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1.
Alfonso Valenzuela Susana Nieto Bruce K. Cassels Hernan Speisky 《Journal of the American Oil Chemists' Society》1991,68(12):935-937
The antioxidative effect of boldine, an alkaloid extracted fromPeumus boldus Mol. (boldo), was assayed on the spontaneous and on the metal-induced oxidation of fish oil. The inhibitory effect of boldine
was compared to those of dl-α tocopherol, the flavonoid quercetin and the synthetic antioxidants butylated hydroxytoluene
and butylated hydroxyanisole. Boldine, in all assays, showed a good antioxidative effect, which was comparable to that of
quercetin and even better than that of dl-α tocopherol and the synthetic antioxidants. Additive effects were observed when
mixtures of boldine and quercetin or dl-α tocopherol were assayed. The present study supports the potential use of boldine
as a novel natural antioxidant for fish oil. 相似文献
2.
Alfonso Valenzuela Julio Sanhueza Susana Nieto 《Journal of the American Oil Chemists' Society》2002,79(4):325-328
As a molecule with an unsaturated bond, cholesterol is prone to oxidation. Cholesterol oxidation products (COP) are found
in many common foods and have been shown to be atherogenic, cytotoxic, mutagenic, and possibly carcinogenic. Efforts to reduce
the formation of oxidation products are considered important during the manufacture and processing of foods. The effect of
synthetic antioxidants on cholesterol oxidation has not been extensively studied. We assayed the effect of five commonly used
antioxidants—BHT, BHA, the n-propyl ester of 3,4,5-trihydroxy benzoic acid (PG), TBHQ, and 6-ethoxy-1,2-dihydro-2,4-trimethylquinoline (EQ)—on cholesterol
stability when oxidation is induced in a Rancimat 679 instrument by bubbling air through the sample at 150°C. The sample consisted
of 200 mg cholesterol dispersed in 100 g of a polyunsaturated vegetable oil (soybean oil). Formation of six COP was measured
at the induction period, and at the 50 and 100 μS conductivity values. Under the experimental conditions, BHT and TBHQ were
the most effective inhibitors of cholesterol oxidation. BHA and EQ were less effective, and PG was unable to prevent cholesterol
oxidation. Synthetic antioxidants were more effective in preventing COP formation at the nucleus of the cholesterol structure
than at the lateral chain. 相似文献
3.
Udaya N. Wanasundara Fereidoon Shahidi 《Journal of the American Oil Chemists' Society》1994,71(8):817-822
The antioxidative activity of ethanolic extracts of canola meal at 100, 200, 500 and 1000 ppm on refined-bleached (RB) canola
oil was examined and compared with commonly used synthetic antioxidants, such as butylated hydroxyanisole (BHA), butylated
hydroxytoluene (BHT), BHA/BHT/monoglyceride citrate (MGC) andtert-butyl-hydroquinone (TBHQ). Stability of RB oil was monitored under Schaal oven test conditions at 65°C over a 17-d period.
Progression of oxidation was monitored by weight gain, peroxide, conjugated diene, 2-thiobarbituric acid and total oxidation
values. Canola extracts at 500 and 1000 ppm were more active than BHA, BHT and BHA/BHT/MGC and less effective than TBHQ at
a level of 200 ppm. 相似文献
4.
Abilities of some antioxidants to stabilize soybean oil in industrial use conditions 总被引:2,自引:2,他引:0
Christopher W. Ruger Eric J. Klinker Earl G. Hammond 《Journal of the American Oil Chemists' Society》2002,79(7):733-736
Antioxidants, chelators, and alcohols were screened at 0.01 and 1.28% by weight for their ability to delay viscosity increase
in soybean oil in the presence of metallic colloidal copper and iron at 105°C with air flowing through the sample. Most substances
did not significantly enhance the effect of the natural tocopherols in the soybean oil at 0.01%. A few substances were mildly
prooxidant, and a few delayed the increase in viscosity significantly. TBHQ at 0.01% was the best antioxidant of those tested.
At 1.28% ascorbyl palmitate, BHT, hydroquinone, and TBHQ increased the stability significantly. Again, TBHQ was the most effective.
As measured by viscosity increase to 150 CP, TBHQ increased stability about five times over that of soybean oil controls. 相似文献
5.
Yukihisa Tanaka Jiro Hirano Tadashi Funada 《Journal of the American Oil Chemists' Society》1992,69(12):1210-1214
In an attempt to concentrate the content of DHA (docosahexaenoic acid) in a glyceride mixture containing triglyceride, diglyceride
and monoglyceride, fish oil was hydrolyzed with six kinds of microbial lipase. After the hydrolysis, free fatty acid was removed
and fatty acid components of the glyceride mixtures were analyzed. When the hydrolysis withCandida cylindracea lipase was 70% complete, the DHA content in the glyceride mixture was three times more than that in the original fish oil.
The EPA (eicosapentaenoic acid) content became almost 70% of the original fish oil. Hydrolysis with other lipases did not
result in an increase in the DHA content in the glyceride mixtures. Hydrolysis of DHA-rich tuna oil (DHA content is about
25%) withCandida cylindracea lipase resulted in 53% DHA in the glyceride mixture. The EPA content, however, remained close to that of the original tuna
oil. In this report, the acyl chain specificity of lipases is evaluated in terms of hydrolysis resistant value (HRV). HRV
is the ratio between the DHA contents in the glyceride mixture of hydrolyzed oil and original oil. HRV clearly indicates differences
in hydrolysis between DHA and other fatty acids (e.g., saturated and monoenoic acids). 相似文献
6.
G. O. Adegoke A. G. Gopala Krishna 《Journal of the American Oil Chemists' Society》1998,75(8):1047-1052
Successive extractions with diethyl ether and methanol of the whole seeds of the spice Aframomum danielli yielded diethyl ether extract (ADEE), 13.9%, and methanol extract (ADM), 3.4%, respectively. Similarly, reextraction of the
defatted seeds of A. danielli successively with diethyl ether and methanol yielded extracts DFADEE (7.9%) and DFADM (6.7%), respectively. When these extracts
were added to refined peanut oil (PNO) at 200 ppm, they showed good antioxidative effects. The percentage antioxidant effectiveness
(AE) values were as follows: DFADM (87.3) > ADM (85.3) > ADEE (83.4)=tert-butyl hydroquinone (83.4) on day 20 of storage in an oven maintained at 65±1°C. Generally, antioxidant extracts prepared
from A. danielli were also more effective than butylated hydroxytoluene and α-tocopherol in stabilizing refined PNO. Antioxidant components
of A. danielli were tentatively identified as phenolic compounds of the trihydroxy type with reducing properties. All extracts prepared
from A. danielli showed strong ultraviolet-absorbing characteristics, and methanol was a good extracting solvent. 相似文献
7.
Christina Anniva Despina Grigoriadou Eleni Psomiadou Maria Z. Tsimidou 《Journal of the American Oil Chemists' Society》2006,83(4):371-375
In previous studies we reported the presence of compounds with spectral characteristics similar to pheophytin α (Pheo α),
which often accompany the Pheo α peak in the chromatographic profile of virgin olive oils (VOO) at 410 nm under normal-phase
HPLC conditions. The occurrence and levels of these compounds were found to be affected by storage conditions of the oil samples.
In the present study we investigated whether the major Pheo a degradation products, identified as pyropheophytin α (coeluting
with the respective epimer) and 132-OH-pheophytin α, could be used as estimates of VOO history. The content of Pheo α and its degradation products was determined
for a great number of authentic olive oil samples of unknown history. Results are discussed in comparison with other quality
indices (e.g., antioxidant content) when necessary. High amounts of the pyro form (20–30% of total pheophytins) were related
to thermal abuse or lengthy storage. The presence of allomers indicated oxygen availability. The levels of these products,
0–20% of the total pheophytin content for 62% of the samples, seemed to be influenced by the presence of pro- and antioxidants.
When low levels of Pheo α are not accompanied by other degradation products, light exposure for a certain period of storage
can be assumed. 相似文献
8.
Tatsuo Yamamura Masaki Arashima Kazumi Nakatani Takafumi Ishida Fukiko Yamada Tomihiro Nishiyama 《Journal of the American Oil Chemists' Society》1995,72(4):497-500
The antioxidant activities of 9H-xanthene-2,7-diols and α-tocopherol were studied during the oxidation of linoleic acid in a homogeneous solution and in an
aqueous micelle dispersion. The antioxidant activities of 9H-xanthene-2,7-diols for both systems were 1.0–2.4 times greater relative to α-tocopherol. In addition, the 1,3,4,5,6,8-hexamethylxanthene-2,7-diol
showed less cytotoxicity toward human fibroblasts than did 2,6-di-t-butyl-4-methylphenol. 相似文献
9.
Production of triglycerides enriched in long-chain n-3 polyunsaturated fatty acids from fish oil 总被引:1,自引:0,他引:1
Stephen R. Moore Gerald P. McNeill 《Journal of the American Oil Chemists' Society》1996,73(11):1409-1414
Processes that combine enzymic and physical techniques have been studied for concentrating and separating eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA) from fish oil.Candida rugosa lipase was used in hydrolysis reactions to concentrate these acids in the glyceride fraction. By controlling the degree of
hydrolysis, two products have been obtained, one enriched in total n-3(∼50%), the other enriched in DHA and depleted in EPA
(DHA∼40%, EPA∼7%). The glyceride fraction from these reactions was recovered by evaporation and converted back to triglycerides
by partial enzymic hydrolysis, followed by enzymic esterification. Both reactions were carried out withRhizomucor miehei lipase. DHA-depleted free fatty acids from aC. rugosa hydrolysis were fractionated to increase the EPA level (∼30%) and re-esterified to triglycerides by reaction with glycerol
andR. miehei. 相似文献
10.
Separation of EPA and DHA in fish oil by lipase-catalyzed esterification with glycerol 总被引:4,自引:0,他引:4
The objective of this study was to investigate the use of lipases as catalysts for separating EPA and DHA in fish oil by kinetic
resolution based on their FA selectivity. Esterification of FFA from various types of fish oils with glycerol by immobilized
Rhizomucor miehei lipase under water-deficient, solvent-free conditions resulted in a highly efficient separation of EPA and DHA. Reactions
were conducted at 40°C with a 10% dosage of the lipase preparation under vacuum to remove the coproduced water, thus rapidly
shifting the reaction toward the products. The bulk of the FA, together with EPA, were converted into acylglycerols, whereas
DHA remained in the residual FFA. As an example, when FFA from tuna oil comprising 5% EPA and 25% DHA were esterified with
glycerol, 90% conversion into acylglycerols was obtained after 48 h. The residual FFA contained 78% DHA and only 3% EPA, in
79% DHA recovery. EPA recovery in the acylglycerol fraction was 91%. The type of fish oil and extent of conversion were highly
important parameters in controlling the degree of concentration. 相似文献
11.
Pine oil, a by-product of the pulp industry, is a feeding repellent to snowshoe hares and voles. In pen trials with snowshoe hares and field trials with voles, when given a choice between food in a pine oil-treated bowl and a control bowl, the animals fed preferentially from the control bowl. When the hares were presented with food only in a pine oil-treated bowl, two hares showed a reduced rate of food consumption and one hare did not feed at all. Pine oil contains monoterpenes which may inhibit microbial symbionts in the digestive tracts of hares and voles. The repellent action of pine oil is likely based on this interference of digestive processes, and it is of adaptive advantage for cecal digestors to avoid it. Pine oil has potential as a commercial repellent for snowshoe hares and voles. 相似文献
12.
The kinetics of the interesterification reaction between menhaden oil and the ethyl ester of CLA (CLAEE) in the presence of
an immobilized lipase from Rhizomucor miehei was investigated. A 23 factorial design with a central point was used to define the experimental region. The factors considered were the molar ratio
of reactants, the enzyme loading, and the temperature. Optimal results were obtained when the reaction was carried out at
55°C with an enzyme loading of 0.65 g per 12 g mixture and a mole ratio of CLAEE to menhaden oil equal to 0.13. A uniresponse
kinetic model of the Michaelis-Menten type was developed to characterize the rate of consumption of CLAEE and the rate of
release of FA ethyl esters from menhaden oil. The best fit of the data with a uniresponse model was obtained using a form
based on reversible reactions and inhibition by the ethyl esters of the FA residues released by the reaction. 相似文献
13.
Robert L. Wolff Jean-Louis Sébédio 《Journal of the American Oil Chemists' Society》1994,71(2):117-126
Heating of borage oil, either under vacuum as a model or during steam-vacuum deodorization, produces artifacts that are geometrical
isomers of γ-linolenic acid (cis-6,cis-9,cis-12 18∶3 acid). In a first approach, we have studied the behavior of these fatty acids in the form of either methyl or isopropyl
esters on two capillary columns (CP-Sil 88 and DB-Wax). From this study, it appears that the DB-Wax capillary column is the
best suited analytical tool to study in some detail γ-linolenic acid geometrical isomers. In a second approach, the structure
of these isomers was formally established by combining several analytical techniques: Argentation thin-layer chromatography,
comparison of the equivalent chainlengths with those of isomers present in NO2-isomerized borage oil on two different capillary columns, partial hydrazine reduction, oxidative ozonolysis, gas chromatography
coupled with mass spectrometry and gas chromatography coupled with Fourier transform infrared spectroscopy. The two main isomers
that accumulate upon heat treatments are thetrans-6,cis-9,cis-12 andcis-6,cis-9,trans-12 18∶3 acids with minor amounts ofcis-6,trans-9,cis-12 18∶3 acid. One di-trans isomer, supposed to be thetrans-6,cis-9,trans-12 18∶3 acid, is present in low although noticeable amounts in some of the heated oils. The content of these artificial fatty
acids increases with increasing temperatures and duration of heating. The degree of isomerization (DI) of γ-linolenic acid
is less than 1% when the oil is deodorized at 200°C for 2 h. Heating at 260°C for 5 h increases the DI up to 74%. Isomerization
of γ-linolenic acid resembles that of α-linolenic (cis-9,cis-12,cis-15 18∶3) acid in several aspects: The same kinds and numbers of isomers are formed, and similar degrees of isomerization
are reached when the octadecatrienoic acids are heated under identical conditions. It seems that the reactivity of a double-bondvis-à-vis cis-trans isomerization is linked to its relative position, central or external, and not to its absolute position (Δ6, 9, 12 or 15). 相似文献
14.
World landings of fish and shellfish are approaching 100 million metric tons (MMT) annually. Of this total, around 28% is
processed into fish meal and oil. Economic pressures due to poor landings, low prices in traditional markets and high fuel
costs have forced the industry to seek new markets and products that can take advantage of the unique properties of fish proteins
and oils.
Fish meal processing continues to evolve. Fresh raw materials and new, low-temperature processing techniques lead to products
with excellent nutritional value. These new, special meals are finding uses in feeding farmed fish, early-weaned pigs, ruminants
and pets.
Fish oils, whether present as fat in the fish meal or as separated oil, are rich in ω3 fatty acids. When fed to food animals,
these ω3 fatty acids deposit in the meat and depot fat. Concepts for poultry with an equivalent amount of ω3 fatty acids to
lean fish are being developed. Eggs with a high ω3 fatty acid content and good functionality and flavor are under evaluation.
Catfish with shelf-stable flavors and high ω3 fatty acids are also under study. ω3 Fatty acids may affect the immune function
of livestock. Future research will evaluate the overall immune function of animals, including resistance to disease, survival
under stress and hatchability. 相似文献
15.
F. Comes M. Farines A. Aumelas J. Soulier 《Journal of the American Oil Chemists' Society》1992,69(12):1224-1227
Cherry seed oil, from the Rosaceae family, prunoid subfamily, is characterized by the existence of about 10% α-eleostearic
acid. The structure of the acid was proven by H and13C nuclear magnetic resonance. The triacylglycerols of this oil were identified and quantitated by highperformance liquid chromatography
by means of several types of detectors. α-Eleostearic acid was not found in the seeds of previously studied prunoids (almond,
peach, apricot and plum). The main fatty acids found in the seeds of cherry and other prunoids were linoleic (L), oleic (O)
and palmitic acids, and the major triacylglycerols were LLO, LOO and OOO. These chemical data support the botanical relationship
within the prunoid subfamily and show the proximity of cherry to the Chrysobalanaceae family. 相似文献
16.
High-performance liquid chromatography and spectroscopic studies on fish oil oxidation products extracted from frozen atlantic mackerel 总被引:4,自引:0,他引:4
The formation of stable hydroxy derivatives from hydroperoxides produced during the oxidation of linoleic acid methyl ester
and fish oil were studied by reverse-phase high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry
(GC-MS) and 13C nuclear magnetic resonance (NMR) spectroscopy. The oxidation products identified were mixtures of four isomeric hydroxy
derivatives: 13-hydroxy-9-cis,11-trans-octadecadienoic, 13-hydroxy-9-trans,11-trans-octadecadienoic, 9-hydroxy-10-trans,12-cis-octadecadienoic, and 9-hydroxy-10-trans,12-trans-octadecadienoic acids. The presence of hydroxy compounds was confirmed by 13C NMR, which gave rise to a hydroxy carbon peak at 87 ppm, and by GC-MS, which showed three peaks corresponding to isomeric
mixtures of trimethylsilyl ethers of the oxidized linoleic acid methyl ester. The mass spectra scans of the three peaks showed
that they represent isomers of molecular weight 382 and are consistent with the molecular formula C22H42O3Si. In oil extracted from stored frozen mackerel, 13-hydroxy-9-cis,11-trans-octadecadienoic acid was more prominent compared to the model lipid systems. HPLC offered a sensitive means of detection
of hydroxy compounds produced both in the initiation and latter stages of oxidation. The effect of antioxidants added to the
fish mince prior to storage can also be monitored by HPLC. Thus, the monitoring of lipid oxidation hydroxy derivatives by
HPLC is of practical value in the efficient processing and quality control of fish, fish oils, and other fatty foodstuffs
in order to enhance the acceptability, nutritional, and safety aspects. 相似文献
17.
Gudmundur G. Haraldsson Björn Kristinsson Ragnheidur Sigurdardottir Gudmundur G. Gudmundsson Harald Breivik 《Journal of the American Oil Chemists' Society》1997,74(11):1419-1424
The objective of this study was to investigate the use of lipases as catalysts for producing concentrates of eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA) from fish oil as an alternative to conventional chemical procedures. Transesterification
of fish oil with ethanol was conducted under anhydrous solvent-free conditions with a stoichiometric amount of ethanol. Among
the 17 lipases tested, the results showed that Pseudomonas lipases had the highest activity toward the saturated and monounsaturated fatty acids in the fish oil, much lower activity
toward EPA and DHA and, at the same time, good tolerance toward the anhydrous alcoholic conditions. With 10 wt% of lipase,
based on weight of the fish oil triacylglycerol substrate (15% EPA and 9% DHA initial content), a 50% conversion into ethyl
esters was obtained in 24 h at 20°C, in which time the bulk of the saturated and monounsaturated fatty acids reacted, leaving
the long-chain n-3 polyunsaturated fatty acids unreacted in the residual mixture as mono-, di-, and triacylglycerols. This
mixture comprised approximately 50% EPA+DHA. Total recovery of DHA and EPA was high, over 80% for DHA and more than 90% for
EPA. The observed fatty acid selectivity, favoring DHA as a substrate, was most unusual because most lipases favor EPA. 相似文献
18.
Separation of eicosapentaenoic acid and docosahexaenoic acid in fish oil by kinetic resolution using lipase 总被引:5,自引:0,他引:5
Gudmundur G. Haraldsson Björn Kristinsson 《Journal of the American Oil Chemists' Society》1998,75(11):1551-1556
The objective of this study was to investigate the use of lipases as catalysts for separating eicosapentaenoic acid (EPA)
and docosahexaenoic acid (DHA) in fish oil by kinetic resolution. Transesterification of various fish oil triglycerides with
a stoichiometric amount of ethanol by immobilized Rhizomucor miehei lipase under anhydrous solvent-free conditions resulted in a good separation. When free fatty acids from the various fish
oils were directly esterified with ethanol under similar conditions, greatly improved results were obtained. By this modification,
complications related to regioselectivity of the lipase and nonhomogeneous distribution of EPA and DHA into the various positions
of the triglycerides were avoided. As an example, when tuna oil comprising 6% EPA and 23% DHA was transesterified with ethanol,
65% conversion into ethyl esters was obtained after 24 h. The residual glyceride mixture contained 49% DHA and 6% EPA (8:1),
with 90% DHA recovery into the glyceride mixture and 60% EPA recovery into the ethyl ester product. When the corresponding
tuna oil free fatty acids were directly esterified with ethanol, 68% conversion was obtained after only 8h. The residual free
fatty acids comprised 74% DHA and only 3% EPA (25:1). The recovery of both DHA into the residual free fatty acid fraction
and EPA into the ethyl ester product remained very high, 83 and 87%, respectively. 相似文献
19.
Tatsuo Yamamura Takafumi Ishida Hiroyuki Tatara Tomihiro Nishiyama 《Journal of the American Oil Chemists' Society》1997,74(6):739-744
We evaluated the antioxidant activities of 9H-xanthene-2,7-diols and α-tocopherol (α-Toc) upon the oxidation of soybean phosphatidylcholine liposomal membranes, induced
by 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) and 2,2′-azobis(2,4-dimethylvaleronitrile (AMVN). The stoichiometric
factors of 9H-xanthene-2,7-diols, initiated with water-soluble AAPH and lipid-soluble AMVN, were 1.9–2.7 and 1.2–1.8-fold greater than
those of α-Toc, respectively. The consumption profile of the antioxidant confirmed that 9H-xanthene-2,7-diol was completely consumed within the induction period (t
inh) and that the 9H-xanthene-2,7-diol oxidation product was formed. When all oxidation product was depleted, t
inh was terminated, and rapid oxidation occurred. These results suggested that the antioxidant activities of 9H-xanthene-2,7-diol depend not only on the initial hydrogen abstraction from 9H-xanthene-2,7-diol but also on a second hydrogen abstraction from the residual phenolic OH group of the oxidation product.
Ascorbic acid (AsA) could not scavenge the radicals by itself in the lipid bilayer. However, when 9H-xanthene-2,7-diol was located in the lipid bilayer, the addition of AsA into the aqueous phase prolonged t
inh and reduced the rate of decay of 9H-xanthene-2,7-diol. 相似文献
20.
Activation of soil respiration and shift of the microbial population balance in soil as a response to Lavandula stoechas essential oil 总被引:1,自引:0,他引:1
Lavandula stoechas, a native plant of Greece, is rich in essential oil and fenchone is its major constituent. We examined the effect of the essential oil and its main constituents on soil metabolism and microbial growth. Addition of the essential oil or fenchone to soil samples induced a remarkable increase in soil respiration. This was accompanied by an increase in the soil bacterial population of three orders of magnitude. This sizable population was not qualitatively similar to that of the control soil samples. One bacterial strain dominated soil samples treated with L. stoechas essential oil or fenchone. By use of the disk diffusion assay, we evaluated the capacity of three bacterial strains that we isolated from the soil samples, as well as Escherichia coli and Bacillus subtilis (reference strains), to grow in the presence of the essential oil and three of its main constituents (fenchone, cineol, -pinene). The substances tested did not inhibit the growth of the strain found to dominate the bacterial populations of treated soil samples; they severely inhibited B. subtilis. The other two isolated strains could also grow in liquid cultures in the presence of different quantities of essential oil or fenchone. Addition of fenchone at the end of the exponential phase increased the cell numbers of the strain that dominated the bacterial populations of treated soil samples, indicating use of the substrate added. On the basis of these results, we propose a scheme of successional stages during the decomposition process of the rich-in-essential-oil litter of aromatic plants that abound in the Mediterranean environment. 相似文献