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1.
Production of cocoa butter-like fats by the lipase-catalyzed interesterification of palm oil and hydrogenated soybean oil 总被引:1,自引:0,他引:1
Cocoa butter-like fats were prepared from refined, bleached, and deodorized palm oil (RBD-PO) and fully hydrogenated soybean
oil (HSO) by enzymatic interesterification at various weight ratios of substrates. The cocoa butter-like fats were isolated
from the crude interesterification mixture by fractional crystallization from acetone. Analysis of these fat products by RP-HPLC
in combination with ELSD or MS detection showed that their TAG distributions were similar to that of cocoa butter but that
they also contained MAG and DAG, which were removed by silica chromatography. The optimal weight ratio of RBD-PO to HSO found
to produce a fat product containing the major TAG component of cocoa butter, namely, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein
(POS), was 1.6∶1. The m.p. of this purified product as determined by DSC was comparable to the m.p. of cocoa butter, and its
yield was 45% based on the weight of the original substrates. 相似文献
2.
3.
Triglyceride interesterification by lipases. 1. Cocoa butter equivalents from a fraction of palm oil 总被引:3,自引:0,他引:3
Scott Bloomer Patrick Adlercreutz Bo Mattiasson 《Journal of the American Oil Chemists' Society》1990,67(8):519-524
Twelve commercially available triacylglycerol lipase preparations were screened for their suitability as catalysts in the
interesterification of palm oil mid fraction and ethyl stearate to form a cocoa butter equivalent. Five fungal lipase preparations
were found to be suitable. The hydrolytic activity of the commercial lipase preparations was tested with sunflower seed oil
and was independent of their interesterification activity. The operational stability of three of the preparations most suited
for production of cocoa butter equivalents was examined. The amount of a commercial lipase preparation loaded onto a support
was surveyed for optimum short-term catalytic activity.
The influence of solvent concentration on the reaction rate and the purity of the product was examined at two temperatures.
The optimum solvent concentration at 40°C was 1–1.5 grams of solvent/gram of substrate; at 60°C, the rate of interesterification
diminished and the purity of the product decreased with increasing amounts of solvent.
Four of the commercial lipase preparations found to be suitable interesterification catalysts were immobilized on five supports
and their ability to catalyze the interesterification of a triglyceride and palmitic acid or ethyl palmitate was measured.
The choice of support and substrate form (esterified or free fatty acid) greatly affected the catalytic activity. Some preparations
were more affected by the choice of support, others by the form of the substrate. No preparation yielded maximum activity
on all supports, and no support was found which produced an immobilized enzyme preparation of high activity with every commercial
lipase preparation. Caution is advised in transferring observations about the suitability of a support from tests on one commerical
enzyme preparation to others; individual testing is required. 相似文献
4.
A new industrial process for extracting cocoa butter and xanthines with supercritical carbon dioxide
This research explores the feasibility of extracting cocoa butter and xanthines (theobromine and caffeine) from cocoa beans
with supercritical CO2. It is difficult to carry out the extraction with CO2 alone in the temperature range 40–90°C at pressures between 80 to 300 bar. However, the addition of a polar cosolvent, such
as ethanol, greatly enhances solubilities, especially that of cocoa butter. Based on experimental investigations and theoretical
inference, the design of a potential industrial process for extracting cocoa butter and xanthines is proposed, in which ethanol
is used as cosolvent, and distillation is used to separate and regenerate ethanol. The pressure required is much less than
that for CO2 alone as specified in the patent literature. 相似文献
5.
Akihiro Shishikura Kenshiro Fujimoto Teruhiko Suzuki Kunio Arai 《Journal of the American Oil Chemists' Society》1994,71(9):961-967
Displacement of the equilibrium of the lipase-catalyzed interesterification between medium-chain triglyceride (MCT) and long-chain
polyunsaturated fatty acid was accomplished by the removal of by-products with continuous supercritical carbon dioxide (SC−CO2) extraction at 60°C and 100 kg/cm2. The incorporation of eicosapentaenoic acid to MCT was appreciably improved by this method and was 1.3 times higher than
that of the equilibrium state (47 wt%) that was obtained in a closed system. The immobilizedMucor miehei lipase was stable for more than 180 h in SC−CO2 at 60°C and 100 kg/cm2.
Presented at ISF-JOCS World Congress, Tokyo, Japan, September 26–30, 1988. 相似文献
6.
Enzymatic alcoholysis of cod liver oil, with an immobilized lipase, was carried out in supercritical carbon dioxide. The enzyme
was catalytically active under the experimental conditions used. The reaction medium was investigated to preferentially extract
ethyl esters, synthesized during the course of the experiment, from the unconverted cod liver oil substrate and side-products.
The effect of pressure changes on the amount of tri-, di-, and monoglycerides and ethyl esters, present in both the extract
and the remaining lipid residue, was determined. Furthermore, the fatty acid compositions of the lipid classes were analyzed,
and the relative amounts of both eicosapentaenoic acid and docosahexaenoic acid to palmitic acid were determined. The results
show that it is possible to preferentially extract the synthesized ethyl esters at low pressures. The extract collected at
9 MPa contained 64 g ethyl esters/100 g extract, while the total amount of all other lipid classes detected was 19 g/100 g
extract. As the pressure was increased, the relative amount of the other lipid classes detected in the extract, especially
triglycerides, was enhanced. The relative amounts of both eicosapentaenoic acid and docosahexaenoic acid to palmitic acid
increased for some lipid classes in the extract. This increase was most pronounced for the monoglyceride lipid class. The
integration of biocatalysis and product fractionation, applied in this study, suggests that the potential for biocatalysis
in industrial processes is considerably wider than had been thought. 相似文献
7.
C. Tsitsimpikou H. Stamatis V. Sereti H. Daflos F. N. Kolisis 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1998,71(4):309-314
The acylation of glucose with lauric acid in a reaction catalysed by two Candida lipases and a Mucor miehei lipase in supercritical carbon dioxide (SCCO2) was investigated. A linear dependence of the reaction rate on enzyme concentration was observed. Studies on the effect of temperature on enzyme activity showed that Candida antarctica lipase remains stable at temperatures as high as 70°C. Non-immobilised Candida rugosa lipase was found to have a temperature optimum at 60°C. The acylation reaction rate depended on the initial water activity of both substrates and enzyme; the optimum was 0·75 for Candida antarctica lipase, 0·53 for Candida rugosa lipase, and between 0·3 and 0·5 for Mucor miehei lipase. Candida rugosa lipase was most active at a molar ratio of sugar: acyl donor of 1: 3, while the optimum ratio was found to increase to 1: 6 when the reaction was catalysed by Candida antarctica and Mucor miehei lipases. © 1998 SCI 相似文献
8.
9.
Modification of selected indian vegetable fats into cocoa butter substitutes by lipase-catalyzed ester interchange 总被引:2,自引:0,他引:2
R. Sridhar G. Lakshminarayana T. N. B. Kaimal 《Journal of the American Oil Chemists' Society》1991,68(10):726-730
A few solid and semi-solid fats of tree origin in India, namely sal (Shorea robusta), kokum(Garcinia indica), mahua (Madhuca latifolia), dhupa (Vateria indica) and mango (Mangifera indica), were chosen for modification into cocoa butter substitutes by lipase-catalyzed ester interchange with methyl palmitate
and/or stearate. Hexane solutions of mixtures of fat and methyl ester(s) in various molar proportions were passed through
a column of Lipozyme™, a lipase fromMucor miehei immobilized on a macroparticulate ion-exchange resin. The interesterified fats were purified by extraction with 95% ethanol
followed by silica column chromatography. Interesterified dhupa, kokum and sal fats compared well with cocoa butter in the
total fatty acid composition and the 2-position of triacylglycerols, as well as glyceride composition. In particular, interesterified
kokum fat resembled cocoa butter well in solid fat content and peak melting temperature as determined by differential scanning
calorimetry.
IICT Communication No. 2743. 相似文献
10.
Continuous supercritical carbon dioxide processing of palm oil 总被引:2,自引:0,他引:2
C. K. Ooi A. Bhaskar M. S. Yener D. Q. Tuan J. Hsu S. S. H. Rizvi 《Journal of the American Oil Chemists' Society》1996,73(2):233-237
Crude palm oil was processed by continuous supercritical carbon dioxide. The process reduces the contents of free fatty acids,
monoglycerides and diglycerides, certain triglycerides, and some carotenes. The refined palm oil from the process has less
than 0.1% free fatty acids, higher carotene content, and low diglycerides. Solubility of palm oil in supercritical carbon
dioxide increased with pressure. A co-solvent improves the refining process of palm oil. 相似文献
11.
M. A. Jackson J. W. King G. R. List W. E. Neff 《Journal of the American Oil Chemists' Society》1997,74(6):635-639
Enzymes can frequently impart more selectivity to a reaction than chemical catalysts. In addition, the use of enzymes can
reduce side reactions and simplify post-reaction separation problems. In combination with an environmentally benign and safe
medium, such as supercritical carbon dioxide (SC-CO2), enzymatic catalysis makes supercritical fluids extremely attractive to the food industry. In this study, randomization
of fats and oils was accomplished with an immobilized lipase in flowing SC-CO2. Triglycerides, adsorbed onto Celite, are solubilized in CO2 and carried over 1–10 g immobilized lipase derived from Candida antarctica. The degree of randomization and rate of triglyceride throughput could be controlled by CO2 pressure and flow rate and quantity of enzyme used. The dropping points and solid fat indices of the resulting randomized
oils were compared to oils that were randomized by conventional methods with sodium methoxide. Reversed-phase high-performance
chromatography with flame-ionization detection was used to quantitate changes in triglyceride composition of various substrates,
such as palm olein and high-stearate soybean oil. The resultant randomized oil mixtures have properties, e.g., solid fat index,
that make them potential candidates for incorporation into traditional margarine formulations. 相似文献
12.
The direct methanolysis of triglycerides in flowing supercritical carbon dioxide by an immobilized lipase is described. The
reaction system consists of two syringe pumps for substrate addition and another two syringe pumps for delivering CO2 at 24.1 MPa. Corn oil is pumped into the carbon dioxide stream at a rate of 4 μL/min, and methanol is pumped at 5 μL/min
to yield fatty acid methyl esters (FAME) at >98% conversion. Direct methanolysis of soy flakes gives FAME at similar yields.
This combined extraction/reaction is performed at 17.2 MPa and 50°C. The fatty acid profiles obtained for these seed oils
matches those obtained by classical chemical synthesis. 相似文献
13.
14.
A. Molero G mez E. Mart nez de la Ossa 《Journal of the American Oil Chemists' Society》2000,77(9):969-974
The extraction of wheat germ oil by liquid and supercritical CO2 is described from the point of view of both operative method and pretreatment of raw material. The best conditions for wheat
germ oil extraction are: pressure, 150 bar; temperature, 40°C; and solvent flow rate, 1.5 L/min at standard temperature and
pressure. The yields and fatty acid compositions obtained are very similar to those resulting from the conventional extraction
process using hexane as solvent (8.0 wt%), although a higher-quality oil is obtained by using CO2 as solvent (free fatty acids, 12.4%; tocopherol content, 416.7 mg tocopherol/g wheat germ oil). These factors lead to the
conclusion that the extraction process using CO2 could be economically competitive with the conventional process, since it considerably simplifies the oil refinement stages
and completely eliminates the solvent distillation stage, which are the most costly processing steps in terms of energy consumption. 相似文献
15.
M. -K. Chang G. Abraham V. T. John 《Journal of the American Oil Chemists' Society》1990,67(11):832-834
Cocoa butter-like fat was prepared from completely hydrogenated cottonseed and olive oils by enzymatic interesterification.
The optimum reaction time to produce the major-component of cocoa butter, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS),
was 4 hr. The cocoa butter-like fat was isolated from the reaction mixture by two filtration steps. The yield of cocoa butter-like
fat was 19%, based on the weight of the original oils. Chromatographic analysis of the product by reversephase high-performance
liquid chromatography (HPLC) has shown it contains triglyceride components similar to those of cocoa butter, but that it has
slightly more diglycerides. The melting point of this product, as measured by a differential scanning calorimeter, is 39°C,
which compares well to the 36°C melting point of natural cocoa butter.
Presented in part at the AOCS meeting in Cincinnati, Ohio, in 1989. 相似文献
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17.
A supercritical fluid extraction method has been applied to test the feasibility of tocopherol concentration from soybean
sludge with carbon dioxide at temperatures and pressures ranging from 35 to 70°C and 200 to 400 bar, respectively. The supercritical
solubility of the esterified soybean sludge was over 4–6 times greater than that of the original soybean sludge. By a simple
batch-type one-stage method the tocopherols in the esterified soybean sludge could be concentrated up to 40 wt%. The overall
results of the present study show that soybean sludge initially containing about 13–14 wt% tocopherols may require a countercurrent
multistage column to be highly and effectively concentrated. 相似文献
18.
19.
Structural evolution in tempered cocoa butter (CB) and CB mixed with a cocoa butter equivalent (CBE) was examined during 26 wk of storage (at 25 °C) using atomic force microscopy, X‐ray powder diffraction, colorimetry and pulsed nuclear magnetic resonance. The form V‐to‐VI polymorphic transition in CB started after 1 week of storage. However, fat bloom was not detected until week 3 when large crystals started to appear on the CB surface. Changes in surface topography coincided with an increase in the surface whiteness index. Addition of CBE delayed bloom development by 1–2 wk. The solid fat content (SFC) of both CB and CB + CBE increased gradually during the early wk of storage before reaching a summit and then decreasing slowly with time (at 25 °C). Concurrently, the surface roughened and the whiteness index increased for both CB and CB + CBE. We postulate that, upon bloom formation, parallel phenomena took place: (i) There was exclusion of triglyceride molecules from the CB and CB + CBE fat crystal networks due to continued contraction, and (ii) less stable crystals melted due to the heat release from the (re)crystallization of liquid fat onto existing surface crystals and from the ongoing form V → VI polymorphic transition. These events resulted in the gradual decrease in SFC seen at longer storage times. In conclusion, this study demonstrated that kinetic and thermodynamic phenomena take place in CB long after it has been tempered. 相似文献