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1.
Formation and partial characterization of canola oil sediment 总被引:2,自引:0,他引:2
R. Przybylski C. G. Biliaderis N. A. M. Eskin 《Journal of the American Oil Chemists' Society》1993,70(10):1009-1015
The occasional development of a haze in canola oil represents a problem to the quality and acceptability of this oil. The
present study examined the formation of sediment in bottled canola oil during storage at 2, 6 and 12°C over a 4-d period.
Oils stored at 2°C showed the highest rate of sediment formation, followed by storage at 6°C. Removal of sediment from canola
oil prior to storage by cold precipitation and filtration did not eliminate this phenomenon, which still developed rapidly
at 2°C. Chemical composition and thermal properties of canola oil sediment were compared to sediment obtained from commercial
winterization of this oil. The thermal properties of the purified winterization sediment (melting temperature, 74.9°C) closely
resembled those of the sediment from bottled canola oil. Saponification of both sediments yielded large amounts of long-chain
fatty acids and alcohols, which were identified by gas chromatography-mass spectrometry. Sediment from commercial winterization
contained higher amounts of fatty acids and alcohols with more than 24 carbon atoms in the chain.
Presented in part at the AOCS meeting in Toronto, Ontario, May 1992. 相似文献
2.
Canola oil extracted from seeds with a high-chlorophyll content can contain chlorophyll derivatives in excess of 30 ppm. When
processed, this oil has been observed to be less stable than oil (typically containing 5 to 25 ppm chlorophyll) processed
from high-grade seed. Possible causes for this phenomenon were investigated in this study. The effect of initial pheophytin
content was examined by mixing fully saturated oil (tricapryloylglycerol) with increasing amounts of pheophytin and then by
subjecting the mixtures to processing conditions. When the processed oils were combined with an unsaturated oil (canola oil),
the oxidative stabilities decreased as the pre-processing content of pheophytin increased. Examination of the effect of increased
bleaching to remove excessive levels of pheophytin showed that oil stability decreased with increasing exposure to bleaching
clay. Additionally, processing treatments did not remove secondary autoxidation products from oil that was abused prior to
processing. Such a finding revealed the importance of initial oil quality on processed oil stability, i.e., the greater abuse
of the crude oil (resulting in greater contents of secondary oxidation products), the lower the stability of the processed
oil. Finally, previous reports by other researchers of pheophytin's pro-oxidative effect in oil stored in light were confirmed. 相似文献
3.
Because of the high level of chlorophyll-type compounds found in canola oil, bleaching is an important and critical step in
the canola oil refining process. In this study, a new method for reducing the chlorophyll-type impurities prior to the bleaching
step was developed. This method is based on precipitating the chlorophyll compounds with mineral acids. Concentrations of
chlorophyll-type compounds of up to 30 ppm could be reduced to amounts of less than 0.01 ppm by mixing the crude canola oil
with a 0.4 wt% mixture of phosphoric and sulfuric acids (2:0.75, vol/vol) for 5 min at 50°C. Centrifugation and filtration
also were examined as two main methods for separating the chlorophyll precipitates. The results showed that filtration by
a precoated textural filter with filter-aid clay could separate the precipitates as well as the centrifugation method. 相似文献
4.
The objective of this study was to explore the use of reversed-phase high-performance liquid chromatography (RP-HPLC) as a
means to detect adulteration of olive oil with less expensive canola oil. Previously this method has been shown to be useful
in the detection of some other added seed oils; however, the detection of adulteration with canola oil might be more difficult
due to similarities in fatty acid composition between canola oil and olive oil. Various mixtures of canola oil with olive
oils were prepared, and RP-HPLC profiles were obtained. Adulteration of olive oil samples with less than 7.5% (w/w) canola
oil could not be detected. 相似文献
5.
Characterization and oxidative stability of enzymatically produced fish and canola oil-based structured lipids 总被引:1,自引:7,他引:1
Casimir C. Akoh Charment O. Moussata 《Journal of the American Oil Chemists' Society》2001,78(1):25-30
Two-kilogram quantities of structured lipids (SL) of menhaden fish and canola oils containing caprylic acids (8∶0) were produced
in a laboratory-scale packed-bed bioreactor by acidolysis catalyzed by an immobilized lipase, Lipozyme IM, from Rhizomucor miehei. SL were characterized and their oxidative stabilities investigated. The SL contained 29.5% 8∶0 for fish oil and 40.15 for
canola oil. Polyunsaturated fatty acids (PUFA) of fish oil remained unchanged after the modification while PUFA of canola
oil were reduced from 29.6 to 21.2%. Monoenes, especially 18∶1n−9, were completely replaced by 8∶0 in fish oil and reduced
from 61.9 to 34.7% in canola oil. Downstream processing of enzymatically produced SL led to loss in natural total tocopherol
contents of the fish and canola oils. The effects of antioxidants such as α-tocopherol (TOC), tert-butylhydroxyquinone (TBHQ), and combinations thereof on the oxidative stability of SL were investigated. SL were analyzed
for oxidative stability index, peroxide value, conjugated diene content, free fatty acid content, iodine value, saponification
number, and thiobarbituric acid value. Iodine value of unmodified fish oil (154.71) was reduced to 144.10 and that of canola
oil (114.49) to 97.27 after modification. The SN increased from 183.72 to 242.63 for fish oil and from 172.50 to 227.90 for
canola oil. TBHQ exhibited better antioxidant effects than TOC. A combination of TBHQ/TOC also proved to be an effective antioxidant
for SL. We suggest the addition of antioxidants to enzymatically produced and purified SL. 相似文献
6.
Kerry Ward Rachael Scarth J. K. Daun C. T. Thorsteinson 《Journal of the American Oil Chemists' Society》1994,71(9):931-934
There are several methods available to measure chlorophyll in canola oil and seed, and these will not necessarily yield the
same results and should not be used in terchangeably. Total chlorophyll was determined for samples of canola seed and commercial
canola oil by recognized spectrophotometric methods and by high-performance liquid chromatography (HPLC). The HPLC method,
which summed all chlorophyll-related pigments detected, found approximately 1.4 times more total chlorophyll per sample than
did the spectrophotometric methods. The spectrophotometric methods are calibrated with only chlorophyll a and underestimate
other chlorophyll pigments, which have lower extinction, coefficients and different absorption maxima. The HPLC method detects
each pigment at its absorption maxima and applies the appropriate absorptivity factor. Care must be taken when comparing results
obtained by different methods. There appears to be a need for a standardized method of chlorophyll pigment measurement by
HPLC. 相似文献
7.
Rubeena Mungroo Vaibhav V. Goud Satya Narayan Naik Ajay K. Dalai 《European Journal of Lipid Science and Technology》2011,113(6):768-774
Green seed canola oil is underutilized for edible purposes due to its high chlorophyll content, which makes it more susceptible to photo‐oxidation and ultimately reduces the oxidation stability. The present work is an attempt to compare the kinetics of epoxidation of crude green seed canola oil (CGSCO) and treated green seed canola oil (TGSCO) with peroxyacids generated in situ in presence of an Amberlite IR‐120 acidic ion exchange resin (AIER) as catalyst. Among the two oxygen carrier studied, acetic acid was found to be a better carrier than the formic acid, as it gives 8% more conversion of double bond than the formic acid. A detailed process developmental study was then performed with the acetic acid/AIER combination. For the oils under investigation parameters optimized were temperature (55°C), hydrogen peroxide to double bond molar ratio (2.0), acetic acid to double bond molar ratio (0.5), and AIER loading (15%). An iodine conversion of 90.33, 90.20%, and a relative epoxide yield of 90, 88.8% were obtained at the optimum reaction conditions for CGSCO and TGSCO, respectively. The formation of the epoxide product of CGSCO and TGSCO was confirmed by Fourier Transform IR Spectroscopy (FTIR) and NMR (1H NMR) spectral analysis. 相似文献
8.
Separation of saturated and unsaturated acids from rice bran oil 总被引:2,自引:0,他引:2
9.
采用甲醇溶剂法分离蚕蛹油多不饱和脂肪酸。通过单因素实验探讨了温度、甲醇浓度、甲醇脂肪比、时间对多不饱和脂肪酸分离效果的影响,然后通过正交实验确定了多不饱和脂肪酸分离的较佳条件。结果表明,适宜的分离条件为:温度-10℃,甲醇浓度90%(w),甲醇脂肪比2.5,结晶时间30min,在上述条件下多不饱和脂肪酸得率为62.3%,含量由71.0%提高到95.8%。 相似文献
10.
The lipase-assisted acidolysis of high-laurate canola oil (HLCO; Laurical 25) with long-chain n−3 FA (DHA and EPA) was studied.
Response surface methodology was used to obtain a maximal incorporation of DHA or EPA into HLCO. The studied process variables
were the amount of enzyme (2–6%), reaction temperature (35–55°C), and incubation time (12–36 h). The amount of water added
and the mole ratio of substrates (oil to DHA or EPA) were kept at 2% and 1∶3, respectively. All experiments were conducted
according to a face-centered cube design. Under optimal conditions (4.79% of enzyme; 46.1°C; 30.1 h), the incorporation of
DHA into HLCO was 37.3%. The corresponding maximal incorporation of EPA (61.6%) into Laurical 25 was obtained using 4.6% enzyme,
a reaction temperature of 39.9°C, and a reaction period of 26.2 h. Examination of the positional distribution of FA on the
glycerol backbone of modified HLCO with DHA showed that the DHA was primarily located in the sn-1,3 positions of the TAG molecules. However, lauric acid also remained mainly in the sn-1,3 positions of the modified oil. For EPA-modified Laurical 25, lauric acid was present mainly in the sn-1,3 positions, whereas EPA was randomly distributed over the three positions. 相似文献
11.
Suresh Ramamurthi Prakash R. Bhirud Alan R. McCurdy 《Journal of the American Oil Chemists' Society》1991,68(12):970-975
Methylation of canola oil deodorizer distillate catalyzed by a nonspecific lipase was investigated. The conversion of fatty
acids to methyl esters has been optimized by using a statistical design. Up to 96.5% conversion of fatty acids to their methyl
esters has been achieved without the aid of vacuum or any water-removing agent. The effects of temperature, ratio of the reactants
(methanol: fatty acids in the deodorizer distillate) and enzyme concentration on the equilibrium conversion were studied.
The temperature and ratio of the reactants showed a significant effect on the conversion of fatty acids to methyl esters and
they exhibited a strong interactive effect. Enzyme concentration in the range of 2.7% to 4.3% did not show a significant effect
on the equilibrium conversion of fatty acids. Greater than 95% conversion of fatty acids to methyl esters was achieved at
temperatures around 50°C and at a ratio of the reactants between 1.8 and 2.0. The inhibitory effect of hydrophilic methanol
on the enzyme activity was largely reduced by working at the lower temperature range (around 50°C). 相似文献
12.
Ting Sun Zhimin Xu Witoon Prinyawiwatkul 《Journal of the American Oil Chemists' Society》2006,83(7):615-619
The FA composition of visceral oil extracted from farmed Atlantic salmon (Salmo salar L.) viscera was studied. Seventeen FA were identified in the extracted visceral oil, and the major FA were 18∶1n9, 16∶0,
16∶1n7, 20∶5n3 (EPA), 14∶0, and 22∶6n3 (DHA). The percentages of saturated, monounsaturated, and polyunsaturated FA in the
total FA were 31.7, 36.0, and 32.2%, respectively. Compared with other fish oils, oil from farmed Atlantic salmon had much
higher EPA (1.64 g/100 g) and DHA (1.47 g/100 g) contents. The FA profile of the salmon visceral oil was similar to that of
the salmon fillet. Thus, the salmon visceral oil could be a replacement for the oil obtained from edible salmon fillet and
used in functional foods or feeds requiring a high level of omega-3 FA. Furthermore, producing visceral oil is also beneficial
to salmon fish industry by adding value back to the processing waste. 相似文献
13.
V. Petrauskaitè W. F. De Greyt M. J. Kellens 《Journal of the American Oil Chemists' Society》2000,77(6):581-586
In the present study, neutral oil loss (distillative and mechanical carry-over) during physical refining of coconut oil was
quantified. Neutral oil loss seems to depend on both the crude oil quality and the process conditions during deodorization.
The distillation of volatile glyceridic components (monoand diglycerides), originally present in the crude oil, was confirmed
as the major cause for the neutral oil loss. The amount of these volatile components in crude coconut oils cannot be derived
as such from the initial free fatty acid content. A lower deodorization pressure with less sparge steam resulted in a larger
neutral oil loss than a higher pressure with more steam. A “deodorizability” test on a laboratory scale under standardized
conditions (temperature=230°C, pressure=3 mbar, time=60 min, sparge steam=1%), to evaluate crude oil quality and to obtain
a more accurate prediction of the expected neutral oil loss and free fatty acid content in the fatty acid distillate, is described. 相似文献
14.
Y. Endo C. T. Thorsteinson J. K. Daun 《Journal of the American Oil Chemists' Society》1992,69(6):564-568
Chlorophyll pigments present in canola seed, meal and crude and degummed oils were analyzed by high-performance liquid chromatography
(HPLC) with a fluorescence detector. Chlorophylls a and b, low levels of pheophytin a, and occasionally traces of pheophorbide
and its methyl ester were present in canola seed. Meals and oils contained magnesium-deficient chlorophyll pigments such as
pheophorbide a, methylpheophorbide a, pheophytins a and b, and pyropheophytins a and b but not chlorophyll a or b. The amounts
of chlorophyll pigments were oil > seed >> meal. Both crude and degummed oils contained pheophytin a and pyropheophytin a
as main components, but the ratio of pyropheophytin a to pheophytin a was markedly higher in degummed oils. No pheophorbides
were detected in degummed oils. These results suggest that oil processing steps such as extraction and degumming affect the
composition of chlorophyll pigments.
Publication No. 678 Canadian Grain Commission. 相似文献
15.
Hemendra N. Basu Anthony Del Vecchio 《Journal of the American Oil Chemists' Society》2001,78(4):375-380
Cyclodextrin complexes were prepared using 1∶1 and 1∶0.5 molar ratios of cyclodextrins and high-carotenoid canola oil. β-Cyclodextrin formed powdered complexes with a molar ratio of 1∶0.5, cyclodextrin/high-carotenoid canola oil. With a 1∶1 molar ratio, the complex was clumpy. In the case of α-cyclodextrin, powdery complexes were formed with either 1∶1 or 1∶0.5 molar ratio. The triglyceride oil present in the complexes varied between 28.87 and 48.2%, and there, was no segregation of the triglyceride oil during complex formation. The stability of carotenoids and tocopherols was also the same in brown bottles whether the complexes were kept under nitrogen or under oxygen. In clear glass vials, the amounts of α-and β-carotene went down, but there was very little change in tocopherols. With respect to sterols, more than 90% of the sterols present in the degummed oil were present in the α-cyclodextrin complexes, thereby indicating a higher affinity of the sterols in the cyclodextrin cavity. Presented in a seminar at Institutionen for livsmedelsvetenskap, Department of Food Science, Swedish University of Agricultural Science, Uppsala, Sweden, on June 13, 2000. 相似文献
16.
Sprouting has been considered as a damage factor in grading canola. This project deals with the evaluation of the effect of
sprouting on the quality and composition of canola seed and oil. Sprouted seeds had lower oil content than nonsprouted seeds
as determined by exhaustive petroleum ether extraction. The difference, although statistically significant, was small, less
than 0.1% oil at the maximum level of sprouting allowed in topgrade canola. There were no differences in chlorophyll contents
or moisture contents between sound and sprouted seeds. Sprouted seeds had significantly higher levels of FFA and crude protein
than sound seeds. Oxidation parameters (diene and aldehyde) were higher in oils from sound seeds than oils from sprouted seeds,
but there was no statistically significant difference in PV. Sprouted seeds had higher levels of tocopherols and sucrose,
but lower levels of raffinose, stachyose, and total sugars than sound seeds. There was no difference in overall FA composition
of the oil between sound and sprouted seeds. The second extraction of the Federation of Oils Seeds and Fat Associations (FOSFA)
extraction method, which allowed the extraction of more polar lipids, contained significantly more saturated FA. However,
this was not significant in the overall FA composition of the oils because this fraction counted for about 2% of the total
lipid content. The presence of sprouted seed had an effect on results for oil and crude protein determined by NIR as compared
with results by FOSFA extraction, or pulsed NMR for oil and Dumas combustion for crude protein. Addition of sprouted seed
samples to the NIR, calibration set overcame this problem. These results suggested that sprouting did not have a highly damaging
effect on the quality and composition of canola seed and oil when less than 10% of the seeds in a sample were sprouting. 相似文献
17.
Kerry Ward Rachael Scarth J. K. Daun C. T. Thorsteinson 《Journal of the American Oil Chemists' Society》1994,71(8):811-815
This study characterizes the chlorophyll pigments present in canola oil immediately after commercial extraction and following
oil storage to determine the best storage conditions for analytical samples and to examine the changes that chlorophyll derivatives
undergo during oil processing and storage. Samples of pressed, solvent-extracted, crude and degummed canola oils, obtained
from a commercial crushing plant, were stored for one month under four different conditions—in the freezer, in a refrigerator
and at room temperature both in the light and in the dark. Chlorophyll derivatives (chlorophylls, pheophytins, pyropheophytins)
were measured by high-performance liquid chromatography immediately after sampling and then on a weekly basis. The main pigments
present in commercially extracted canola oil were pheophytin a, pyropheophytin a, chlorophyll a and chlorophyll b. The “a”
derivatives comprised 81 to 100% of total chlorophyll pigments in the fresh oil samples. During degumming, the remaining chlorophylls
were converted to pheophytins and pyropheophytins. During oil storage, exposure to light at room temperature affected the
composition of chlorophyll derivatives as chlorophyll b was converted to pheophytin b and chlorophyll a was converted first
to pheophytin a, then to pyropheophytin a. 相似文献
18.
The production of prooxidant compounds brought about through subjecting chlorophyll a or pheophytin a to laboratory-scale
processing in the presence of canola oil or tricapryloylglycerol was investigated. The addition of chlorophyll a (60 ppm)
to canola oil prior to processing resulted in an oil of lowered stability. No large contribution to the produced instability
by any one processing step was found when pheophytin a was added (60 ppm) to canola oil prior to processing. To isolate the
effect of processing on the pigment, tricapryloylglycerol was used in the place of unsaturated canola oil as a carrier for
pheophytin a (60 ppm). A control consisted of processed tricapryloylglycerol that had no added pheophytin prior to processing.
The subsequent addition of pigment-treated processed tricapryloylglycerol to linseed oil (1:1, w/w) caused a decrease in the
stability of the latter, when compared with the control. No differences were observed between the prooxidant tricapryloylglycerol
and the control tricapryloylglycerol by methods involving ultraviolet spectroscopy and thin-layer or gas chromatography. 相似文献
19.
Comparison of the composition and properties of canola and sunflower oil sediments with canola seed hull lipids 总被引:1,自引:0,他引:1
H. Liu R. Przybylski K. Dawson N. A. M. Eskin C. G. Biliaderis 《Journal of the American Oil Chemists' Society》1996,73(4):493-498
The phase transition behavior and chemical composition of sediments from Canadian and Australian canola oils, as well as from
sunflower oil, were studied by differential scanning calorimetry, X-ray diffraction, polarized-light microscopy, and chromatographic
techniques. Australian canola sediment was similar to Canadian canola sediment in both melting and crystallization behaviors
and chemical composition. Compared to canola sediment, sunflower sediment underwent phase transformation (melting and crystallization)
at lower temperatures, and the enthalpies associated with the phase changes were greater. The X-ray diffraction patterns for
these materials were similar, indicating identical crystalline structures. Sunflower sediment contained mainly wax esters
(99%), while canola sediment contained about 72–74% of waxes. Moreover, sunflower sediment consisted of shorter-chainlength
fatty acids and alcohols than canola sediment. A hexane-insoluble fraction from Canadian canola hull lipids had fatty acid
and alcohol profiles and X-ray diffraction pattern similar to the corresponding oil sediment. 相似文献
20.
Purification of polyunsaturated fatty acid esters from tuna oil with supercritical fluid chromatography 总被引:7,自引:0,他引:7
M. Alkio C. Gonzalez M. Jäntti O. Aaltonen 《Journal of the American Oil Chemists' Society》2000,77(3):315-321
The technical and economic feasibility of producing docosahexaenoic acid (DHA)- and eicosapentaenoic acid (EPA)-ethyl ester concentrates from transesterified tuna oil using supercritical fluid chromatography (SFC) was studied. A systematic experimental procedure was used to find the optimal values for process parameters and the maximal production rate. DHA ester concentrates up to 95 wt% purity were obtained in one chromatographic step with SFC, using CO2 as the mobile phase at 65°C and 145 bar and octadecyl silane-type reversed-phase silica as the stationary phase. DHA ester, 0.85 g/(kg stationary phase · h) and 0.23 g EPA ester/(kg stationary phase · h) can be simutaneously produced at the respective purities of 90 and 50 wt%. The process for producing 1,000 kg DHA concentrate and 410 kg EPA concentrate per year requires 160 kg stationary phase and 2.6 tons/h carbon dioxide eluant recycle. The SFC operating cost is U.S. $550/kg DHA and EPA ethyl ester concentrate. 相似文献