. Thedav,w/oand viscosity of the W/O emulsions increased with an increase in internal water phase content. Straight‐through MC emulsification was performed using the W/O emulsions as the to‐be‐dispersed phase and polyoxyethylene (20) sorbitan monooleate (Tween®80) as a surfactant dissolved in the external water phase. Monodisperse W/O/W emulsions withdav,w/o/wof 39.0–41.0 μm and CVw/o/wbelow 5% were successfully formed from a straight‐through MC with an oblong section (42.8×13.3 μm), using the TGCR‐containing systems. Thedav,w/o/wof the monodisperse W/O/W emulsions decreased as the internal water phase content increased because of the increase in viscosity of the to‐be‐dispersed phase. Little leakage of the internal water droplets and no droplet coalescence or droplet break‐down were observed during straight‐through MC emulsification.
New technologies to determine solid fat content on‐line
Authors: Martini Silvana , Herrera Maria Lidia , Marangoni Alejandro 
Published: November 2006

AbstractThe determination of solid fat content (SFC) is an important analytical procedure in the food industry. The most common way to determine SFC is by low‐resolution pulsed NMR (p‐NMR). Although this technique is very sensitive and easy to use, it has the disadvantage that it cannot be used for on‐line measurements. The present work compares new technologies to determine SFC on‐line. On‐line ultrasonic spectroscopy and NMR‐MOUSE (NMR mobile universal surface explorer) techniques were compared with off‐line p‐NMR measurements and there was a good correlation between the values obtained. Ultrasonic measurements accurately described the SFC variation, whereas NMR‐MOUSE determinations need to be improved to some extent owing to a strong temperature and motion dependence. These two techniques can be used as on‐line methodologies to determine SFC during the crystallization of fats.
Diacylglycerol synthesis by enzymatic glycerolysis: Screening of commercially available lipases
Authors: Kristensen Janni Brogaard , Xu Xuebing , Mu Huiling 
Published: November 2006

AbstractSeven lipases were screened for their ability to synthesize DAG in the glycerolysis of rapeseed oil. In batch reactions with free glycerol, the lipase carrier was of great importance for catalysis. Catalysis did not take place in reactions with lipases having hydrophilic carriers. The best DAG yield (approx. 60 wt%) was achieved with Novozym 435 and Lipase PS‐D after 7 h, and an equilibrium was obtained. Stepwise addition of glycerol allowed catalysis with Novozym CALB L (immobilized) to take place in spite of the hydrophilic carrier; however, the DAG yield was only 19 wt%. This result suggests that glycerol forms a layer around the hydrophilic lipase particles, limiting contact between the lipases and the hydrophobic oil phase. With glycerol absorbed on silica gel, all lipases catalyzed the glycerolysis reaction. Faster conversion of TAG was obtained with Lipase PS‐D, Lipase AK, and Lipase F‐AP15 than in reactions with free glycerol, but the DAG yield remained approximately 60–65 wt%. Nonspecific lipases yielded more 1,3‐DAG early in the reaction.
Enzymatic production of alkyl esters through alcoholysis: A critical evaluation of lipases and alcohols
Authors: Deng Li , Xu Xuebing , Haraldsson Gudmundur G. , Tan Tianwei , Wang Fang 
Published: November 2006

AbstractThis paper focuses on a detailed evaluation of commercially available immobilized lipases and simple monohydric alcohols for the production of alkyl esters from sunflower oil by enzymatic alcoholysis. Six lipases were tested with seven alcohols, including straight and branched‐chain primary and secondary alcohols. The reactions were conducted in a batch stirred reaction vessel using stoichiometric amounts of substrates under solvent‐free conditions. Dramatic differences in alcoholysis performance were observed among the different lipases. For most of the alcohols, Novozym 435 produced the highest yield of FA alkyl esters, with yields well over 90% for methanol, absolute ethanol, and 1‐propanol. Overall, 96% ethanol was the preferred alcohol for all lipases except Novozym 435, and ethanolysis reactions reached the maximal conversion efficiency. Increasing the water content in the system resulted in an increased degree of conversion for all lipases except Novozym 435. The secondary alcohol 2‐propanol significantly reduced the alcoholysis reaction with all lipases; however, the branch‐chain isobutanol was more advantageous than linear 1‐butanol for Novozym 435, Lipozyme RMIM, and Lipase PS‐C. Many commercial immobilized lipases are highly efficient and promising for the production of alkyl esters, offering high reaction yields and a simple operation process.
Polyurethane networks from formiated soy polyols: Synthesis and mechanical characterization
Authors: Monteavaro Luciane L. , da Silva Eduardo O. , Costa Ana Paula O. , Samios Dimitrios , Gerbase Annelise E. , Petzhold Cesar L. 
Published: November 2006

AbstractPolyurethanes can be prepared using polyols obtained from vegetable oils in natura, such as castor oil, or from functionalized vegetable oils, such as hydroxylated soybean oil. These polyurethanes have different valuable properties, determined by their chemical composition and cross‐linking density. In this study, soy epoxy polyols with different OH contents were prepared through a one‐step reaction using the method of in situ performic acid generation. Polyols with OH functionalities from 1.9 to 3.2 were reacted in bulk with different diisocyanates at a NCO/OH molar ratio of 0.8 and 60°C for 24 h. Mechanical properties of the polyurethanes were determined by dynamic mechanical thermal analysis, hardness (Shore A), and swelling measurements. Polymer networks with glass‐transition temperatures (Tg) from −13 to 48°C were obtained. We observed that the higher the OH functionality of the polyols, the higher the Tg and cross‐linking density of the polyurethane network. The influence of diisocyanate structure (rigid or flexible chain), curing temperature, and curing reaction time on mechanical properties was also investigated.
Retardation effect of jojoba chain length on the chemical reactivity of the liquid wax
Authors: Gorodetsky Aleksandra , Zeltser Inna , Shani Arnon 
Published: November 2006

AbstractJojoba wax and its derivatives are slow‐reacting compounds. To elucidate the reasons for this phenomenon, we reacted jojoba mono‐ and bis‐epoxide and trans‐jojoba bis‐epoxide (C38–C44 long‐chain esters), as well as side chain esters of three steroid skeleton mono‐epoxide derivatives with NaI under acidic conditions to yield the corresponding iodohydrins, which then formed the respective bis‐keto (or mono‐ketone) derivatives. The kinetics, activation energies, and thermodynamic parameters of activation of nucleophilic epoxide opening and pinacol rearrangement were determined for all these compounds. The reaction rates of the jojoba derivatives were similar to those of two of the epoxides derived from the steroid skeleton compounds, and in the third case the steroid derivative reacted somewhat faster than all the rest. This pattern of rate retardation could stem either from folding of the long jojoba chain, resulting in steric hindrance around the reaction centers, or from repeated unproductive collisions along the long hydrocarbon chain of the jojoba wax (statistical effect). Our results appear to suggest that the multiple unsuccessful collisions were the dominant factor, although steric hindrance cannot be ruled out.
Oxidative stability of soybean oil fatty acid methyl esters by oil stability index (OSI)
Authors: Dunn Robert O. 
Published: November 2006

AbstractBiodiesel, an alternative diesel fuel derived from transesterification of vegetable oils or animal fats, is composed of saturated and unsaturated long‐chain FA alkyl esters. During long‐term storage, oxidation caused by contact with air (autoxidation) presents a legitimate concern with respect to monitoring and maintaining fuel quality. Extensive oxidative degradation may compromise quality by adversely affecting kinematic viscosity, acid value, or PV. This work examines the oil stability index (OSI) as a parameter for monitoring the oxidative stability of soybean oil FAME (SME). SME samples from five separate sources and with varying storage and handling histories were analyzed for OSI at 60°C using an oxidative stability instrument. Results showed that OSI may be used to measure relative oxidative stability of SME samples as well as to differentiate between samples from different producers. Although addition of α‐tocopherol or TBHQ increased OSI, responses to these antioxidants varied with respect to SME sample. Variations in response to added antioxidant were attributed to aging and other effects that may have caused oxidative degradation in samples prior to acquisition for this study. Results showed that OSI was more sensitive than iodine value in detecting the effects of oxidative degradation in its early stages when monitoring SME during storage.
Oxidation kinetics of linoleic acid in the presence of saturated acyl l‐ascorbate
Authors: Watanabe Yoshiyuki , Ishido Eiichiro , Fang Xu , Adachi Shuji , Matsuno Ryuichi 
Published: November 2006

AbstractThe oxidation processes of linoleic acid (LA) in the presence of l‐ascorbic acid or saturated acyl l‐ascorbate additives were measured at various temperatures and molar ratios of the additive to LA. Higher oxidative stability of LA was observed at higher additive levels for all additives. The addition of the ascorbates lengthened the induction period for the oxidation of LA. An autocatalytic kinetic rate equation was used to model the oxidation processes of LA mixed with the ascorbates, and the dependence of the rate constant, k, on acyl‐chain carbon number was determined. At any temperature, the use of ascorbate additives decreased the k value for LA, and there was a slight tendency for k values to decrease with increasing acyl‐chain length. The apparent activation energy, Ea, and the frequency factor, k0, for the rate constant were determined from Arrhenius plots. The calculated Ea and k0 values also decreased with increasing ascorbate acyl‐chain length.
Influence of formulation on the thermal behavior of ice cream mix and ice cream
Authors: Granger C. , Schöppe A. , Leger A. , Barey P. , Cansell M. 
Published: November 2006

AbstractThe influence of fat and emulsifier types on particle size and thermal behavior of aged mixes and the corresponding ice creams was investigated. Mixes and ice creams based on partially unsaturated monodiglycerides (MDG) were characterized by an increased percentage of agglomerated fat globules compared with saturated MDG‐based system. DSC thermograms obtained for refined coconut oil in mix showed a displacement of the main crystallization event toward lower crystallization teperatures compared with fat in the bulk phase. This supercooling effect was more or less pronounced for the three other fats used (hydrogenated coconut oil, refined palm oil, and anhydrous milk fat). In emulsified systems, an additional exotherm was observed that was interpreted in terms of MDG crystallization. The fact that this peak appeared at different temperatures ranging from 32 to 41°C as a function of the fat selection suggested that different fat‐emulsifier interactions would occur. In the case of ice creams, although the water peak interfered with the fat peak, melting DSC curves allowed the discrimination between the fat types used in the formulation
Linalyl oleate as a frying oil autoxidation inhibitor
Authors: Onal‐Ulusoy Baran , Hammond Earl , White Pamela 
Published: November 2006

AbstractLinalyl oleate (LO), an interesterification product of linalyl acetate (LA) and methyl oleate catalyzed with sodium methoxide, was studied to determine its effectiveness in retarding oxidative changes in soybean oil heated continuously at 180±5°C for 32 h. The identity of LO was established by GC‐MS and NMR. LO was tested at levels of 0.05 and 0.1% and compared with the more commonly used synthetic autoxidation inhibitor methyl silicone (MS) at levels of 5 and 10 ppm. FA changes and conjugated dienoic acid formation were monitored. First‐order kinetic equations were used to model the decreases in linoleate (18∶2)/palmitate and linolenate (18∶3)/palmitate ratios. Plots of the data show an inflection point at ∼11 h. Oils with either level of MS and LO had lower reaction rate constants before the inflection points, and lower conjugated diene values and higher 18∶2 and 18∶3 percentages at the end of the 32‐h heating period than did oil without additives and with LA. LO could replace methyl silicone in soybean oil during deep‐fat frying but at levels about 100 times greater. [We propose to use the term “autoxidation inhibitor” for substances that inhibit autoxidation when added to fats and oils at low concentrations and whose mechanism of action may be unknown. Some may wish to call such substances “antioxidants” but others wish to reserve this term for substances that end free radical chains by hydrogen radical donation. Some refer to methyl silicone as a “polymerization inhibitor”, but this term suggests more about its mechanism of action than seems warranted.]
Phytosterols in cereal by‐products
Authors: Jiang Yongzhi , Wang Tong 
Published: November 2006

AbstractPhytosterols are hypocholesterolemic. Like corn fiber oil, the lipid extracts of certain cereal by‐products may be rich sources of these health‐promoting compounds. The objective of this research was to examine the phytosterol content and composition of various cereal by‐products. Total lipids in rice bran, wheat bran, wheat germ, durum wheat (bran and germ mixture), oat bran, oat hull, and corn fine fiber were extracted, and the sterol profiles of the extracted lipids were analyzed by GC. Rice bran contained the most lipids (22.2%), followed by wheat germ, durum wheat, oat bran, wheat bran, and oat hull; corn fine fiber contained the least amount of lipids (1.7%). Sitosterol, campesterol, and stigmasterol were the major phytosterols in these lipid extracts, whereas brassicasterol was detected only in wheat samples. Rice bran oil contained considerable amounts of cycloartenol and 24‐methylenecycloartanol, which were unique to these samples. Total sterol concentrations in extracted lipids were similar for rice bran, wheat bran, wheat germ, and durum wheat (21.3–15.1 mg/g), but they were very low in oat bran lipids and oat hull lipids (3.4 and 8.2 mg/g, respectively). Corn fine fiber lipids contained the highest amount of sterols (48.3 mg/g). Rice bran appears to be the best source of phytosterols, with the highest oil content and high concentration of sterols.
Effect of alkali on the refunctionalization of soy protein by hydrothermal cooking
Authors: Wang H. , Wang T. , Johnson L. A. 
Published: November 2006

AbstractThe effects of hydrothermal cooking (HTC) at alkaline conditions on refunctionalization of heat‐denatured protein of extruded‐expelled (EE) soy meals and on preparation of soy protein isolate (SPI) from EE soy meal were determined. Two HTC setups, flashing‐out HTC (without holding period) and HTC with holding for 42 s at 154°C, were evaluated. Alkali (NaOH) addition dramatically enhanced the refunctionalization of EE meal having an initial protein dispersibility index of 35. The more alkali added, the more refunctionalization occurred. Extensive refunctionalization was achieved at 0.6 mmol alkali/g EE meal, and additional improvement was small with more alkali. For both HTC setups, the solids and protein yields of SPI from alkali‐HTC‐treated EE meals were significantly higher than those from HTC without alkali addition. The yield of protein as SPI increased from 40 to 82% after HTC treatment at 0.6 mmol alkali/g EE meal compared with no alkali addition. The emulsification capacities of SPI after alkali‐HTC were similar to those from HTC without alkali. SPI from holding‐tube HTC‐treated EE meals had higher emulsification capacities than those prepared by flashing‐out HTC.
Surface roughness during storage of chocolate: Fractal analysis and possible mechanisms
Authors: Quevedo Roberto , Brown Christopher , Bouchon Pedro , Aguilera José M. 
Published: November 2006

AbstractLaser scanning microscopy and fractal analysis were used to determine roughness in the surface of chocolate samples stored under cycling temperature conditions (16 to 26°C) for 24 d. The four samples varied in the source of fat: 100% cocoa butter (CB), lauric and nonlauric fat replacers, and CB with 2% of nonlauric fat replacer. The response variable was the area‐scale fractal complexity (Asfc), equivalent to a fractal dimension. Asfc increased with time to an asymptotic value (AV) in much the same way as whiteness index, both being accepted proxies of surface bloom. Images produced from topographical data revealed clearly the increase in roughness. Chocolate samples prepared with CB replacers exhibited an induction period and a slower rate of change in surface roughness than chocolate containing only CB. A linear relationship between a normalized roughness and the square root of time was followed by CB chocolate samples for the period before reaching AV. This result suggests that either diffusion or capillary flow may be the mechanism involved in fat migration to the surface.
Rubber seed oil quality assessment and authentication
Authors: Aigbodion A. I. , Bakare I. O. 
Published: November 2006

AbstractPhysicochemical and instrumental characterization of rubber (Hevea brasiliensis Müll. Arg.) seed oil (RSO) was carried out for the purposes of quality assessment, identification, and authentication. Properties such as color (Lovibond), specific gravity, percent FFA (as oleic acid), acid value, saponification value, iodine value, and viscosity were determined. FA composition and M.W. averages of RSO were determined using GLC and gel permeation chromatography (GPC), respectively. Structural features of RSO were also determined using FTIR, 1H NMR, and 13C NMR spectroscopy. The natural form of RSO is highly acidic (acid value≈43.6 mg KOH/g). The saturated FA are palmitic (17.50%) and stearic (4.82%), and the main unsaturated FA are oleic (25.33%), linoleic (37.50%), and linolenic (14.21%). The oil can be classified as semidrying. GPC shows an unusual peak that is due to a very high M.W. (≈38,800) fraction that is not found in the chromatogram of known vegetable oils and is therefore unique to RSO. FTIR, 1H NMR, and 13C NMR analyses confirmed that RSO is composed mainly of TAG of saturated and unsaturated FA. Functional groups such as carbonyl, olefinic unsaturation, esters, glyceryl, methylene, and terminal methyl that are present in vegetable oils are also present in RSO.
Preparation of fatty amide polyols via epoxidation of vegetable oil amides by oat seed peroxygenase
Authors: Piazza George J. , Foglia Thomas A. 
Published: November 2006

AbstractPrior work has shown that oat (Avena sativa) seeds are a rich source of peroxygenase, an enzyme that promotes the oxidation of carbon‐carbon double bonds to form epoxides. Ground and defatted oat seeds were used as a low‐cost source of peroxygenase. A systematic study of the epoxidation of i‐butyl amides from linseed oil was conducted. Hexane was used as the primary component of the reaction media to eliminate the need for extraction. We found that the addition of a small amount of buffered water containing Tween 20 enhanced the epoxidation activity when using t‐butyl hydroperoxide and cumene hydroperoxide as oxidants. This activity could be further enhanced by the addition of isopropyl ether. Conditions for larger‐scale reactions were developed and applied to amides prepared from linseed, soybean, and canola oils. Because of enzymatic selectivity, the epoxidation of adjacent double bonds was low, and monoepoxides from the amides of oleate and linoleate predominated; the diepoxide, N‐i‐butyl‐9,10–15,16‐diepoxy‐12(Z)‐octadecenamide, was obtained from the amide of linolenate. The enzymatically epoxidized amides from the oils were hydrolyzed in dilute acid, and the distribution of the various classes of polyols was determined. Reflecting the high proportion of starting monoepoxides, saturated diols and diols with one double bond were the major polyols obtained from soybean and canola oils. Because linseed oil contains a high proportion of linolenate, polyols obtained from the epoxides of this oil had a major amount of the tetrol, N‐i‐butyl‐9,10,15,16‐tetrahydroxy‐12(Z)‐octadecenamide. In contrast, the components of polyols obtained from the hydrolysis of commercial epoxide preparations of soybean and linseed methyl esters followed by amide formation were primarily saturated diols and furan derivatives resulting from the presence of adjacent epoxide groups in these preparations.
Feed batch addition of saccharide during saccharide‐fatty acid esterification catalyzed by immobilized lipase: Time course, water activity, and kinetic model
Authors: Dang Hung T. , Obiri Oriana , Hayes Douglas G. 
Published: November 2006

AbstractA conversion of 80–93% was achieved for esterification of oleic acid and fructose (or sucrose) catalyzed by immobilized Rhizomucor miehei lipase (Lipozyme IM; Novozymes, Franklinton, NC) at 65°C using near‐stoichiometric amounts of substrates. The product consisted of mono‐ and diester at a ratio of 9∶1 gg−1. The main obstacle for achieving a high rate of reaction, the poor miscibility of the substrates, was overcome by taking advantage of the greatly increased solubility of fructose as the proportion of ester increased. A phase diagram demonstrated that the solubility of fructose increased linearly from 0.002 to 0.07 to 0.13 gg−1 as the ester mass fraction increased from 0.00 to 0.47 to 0.80, respectively. Solvent (tert‐butanol) was present only during the first phase of the time course of the reaction to enhance fructose solubility and was allowed to evaporate away completely on reaching 25% conversion. A conversion higher than 80–93% could not be achieved by reducing the bioreactor's water content through use of vacuum pressure or water activity control. Water adsorption isotherms demonstrate the significant increase of equilibrium liquid phase water content as the reaction progressed, which was due to higher water adsorption by the monoester relative to oleic acid. Increased removal of liquid phase water may result in the loss of water from the lipase, resulting in a reduction of its biocatalytic activity. Initial rate experiments were used to derive a Ping‐Pong Bi Bi kinetic model that strongly agreed with measured data for the time course of the reaction. Lipozyme IM did not lose activity when employed for three successive fructose‐oleate esterification batch reactions or, equivalently, for a 24‐d reaction period.