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1.
T. M. Aye M. J. Hedley P. Loganathan R. D. B. Lefroy N. S. Bolan 《Nutrient Cycling in Agroecosystems》2009,83(2):111-123
Phosphorus (P) deficiency is a major constraint for crop production in many parts of the world including Myanmar and field
research into management of P fertilizers and P responsiveness of crops on infertile soils has been limited. The purpose of
this study is to determine maize yield response to different forms of P fertilizers on an acidic (pH 4.9) P deficient (Olsen-P
8 mg kg−1) Yellow Earth (Acrisol) in Southern Shan State, Myanmar and to establish relationships between soil Olsen-P test values (0.5 M
sodium bicarbonate extracted P) and maize yield. Field experiments were conducted during two cropping seasons. There were
15 treatments in total: P was applied at seven rates of a soluble P fertilizer as Triple superphosphate (TSP) (0–120 kg P ha−1) to establish a P response curve; one rate of a partially soluble P fertilizer (Chinese partially acidulated phosphate rock,
CPAPR) and two organic P fertilizers (farmyard manure (FYM) and Tithonia diversifolia) at 20 kg P ha−1; combination of TSP and CPAPR at 20 kg P ha−1 with FYM and Tithonia at 20 kg P ha−1; an additional treatment (TSP 20 kg P ha−1 plus 2.5 t ha−1 dolomite) for assessing the liming effect of a local dolomite. In Year 1, applications of TSP at 40–60 kg P ha−1 produced near maximum grain yields, whereas in Year 2 this could be achieved with a reapplication of 20–30 kg P ha−1 on top of the residual value of the Year 1 application. In both years, CPAPR, TSP and Tithonia at 20 kg P ha−1 significantly increased maize grain yield, but FYM failed to increase grain yield. In Year 1, CPAPR and TSP effects on grain
yield were higher than that of Tithonia but in Year 2 the effects were same for all these three treatments. In both years
the combination of FYM (20 kg P ha−1) with TSP (20 kg P ha−1) produced significantly higher grain yield than TSP at 20 kg P ha−1 whereas 40 kg P ha−1 of TSP application did not significantly increase grain yield over the TSP application at 20 kg P ha−1. Similar results were obtained when half the P applied as CPAPR was substituted with P from Tithonia and FMP during the first
year. The combined data from the two years experiment suggests that 90% of maximum maize grain yields can be obtained by raising
the Olsen-P to 30–35 mg P ha−1 soil at the silking stage of growth. Olsen-P for the treatments at silking in Year 1 was: Control < FYM, Tithonia < TSP,
CPAPR and in Year 2 was: Control < FYM < Tithonia < TSP, CPAPR. The results showed that for a long-term approach, repeated
annual applications of Tithonia can be considered as a potential P source for improving soil P status in P deficient Yellow
Earths. 相似文献
2.
Hui Guo Chen Hu Junqing Qian De Wu 《Journal of the American Oil Chemists' Society》2012,89(2):183-187
A high-performance liquid chromatographic method with an evaporative light-scattering detector has been developed for the
separation and quantitative analysis of four underivatized long chain fatty acids in four different oil matrices. An isocratic
elution mode using methanol/water/acetic acid and an Agilent Eclipse XDB-C18 analytical column was used. Calibration curves
of the four fatty acids (FA) were well correlated (r
2 > 0.999) within the range of 1–10 mg mL−1 for linoleic acid, 0.8–10 mg mL−1 for stearic acid and 0.5–10 mg mL−1 for the other FA. Four oil samples were examined; camellia oil, olive oil, Brucea javanica oil and sesame oil. Good agreement was found with the standard gas chromatographic (GC) method. The proposed method offers
distinct advantages over the official GC method; better separation and precision, and the sample components do not need to
be derivatized. 相似文献
3.
Xian-Yue Guan Chuan-Chao Dai Yu-Fen Xu 《Journal of the American Oil Chemists' Society》2010,87(11):1309-1317
The effect of selenium (Se) treatment on the content of intracellular polyunsaturated fatty acids (PUFA) was investigated.
Selenium treatment could effectively increase the yields of arachidonic acid (AA) and linoleic acid (LA). When AA-producing
Diasporangium
jonesianum recombinant strain D-A1 was cultured in a medium containing 90 μg mL−1 Se, the growth of D.
jonesianum recombinant strain D-A1 was constrained, but the content of AA in the total fatty acids reached 9.3%, 1.7-fold higher than
the control. The content of LA was also increased from 25.9 to 37.7%. Under various culture conditions, Se treatment (90 μg mL−1) was generally beneficial to the yields of LA and AA. However, there was no significant increase in the contents of eicosapentaenoic
acid (EPA) and γ-linolenic acid. Therefore, the use of Se is advantageous for regulating the content of intracellular PUFA
in D.
jonesianum recombinant strain D-A1, and could be good enhancer in the yields of AA and LA. 相似文献
4.
Valéria T. Crexi Micheli L. Monte Maurício L. Monte Luiz A. A. Pinto 《Journal of the American Oil Chemists' Society》2012,89(2):329-334
The aims of this study were to compare three treatments in the chemical hydrolysis reaction of bleached oil from carp (Cyprinus carpio) heads and to obtain polyunsaturated fatty acid concentrates by urea complexation. The three treatments were carried out
with different oil:ethanol molar ratios. In the treatment with a 1:39 molar ratio, a higher yield of free fatty acids was
found. These fatty acids were submitted to urea complexation (−10 °C for 20 h, and urea–fatty acid ratio of 4.5–1). There
was a 31.4% increase in monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) content and a 75% decrease in saturated
fatty acids (SAF) content. An increase of 85.4% in the EPA + DHA content was found. The non-urea complexing fraction can be
considered a rich source of MUFA and PUFA with a total amount of 88.9%. 相似文献
5.
Phosphate rock with proper management could be a sustainable source of phosphorus for increased cowpea production on the Entisols of Sokoto Semi-arid zone. Therefore, field experiments were conducted in 2004 and 2005 rainy seasons to determine the influence
of Sokoto phosphate rock (SPR) and placement methods on the yield of cowpea varieties. Treatments consisted of factorial combination
of two varieties (Ba’adare and IAR48), three levels of SPR (25, 50 and 75 kg SPR ha−1) along with a control (0 kg SPR ha−1) and three placement methods (plough sole, broadcast and side-band) laid out in a randomized complete block design replicated
3 times. Results of phosphate rock and placement methods are presented in this paper. The study indicated significant (P < 0.01) response to applied SPR compared to control (1074 kg grain ha−1) in most parameters studied. Application of 25 kg SPR ha−1 significantly (P < 0.05) influenced higher pod yield and number of pods plant−1 only in 2004 trial. But, shelling percentage, grain yield, stover yield, 1000-grain weight, harvest index (HI) and number
of seeds pods−1 were not influenced by SPR levels. Significantly (P < 0.05) higher pod yield in 2004, grain yield, 1000-grain weight and number of pods per plant in 2004 and 2005, HI, shelling
percentage and number of seeds pod−1 in 2005, were observed in plough-sole than broadcast and band-side methods of fertilizer placement. Therefore, from this
study, it was concluded that SPR could be directly used as a source of P to sustain cowpea production (1527 kg grain ha−1 with 25 kg SPR compared to 1074 kg ha−1with 0 kg SPR). Application of 25 kg SPR ha−1 (3.74 kg P ha−1) using plough-sole method of fertilizer placement was most efficient under Sokoto semi-arid condition. 相似文献
6.
Reza Farhoosh Javad Tavakoli Mohammad Hossein Haddad Khodaparast 《Journal of the American Oil Chemists' Society》2008,85(8):723-729
Pistacia atlantica subsp. mutica (PAM) and kurdica (PAK) kernel oils showed significantly lower unsaturated to saturated fatty acid ratios (6.39, 6.33, respectively) and calculated
oxidizability (Cox) values (3.99, 4.13, respectively) than those of the P. vera L. cv. Ohadi (PVO) kernel oil (8.91, 4.41) samples. The highest peroxide value was observed for the PAK oil (4.07 mequiv kg−1) (PAM, 1.94; PVO, 0.37) samples. Iodine values for the PAM, PAK, and PVO oils were 104.26, 104.77, and 110.66, respectively.
The saponification number of the PVO oil was significantly greater than the PAM and PAK oils, which were statistically not
different. The unsaponifiable contents, which were composed mainly of sterols, ranged from 5.63 to 6.14%. Statistically the
total tocopherols contents of the PAM (818.58 mg α-tocopherol kg−1) and PVO (815.90 mg α-tocopherol kg−1) oils were significantly higher than that of the PAK oil (499.91 mg α-tocopherol kg−1). Total phenolics contents differed significantly, the greatest concentration was for the PAM oil (81.12 mg gallic acid kg−1), followed by the PVO (62.84 mg gallic acid kg−1) and PAK (56.51 mg gallic acid kg−1) oil samples. The wax contents of the oil samples were statistically in the same range, namely 5.67–6.48%. Oxidative stability
data indicated that the PAM oil is the most resistant to the formation of lipid oxidation products, followed by the PAK and
PVO oil samples. 相似文献
7.
Sean F. O’Keefe V. A. Wiley D. Wright 《Journal of the American Oil Chemists' Society》1993,70(9):915-917
Oil was extracted from soybeans, degummed, alkalirefined and bleached. The oil was heated at 160, 180, 200, 220 and 240°C
for up to 156 h. Fatty acid methyl esters were prepared by boron trifluoride-catalyzed transesterification. Gas-liquid chromatography
with a cyanopropyl CPSil88 column was used to separate and quantitate fatty acid methyl esters. Fatty acids were identified
by comparison of retention times with standards and were calculated as area % and mg/g oil based on 17:0 internal standard.
The rates of 18:3ω3 loss and 18:3 Δ9-cis, Δ12-cis, Δ15-trans (18:3c,c,t) formation were determined, and the activation energies were calculated from Arrhenius plots. Freshly prepared soy oil had
10.1% 18:3ω3 and no detectable 18:3c,c,t. Loss of 18:3ω3 followed apparent first-order kinetics. The first-order rate constants ranged from .0018±.00014 min−1 at 160°C to .083±.0033 min−1 at 240°C. The formation of 18:3c,c,t did not follow simple kinetics, and initial rates were estimated. The initial rates (mg per g oil per h) of 18:3c,c,t formation ranged from 0.0031±0.0006 at 160°C to 2.4±.24 at 240°C. The Arrhenius activation energy for 18:3ω3 loss was 82.1±7.2
kJ mol−1. The apparent Arrhenius activation energy for 18:3c,c,t formation was 146.0±13.0 kJ mol−1. The results indicate that small differences in heating temperature can have a profound affect on 18:3c,c,t formation. Selection of appropriate deodorization conditions could limit the amount of 18:3c,c,t produced. 相似文献
8.
Effect of conjugated linoleic acid on body composition in mice 总被引:55,自引:7,他引:55
Yeonhwa Park Karen J. Albright Wei Liu Jayne M. Storkson Mark E. Cook Michael W. Pariza 《Lipids》1997,32(8):853-858
The effects of conjugated linoleic acid (CLA) on body composition were investigated. ICR mice were fed a control diet containing
5.5% corn oil or a CLA-supplemented diet (5.0% corn oil plus 0.5% CLA). Mice fed CLA-supplemented diet exhibited 57% and 60%
lower body fat and 5% and 14% increased lean body mass relative to controls (P<0.05). Total carnitine palmitoyltransferase activity was increased by dietary CLA supplementation in both fat pad and skeletal
muscle; the differences were significant for fat pad of fed mice and skeletal muscle of fasted mice. In cultured 3T3-L1 adipocytes
CLA treatment (1×10−4 M) significantly reduced heparin-releasable lipoprotein lipase activity (−66%) and the intracellular concentrations of triacylglyceride
(−8%) and glycerol (−15%), but significantly increased free glycerol in the culture medium (+22%) compared to control (P<0.05). The effects of CLA on body composition appear to be due in part to reduced fat deposition and increased lipolysis
in adipocytes, possibly coupled with enhanced fatty acid oxidation in both muscle cells and adipocytes. 相似文献
9.
Alain Bitar Tarek Ghaddar Amal Malek Tharwat Haddad Imad Toufeili 《Journal of the American Oil Chemists' Society》2008,85(7):641-646
The odor detection thresholds of carvacrol (5-isopropyl-2-methyl-phenol), thymol (2-isopropyl-5-methyl-phenol) and p-cymene 2,3-diol (2,3-dihydroxy-4-isopropyl-1-methyl-benzene) in sunflower oil, determined by the three-alternative, forced-choice
procedure, were 30.97, 124 and 794.33 mg kg−1, respectively. Sunflower oil containing 13, 70, or 335 mg kg−1 of carvacrol, thymol or p-cymene 2,3-diol, respectively, was judged to be similar (P < 0.01) in taste and odor to its antioxidant-free counterpart. The rate constant of sunflower oil oxidation, measured from
the increase in peroxide value during storage at 25 °C, was 9.2 × 10−9 mol kg−1 s−1 while the rate constants were 9.3 × 10−9, 9.8 × 10−9, and 4.3 × 10−9 mol kg−1 s−1 in the presence of 13 mg kg−1 carvacrol, 70 mg kg−1 thymol, and 335 mg kg−1
p-cymene 2,3-diol, respectively. At a level of 335 mg kg−1, p-cymene 2,3-diol did not impart flavor taints and effected a 46.7% reduction in the rate of oxidation of sunflower oil. These
findings indicate that the diphenolic p-cymene 2,3-diol could potentially replace synthetic antioxidants and is a valuable addition to the antioxidants used by the
food industry in its quest to meet consumer demands for synthetic-additives-free and ‘natural’ foods. 相似文献
10.
Antonio Marcos Jacques Barbosa Tatiane Alfonso de Araújo Magno Aparecido Gonçalves Trindade Valdir Souza Ferreira 《Journal of Applied Electrochemistry》2011,41(2):249-255
A simple electroanalytical method was developed to determine the antibiotic ceftiofur (CF) in milk. The method is based on
the adsorptive accumulation of the drug on a hanging mercury-drop electrode (HMDE) and the accompanying initiation of a negative
square wave, which yielded well-defined cathodic peaks at −0.60 V (1C) and −0.91 V (2C) vs. Ag/AgCl. Calibration graphs were
constructed and statistical parameters were evaluated. At pH 2.5, the square-wave voltammetry method revealed linearity from
52.4 to 524 ng mL−1 (r = 0.997), which is in accordance with the tolerance level of 100 ng mL−1 for CF as a residue in bovine milk established by the Food and Drug Administration (FDA) and the European Union. The limits
of detection and quantification were 1.86 and 6.20 ng mL−1, respectively. The method was tested to determine CF in spiked milk samples using HPLC as reference method. 相似文献
11.
Alberta N. A. Aryee Benjamin K. Simpson Leroy E. Phillip Roger I. Cue 《Journal of the American Oil Chemists' Society》2012,89(2):287-292
The effect of 45 days of storage at 25, 4, −18 and −80 °C on the quality indices; free fatty acid (FFA) content, peroxide
value (PV), thiobarbituric acid reactive substances (TBARS), and changes in the fatty acid (FA) profile of crude oil recovered
from salmon fish skins were evaluated at 5 day intervals using spectrophotometric and titrimetric methods. Higher temperatures
and longer storage time resulted in higher quantities of oxidative products in the salmon skin oil (SSO). By day 45, SSO stored
at 25 and 4 °C had 8.50 and 8.29% FFA, 32.43 and 26.33 μg malondialdehyde (MDA) eq g−1 oil, and 88.19 and 64.53 mequiv peroxide kg−1 oil, respectively. No significant (p > 0.05) changes in fatty acid profile were observed at all the storage temperature and time studied. 相似文献
12.
Xiying Hao Kim Stanford Tim A. McAllister Francis J. Larney Shanwei Xu 《Nutrient Cycling in Agroecosystems》2009,83(3):289-299
The increased disposal costs of cattle specified risk materials (SRM) have reduced the competitiveness of the Canadian beef
industry. The SRM materials include the skull, brain, trigeminal ganglia, eyes, palatine tonsils, spinal cord and dorsal root
ganglia. This study investigates greenhouse gas (GHG) emissions and final compost properties from open windrow co-composting
of manure with bovine SRM and mortalities. There were two compost treatments with four replications: SRMC consisting of SRM,
cattle manure and barley straw and COWC consisting of cattle mortalities, cattle manure and barley straw. Average windrow
temperature was higher (P < 0.05) for SRMC (47.1°C) than for COWC (44.1°C) over the first 139 days. The final compost coliform count, moisture, pH and TC contents
were not significantly different between treatments while TN and available N (NH4
+ + NO3
− + NO2
−) were lower for SRMC than for COWC. The average surface GHG flux from SRMC were 24.3 g C day−1 m−2 and 0.17 g N day−1 m−2 for CO2 and N2O, respectively, and were not significantly different from those from COWC (31.6 g C day−1 m−2 and 0.17 g N day−1 m−2 for CO2 and N2O, respectively), but CH4 emissions from SRMC (0.47 g C day−1 m−2) were lower than from COWC (1.57 g C day−1 m−2). While a few large bones were left in the cattle mortality treatment, composting decomposed all SRM suggesting that it may
be a viable alternative to rendering for SRM disposal. 相似文献
13.
The effects of temperature and temperature shift on the fatty acid composition and docosahexaenoic acid (DHA, C22∶6n−3) content
and productivity of the marine microalga Crypthecodinium cohnii ATCC 30556 were investigated. The microalga grew well over the entire range of temperatures (15–30°C) studied. High temperature
favored the growth of the microalga with the highest specific growth rate of 0.092 h−1 at 30°C. In contrast, low temperature favored the formation of polyunsaturated fatty acids. The highest DNA content was obtained
at 15°C in the early stationary phase (i.e., 72h). In order to achieve high DHA productivity, a shift from high temperature
to low temperature at a later stage of cultivation (i.e., 48h) was also attempted. A temperature shift from 25°C (for 48 h)
to 15°C (for 24 h) resulted in an increase in cellular DHA content by 19.9% and productivity by 6.5% as compared to that maintained
at 25°C (for 72 h). 相似文献
14.
Kinetic Study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical 总被引:1,自引:0,他引:1
Aya Ouchi Masaharu Ishikura Kensuke Konishi Shin-ichi Nagaoka Kazuo Mukai 《Lipids》2009,44(10):935-943
A kinetic study of the prooxidant effect of α-tocopherol was performed. The rates of allylic hydrogen abstraction from various
unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order
rate constants (k
p) obtained are <1 × 10−2 M−1 s−1 for 1, 1.90 × 10−2 M−1 s−1 for 2, 8.33 × 10−2 M−1 s−1 for 3, 1.92 × 10−1 M−1 s−1 for 4, and 2.43 × 10−1 M−1 s−1 for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH2– hydrogen atoms activated by two π-electron systems (–C=C–CH2–C=C–). On the other hand, fatty acid ester 2 has four –CH2– hydrogen atoms activated by a single π-electron system (–CH2–C=C–CH2–). Thus, the rate constants, k
abstr/H, given on an available hydrogen basis are k
p/4 = 4.75 × 10−3 M−1 s−1 for 2, k
p/2 = 4.16 × 10−2 M−1 s−1 for 3, k
p/4 = 4.79 × 10−2 M−1 s−1 for 4, and k
p/6 = 4.05 × 10−2 M−1 s−1 for 5. The k
abstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils, fats, and low-density lipoproteins
may be induced by the above hydrogen abstraction reaction. 相似文献
15.
The suppression of plasma very low density lipoprotein (VLDL) triglyceride levels by dietary fish oils rich in polyunsaturated
n−3 fatty acids has been attributed to decreased hepatic VLDL secretion. To investigate the effect of n−3 fatty acids on lipid
metabolism and VLDL secretion in a tissue culture system, we incubated rabbit hepatocytes with oleic acid and eicosapentaenoic
acid (EPA) and examined [3H]glycerol and [14C]fatty acid incorporation into hepatocyte triglyceride and phospholipid and into media VLDL. Glycerol incorporation studies
showed that EPA failed to stimulate VLDL triglyceride secretion from hepatocytes as occurred with oleic acid (P<0.05). Oleic
acid preferentially enhanced hepatocyte triglyceride synthesis while EPA stimulated significantly phospholipid synthesis (P<0.01).
Varying the relative concentrations of oleic acid and EPA at a constant total fatty acid concentration corroborated preferential
triglyceride synthesis from oleic acid. Synthesis shifted predominantly to phospholipids with increasing concentrations of
EPA and lower levels of oleic acid. Incorporation of the [14C]fatty acids (800 μM) followed similar patterns: 87% of [14C]oleic acid was incorporated into hepatocyte triglyceride and 44% of [14C]EPA was assimilated in hepatocyte phospholipid (p<0.001). Fatty acids at trace concentrations (53 nM) showed a more divergent
pattern of lipid incorporation: 60% of [14C]oleic acid was incorporated into triglyceride while 91% of [14CEPA was incorporated into phospholipid (p<0.001). We conclude that in primary rabbit hepatocyte culture, which appears to
be a useful model to study lipid metabolism and VLDL secretion, EPA is avidly incorporated into phospholipid while oleic acid
predominantly becomes esterified in triglyceride. In addition, EPA, unlike oleic acid, fails to stimulate hepatocyte VLDL
secretion. These divergent effects on hepatocyte lipid metabolism are, at least in part, likely to be responsible for fish
oil induced suppression of plasma triglycerides. 相似文献
16.
Maleeha Manzoor Farooq Anwar Tahira Iqbal M. I. Bhanger 《Journal of the American Oil Chemists' Society》2007,84(5):413-419
The present work reports the characterization and comparison of Moringa concanensis seed oil from Tharparkar (a drought hit area), Pakistan. The hexane-extracted oil content of M. concanensis seeds ranged from 37.56 to 40.06% (average 38.82%). Protein, fiber, moisture and ash contents were found to be 30.07, 6.00,
5.88 and 9.00%, respectively. The extracted oil exhibited an iodine value of 67.00; a refractive index (40 °C) of 1.4648;
its density (24 °C) was 0.8660 mg mL−1; the saponification value (mg of KOH g−1 of oil) was 179.00; unsaponifiable matter 0.78%; color (1 in. cell) 1.90R + 19.00Y; and acidity (% as oleic acid) 0.34%.
Tocopherols (α, γ, and δ) in the oil accounted for 72.11, 9.26 and 33.87 mg kg−1, respectively. Specific extinctions at 232 and 270 nm were 3.17 and 0.65, respectively. The peroxide and p-anisidine values of the oil were found to be 1.75 and 1.84 meq kg−1, respectively. The induction periods (Rancimat, 20 L h−1, 120 °C) of the crude oil was 10.81 h and reduced to 8.90 h after degumming. The M.
concanensis oil was found to contain high levels of oleic acid (up to 68.00%) followed by palmitic, stearic, behenic, and arachidic acids
up to levels of 11.04, 3.58, 3.44 and 7.09%, respectively. The results of the present analytical study, compared with those
for other Moringa species and different vegetable oils, showed M. concanensis to be a potentially valuable non-conventional seed crop for high quality oil. 相似文献
17.
Menhaden oil (MO) and partially hydrogenated menhaden oil (PHMO) were dry-fractionated and solvent-fractionated from acetone.
After conversion to fatty acid methyl esters, the compositional distribution of saturated, monounsaturated, trans, and n−3 polyunsaturated fatty acids (PUFA) in the isolated fractions was determined by gas chromatography. Acetone fractionation
of MO at −38°C significantly increased the n−3 PUFA content in the liquid fractions over that of starting MO (P<0.05). For PHMO, liquid fractions obtained by low-temperature crystallization (−38, −18, and 0°C) from acetone showed significant
increases (P<0.05) in monounsaturated fatty acid (MUFA) content over that of the starting PHMO. For selected MUFA-enriched fractions,
reversed-phase high-performance liquid chromatography (HPLC) was used to separate, isolate, and characterize the major triacylglycerol
(TAG) molecular species present. Thermal crystallization patterns for these fractions also were determined by differential
scanning calorimetry (DSC). The results demonstrated that under the appropriate conditions it is possible to dry-fractionate
or solvent-fractionate MO and PHMO into various solid and liquid fractions that are enriched in either saturated, monounsaturated,
polyunsaturated, or the n−3 classes of fatty acids. Moreover, characterization of these TAG fractions by reversed-phase HPLC
gives insight into the compositional nature of the TAG that are concentrated into the various fractions produced by these
fractionation processes. Finally, the DSC crystallization patterns for the fractions in conjunction with their fatty acid
compositional data allow for the optimization of the fractionation schemes developed in this study. This information allows
for the production of specific TAG fractions from MO and PHMO that are potentially useful as functional lipid products. 相似文献
18.
Liliana N. Ceci Amalia A. Carelli 《Journal of the American Oil Chemists' Society》2010,87(10):1189-1197
The relation between oxidative stability and composition in 58 virgin olive oils from different cultivars and Argentinian
regions was studied over four harvest years. The oxidative stability of the oils was assessed using the OSI index (110 °C,
20 L/h air flow). A multiple linear regression model is proposed using OSI values as the dependent variable (multiple R = 0.933, p = 1 × 10−15), with positive contributions of the independent variables: fatty acid composition [oleic acid/(linoleic acid + linolenic
acid), 55.3%, p = 1 × 10−15], total polyphenols (24.1%, p = 1.8 × 10−9), carotenes (4.8%, p = 6.1 × 10−5), β-tocopherol (1.9%, 6.0 × 10−3) and other compounds (13.9%). Highly significant correlation was observed between oxidative stability indexes estimated by
the compositional model and those experimentally determined by Rancimat method (b = 0.981, R = 0.924). Chlorophylls and Δ-5-avenasterol contributions to the model were non-significant when variables related with fatty
acids and polyphenols were included. The results suggest that the fatty acid composition and the polyphenol content are the
main factors that affect the oxidative stability of olive oils. The proposed model allows the estimation of the oxidative
stability in olive oils independently of the cultivar. The model was obtained also taking into account samples that lie out
of the international legal limits in some compositional values due to natural variations. 相似文献
19.
Kang Du Weihua Liu Shuang Qiao Changli Zhou Wei Cao 《Journal of Inorganic and Organometallic Polymers and Materials》2011,21(4):881-885
It is found that nucleic acids can greatly enhance the fluorescence intensity of morin–nanoTiO2. Under optimum conditions, the enhanced fluorescence intensity of the system is in proportion to the concentration of nucleic
acids in the range of 2.0 × 10−8 to 2.2 × 10−7 g mL−1 for calf thymus DNA (ctDNA) and 1.0 × 10−8 to 2.5 × 10−7 g mL−1 for yeast RNA (yRNA). The detection limits are 4.8 × 10−9 g mL−1 for ctDNA and 1.2 × 10−9 g mL−1 for yRNA, respectively. This method has satisfactorily been used for the determination of nucleic acids in actual sample. 相似文献
20.
The fatty acid composition of diacyl- and alkylacylglycerophosphocholine (PC), phosphatidylinositol (PI), phosphatidylserine
(PS), alkenylacyl-glycerophosphoethanolamine (aPE), and diacyl- and alkylacyl-glycerophosphoethanolamine (dPE) was assessed
in isolated splenocytes from C3H/Hen mice fed one of four purified isocaloric diets for six weeks. Diets contained 20% by
weight of either a high-linoleate sunflower oil (Hi 18∶2), a high-oleate sunflower oil (Hi 18∶1), a mixture of 17% menhaden
fish oil and 3% high-linoleate sunflower oil (Hi n−3), or a mixture of 17% coconut oil and 3% high-linoleate sunflower oil
(Hi SFA). Spleen weight and immune cell yield were significantly higher (P<0.05) in mice fed the Hi 18∶1 or the Hi n−3 diets
compared with those fed the Hi 18∶2 and Hi SFA diets. Distinctive patterns of fatty acids were observed for each phospholipid
in response to dietary fatty acids. Dietary fat significantly affected (P<0.05) total polyunsaturated fatty acids (PUFA) in
PC and dPE, total saturated fatty acids (SFA) in PC, total monounsaturated fatty acids (MUFA), and n−3 PUFA in all phospholipid
classes examined. In mice fed the Hi n−3 diet, n−3 PUFA were significantly elevated, whereas n−6 PUFA decreased in all of
the phospholipids. In these mice, eicosapentaenoic acid (EPA) was the predominant n−3 PUFA in PC and PI, whereas docosahexaenoic
acid (DHA) was the major n−3 PUFA in aPE and PS. Interestingly, the ratios of n−3/n−6 PUFA in the phospholipids from these
mice were 3.2, 2.4, 1.8, 0.8 and 0.8 for aPE, PS, dPE, PC and PI, respectively. These data suggest a preferential incorporation
of n−3 PUFA into aPE, PS and dPE over PC and PI. 相似文献