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1.
The fatty acid composition of partially hydrogenated arachis (HAO), partially hydrogenated soybean (HSO) and partially hydrogenated
herring (HHO) oils and of a normal, refined arachis oil (AO) was studied in detail by means of direct gas liquid chromatography,
ultraviolet and infrared spectrophotometry and by thin layer chromatography fractionation on silver nitrate-silica gel plates
followed by gas liquid chromatography. It was shown that the partially hydrogenated oils all contained fatty acids withtrans double bonds. In the plant oils, thetrans acids were present mainly as elaidic acid. The HHO showed an almost equal distribution betweentrans 18∶1 ω9,trans 20∶1 ω>9 andtrans 22∶1 ω>9. Sometrans configuration was also found in the C20-and C22-dienes and trienes of the HHO. In all the oils, conjugated fatty acids were present in minor amounts only (<0.5%). Special
attention was given to the ω-acids known to be of specific nutritional value. The HSO contained about 32% linoleic acid, whereas
the content ofcis, trans+trans, cis andtrans, trans octadecadienoic isomers was 1.7% and 0.5%, respectively. The amount of linoleic acid in the HSO was even higher than that
of AO (29%). The HAO contained only 0.8% 18∶2 ω6 (linoleic acid). Further, two 18∶2 fatty acids with ω>6, acis, cis and atrans, trans isomer, were present in small amounts. The HHO contained 0.5% 18∶2 ω6 (linoleic acid). Isomers of 18∶2 ω>6 were also found
in the HHO. They may be hydrogenation products of higher unsaturated C18-acids orginally present. All the C20- and C22-dienes and trienes were shown to have an ω-chain greater than 6. Fatty acids with ω6-structure were not formed during partial
hydrogenation of the oils studied. 相似文献
2.
P. K. Pal D. K. Bhattacharyya S. Ghosh 《Journal of the American Oil Chemists' Society》2000,77(11):1215-1218
Fractionation of butter oil from isopropanol and characterization of the chemical composition and the melting properties of
the fractions obtained have been investigated. Butter oil was fractionated from isopropanol (1∶4 wt/vol) at 15 to 30°C. The
yields of stearins and oleins were dependent on the temperature employed during fractionation. Thus, 24.8 to 48.9% of stearins
and 51.5 to 75.2% of oleins could be obtained as the crystallization temperature varied from 15 to 30°C. The stearin fractions
displayed a distinct variation in the fatty acid compositions. The palmitic acid content of the stearin fractions varied from
39.1 to 44.0%, and that of stearic from 15.1 to 16.8%, respectively. The olein fractions contained 43.2% stearic acid, and
2.4 to 2.8% palmitoleic acid (C16∶1). The solid fat content values of the stearin fractions obtained were 62–67, 39–50, and
21–25 at 10, 20, and 30°C, respectively. From the results, it is evident that anhydrous milk fat can be fractionated at relatively
high temperatures from isopropanol to produce stearin and olein fractions of specific composition and properties. 相似文献
3.
Palm stearin with a melting point (m.p.) of 49.8°C was fractionated from acetone to produce a low-melting palm stearin (m.p.=35°C)
and a higher-melting palm stearin (HMPS, m.p.=58°C) fraction. HMPS was modified by interesterification with 60% (by weight)
of individual liquid oils from sunflower, soybean, and rice bran by means of Mucor miehei lipase. The interesterified products were evaluated for m.p., solid fat content, and carbon number glyceride composition.
When HMPS was interesterified individually with sunflower, soybean or rice bran at the 60% level, the m.p. of the interesterified
products were 37.5, 38.9, and 39.6°C, respectively. The solid fat content of the interesterified products were 30–35 at 10°C,
17–19 at 20°C, and 6–10 at 30°C, respectively. The carbon number glyceride compositions also changed significantly. C48 and C54 glycerides decreased remarkably with a corresponding increase of the C50 and C52 glycerides. All these interesterified products were suitable for use as trans acid-free and polyunsaturated fatty acid-rich shortening and margarine fat bases. 相似文献
4.
A series of plastic fats containing no trans FA and having varying melting or plastic ranges, suitable for use in bakery, margarines, and for cooking purposes as vanaspati,
were prepared from palm oil. The process of fractionating palm oil under different conditions by dry and solvent fractionation
processes produced stearins of different yields. Melting characteristics of stearin fractions varied depending on the yield
and the process. The lower-yield stearins were harder and had a wider plastic range than those of higher yields. The fractions
with yields of about 35% had melting profiles similar to those of commercial vanaspati. The plastic range of palm stearins
was further improved by blending them with corresponding oleins and with other vegetable oils. The plasticity or solid fat
content varied depending on the proportion of stearin. Blends with higher proportions of stearins were harder than those with
lower proportions. the melting profiles of some blends, especially those containing 40–60% stearin of about 25% yield and
40–60% corresponding oleins or mahua or rice bran oils, were similar to those of commercial vanaspati and bakery shortenings.
These formulations did not contain any trans FA, unlike those of commercial hydrogenated fats. Thus, by fractionation and blending, plastic fats with no trans acids could be prepared for different purposes to replace hydrogenated fats, and palm oil could be utilized to the maximum
extent. 相似文献
5.
Bakery shortenings prepared by hydrogenation contain high levels of trans fatty acids, which are considered to be risk factors for cardiovascular disease. The shortenings prepared from maogo kernel
and mahua fats have no trans fatty acids. Mahua fat was fractionated by dry fractionation to obtain a high-melting fraction (10% yield, Mh1). Mango fat
was fractionated by two-stage solvent fractionation, separating about 15% high-melting fraction (Mk1) in the first stage,
followed by 40% stearin (Mk2) in the second stage. The formulation containing 80% Mh1 and 20% of mango middle stearin fraction
(Mk2) showed melting characteristics and onset and enthalpy of crystallization similar to those of commercial hydrogenated
shortenings designed for cakes and biscuits. The formulation suitable for puff pastry shortening was prepared by blending
50% mango 1st stearin (Mk1) and 50% mahua fat with addition of 5–7% of fully hydrogenated vegetable oil. The formulations
having melting characteristics similar to those of commercial cake and biscuit shortenings were also prepared by blending
40% mango fat and 60% mahua fat with 5–7% incorporation of fully hydrogenated peanut oil. However, these formulations showed
delayed transition to the stable forms compared to those of commercial samples. Fatty acid composition revealed that commercial
hydrogenated shortenings consisted of 18–29% trans oleic acid, whereas the formulations we prepared did not contain any trans acids. The iodine values of commercial samples were 57–58, whereas the value for the formulations prepared were 47–53. The
consistency of the prepared samples as measured by cone penetrometer was slightly harder than commercial samples. These studies
showed that it is possible to prepare bakery shortenings with no trans fatty acids by using mango and mahua fats and their fractions. 相似文献
6.
The paper describes a method of fractionating vegetable, animal and fish oils, and in particular palm oil. The method involves
addition of a medium comprising two common solvents to the semisolid oils. On centrifugation, the olein and stearin are separated
by the medium in the middle. Thirteen media made up from binary combinations of nine solvents, viz. water, propylene glycol,
glycerine, methanol, ethanol,n-propanol, isopropanol (IPA), acetone and butanone, are found to be effective in olein-stearin separation. However, only the
water/IPA and water/methanol systems have been studied in detail. The aqueous IPA provides a higher yield of olein than water/
methanol but intersolubility between oil and medium is also greater. The fractionation process can be carried out at any suitable
temperature. Fractionation of the special prime bleached (SPB) palm oil at 16 C yields an olein with a cloud point of 4.8
C. Some hybrid palm oils produce a large quantity of low cloud point olein which can be bleached readily. The process can
be extended to include degumming and neutralization by using an alkaline medium for centrifugation. The olein fractions obtained
have been found to be free of phosphatides and the free fatty acids reduced to as low as 0.02%. Metal-scavenging agents have
also been added to the medium in an attempt to remove copper and iron. The development of this process into a continuous one
has been demonstrated on the AlfaLaval LAPX 202 Separator. Fractionation of crude palm oil using a density gradient provides
seven fractions of different characteristics. The iodine values vary from 37.5 to 57.4 and the unsaturated fatty acids range
from 32.7% to 51.2%. Triglyceride analysis by carbon numbers shows great differences in the C48 and C52 constituents of the fractions.
aThe volume ratio of oil to medium in each case was 1:1.
The separation involved the oil and wax. 相似文献
7.
Robert L. Wolff Laurent G. Deluc Anne M. Marpeau 《Journal of the American Oil Chemists' Society》1996,73(6):765-771
The seed oils from twenty-five Conifer species (from four families—Pinaceae, Cupressaceae, Taxodiaceae, and Taxaceae) have
been analyzed, and their fatty acid compositions were established by capillary gas-liquid chromatography on two columns with
different polarities. The oil content of the seeds varied from less than 1% up to 50%. Conifer seed oils were characterized
by the presence of several Δ5-unsaturated polymethylene-interrupted polyunsaturated fatty acids (Δ5-acids) with either 18
(cis-5,cis-9, 18∶2,cis-5,cis-9,cis-12 18∶3, andcis-5,cis-9,cis-12,cis-15 18∶4 acids) or 20 carbon atoms (cis-5,cis-11 20∶2,cis-5,cis-11,cis-14, 20∶3, andcis-5,cis-11,cis-14,cis-17 20∶4 acids). Pinaceae seed oils contained 17–31% of Δ5-acids, mainly with 18 carbon atoms. The 20-carbon acids present
were structurally derived from 20∶1n-9 and 20∶2n-6 acids. Pinaceae seed oils were practically devoid of 18∶3n-3 acid and did
not contain either Δ5-18∶4 or Δ5-20∶4 acids. Several Pinaceae seeds had a Δ5-acid content higher than 50 mg/g of seed. The
only Taxaceae seed oil studied (Taxus baccata) had a fatty acid composition related to those of Pinaceae seed oils. Cupressaceae seed oils differed from Pinaceae seed
oils by the absence of Δ5-acids with 18 carbon atoms and high concentrations in 18∶3n-3 acid and in Δ5-acids with 20 carbon
atoms (Δ5-20∶3 and Δ5-20∶4 acids). Δ5-18∶4 Acid was present in minute amounts. The highest level of Δ5-20∶4 acid was found
inJuniperus communis seed oil, but the best source of Δ5-acids among Cupressaceae wasThuja occidentalis. Taxodiaceae seed oils had more heterogeneous fatty acid compositions, but the distribution of Δ5-acids resembled that found
in Cupressaceae seed oils. Except forSciadopytis verticillata, other Taxodiaceae species are not interesting sources of Δ5-acids. The distribution profile of Δ5-acids among different
Conifer families appeared to be linked to the occurrence of 18∶3n-3 acid in the seed oils. 相似文献
8.
Yukio Kakuda Firouz Jahaniaval Massimo F. Marcone Lourdes Montevirgen Quintin Montevirgen Joselyn Umali 《Journal of the American Oil Chemists' Society》2000,77(9):991-997
The fatty acid and triacylglycerol composition of pili nut (Canarium ovatum) oil and fractions were analyzed by gas chromatography and reversed-phase high-performance liquid chromatography, respectively.
The oil obtained by solvent extraction was low in polyunsaturated fatty acids and high in saturates. The polyunsaturated fatty
acid (18∶2 and 18∶3) contents were less than 11%, whereas palmitic (16∶0) and stearic acid (18∶0) were 33.3 and 10.9%, respectively.
The saturated fatty acid level of the low-melting fraction oil was reduced from 44.4 to 35.5% and the total unsaturated fatty
acid levels were increased from 55.6 to 65% by fractional crystallization. Triacylglycerol analysis showed that the high-melting
fraction (HM) from pili nut oil consisted of POP, POS, and SOS+SSO (P=palmitic acid, O=oleic acid, and S=stearic acid) in
the proportion of 48.6, 38.8, and 8.7%, respectively. The physicochemical properties of the HM fraction were studied using
differential scanning calorimetry and pulsed nuclear magnetic resonance. The results showed that the melting range and solid
fat content of the HM fraction were very similar to those isolated from cocoa butter and olive oil. The content of POP played
an important role in determining the melting range of the HM fraction. It is suggested that this HM fraction may have applications
as a cocoa butter substitute in confectionery products. 相似文献
9.
Simarouba glauca is a rich source of fat, having a melting point of about 29°C and consisting of palmitic (12.5%), stearic (27%) and oleic
(56%) as major fatty acids. It consists of about 30% of symmetrical monounsaturated-type triacylglycerols and appears to be
a good source of fat for preparation of cocoa butter (CB) extender. The stearin fraction (35% yield) obtained by solvent fractionation
showed an increased supercooling property and a sudden rise in temperature during solidification compared to native fat as
shown by cooling curves. The fraction had a narrow melting range and consisted of a high content (66%) of symmetrical monounsaturated-type
triacylglycerols like CB. The fraction was compatible with CB even at 50% substitution. In addition, the fraction did not
affect the formation of stable or other polymorphic forms of CB at different tempering conditions. The fraction obtained by
dry fractionation also had properties similar to that obtained by solvent fractionation. The conditions of the fractionation
determine the yield of stearin, which in turn alters the melting characteristics of the fractions. The stearin obtained after
removal of about 60–65% olein was found to be suitable as a CB extender to replace up to 25% of CB in chocolate products. 相似文献
10.
Paresch Chandra Dutta Seved Helmersson Eshetu Kebedu Getinet Alema Lars-Åke Appelqvist 《Journal of the American Oil Chemists' Society》1994,71(8):839-843
Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid,
tocopherol and sterol composition in the seed oil by gas-liquid chromatography and high-performance liquid chromatography
methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic
acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1)
at a range of 6 to 11% each. Total polar lipids recovered after preparative thin-layer chromatography comprised a small fraction
of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α-Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40%
of the total sterols wasβ-sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5- and Δ7-avenasterols were
in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location
on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison
with known data for common oils from Compositae,viz, safflower and sunflower. 相似文献
11.
Position 1 of the phospholipid and triglyceride fractions isolated fromMycobacterium smegmatis andM. bovis BCG was esterified principally with C18 related fatty acids (18∶0, 18∶1 and 19Br). Position 2 was occupied principally by C16 fatty acids. The third position of the triglycerides was esterified with a preponderance of C20+fatty acids. Seventysix per cent of position 3 fatty acids in BCG and 43% inM. smegmatis triglycerides contained fatty acids of greater than 20 carbon atoms. 相似文献
12.
Nutritional and toxicological evaluation of rubber seed oil 总被引:2,自引:0,他引:2
V. M. Gandhi K. M. Cherian M. J. Mulky 《Journal of the American Oil Chemists' Society》1990,67(11):883-886
Rubber (Hevea brasiliensis) seed oil (RSO) is available in India (Ca. 4500 tons per year) and is used mainly as a drying oil. The oil does not contain
any unusual fatty acids, and it is a rich source of essential fatty acids C18∶2 and C18∶3 that make up 52% of its total fatty acid composition. Acute toxic potential in rats and the systemic effects and nutritional
quality were assessed in a 13 week feeding study in weanling albino rats using a diet containing RSO or groundnut oil (GNO)
(as the control) at a 10% level as the sole source of dietary fat. RSO did not manifest any acute toxic potential. Food consumption,
growth rate and feed efficiency ratio of rats fed RSO were similar to those fed GNO. The digestibility of this oil was found
to be 97%, as compared to 94% for GNO. There were no macroscopic or microscopic lesions in any of the organs which could be
ascribed to the RSO incroporation in the diet. Thus the current data show that RSO could be used for edible purposes. However,
it will be necessary to process the oil to achieve deodorization and to remove free fatty acids to make it organoleptically
acceptable. 相似文献
13.
In this study we determined in rats the complete 24-h lymphatic fatty acid profile after administration of either rapeseed
oil (RO) or rapeseed oil interesterified with 10∶0 (RO/C10) with special emphasis on the transition from absorptive to postabsorptive phase. Rats were subjected to cannulation of the
main mesenteric lymph duct and the next day oils were administered through a gastric feeding tube. Lymph was collected in
1-h fractions for the following 24 h. The time for maximum lymphatic transport of fatty acids was at 4 h with fast changes
in fatty acid composition from the fatty acids of endogenous origin to those of the administered oils. Seven to eight hours
after administration the transport was significantly lower than maximum, indicating the change from absorptive to postabsorptive
phase. At 24 h after administration of either oil the transport of total fatty acids, palmitic acid (16∶0), and linoleic acid
(18∶2n−6) together with oleic acid (18∶1n−9) after RO had not returned to the transport at baseline. In contrast, the transport
of decanoic acid (10∶0) and α-linolenic acid (18∶3n−3) returned to baseline values between 12 and 15 h. This indicated that
the absorption of purely exogenous fatty acids (illustrated by 10∶0 and 18∶3n−3) was complete at 15 h and that the fatty acids
transported between 15 and 24 h were derived mostly from endogenous stores. 相似文献
14.
Fatty acid composition of neutral and polar lipid fractions from rat hearts was determined in rats of different ages as their
diet source changed. Piebald rats were weaned at 21 days and were fed standard lab chow. Lipids from rat hearts, mothers milk
and lab chow were purified on a Sephadex G-25 fine column and separated into neutral and polar lipid fractions by silicic
acid column chromatography. These lipid fractions were then hydrolyzed and methylated with BF3 in methanol, prior to gas liquid chromatographic separation on a 1/8 in. × 10 ft aluminum column of 15% EGS on 80–100 mesh
acid-washed Chromosorb W. Three major fatty acids in the neutral lipid fraction comprised 72% of total neutral lipid fatty
acids from young hearts. At sexual maturity (at least 74 days old) C18∶1 was the major fatty acid, followed by C16∶0 and C18∶0. The same three fatty acids comprised 83% of total polar lipid fatty acids, but C18∶0 was the major fatty acid, followed by C16∶0 and C18∶1. The fatty acid composition of dietary lipids influenced the total neutral lipid fatty acid composition of the rat heart,
but had little influence on the fatty acid composition of the polar lipid fraction.
Presented in part at the AOCS Meeting, New Orleans, April 1970. 相似文献
15.
Uncommoncis andtrans fatty acids can be desaturated and elongated to produce unusual C18 and C20 polyunsaturated fatty acids in animal tissues. In the present study we examined the formation of such metabolites derived
fromcis andtrans isomers of oleic and linoleic acids of partially hydrogenated vegetable oil origin in rats. For two months, aduut male rats
were fed a partially hydrogenated canola oil diet containing moderately high levels oftrans fatty acids (9.6 energy%) and an adequate level of linoleic acid (1.46 energy%). Analysis of the phospholipid (PL) fatty
acids of liver, heart, serum and brain showed no new C18 polyunsaturated fatty acids, except for those uncommon 18∶2 isomers originating from the diet. However, minor levels (each
<0.3% PL fatty acids) of six unusual C20 polyunsaturated fatty acids were detected in the tissues examined, except in brain PL. Identification of their structures
indicated that the dietary 9c,13t−18∶2 isomer, which is the majortrans polyunsaturated fatty acid in partially hydrogenated vegetable oils, was desaturated and elongated to 5c,8c,11c,15t−20∶4, possibly by the same pathway that is operative for linoleic acid. Furthermore, dietary 12c−18∶1 was converted to 8c,14c−20∶2 and 5c,8c,14c−20∶3; dietary 9c,12t−18∶2 metabolized to 11c,14t−20∶2 and 5c,8c,11c14t−20∶4, and dietary 9t,12c to 11t,14c−20∶2. These results suggested that of all the possible isomers of oleic and linoleic acids in partially hydrogenated vegetable
oils, 12c−18∶1, 9c,13t−18∶2, 9c,12t−18∶2 and 9t,12c−18∶2 are the preferred substrates for desaturation and elongation in rats. However, their conversions to C20 metabolites were not as efficient as that of oleic or linoleic acids. 相似文献
16.
Daniel P. Schwartz Dora G. Gadjeva 《Journal of the American Oil Chemists' Society》1988,65(3):378-380
The unesterified fatty acids (UFA) present in fats and oils are isolated cleanly and without the formation of detectable artifacts
due to saponification. The lipid (≤0.5 g) dissolved in 5 ml of n-hexane is passed over a 300-mg bed of Celite impregnated
with saturated, aqueous Na3PO4 so that the solution passes through the bed in 3–4 min. After the bed has been washed, the UFA are freed from their salts
by pumping of HC1 vapor over the bed. The acids are eluted with CH2Cl2 and subsequently separated underivatized by gas liquid chromatography. The C10 through C18.3 acids are separated in <15 min. Recovery of the C10-C18∶0 and C18∶1, C18∶2 and C18∶3 acids added to fatty acid-free fats and oils in several concentrations was nearly 100% 相似文献
17.
Trans fatty acids from hydrogenated vegetable and marine oils could be as hypercholesterolemic and atherogenic as saturated fatty
acids. Hence, it is important to know the fatty acid composition in major food contributors, e.g., margarines and shortenings.
In 1992 margarines were examined, and in 1995 brands covering the entire Danish market were examined. Significant amounts
oftrans-18∶1 were found only in hard margarines (mean: 4.2±2.8%) and shortenings (mean: 6.8 ±3.1%), whereas the semisoft and soft
margarines contained substantially lesstrans-18∶1 in 1995 than in 1992. Where marine oils had been used to a larger degree the meantrans-monoenoic content was about 15%, of which close to 50% was made up of long-chain (C20 and C22)trans fatty acids. A note-worthy decrease in the content oftrans-18∶1 had occurred for the semisoft margarines, from 9.8±6.1% in 1992 to 1.2±2.2% in 1995. Calculated from sales figures,
the supply oftrans-18∶1 plus saturated fatty acids from margarines had decreased over this three-year period by 1.4 g/day, which has been replaced
bycis monounsaturated and polyunsaturated fatty acids. 相似文献
18.
Effects of dietary vegetable oil on atlantic salmon hepatocyte fatty acid desaturation and liver fatty acid compositions 总被引:5,自引:0,他引:5
Fatty acyl desaturase activities, involved in the conversion of the C18 EFA 18∶2n−6 and 18∶3n−3 to the highly unsaturated fatty acids (HUFA) 20∶4n−6, 20∶5n−3, and 22∶6n−3, are known to be under
nutritional regulation. Specifically, the activity of the desaturation/elongation pathway is depressed when animals, including
fish, are fed fish oils rich in n−3 HUFA compared to animals fed, vegetable oils rich in C18 FFA. The primary aims of the present study were (i) to establish the relative importance of product inhibition (n−3 HUFA)
vs. increased substrate concentration (C18 EFA) and (ii) to determine whether 18∶2n−6 and 18∶3n−3 differ in their effects on the hepatic fatty acyl desaturation/elongation
pathway in Atlantic salmon (Salmo salar). Smolts were fed 10 experimental diets containing blends of two vegetable oils, linseed (IO), and rapeseed oil (RO), and
fish oil (FO) in a triangular mixture design for 50 wk. Fish were sampled after 32 and 50 wk, lipid and FA composition of
liver determined, fatty acyl desaturation/elongation activity estimated in hepatocytes using [1-14C]18∶3n−3 as substrate, and the data subjected to regression analyses. Dietary 18∶2n−6 was positively correlated, and n−3
HUFA negatively correlated, with lipid content of liver. Dietary 20∶5n−3 and 22∶6n−3 were positively correlated with liver
FA with a slope greater than unity suggesting relative retention and deposition of these HUFA. In contrast, dietary 18∶2n−6
and 18∶3n−3 were positively correlated with liver FA with a slope of less than unity suggesting metabolism via β-oxidation and/or desaturation/elongation. Consistent with this, fatty acyl desaturation/elongation in hepatocytes was significantly
increased by feeding diets containing vegetable oils. Dietary 20∶5n−3 and 22∶6n−3 levels were negatively correlated with hepatocyte
fatty acyl desaturation. At 32 wk, 18∶2n−6 but not 18∶3n−3 was positively correlated with hepatocyte fatty acyl desaturation,
wheres the reverse was true at 50 wk. The data indicate that both feedback inhibition through increased n−3 HUFA and decreased
C18 fatty acyl substrate concentration are probably important in determining the level of hepatocyte fatty acyl desaturation
and that 18∶2n−6 and 18∶3n−3 may differ in their effects on this pathway. 相似文献
19.
Like the fruits ofElaeis guineensis, the seeds ofAcacia holosericea have two types of oils. One is present in the yellow aril (56%), which is attached to the black seed, and the other is in
the kernel of the seed (12%). The proximate composition of seed and the physicochemical characteristics of the solvent-extracted
oils are reported. The aril fat is quite different from the seed oil in all respects. In descending order, the major fatty
acids in aril fat are 18∶1 (54.35%), 16∶0 (29.3%), and 18∶2 (8.0%), whereas in seed (−aril) oil, the order is 18∶2 (59.45%)
18∶1 (20.2%), and 16∶0 (10.0%). In whole seed (+aril) oil, the order is 18∶2 (53.3%), 18∶1 (25%), 16∶0 (12.6). 相似文献
20.
A. R. Bhaskar S. S. H. Rizvi C. Bertoli L. B. Fay B. Hug 《Journal of the American Oil Chemists' Society》1998,75(10):1249-1264
Milk fat fractions from supercritical carbon dioxide (SC-CO2) extraction were compared with commercial melt crystallization (MC) fractions for their physical and chemical properties.
The fractions were analyzed for fatty acids, triacylglycerols, cholesterol, total carotenoid content, and volatile compounds.
The fractions were also evaluated for solid fat content (SFC) by pulsed nuclear magnetic resonance and thermal profiles by
differential scanning calorimeter (DSC). The distribution of fatty acids and triacylglycerols in the fractions depended on
the fractionation technique used. SC-CO2 separated fractions based on molecular weight rather than on melting point, which is the driving force for the MC process.
The differences among the fractions were quantified from their SFC and DSC curves. Triacylglycerol profiles by high-performance
liquid chromatography showed that the SC-CO2 fractions were distinctly different from each other and from MC fractions. The SC-CO2 solid fraction (super stearin) was the most unique. It had a high concentration of long-chain, unsaturated fatty acid-containing
triacylglycerols in a narrow range of high molecular weight, indicating a homogeneity of this fraction that has not been attainable
by other techniques. It was also enriched in β-carotene and was devoid of volatile compounds. As compared to liquid MC fractions,
the liquid SC-CO2 fraction had a high concentration of low-melting triacylglycerols and was enriched in volatile compounds. With SC-CO2, it is thus possible to simultaneously fractionate and produce a flavor-rich concentrate at no extra processing cost. 相似文献