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1.
G. R. List T. L. Mounts F. Orthoefer W. E. Neff 《Journal of the American Oil Chemists' Society》1997,74(3):327-329
Triglyceride structures of genetically modified soybean oils high in stearic acid were determined by high-pressure liquid
chromatography, and their physical properties were assessed by dilatometry and dropping point. In their natural state, these
oils lack sufficient solids at 10–33°C to qualify as margarine oils. However, after random interesterification, soybean oil
containing 17% stearic acid shows a solid fat index (SFI) profile and dropping point closely matching those of a liquid margarine
oil. Other oils, with stearic acid contents in the range of 20–33%, showed appreciable SFI values at 10°C but lacked sufficient
solids at 21.1–33.3°C. After random interesterification, these oils also exhibited SFI profiles suitable for soft tub margarine,
and their drop points increased from 18–19°C to 36–38°C. 相似文献
2.
Immobilised lipases have now become accepted as a mainstream technology for fat modification. This paper presents the development of this technology in particular for the production of trans‐free fats. One of the factors influencing this development has been concern for health, which has made trans fats a major issue for food manufacturers and consumers. Enzymatic interesterification is a relatively new method for producing trans‐free alternatives for fats used in conventional margarines and shortenings. The development of this technology is examined from the perspective of an eventual industrial application rather than operation only at the laboratory scale. This paper also covers the practical means of operating immobilised enzyme columns and gives examples of how formulations can be adapted to match existing specifications. There are environmental benefits when choosing enzyme technology in comparison with chemical‐based routes. Life cycle assessments have been used to quantify the differences in environmental impact of this new technology. The final process is both capable of providing fats with the correct melting properties but without trans fats and of reducing the environmental impact of fat processing. Finally, the future developments that are anticipated in the applications of this technology are considered. 相似文献
3.
Enzymatic interesterification of tallow-sunflower oil mixtures 总被引:2,自引:0,他引:2
Thomas A. Foglia Kimberly Petruso Stephen H. Feairheller 《Journal of the American Oil Chemists' Society》1993,70(3):281-285
In an effort to improve the physical and/or thermal characteristics of solid fats, the enzymatic interesterification of tallow
and butterfat with high-oleic sunflower oil and soybean oil was investigated. The two simultaneously occurring reactions,
interesterification and hydrolysis, were followed by high-performance liquid chromatography of altered glycerides and by gas-liquid
chromatography of liberated free fatty acids. The enzymes used in these studies were immobilized lipases that included either
a 1,3-acyl-selective lipase or acis-9-C18-selective lipase. The degree of hydrolysis of the fat/oil mixtures was dependent upon the initial water content of the reaction
medium. The extent of the interesterification reaction was dependent on the amount of enzyme employed but not on the reaction
temperature over the range of 50–70°C. Changes in melting characteristics of the interesterified glyceride mixtures were followed
by differential scanning calorimetry of the residual mixed glycerides after removal of free fatty acids. Interesterification
of the glyceride mixes with the two types of enzymes allowed for either a decrease or increase in the solid fat content of
the initial glyceride mix. 相似文献
4.
Reprocessing neat vicinal polyformate esters of milkweed and soybean triglycerides in a silica-drying column with mild heating resulted in a light reddish-orange gel formation of the column eluate on cooling. Analysis of gel by 1H- and 13C-NMR showed characteristics of possible elimination, which include olefinic/aromatic moieties and formic acid. Rearrangement of triglyceride skeleton leads to crosslinking. FTIR spectrum of the gel suggested formation of olefinic species. Trial runs to reproduce the column results by heating aliquots of the neat vicinal polyformate under N2 with and without silica gel generated a gas that discharged basic phenolphthalein solution. Further heating gave a tacky off-white polymer that was chloroform insoluble. In contrast, the vicinal polyacetate derivatives of milkweed and soybean oils were stable under similar reaction conditions. From the rheological similarity of their power-law exponents, 0.63 and 0.70, respectively, MWF gel and SoyF gel can have similar behavior during processing. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. J. Appl. Polym. Sci. 2019 , 136, 48225. 相似文献
5.
Hong Zhang Xuebing Xu Jörgen Nilsson Huiling Mu Jens Adler-Nissen Carl-Erik Høy 《Journal of the American Oil Chemists' Society》2001,78(1):57-64
Interesterification of a blend of palm stearin and coconut oil (75∶25, w/w), catalyzed by an immobilized Thermomyces lanuginosa lipase by silica granulation, Lipozyme TL IM, was studied for production of margarine fats in a 1- or 300-kg pilot-scale
batch-stirred tank reactor. Parameters and reusability were investigated. The comparison was carried out between enzymatic
and chemical interesterified products. Experimentally, Lipozyme TL IM had similar activity to Lipozyme IM for the interesterification
of the blend. Within the range of 55–80°C, temperature had little influence on the degree of interesterification for 6-h reaction,
but it had slight impact on the content of free fatty acids (FFA). Drying of Lipozyme TL IM from water content 6 to 3% did
not affect its activity, whereas it greatly reduced FFA and diacylglycerol contents in the products. Lipozyme TL IM was stable
in the 1-kg scale reactor at least for 11 batches and the 300-kg pilot-scale reactor at least for nine batches. Due to regiospecificity
of the lipase (sn-1,3 specific), enzymatically interesterified products had different fatty acid distribution at sn-2 position from the chemically randomized products, implying the potential nutritional benefits of the new technology.
Presented at the 91st American Oil Chemists' Society Annual Meeting in San Diego, April 28, 2000. 相似文献
6.
Sakina Khatoon Sunki Reddy Yella Reddy 《European Journal of Lipid Science and Technology》2005,107(11):786-791
Speciality plastic fats with no trans fatty acids suitable for use in bakery and as vanaspati are prepared by interesterification of blends of palm hard fraction (PSt) with mahua and mango fats at various proportions. It was found that the interesterified samples did not show significant differences in solid fat content (SFC) after 0.5 or 1 h reaction time. The blends containing PSt/mahua (1:1) showed three distinct endotherms, indicating a heterogeneity of triacylglycerols (TG), the proportions of which altered after interesterification. The SFC also showed improved plasticity after interesterification. Similar results were observed with other blends of PSt/mahua (1:2). These changes in melting behavior are due to alterations in TG composition, as the trisaturated‐type TG were reduced and the low‐melting TG increased after interesterification. The blends containing PSt/mango (1:1) showed improvement in plasticity after interesterification, whereas those containing PSt/mango (2:1) were hard and showed high solid contents at higher temperature and hence may not be suitable for bakery or as vanaspati. The blends with palm and mahua oils were softer and may be suitable for margarine‐type products. The results showed that the blends of PSt/mahua (1:1, 1:2) and PSt/mango (1:1) after interesterification for 1 h at 80 °C showed an SFC similar to those of commercial hydrogenated bakery shortenings and vanaspati. Hence, they could be used in these applications in place of hydrogenated fats as they are free from trans acids, which are reported to be risk factors involved in coronary heart disease. For softer consistency like margarine applications, the blends containing palm oil and mahua oil are suitable. 相似文献
7.
Amy E. Clough 《Journal of the American Oil Chemists' Society》1992,69(5):456-460
Square-wave voltammetry (SWV) has been applied to the determination of tocopherol concentrations in eight vegetable oils:
canola, corn, olive, peanut, safflower, sesame, soybean, and sunflower. This technique has a lower limit of detection and
somewhat better resolution than differential-pulse voltammetry (DPV) and is significantly faster than both DPV and high-performance
liquid chromatography (HPLC), the technique most often used for tocopherol determinations. The tocopherols are oxidized at
a stationary glassy carbon electrode as its potential is scanned from 0.40 to 1.00 Vvs Ag/AgCl at a rate of 20 mV/s. The currents that arise from these oxidations are directly proportional to the tocopherols’
concentrations. A standard addition method is used to determine the tocopherol contents of the oils listed. Under the conditions
employed, the limit of detection is 10 mg/L tocopherol in oil. 相似文献
8.
In previous studies on the drying performance of oleoresinous and solvent-based offset lithographic printing inks, a test
was devised to determine the rate of absorption of drops of vegetable oils and solvents deposited on the surface of a paper
substrate. The influence of viscosity on the rate of horizontal capillary absorption indicated a potential use of the absorption
data to predict viscosity in the oxidative polymerization of polyunsaturated vegetable oils. Volumes as low as 1.0 mL could
be used in thermal oxidative polymerization studies and tested by the Drop Deposition method. The stain radii R
s of absorbed drops of the oil, e.g., on blotting paper or filter paper substrates, follow a linear relationship with the square
root of time (
s) and the slopes m of the R
s vs graphs are converted to dynamic viscosity in dPa.s units using a modified form of the Lucas Washburn equation from which
. The study has implications for assessing the stability of vegetable oils used in frying operations. The test method may
also be used in the study of room temperature oxidative polymerization of polyunsaturated vegetable oils to evaluate drier
catalysts used in surface coatings.
An erratum to this article can be found at 相似文献
9.
Victor M. Balcão Asmo Kemppinen F. Xavier Malcata Paavo J. Kalo 《Journal of the American Oil Chemists' Society》1998,75(10):1347-1358
Butterfat was chemically modified via combined hydrolysis and interesterification, catalyzed by a commercial lipase immobilized onto a bundle of hydrophobic hollow
fibers. The main goal of this research effort was to engineer butterfat with improved nutritional properties by taking advantage
of the sn-1,3 specificity and fatty acid specificity of a lipase in hydrolysis and ester interchange reactions, and concomitantly decrease
its level of long-chain saturated fatty acid residues (viz., lauric, myristic, and palmitic acids) and change its melting properties. All reactions were carried out at 40°C in a solvent-free
system under controlled water activity, and their extent was monitored via chromatographic assays for free fatty acids, esterified fatty acid moieties, and triacylglycerols; the thermal behavior of
the modified butterfat was also assessed via calorimetry. Lipase-modified butterfat possesses a wider melting temperature range than regular butterfat. The total saturated
triacylglycerols decreased by 2.2%, whereas triacylglycerols with 28–46 acyl carbons (which contained two or three lauric,
myristic, or palmitic acid moieties) decreased by 13%. The total monoene triacylglycerols increased by 5.4%, whereas polyene
triacylglycerols decreased by 2.9%. The triacylglycerols of interesterified butterfat had ca. 10.9% less lauric, 10.7% less myristic, and 13.6% less palmitic acid residues than those of the original butterfat. 相似文献
10.
Dorin Dadarlat Dane Bicanic Henk Visser Fulvio Mercuri Angela Frandas 《Journal of the American Oil Chemists' Society》1995,72(3):281-287
The photopyroelectric (PPE) technique was used to detect solid-to-liquid phase transitions in saturated [C6:0, C10:0, C12:0,
C16:0 palmitic acid (P), C18:0 stearic acid (S)] and unsaturated (C18:2) fatty acids and some triglycerides (PSP, PPS). By
using the standard PPE configuration with a thermally thin and optically opaque sample and a thermally thick sensor (a1.1);
the temperature behavior of the volume-specific heat in a temperature range that includes the melting points for C10:0, C12:0,
C16:0, and C18:0 was obtained. When the standard PPE configuration, with sample and sensor both being thermally thick and
the sample being optically opaque (a1.2), was used, the information contained in the phase of the PPE signal allowed direct
measurement of the thermal diffusivity for C10:0, C12:0, and PSP. The inverse configuration with a thermally thick sample
and thermally thin sensor (b1.2) or a semitransparent thermally thick sensor (b2) was used to obtain critical behavior of
the thermal effusivity for C10:0 and C12:0, respectively. Critical behavior of the thermal conductivity for same samples was
computed from information obtained from amplitude and phase measurements (a1.2), or by combining a1.1 and b1.2 data. The history
(age, storage conditions, annealing) of the samples affects the critical behavior of thermal parameters. 相似文献
11.
H. Noureddini B. C. Teoh L. Davis Clements 《Journal of the American Oil Chemists' Society》1992,69(12):1189-1191
Data for viscosity as a function of temperature from 24 to 110°C (75 to 230°F) have been measured for a number of vegetable
oils (crambe, rapeseed, corn, soybean, milk-weed, coconut, lesquerella) and eight fatty acids in the range from C9 to C22. The viscosity measurements were performed according to ASTM test methods D 445 and D 446. Several correlations were fitted
to the experimental data. Correlation constants for the best fit are presented. The range of temperature in which the correlations
are valid is from 24°C (75°F), or the melting point of the substance, to 110°C (230°F). The correlation constants are valuable
for designing or evaluating such chemical process equipment as heat exchangers, reactors, distillation columns, mixing vessels
and process piping. 相似文献
12.
Dorin Dadarlat Dane Bicanic Henk Visser Fulvio Mercuri Angela Frandas 《Journal of the American Oil Chemists' Society》1995,72(3):273-279
The photopyroelectric (PPE) technique is proposed to detect solid-to-liquid phase transitions in fatty acids and triglycerides.
Various PPE configurations and cell geometries were used to obtain thermal parameters in the vicinity of the melting points
for these samples. In the standard (SPPE) configuration used to determine specific heat, the sample is thermally thin and
optically opaque, while the sensor itself is thermally thick. The same configuration, but with a thermally thick sample instead,
allows direct measurement of the sample’s thermal diffusivity. The temperature dependence of the thermal effusivity was obtained
for a thermally thick sample and a thermally thin sensor [inverse (IPPE) configuration], and for a semitransparent thermally
thick sensor by making use of the front configuration. 相似文献
13.
G. R. List T. L. Mounts F. Orthoefer W. E. Neff 《Journal of the American Oil Chemists' Society》1996,73(6):729-732
Genetically modified soybeans were processed into finished, refined, bleached, and deodorized oils. Fatty acid composition
was determined by gas-liquid chromatography. Glyceride structure was characterized according to degree of unsaturation by
high-performance liquid chromatography, lipase hydrolysis, and gas-liquid chromatography. Compared to common varieties with
15% saturated acids, genetically modified soybeans yielded oils containing 24–40% saturated acids. Several varieties were
examined, including the Pioneer A-90, Hartz HS-1, and Iowa State A-6 lines. Pioneer A-90 contained 17% stearic acid, had a
solid fat index (SFI) of 6.0 at 10°C (50°F) and zero from 21.1 to 40°C (70 to 104°F), and therefore lacked sufficient solids
for tub-type margarine. To improve its plastic range, the Pioneer oil was blended with palm oil, randomized palm oil, or interesterified
palm/soy trisaturate basestock. After blending with 10–40% of these components, the high-stearic acid oil had an SFI profile
suitable for soft tube margarine. The A-6 varieties, 32–38% saturates, showed SFI profiles with sufficient solids at 10°C
(50°F) and 21.1°C (70°F) to qualify as a stick-type margarine oil, but lacked sufficient solids at 33.3°C (92°F); however,
after small amounts (2–3%) of cottonseed or soybean hardstocks were added, the A-6 oils qualified as stick margarine oil.
The HS-1 variety, when blended with small amounts (2–3%) of hardstock, possessed sufficient solids at 10°–33.3°C (50–92°F)
to prepare soft tub margarine oil.
Presented at the AOCS Annual Meeting & Expo, San Antonio, Texas, May 8–12, 1995. 相似文献
14.
Physical and chemical properties of trans-free fats produced by chemical interesterification of vegetable oil blends 总被引:1,自引:0,他引:1
V. Petrauskaite W. De Greyt M. Kellens A. Huyghebaert 《Journal of the American Oil Chemists' Society》1998,75(4):489-493
Fat blends, formulated by mixing a highly saturated fat (palm stearin or fully hydrogenated soybean oil) with a native vegetable
oil (soybean oil) in different ratios from 10:90 to 75:25 (wt%), were subjected to chemical interesterification reactions
on laboratory scale (0.2% sodium methoxide catalyst, time=90 min, temperature=90°C). Starting and interesterified blends were
investigated for triglyceride composition, solid fat content, free fatty acid content, and trans fatty acid (TFA) levels. Obtained values were compared to those of low- and high-trans commercial food fats. The interesterified blends with 30–50% of hard stock had plasticity curves in the range of commercial
shortenings and stick-type margarines, while interesterified blends with 20% hard stock were suitable for use in soft tubtype
margarines. Confectionery fat basestocks could be prepared from interesterified fat blends with 40% palm stearin or 25% fully
hydrogenated soybean oil. TFA levels of interesterified blends were low (0.1%) compared to 1.3–12.1% in commercial food fats.
Presented at the 88th AOCS Annual Meeting and Expo, May 11–14, 1997, Seattle, Washington. 相似文献
15.
Dorota Johansson 《Journal of the American Oil Chemists' Society》1995,72(10):1235-1237
The formation of fat crystal gels in soybean oil has been studied by sedimentation in a low concentration region at 10–25°C.
At 10°C, weak gels were formed with 1% crystals, and no gels formed at concentrations of 2–5%. At temperatures of 15–25°C,
no gels were formed at concentrations of 1–5%, and samples sedimented. Stronger gels of fat crystals were formed with ∼10%
fat crystals at all temperatures examined. Formation of weak gels is a consequence of the fractal nature of fat crystal aggregates
and sediments. At low temperature, the interaction is weak. The fractal dimension is then high, and the floc size is large
for low crystal concentrations. These large flocs form a three-dimensional network that act as a weak gel and withstand gravitational
force. When the temperature is increased, the fat crystal interaction becomes stronger, fractal dimension decreases, and floc
size decreases. Smaller flocs have a higher density, pack more easily, and sediment. Similar effects are observed when the
concentration of fat crystals is increased at low temperature due to a decrease in floc size. 相似文献
16.
Noor Lida Habi Mat Dian Kalyana Sundram Nor Aini Idris 《Journal of the American Oil Chemists' Society》2006,83(8):739-745
Changes in DSC melting properties of palm oil (PO), sunflower oil (SFO), palm kernel olein (PKOo), and their belends in various
ratios were studied by using a combination of blending, and chemical interesterification (CIE) techniques and determining
total melting (ΔH
f
) and partial melting (ΔH
i°C
) enthalpies. Blending and CIE significantly modified the DSC melting properties of the PO/SFO/PKOo blends. PO and blends
containing substantial amounts of PO and PKOo experienced an increase in their DSC ΔH
f
and ΔH
i°C
following CIE. The DSC ΔH
f
and ΔH
i°C
of PKOo, blends of PO/SFO at 1∶1 and 1∶3 ratios, and all blends of PKOo/SFO significantly decreased after CIE. The DSC ΔH
f
and ΔH
i°C
of SFO changed little following CIE. Randomization of FA distribution within and among TAG molecules of PO and PKOo led to
modification in TAG composition of the PO/PKOo blends and improved miscibility between the two fats and consequently diminished
the eutectic interaction that occurred between PO and PKOo. 相似文献
17.
H. Noureddini B. C. Teoh L. Davis Clements 《Journal of the American Oil Chemists' Society》1992,69(12):1184-1188
Complete data for density as a function of temperature have been measured for a number of vegetable oils (crambe, rapeseed,
corn, soybean, milkweed, coconut, lesquerella), as well as eight fatty acids in the range C9 to C22 at temperatures from above their melting points to 110°C (230°F). The specific gravity and density measurements were performed
according to American Society for Testing and Materials (ASTM) standard test methods D 368, D 891 and D 1298 for hydrometers
and a modified ASTM D 369 and D 891 for pycnometers. Correlation constants, based on the experimental data, are presented
for calculating the density of fatty acids and vegetable oils in the range of temperature from 24°C (75°F) or the melting
point of the substance, to 110°C (230°F). The constants are valuable for designing or evaluating such chemical process equipment
as heat exchangers, reactors, process piping and storage tanks. Estimated density of fatty acids by a modified Rackett equation
is also presented. 相似文献
18.
R. Ap. Ferrari W. Esteves K. D. Mukherjee 《Journal of the American Oil Chemists' Society》1997,74(2):93-96
Steryl ester content of refined and interesterified corn, soybean, and rapeseed oils has been measured via clean-up on a short silica gel column, followed by high performance liquid chromatography with evaporative light-scattering
mass detector. Chemical interesterification, catalyzed by sodium methoxide, led to random positional distribution of fatty
acids in triacylglycerols and some increase in the steryl ester content of all three oils. Enzymatic interesterification,
catalyzed by the immobilized lipase from Rhizomucor miehei (Lipozyme), resulted in a distinct reduction in steryl ester content, but essentially no alteration in positional distribution
of fatty acids in triacylglycerols occurred. Formation of steryl esters during chemical and enzymatic interesterification
was also examined by radioactive tracer technique with [4-14C]β-sitosterol added as marker to refined rapeseed oil and measurement of the radioactive steryl esters formed. Chemical interesterification
of rapeseed oil resulted in moderate formation (10% of total radioactivity) of radioactive β-sitosteryl esters. Enzymatic
interesterification of the oil, catalyzed by Lipozyme, led to little formation of radioactive β-sitosteryl esters, whereas
with the lipase from Candida cylindracea high proportions (>90% of total radioactivity) of 14C-labeled β-sitosteryl esters were formed.
Part of doctoral thesis of Roseli Ap. Ferrari to be submitted to Faculdade de Engenharia de Alimentos, Universidade de Campinas,
Campinas, Brazil. 相似文献
19.
The development and application of novel vegetable oils tailor‐made for specific human dietary needs
Hidetoshi Sakurai Jan Pokorný 《European Journal of Lipid Science and Technology》2003,105(12):769-778
Conventional edible oils, such as sunflower, safflower, soya bean, rapeseed (canola) oils, were modified to obtain high‐oleic, low‐linoleic or even low‐linolenic oils. The aim was to develop salad, cooking and frying oils, that are very stable against lipid peroxidation. They are also suitable for margarine blends, as additives to cheeses and sausages, or even as feed components. Oils containing higher amounts of medium‐chain length or long‐chain polyunsaturated fish oil fatty acids are suitable as special dietetic oils or as nutraceuticals. High‐stearic oils are designed as trans‐fatty acid‐free substitutes for hydrogenated oils. New tailor‐made (designer) oils are thus a new series of vegetable oils suitable for edible purposes, where conventional oils are not suitable. 相似文献
20.
James W. Peterson Karry L. Muzzey David Haytowitz Jacob Exler Linda Lemar Sarah L. Booth 《Journal of the American Oil Chemists' Society》2002,79(7):641-646
Assessment of vitamin K (VK) dietary intakes has been limited by the incompleteness of VK food composition data for the U.S.
food supply, particularly for VK-rich oils. The phylloquinone (VK-1) and 2′,3′-dihydrophylloquinone (dK) concentrations of
margarines and spreads (n=43), butter (n=4), shortening (n=4), vegetable oils (n=6), and salad dressings (n=24) were determined by RP-HPLC with fluorescence detection. Each sample represented a composite of units or packages obtained
from 12 or 24 outlets, which were geographically representative of the U.S. food supply. Butter, which is derived from animal
fat sources, had less VK-1 compared to vegetable oil sources. The VK-1 and dK of the margarines and spreads increased with
fat content and the degree of hydrogenation, respectively. In some margarines or spreads and in all shortenings, the dK concentrations
were higher than the corresponding VK-1 concentrations. As the fat content of salad dressings increased, the VK-1 concentrations
also increased. Fat-free foods had <1 μg/100 g of either form of the vitamin. No dK was detected in the salad dressings or
oils tested. Some margarines, spreads, and salad dressings may be significant sources of vitamin K in the U.S. food supply. 相似文献