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1.
Chia seeds as a source of natural lipid antioxidants   总被引:8,自引:0,他引:8  
Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10−4 mol/kg of seed) and caffeic acid (6.6 × 10−3 m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10−3 m/kg), quercetin (2.0 × 10−4 m/kg) and myricetin (3.1 × 10−3 m/kg); and caffeic acid (1.35 × 10−2 m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.  相似文献   

2.
Hopkins CY  Chisholm MJ  Prince L 《Lipids》1966,1(2):118-122
Seed kernel oils of seven species of Lauraceae were examined and the fatty acid composition of six of these was determined. The oil ofLindera umbellata had 4% ofcis-4-decenoic, 47% ofcis-4-dodecenoic, and 5% ofcis-4-tetradecenoic acid in the total fatty acids. Positive identification of these acids was made and new derivatives were prepared. Possible routes of biosynthesis are discussed. Oils from the other species did not contain more than a trace of unsaturated C10−C14 acids. Their major acids were capric and lauric with varying amounts of unsaturated C18 acids. Issued as NRC No. 8928. Presented at the AOCS Meeting, Cincinnati, October 1965.  相似文献   

3.
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   

4.
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   

5.
C. -E. Høy  G. Hølmer 《Lipids》1988,23(10):973-980
The influence of the linoleic acid levels of diets containing partially hydrogenated marine, oils (HMO) rich in isomeric 16∶1, 18∶1, 20∶1 and 22∶1 fatty acids on the fatty acid profiles of lipids from rat liver, heart and adipose tissue was examined. Five groups of rats were fed diets containing 20 wt% fat−16% HMO+4% vegetable oils. In these diets, the linoleic acid contents varied between 1.9% and 14.5% of the dietary fatty acids, whereas the contents oftrans fatty acids were 33% in all groups. A sixth group was fed a partially hydrogenated soybean oil (HSOY) diet containing 8% linoleic acid plus 32%trans fatty acids, mainly 18∶1, and a seventh group, 20% palm oil (PALM), with 10% linoleic acid and notrans fatty acids. As the level of linoleic acid in the HMO diets increased from 1.9% to 8.2%, the contents of (n−6) polyunsaturated fatty acids (PUFA) in the phospholipids increased correspondingly. At this dietary level of linoleic acid, a plateau in (n−6) PUFA was reached that was not affected by further increase in dietary 18∶2(n−6) up to 14.5%. Compared with the HSOY- or PALM-fed rats, the plateau value of 20∶4(n−6) were considerably lower and the contents of 18∶2(n−6) higher in liver phosphatidylcholines (PC) and heart PC. Heart phosphatidylethanolamines (PE) on the contrary, had elevated contents of 20∶4(n−6), but decreased 22∶5(n−6) compared with the PALM group. All groups fed HMO had similar contents oftrans fatty acids, mainly 16∶1 and 18∶1, in their phospholipids, irrespective of the dietary 18∶2 levels, and these contents were lower than in the HSOY group. High levels of linoleic acid consistently found in triglycerides of liver, heart and adipose tissue of rats fed HMO indicated that feeding HMO resulted in a reduction of the conversion of linoleic acid into long chain PUFA that could not be overcome by increasing the dietary level of linoleic acid.  相似文献   

6.
Female pigs were fed from three wk of age and up to two years a diet containing partially hydrogenated fish oil (PHFO, 28%trans monoenoic fatty acids), partially hydrogenated soybean oils (PHSBO, 36%trans fatty acids) or lard. No consistent differences were found between PHFO and PHSBO with regard to incorporation oftrans fatty acids in organ lipids, buttrans incorporations were highly organ-specific. Notrans fatty acids were detected in brain phosphatidylethanolamine (PE). The incorporation of monoenoictrans isomers, as a percentage of totalcis + trans, in other organs was highest in subcutaneous adipose tissue and liver mitochondria PE, followed by blood lipids with the lowest level in heart PE. The percentage oftrans isomers compared with that of dietary lipids was consistently lower for 20∶1, compared with 18∶1 in organs from PHFO-fed pigs. The only effect of dietarytrans fatty acids on the fatty acid pattern of brain PE was an increased level of 22∶5n−6. Heart PE and total serum lipids of pigs fed the hydrogenated fats contained higher levels of 18∶2n−6, and these lipids of the PHFO-fed group also contained slightly elevated amounts of 20∶3n−6, 18∶3n−3 and 20∶5n−3. Liver mitochondria PE of the PHFO group also contained higher levels of 20∶3n−6 and 22∶5n−6. Dietarytrans fatty acids caused a consistent decrease of saturated fatty acids compensated by increased levels of monoenes. Thus, it may be concluded that dietary long-chaintrans fatty acids in PHFO behaved similarly metabolically to 18∶1-trans in PHSBO in pigs, without noticeable influence on brain PE composition and with moderate to slight effects on the fatty acid profile of the other organs.  相似文献   

7.
Seed oils of some members of the Meliceae (six) and Combretaceae (three) were analyzed for their fatty acid composition. In oils of members of both families palmitic acid was the most abundant saturated acid. Trace amounts of short chain (C12–C14) and long chain (C20–C22) saturated acids were detected in some members of the two families. Oleic acid was the most abundant unsaturated acids in the oils of four members of the Meliaceae. However, in the oils ofCedrella odorata andLovoa trichilloides, dienoic acid (C18:2) was the major unsaturated acid. Strikingly high levels of trienoic (C18:3) and monoenoic (C16:1) acids were detected in the seed oils ofC. odorata andEnthandrophragma angolense, respectively. Oleic acid also was the most abundant unsaturated acid in the Combretaceae. The nutritional value and industrial potentials of these oils are given.  相似文献   

8.
The effects of 0, 1.0 × 10”−5, 2.5 × 10−5, and 5.0 × 10−5 M β-apo-8'-carotenal, β-carotene, and canthaxanthin on the photooxidation of soybean oil in methylene chloride containing 3.3 × 10−9 M chlorophyll b were studied by measuring peroxide values and conjugated diene content. β-Apo-8'-carotenal, β-carotene, and canthaxanthin contain 10,11, and 13 conjugated double bonds, respectively. The peroxide values and conjugated diene contents of oils containing the carotenoids were significantly lower (P<0.05) than those of control oil containing no carotenoid. As the number of conjugated double bonds of the carotenoids increased, the peroxide values of soybean oils decreased significantly (P<0.05). The quenching mechanisms and kinetics of the carotenoids in the photosensitized oxidation of soybean oil were studied by measuring peroxide values. The steady-state kinetics study showed that carotenoids quenched singlet oxygen to reduce chlorophyll-sensitized photooxidation of soybean oil. The singlet-oxygen quenching rate constants ofβ- apo-8'-carotenal, β-carotene, and canthaxanthin were 3.06 × 109, 4.60 × 109, and 1.12 × 1010 M−1sec−1, respectively.  相似文献   

9.
GC analysis was performed to determine regiospecific distribution and FA composition in seed oils of the Aceraceae species, Acer saccharum and A. saccharinum. The oil content in the seeds was low at 5.0% in A. saccharum and 5.8% in A. saccharinum, and the main FA were linoleic (30.8 and 29.4%), oleic (21.3 and 27.6%), palmitic (10.1 and 10.5%), and cis-vaccenic (9.4 and 7.9%) acids, respectively. In addition, both oils contained long-chain monoenes of the n−9 and n−7 groups, including 11-eicosenoic, 13-docosenoic, 15-tetracosenoic, 13-eicosenoic, and 15-docosenoic acids, whereas γ-linolenic acid accounted for 0.8% of total FA in A. saccharum, and 0.5% in A. saccharinum. Regiospecific analysis, performed using the methodology of dibutyroyl derivatives of MAG, indicated that linoleic, oleic, and linolenic acids were mainly esterified at the internal position of TAG in both seed oils, whereas long-chain monoenes of the n−7 group were almost exclusively esterified on the external positions.  相似文献   

10.
To understand how dietary fatty acids differentially modulate mouse skin tumorigenesis, the ability of specific fatty acids and their derivatives to activate murine epidermal protein kinase C (PKC)in vitro was investigated. Total PKC from untreated female SSIN mouse skin was partially purified and incubated with specific fatty acids at concentrations up to 300 μM in the presence of Ca2+ and phosphatidylserine. Thecis-unsaturated fatty acids tested, ranging from 16∶1 to 22∶6, stimulated PKC activity in a similar dose-dependent manner with an approximate threefold maximum increase over control. Neither the number ofcis-double bonds nor the chainlength of these fatty acids affected their relative ability to activate PKC.trans-Fatty acids, with the exception of linoelaidic acid (t,t-18∶2n−6), exhibited about half of the potency of their correspondingcis-isomers in stimulating PKC at the plateau concentration (200 μM) or lower. Substitutions close to the double bond oncis-fatty acids abolished their ability to activate PKC. The hydroxylated metabolites of arachidonic acid (20∶4n−6) and linoleic acid (c,c-18∶2n−6), i.e., the hydroxyeicosatetraenoic acids (HETE) and hydroxyoctadecadienoic acids (HODE), also activated mouse skin PKCin vitro, but only about half as effectively as did the respective parent fatty acids. The results suggest that both hydroxyl substitution andtrans-configuration of HETE and HODE are responsible for their reduced ability to activate PKC. Overall the data suggests that the reduced skin tumor yield observed in mice fed diets high inc,c-18∶2n−6 is not likely to be due to differences in the ability ofc,c-18∶2n−6 or 20∶4n−6, or their matabolites, to activate PKC.  相似文献   

11.
During heat treatment, polyunsaturated fatty acids and specifically 18∶3n−3 can undergo geometrical isomerization. In rat tissues, 18∶3 Δ9c, 12c, 15t, one of thetrans isomers of linolenic acid, can be desaturated and elongated to givetrans isomers of eicosapentaenoic and docosahexaenoic acids. The present study was undertaken to determine whether such compounds are incorporated into brain structures that are rich in n−3 long-chain polyunsaturated fatty acids. Two fractions enriched intrans isomers of α-linolenic acid were prepared and fed to female adult rats during gestation and lactation. The pups were killed at weaning. Synaptosomes, brain microvessees and retina were shown to contain the highest levels (about 0.5% of total fatty acids) of thetrans isomer of docosahexaenoic acid (22∶6 Δ4c, 7c, 10c, 13c, 16c, 19t). This compound was also observed in myelin and sciatic nerve, but to a lesser extent (0.1% of total fatty acids). However, the ratios of 22∶6trans to 22∶6cis were similar in all the tissues studied. When the diet was deficient in α-linolenic acid, the incorporation oftrans isomers was apparently doubled. However, comparison of the ratios oftrans 18∶3n−3 tocis 18∶3n−3 in the diet revealed that thecis n−3 fatty acids were more easily desaturated and elongated to 22∶6n−3 than the correspondingtrans n−3 fatty acids. An increase in 22∶5n−6 was thus observed, as has previously been described in n−3 fatty acid deficiency. These results encourage further studies to determine whether or not incorporations of suchtrans isomers into tissues may have physiological implications. Presented in part at the 32nd International Conference on the Biochemistry of Lipids, 1991, Granada, Spain. Delta nomenclature (Δ) is used fortrans polyunsaturated fatty acids to specify the position and geometry of ethylenic bonds. Polyunsaturated fatty acids containingtrans double bonds are abbreviated giving the locations of thetrans double bonds only; e.g., 20∶5 Δ17t 20∶5 Δ5c,8c,11c,14c,17t; 22∶5 Δ19t, 22∶5 Δ7c,10c,13c,16c,19t; 22∶6 Δ19t 22∶6 Δ4c,7c,10c,13c,16c,19t.  相似文献   

12.
Fatty acids of oil of a current variety of canolaBrassica campestris var Candle, at 3 stages of commercial production and refining, were compared with authentic seed oils, and with the oil ofB. napus var Tower. The proportion ofcis- 9, cis- 12, trans- 15 andtrans- 9, cis-12, cis-lS-octadecatrienoates relative to the all-cis isomer was lower than that previously observed in processed oils. The minor C14, C15, C17 fatty acids previously documented for Tower were also found in the same proportions in the Candle oil. The proportion of 22:1ω7 isomer (1.1% of a total 1.2% 22:1) was intermediate to that of a high erucic variety (0.9% out of 23% 22:1) and the very low 22:1 Tower (2.3% out of 0.1% 22:1). Thus the proportion of ω7 isomers is governed by total 22:1 present.  相似文献   

13.
γ-Linolenic acid containing oils have been found in seed lipids of a number of plants, but are restricted to certain genera and families,e.g., the Boraginaceae. Some of these oils have found considerable interest for pharmaceutical and dietary use,e.g., borage oil and evening primrose oil in treatment of essential fatty acid and Δ6 desaturase deficiency. Our investigation of the seed lipids of certain Mongolian and other Ranunculaceae has now shown the presnce of unusual fatty acids, including considerable amounts (up to 20%) ofγ-linolenic acid in certain species ofAnemone, whereas this acid was found to be absent in other species ofAnemone. A number of other unusual fatty acids are present inA. rivularis but have not yet been identified. The significance of the presence ofγ-linolenic acid, a Δ6 acid, is discussed in relation to δ5 fatty acids that had been reported to occur in the same plant family.  相似文献   

14.
The presence oftrans fatty acids in human milk may be a concern because of their possible adverse nutritional and physiological effects on the recipient infant. The mother's diet is the source of human milktrans fatty acids, and since these fatty acids are prevalent in many common foods of the Canadian diet, thetrans fatty acid content and the fatty acid composition of Canadian human milk were measured by gas-liquid chromatography coupled with silver nitrate-thin layer chromatography. In samples obtained from 198 lactating mothers across Canada, the average percentage of totaltrans (sum oft18∶1,t18∶2, andt18∶3) was 7.2% of breast milk fatty acids with a range of 0.1–17.2%. Analysis oft18∶1 isomer distribution indicated that partially hydrogenated vegetable oils are the major source of thesetrans fatty acids in human milk, whereas contribution from dairy products appeared to be relatively minor. Linoleci and α-linolenic acid levels were inversely related to the totaltrans fatty acids, indicating that the elevation oftrans fatty acids in Canadian human milk is at the expense of n-3 and n-6 essential fatty acids. Levels of arachidonic and docosahexaenoic acids did not correlate with their parent fatty acids, indicating that it might be difficult to elevate the levels of n-6 and n-3 C20–22 polyunsaturated fatty acids in breast milk by increasing levels of linoleic and α-linolenic acids in the mother's diet.  相似文献   

15.
Blubbers of four ringed seal subspecies from Lake Saimaa, Lake Ladoga, the Baltic Sea, and Spitsbergen were analyzed for very long chain polyunsaturated fatty acids (VLCPUFA; >C22) using gas-liquid chromatography and gas chromatography/mass spectrometry. The VLCPUFA of the blubber oils were mainly n−3 polyunsaturated fatty acids—23∶5n−3, 24∶3n−3, 24∶4n−3, 24∶5n−3, 24∶6n−3, 26∶5n−3, 26∶6n−3, and 28∶7n−3. The largest VLCPUFA components in all populations were 24∶5n−3 (0.1–0.2 wt% of total fatty acids) and 24∶6n−3 (0.1%), but 24∶4n−3 (0.1%) was also prominent in the Baltic specimens. The blubber oils of the freshwater species contained considerably more 24∶4n−6 and 24∶5n−6 than the blubbers of the marine species. The differences among the VLCPUFA in these subspecies appear to be mainly due to different dietary VLCPUFA.  相似文献   

16.
A differential infrared spectrophotometric method is described for the determination oftrans unsaturation in fats. The method utilizes absorption at 965 cm−1, due to the C−H out-of-plane deformation vibrations oftrans unsaturated compounds. The method is rapid, accurate, and directly applicable to the determination oftrans unsaturation in triglycerides. It is applicable to samples which contain low concentrations oftrans acids (down to 2%) and also to samples with fatty acids of mixed chain length.  相似文献   

17.
The seeds of 12 species ofAcacia, although rich in C-18 unsaturated acids (47.9–93.5%), have low oil content (2.5–10.2%). Highest concentration of octadecatrienoic acid was inA. lenticularis (80.3%),A. suma (76.8%) andA. tortilis (71.7%) oils.A. mollissima was rich in octadecadienoic (69.1%) andA. senegal in octadecenoic (42.5%) acids. All the seed oils showed the presence of epoxy 18:1 acid, 0.6–3.8%. The protein content of the processed seed meals ranged from 13.4–37.2%, the highest being inA. senegal. Fiber content varied from 8.8–11.9%.  相似文献   

18.
In this study, 10 different vegetable oils were oxidized at four different isothermal temperatures (383, 393, 403, and 413 K) in a differential scanning calorimeter (DSC). The protocol involved oxidizing vegetable oils in a DSC cell with oxygen flow. A rapid increase in evolved heat was observed with an exothermic heat flow appearing during initiation of the oxidation reaction. From this resulting exotherm, the onset of oxidation time (T o) was determined graphically by the DSC instrument. In our experimental data, linear relationships were determined by extrapolation of the log (T o) against isothermal temperature. The rates of lipid oxidation were highly correlated with temperature. In addition, based on the Arrhenius equation and activated complex theory, reaction rate constants (k), activation energies (E a), activation enthalpies (ΔH ), and activation entropies (ΔS ) for oxidative stability of vegetable oils were calculated. The E a′, ΔH , and ΔS for all vegetable oils ranged from 79 to −104 kJ mol−1, from 76 to −101 kJ mol−1, and from −99 to −20 J K−1 mol−1, respectively. Based on the results obtained, differential scanning calorimetry appears to be a useful new instrumental method for kinetic analysis of lipid oxidation in vegetable oil.  相似文献   

19.
Seeds of nine Central Asian species of Boraginaceae were investigated for the first time for their oil content and for the fatty acid composition of their seed oils by capillary gas chromatography. Levels of γ-linolenic acid ranged from 6.6 to 13.0% and levels of stearidonic acid ranged from 2.4 to 21.4% of total seed fatty acids. The seed oil ofHackelia deflexa exhibited the highest stearidonic acid content (21.4%) that has been found so far in nature. Other high contents of this fatty acid were in threeLappula species (17.2 to 18.1%). Seed oils ofCynoglossum divaricatum andAmblynotus rupestris contain considerable amounts ofcis-11-eicosenoic (5.3 to 5.8%) andcis-13-docosenoic acid (7.0 to 9.7%) besides γ-linolenic (10.2 to 13.0%) and stearidonic acid (2.4 to 6.5%), which distinguish these oils from those of other Boraginaceae genera. This paper was presented as a poster at 10th Minisymposium and Workshop on Plant Lipids, Sept. 3–6, 1995, in Berne, Switzerland.  相似文献   

20.
To test if linolenic acid (18∶3n−3) from vegetable oils would affect bleeding times and platelet counts in new-borns, piglets were used as a model fed milk replacer diets containing 25% (by wt) vegetable oils or oil mixtures for 28 d and compared to sow-reared piglets. The oils tested included soybean, canola, olive, high oleic sunflower (HOAS), a canola/coconut mixture and a mixture of oils mimicking canola in fatty acid composition. All piglets fed the milk replacer diets showed normal growth. Bleeding times increased after birth from 4–6 min to 7–10 min by week 4 (P<0.001), and were higher in pigs fed diets containing 18∶3n−3, as well as in sowreared piglets receiving n−3 polyunsaturated fatty acids (PUFA) in the milk, as compared to diets low in 18∶3n−3. Platelet numbers increased within the first week in newborn piglets from 300 to 550×109/L, and remained high thereafter. Milk replacer diets, containing vegetable oils, generally showed a transient delay in the rise of platelet numbers, which was partially associated with an increased platelet volume. The oils showed differences in the length of delay, but by the third week of age, all platelet counts were >500×109/L. The delay in rise in platelet counts appeared to be related to the fatty acid composition of the oil, as the effect was reproduced by a mixture of oils with a certain fatty acid profile, and disappeared upon the addition of saturated fatty acids to the vegetable oil. There were no alterations in the coagulation factors due to the dietary oils. Blood plasma, platelets and red blood cell membranes showed increased levels of 18∶3n−3 and long-chain n−3 PUFA in response to dietary 18∶3n−3. The level of saturated fatty acids in blood lipids was generally lower in canola and HOAS oil-fed piglets as compared to piglets fed soybean oil or reared with the sow. The results suggest that consumption of milk replacer diets containing vegetable oils rich in 18∶3n−3 does not represent a bleeding risk, and that the transient lower platelet count can be counterbalanced by the addition of saturated fatty acids to the vegetable oils.  相似文献   

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