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1.
Bijay Krishna De Jignesh Dahyabhai Patel 《European Journal of Lipid Science and Technology》2011,113(9):1161-1167
The applicability of calcium hydroxide (lime) in the neutralization of rice bran oil (RBO) was investigated. Crude RBO samples of three different free fatty acids (FFAs) (3.5–8.4 wt%) were degummed, dewaxed, bleached, and neutralized with lime and deodorized. The oils obtained thus were characterized by determining the color, peroxide value (PV), content of unsaponifiable matter (UM), and FFA. Conventionally practiced caustic soda neutralization (at 80–90°C) of FFA has in the present investigation been replaced by a high temperature (150–210°C) low pressure (2–4 mm Hg) reaction with lime. It was observed that neutralization with Ca(OH)2 at high temperature (210°C) and under low pressure (2–4 mm Hg pressure) may substantially reduce the FFA content (0.8 wt%, after 2 h). The deodorized oil was found to be of acceptable color, PV, and content of UM and FFA. Neutralization of oil was also carried out by using NaHCO3 and Na2CO3, nonconventional alkalies for neutralization, and the results were compared with NaOH and Ca(OH)2. Overall recovery of oil in Ca(OH)2 refining process (88.5 ± 0.6 wt%, for Sample 1 containing 8.4%‐wt FFA) was found to be more than other competitive processes studied. 相似文献
2.
Basavalingappa Rekha Belur Rangaswamy Lokesh Ambale Gundappa Gopala Krishna 《Journal of the American Oil Chemists' Society》2014,91(10):1665-1676
Compared to other vegetable oils, rice bran oil (RBO) has a characteristic dark color which further deepens upon heating or frying of foods in the oil. Darkening of the oil during heating has been studied. The dark color‐causing material in crude, chemically refined and physically refined rice bran oils was separated using a silica gel column for a hexane‐eluted oil fraction and a methanol eluted fraction. The methanol eluted fraction for all the above three types of RBO produced a dark color upon heating, hence the physically refined RBO methanol fraction was investigated further and contained monoglycerides (23.4 %) and diglycerides (67.4 %) of linoleic + linolenic acids in its methanol fraction as analyzed by column chromatography and HPLC which decreased in concentration after heating. The linoleic acid level of 37.7 % in the methanol fraction was reduced significantly to 18 % after heating (52.3 % reduction). The IR and NMR spectra were similar to those of a monoglyceride/diglyceride with NMR spectra indicating a lower amount of olefinic protons for the heated sample. These results showed that the darkening of RBO was due to the oxidation and polymerization of monoglycerides/diglycerides containing linoleic acid/linolenic acid. 相似文献
3.
A. G. Gopala Krishna K. H. Hemakumar Sakina Khatoon 《Journal of the American Oil Chemists' Society》2006,83(2):117-120
The compositions of rice bran oils (RBO) and three commercial vegetable oils were investigated. For refined groundnut oil,
refined sunflower oil, and refined safflower oil, color values were 1.5–2.0 Lovibond units, unsaponifiable matter contents
were 0.15–1.40%, tocopherol contents were 30–60 mg%, and FFA levels were 0.05–0.10%, whereas refined RBO samples showed higher
values of 7.6–15.5 Lovibond units for color, 2.5–3.2% for unsaponifiable matter, 48–70 mg% for tocopherols content, and 0.14–0.55%
for FFA levels. Of the four oils, only RBO contained oryzanol, ranging from 0.14 to 1.39%. Highoryzanol RBO also showed higher
FFA values compared with the other vegetable oils studied. The analyses of FA and glyceride compositions showed higher palmitic,
oleic, and linoleic acid contents than reported values in some cases and higher partial glycerides content in RBO than the
commonly used vegetable oils. Consequently, the TG level was 79.9–92% in RBO whereas it was >95% in the other oils studied.
Thus, refined RBO showed higher FFA values, variable oryzanol contents, and higher partial acylglycerol contents than commercial
vegetable oils having lower FFA values and higher TG levels. The higher oryzanol levels in RBO may contribute to the higher
FFA values in this oil. 相似文献
4.
C. E. Swift Sara P. Fore F. G. Dollear 《Journal of the American Oil Chemists' Society》1950,27(1):14-16
- The extraction, processing, characteristics, and stability properties of nine batches of hexane-extracted rice bran oil were investigated. The oils were refined, bleached, and deodorized and their color and stability determined. Samples of the bleached oils were hydrogenated to approximately shortening consistency, deodorized, and the stability of the hydrogenated products determined.
- Pilot plant extractions of five batches of rice bran yielded crude oils equivalent to 91% of the hexane-soluble portions of the bran.
- The nine crude oils whose content of free fatty acids ranged from 2.0 to 6.3% were refined by the cup method with losses ranging from 12.0 to 23.5% although the neutral oil content of six crude rice bran oils ranged from 89.9 to 92.6%.
- The Lovibond color of the nine refined oils ranged from 35 yellow and 4.5 red to 70 yellow and 9.5 red, and the color of the bleached oils ranged from 15 yellow and 1.5 red to 35 yellow and 3.2 red.
- Steam-refining, employed in conjunction with alkali-refining, proved effective as a means of reducing the losses in refining rice bran oil.
- The nine batches of refined, bleached, and deodorized rice bran oils had iodine values ranging from 101.3 to 105.7 and stabilities averaging 24 hours.
- Nine bleached oils hydrogenated to approximate shortening consistency had iodine values averaging approximately 66 and stabilities averaging 370 hours.
- Refined, bleached, and deodorized rice bran oil is bland but has some tendency toward flavor reversion.
- The most outstanding characteristics of rice bran oil is its exceptional stability after hydrogenation.
5.
Abdalbasit Mariod Bertrand Matthus Karl Eichner Ismail H. Hussein 《European Journal of Lipid Science and Technology》2006,108(4):298-308
In a refining experiment, on a laboratory scale, crude oils from Sclerocarya birrea (SCO), sorghum bugs (SBO), water‐extracted melon bugs (MBO H2O) and solvent‐extracted melon bugs (MBO SOL) were processed by alkali refining. Quality changes were characterized by the determination of free fatty acids (FFA), peroxide value, tocopherols, sterols, phosphatides and stability against oxidation (Rancimat test). In addition, the fatty acid composition was determined. It is clear that the contents of phosphatides, peroxides, tocopherols, sterols as well as oxidative stability were reduced during processing, while FFA were nearly totally removed. The content of phosphorus was reduced in SCO, SBO, MBO H2O and MBO SOL by 26, 19, 12, and 78%, respectively, while complete oil processing removed 95, 99, 96 and 99% of the FFA in crude oils, respectively. The level of total tocopherols decreased during processing by 38.7, 83.8, 100, and 33.3%, respectively. The color decreased through the processing steps up to bleaching; then, in the deodorization step, it darkened sharply in all samples. No change in the fatty acid composition was observed. The order of oxidation stability was crude > degummed > deodorized > neutralized > bleached, in SCO; and crude > degummed > neutralized > bleached = deodorized, in MBO H2O; and crude > degummed > deodorized > neutralized > bleached in MBO SOL; while in SBO, the order of oxidative stability was deodorized > crude > degummed > neutralized = bleached. Total sterols decreased by 42–92% in the processed oils, compared with crude oils. 相似文献
6.
Effects of processing steps on the contents of minor compounds and oxidation of soybean oil 总被引:4,自引:0,他引:4
The processes of degumming, alkali refining, bleaching and deodorization removed 99.8% phospholipids, 90.7% iron, 100% chlorophyll,
97.3% free fatty acids and 31.8% tocopherols from crude soybean oil. The correlation coefficient between the removals of phosphorus
and iron in soybean oil during processing was r = 0.99. The relative ratios of α-, β -, γ- and δ-tocopherols in crude oil,
degummed oil, refined oil, bleached oil and deodorized soybean oil were almost constant, γ- and δ -tocopherols represented
more than 94% of tocopherols in soybean oil. The order of oxidation stability of oil is crude > deodorized > degummed > refined
> bleached oil. 相似文献
7.
R. E. Beal E. B. Lancaster O. L. Brekke 《Journal of the American Oil Chemists' Society》1956,33(12):619-624
Summary Restricted tests in pilot-plant equipment have indicated that, starting with good quality crude soy-bean oil, the phosphorus
level of the deodorized oil is closely associated with its color and oxidative stability but that the refined or bleached
color is not a good criterion for predicting the quality of the finished oil. Phosphorus is removed by water in the presence
of adequate concentrations of alkali, and optimum oil quality is achieved at phosphorus levels in the deodorized oil of no
less than about 2 and no greater than about 20 p.p.m. Over-refining to a lower phosphorus content, by the use of too great
an excess of caustic (and therefore of water) was harmful to oxidative stability in every instance and generally increased
the color of the deodorized oil. The ash analysis of the deodorized oil is a fair indication of its residual phosphorus content
at levels above 20 p.p.m.
One of the Branches of the Agricultural Research Service, U. S., Department of Agriculture. 相似文献
8.
Kanok Yooritphun Supathra Lilitchan Kornkanok Aryusuk Kanit Krisnangkura 《Journal of the American Oil Chemists' Society》2017,94(2):301-308
Alkaline neutralization is a classical method for removal of free fatty acids (FFA) in crude oil. It is generally accompanied by neutral oil loss. Thus, reduction of refining losses associated with alkaline neutralization is very desirable. Refined, bleached and deodorized (RBD) palm oils with different FFA contents were used as oil models in this study. FFA in the oil models were neutralized with sodium hydroxide in polyhydric alcohols as neutralization media. Glycerol, propylene glycol and ethylene glycol in water were effective neutralization media. FFA in the oil models were totally removed in one step of neutralization, while percentages of refining losses were different. The losses were increased in the order of water > propylene glycol > ethylene glycol > glycerol used as neutralization media. Also, a higher concentration of polyhydric alcohol in the neutralizing media significantly reduced the percentage of refining loss (p < 0.05). Glycerol (90% in water) was the most effective neutralization media (p < 0.05). When neutralization was carried out on crude palm oil (containing 7.53% FFA), refining loss was reduced from 36.1% (in water) to 20.0% (in 90% glycerol in water). 相似文献
9.
Subramaniam Sathivel Witoon Prinyawiwatkul Ioan I. Negulescu Joan M. King 《Journal of the American Oil Chemists' Society》2008,85(3):291-296
Changes in melting points, enthalpy, and specific heat capacity of catfish visceral oil at each step of the purification process
were studied. Melting points of −46.2 to 21.2 °C for crude oil, −45.9 to 11.5 °C for degummed oil, −44.3 to 11.4 °C for neutralized
oil, −47.1 to 9.9 °C for bleached oil and −52.3 to 8.0 °C for deodorized oil were observed. Enthalpy (kJ/kg) was 74.1 for
crude oil, 74.7 for degummed oil, 75.1 for neutralized oil, 79.3 for bleached oil, and 84.3 for deodorized oil. The specific
heat capacities at 20 °C for crude, degummed, neutralized, bleached, and deodorized oils were 1.69, 1.96, 1.97, 1.91, and
1.83 kJ/kg °C, respectively. 相似文献
10.
A modified method for determining free fatty acids from small soybean oil sample sizes 总被引:5,自引:5,他引:0
I. H. Rukunudin P. J. White C. J. Bern T. B. Bailey 《Journal of the American Oil Chemists' Society》1998,75(5):563-568
A modification of the AOCS Official Method Ca 5a-40 for determination of free fatty acids (FFA) in 0.3 to 6.0-g samples of
refined and crude soybean oil is described. The modified method uses only about 10% of the weight of oil sample, alcohol volume,
and alkali strength recommended in the Official Method. Standard solutions of refined and crude soybean oil with FFA concentrations
between 0.01 and 75% were prepared by adding known weights of oleic acid. The FFA concentrations, determined from small sample
sizes with the modified method, were compared with FFA percentages determined from larger sample sizes with the Official Method.
Relationships among determinations obtained by the modified and official methods, for both refined and crude oils, were described
by linear functions. The relationship for refined soybean oil had an R
2 value of 0.997 and a slope of 0.99±0.031. The values for crude soybean oil are defined by a line with R
2=0.9996 and a slope of 1.01±0.013. 相似文献
11.
Short‐path distillation (SPD) has been a technique used to purify products containing monoacylglycerols (MAG), diacylglycerols (DAG), etc. Palm oil and its fractions contain high contents of DAG, typically 5–8%, some of which have significant effects on the crystallization behavior of the fats. A possible way of reducing the DAG to lower levels using SPD is evaluated. Distillation of refined, bleached and deodorized palm olein was performed at different temperatures (220–250 °C) and flow rates (500 and 1000 g/h). Feed oil, residue oil and distillates were characterized in terms of composition and melting and cooling behavior. The DAG content of the feed oil was 6.5%. At high evaporating temperatures, the free fatty acid (FFA) concentration in the residue oil and the distillate oil decreased for the same flow rate. Increasing the feed flow rate while maintaining constant temperature led to a greater FFA concentration in both streams. The DAG content in the distillate increased at higher temperature, reaching 68% at 250 °C, while the residue oil achieved a level of 2.8% at lower flow feeding rates. Melting and cooling behavior were influenced by the composition of DAG and triacylglycerols. Thus, the distillate oils had higher melting profiles in contrast to the feed oil and the residue oil, which had similar profiles despite the removal of higher‐melting components. 相似文献
12.
Chee Beng Yeoh Chiew Let Chong 《European Journal of Lipid Science and Technology》2009,111(6):593-598
Acephate, methamidophos and monocrotophos are insecticides used in oil palm plantations for the control of bagworms and leaf‐eating caterpillars. The main purpose of this study was to determine whether the physical refining process at laboratory scale, which simulated the manufacturing process, could remove the residues of these three insecticides in crude palm oil, in the unlikely event that crude palm oil were contaminated with these organophosphorus insecticides. A series of crude palm oil samples spiked with low (0.1 µg/g) and high (1.0 µg/g) levels of these insecticides were subjected to a laboratory‐scale physical oil refining process. Oil samples drawn at various stages of the refining process, namely, degumming, bleaching and deodorization, were analyzed using an in‐house analytical method. The results obtained from these experiments suggest that the physical refining process is capable of effectively removing residual insecticides from crude palm oil. The final product of crude palm oil refining, the refined, bleached and deodorized palm oil, was found to have no detectable levels of acephate, methamidophos and monocrotophos. 相似文献
13.
P. J. Wan T. W. Hurley J. D. Guy D. L. Berner 《Journal of the American Oil Chemists' Society》1997,74(6):731-738
Color as a fundamental quality of edible oils has been determined primarily by visual comparison methods for many decades.
The automatic colorimeters introduced recently made it possible to replace the manually operated visual color instrument,
which requires experience to master and is often subject to operator variabilities. A previous study with an automatic colorimeter,
Colourscan, to measure the colors of refined and refined bleached cottonseed oils showed good agreement (r
2=0.99) with visual color measurements by means of the Lovibond-AOCS Color Scale. The current work is to establish a broad-scale
correlation between the automated colorimeter and visual color measurements. In this international effort, factory-processed
refined and refined, bleached, deodorized (RBD) canola, corn, cottonseed, peanut, sunflower and soybean oils, as well as refined
palm olein, RBD palm oil, and washed, dried, filtered and deodorized tallow were used. A total of 14 laboratories from the
United States and Canada, and 16 laboratories from 12 countries outside of North America, participated in this collaborative
study. The results of this study, with statistical analyses, are reported. 相似文献
14.
A. C. Lanser G. R. List R. K. Holloway T. L. Mounts 《Journal of the American Oil Chemists' Society》1991,68(6):448-449
A user-interactive computer-assisted Fourier transform infrared (FTIR) method has been developed for estimation of free fatty
acids (FFA) in vegetable oil samples by deconvolution of the infrared (IR) absorbances corresponding to the triglyceride ester
and FFA carbonyl bonds. Peak areas were used to determine FFA as a percentage of the total carbonyl areas in weighed standards
of refined, bleached, deodorized soybean oil containing from 0 to 5% added oleic acid. These data for percent FFA by FTIR
were compared to corresponding FFA data obtained by two titration methods-the AOCS Official Method Ca 5a-40 and the Official
Method with a slight modification. Correlation coefficients were 0.999 for the Ca 5a-40, 0.999 for the modified and 0.989
for the FTIR methods. FFA in samples of crude soybean oils extracted from damaged beans (0.5 to 2.1% FFA) were measured by
FTIR and compared to data obtained by titration of the same samples (correlation coefficient, 0.869).
To whom correspondence should be addressed at National Center for Agricultural Utilization Research, Agriculture Research
Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, IL 61604.
1The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of
Agriculture over other firms or similar products not mentioned. 相似文献
15.
Weiguo Lang Shahab Sokhansanj Frank W. Sosulski 《Journal of the American Oil Chemists' Society》1992,69(10):1054-1055
Viscosities of refined, bleached, deodorized (RBD) and refined, bleached, winterized (RBW) canola oils were measured at temperatures
from 4 to 100°C. The viscosities of these refined canola oils were exponentially related to the oil temperature. Viscosity
of the RBW oil was slightly greater than that of the RBD oil when the temperature was below 15°C. Compared to refined soybean
oil, the canola oils were substantially more viscous. The viscosity of canola oil was modelled asv = exp(C0 + C1T + C2T2). The maximum predicted error was less than 1.6% over the tested temperature range. 相似文献
16.
R. H. Hrushowy 《Journal of the American Oil Chemists' Society》1978,55(3):A190-A191
Palm oil utilization is contingent on three key factors-economic advantage, standards of quality, and customer acceptance.
In order to provide acceptable quality palm oil for direct use of as a portion of a formulation, the oil is pretreated, steam
refined, bleached, and deodorized. A Parkson stripper is employed for steam refining which, with the pretreatment described,
results in yields of the weight of crude oil minus 1.19 x the free fatty acid expressed as oleic and finished oil colors ranging
from 1.0–2.5 Red Lovibind. Potential color problems can be avoided by ensuring that all storage and processing conditions
are controlled. 相似文献
17.
Several different edible oils were compared for their ability to modify eicosanoid biosynthesis following experimentally-induced
myocardial ischemia and reperfusion in the rat. Two types of palm oil [neutralized, bleached, and deodorized (NBDPO) and refined,
bleached, and deodorized (RBDPO)] and partially hydrogenated soybean oil (SBO) were tested against a diet supplemented with
sunflower seed oil (SSO) rich in n−6 polyunsaturated fatty acids (PUFA). Fish oil (FO) rich in n−3 PUFA, with its known cardioprotective
actions, served as an internal reference point for the study. Test oils were fed as a 12% (w/w) supplement for nine months
before the induction of myocardial ischemia and reperfusion. Palm oil diets exerted effects indistinguishable from the SBO
group against cardiac arrhythmia, which occurred following alterations to coronary blood flow. Arrhythmic potentials, as expressed
by a hierarchical scale (0–9) of arrhythmia score, were: SSO, 1.5±0.5; FO, 0.9±0.4; SBO; 3.1±0.5*; NBDPO, 3.2±0.5*; RBDPO, 3.3±0.6*,*
P<0.05 vs. SSO. Following ischemia and reperfusion, both SSO and RBDPO groups tended to show an increase in myocardial prostacyclin,
with the effect being more prominent in the RBDPO group (SSO, 10%; RBDPO, 25%). Thromboxane production was reduced in the
FO group. Interestingly, cardiac muscle from both FO and palm oil groups displayed a reduced capacity to produce 12-hydroxyeicosatetraenoic
acid SSO, 591.9±95.8; SBO, 375.5±48.9; NBDPO, 287.2±64.7*; RBDPO, 230.9±80.2**; FO, 203.7±81.4** (ng/g dry wt,*
P<0.05,**
P<0.01). No clear relationship was seen between the availability of 20∶4n−6 in myocardial phospholipids and eicosanoid profile.
Data suggests that fatty acid composition of edible oils is not the only determinant of arrhythmic vulnerability and eicosanoid
production.
Based on a paper presented at the PORIM International Palm Oil Congress, Kuala Lumpur, Malaysia, September 1993. 相似文献
18.
S. C. Yap Y. M. Choo N. F. Hew S. F. Yap H. T. Khor A. S. H. Ong S. H. Goh 《Lipids》1995,30(12):1145-1150
The oxidative susceptibilities of low density lipoproteins (LDL) isolated from rabbits fed high-fat atherogenic diets containing
coconut, palm, or soybean oils were investigated. New Zealand white rabbits were fed atherogenic semisynthetic diets containing
0.5% cholesterol and either (i) 13% coconut oil and 2% corn oil (CNO), (ii) 15% refined, bleached, and deodorized palm olein
(RBDPO), (iii) 15% crude palm olein (CPO), (iv) 15% soybean oil (SO), or (v) 15% refined, bleached, and deodorized palm olein
without cholesterol supplementation [RBDPO(wc)], for a period of twelve weeks. Total fatty acid compositions of the plasma
and LDL were found to be modulated (but not too drastically) by the nature of the dietary fats. Cholesterol supplementation
significantly increased the plasma level of vitamin E and effectively altered the plasma composition of long-chain fatty acids
in favor of increasing oleic acid. Oxidative susceptibilities of LDL samples were determined by Cu2+-catalyzed oxidation which provide the lag times and lag-phase slopes. The plasma LDL from all palm oil diets [RBDPO, CPO,
and RBDPO(wc)] were shown to be equally resistant to the oxidation, and the LDL from SO-fed rabbits were most susceptible,
followed by the LDL from the CNO-fed rabbits. These results reflect a relationship between the oxidative susceptibility of
LDL due to a combination of the levels of polyun-saturated fatty acids and vitamin E.
Based on a paper presented at the PORIM International Palm Oil Congress (PIPOC) held in Kuala Lumpur, Malaysia, 1993. 相似文献
19.
Oxidative stability of high-fatty acid rice bran oil at different stages of refining 总被引:2,自引:0,他引:2
The contents of natural antioxidants and the oxidative stability of rice bran oils at different refining steps were determined.
Tocopherols and oryzanols were constant in crude and degummed oils but decreased in alkali-refined, bleached and deodorized
oils. The process of degumming, alkali-refining, bleaching and deodorization removed 34% of the tocopherols and 51% of the
oryzanols. During storage of deodorized oil for 7 wk, 34% of the tocopherols and 19% of the oryzanols were lost. The maximum
weight gain, peroxide value and anisidine value were obtained from alkali-refined oil during storage. The order of oxidation
stability was crude ≥ degummed > bleached = deodorized > alkali-refined oil. 相似文献
20.
Effect of refining of crude rice bran oil on the retention of oryzanol in the refined oil 总被引:3,自引:0,他引:3
A. G. Gopala Krishna Sakina Khatoon P. M. Shiela C. V. Sarmandal T. N. Indira Arvind Mishra 《Journal of the American Oil Chemists' Society》2001,78(2):127-131
The effect of different processing steps of refining on retention or the availability of oryzanol in refined oil and the oryzanol
composition of Indian paddy cultivars and commercial products of the rice bran oil (RBO) industry were investigated. Degumming
and dewaxing of crude RBO removed only 1.1 and 5.9% of oryzanol while the alkali treatment removed 93.0 to 94.6% of oryzanol
from the original crude oil. Irrespective of the strength of alkali (12 to 20° Be studied), retention of oryzanol in the refined
RBO was only 5.4–17.2% for crude oil, 5.9–15.0% for degummed oil, and 7.0 to 9.7% for degummed and dewaxed oil. The oryzanol
content of oil extracted from the bran of 18 Indian paddy cultivars ranged from 1.63 to 2.72%, which is the first report of
its kind in the literature on oryzanol content. The oryzanol content ranged from 1.1 to 1.74% for physically refined RBO while
for alkali-refined oil it was 0.19–0.20%. The oil subjected to physical refining (commercial sample) retained the original
amount of oryzanol after refining (1.60 and 1.74%), whereas the chemically refined oil showed a considerably lower amount
(0.19%). Thus, the oryzanol, which is lost during the chemical refining process, has been carried into the soapstock. The
content of oryzanol of the commercial RBO, soapstock, acid oil, and deodorizer distillate were in the range: 1.7–2.1, 6.3–6.9,
3.3–7.4, and 0.79%, respectively. These results showed that the processing steps—viz., degumming (1.1%), dewaxing (5.9%),
physical refining (0%), bleaching and deodorization of the oil—did not affect the content of oryzanol appreciably, while 83–95%
of it was lost during alkali refining. The oryzanol composition of crude oil and soapstock as determined by high-performance
liquid chromatography indicated 24-methylene cycloartanyl ferulate (30–38%) and campesteryl ferulate (24.4–26.9%) as the major
ferulates. The results presented here are probably the first systematic report on oryzanol availability in differently processed
RBO, soapstocks, acid oils, and for oils of Indian paddy cultivars. 相似文献