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1.
One canola oil and six soybean oils with different fatty acid compositions were heated intermittently, and bread cubes were
fried in them to determine the stability of the oils. Two of the soybean oils were commercial varieties Hardin and BSR 101.
The other soybean oils were from experimental lines developed at Iowa State University, and included A17 with 1.5% linolenate
(18:3) and 15.1% palmitate (16:0), A16 with 1.9% 18:3 and 10.6% 16:0, A87-191039 with 1.8% 18:3 and 29.1% oleate (18:1) and
A6 with 27.7% stearate (18:0). The soybean seeds were cold-pressed and crude canola oil was obtained without additives. Oils
were refined, bleached and deodorized under laboratory conditions with additions. Each oil (300 mL) was heated to 180 ± 5°C
in a minifryer. Bread cubes were fried at the beginning of heating, and half of the cubes were used for analyses. The second
half was analyzed after storage at 60°C for seven days. Heating of the oils was continued for 20 h, cooled for 10 h, and then
reheated for another 20 h, after which additional bread cubes were fried and analyzed. Results of sensory evaluation of the
fried cubes, the peroxide values (PV) of oils extracted from the cubes and the conjugated dienoic acid values of the oils
showed that the A17, A16, A87-191039 and A6 oils had better stabilities than did Hardin, BSR 101 and canola oils. The initial
18:3 contents of oils predicted their oxidative and flavor stabilities under heating and frying conditions (for PVvs. 18:3, r=0.89,P=0.008; for flavor qualityvs. 18:3, r=−0.93,P=0.002; for flavor intensityvs. 18:3, r=−0.91,P=0.004). 相似文献
2.
Mixing different proportions of high-oleic sunflower oil (HOSO) with polyunsaturated vegetable oils provides a simple method
to prepare more stable edible oils with a wide range of desired fatty acid composition. Oxidative stability of soybean, canola
and corn oils, blended with different proportions of HOSO to lower the respective levels of linolenate and linoleate, was
evaluated at 60°C. Oxidation was determined by two methods: peroxide value and volatiles (hexanal and propanal) by static
headspace capillary gas chromatography. Determination of hexanal and propanal in mixtures of vegetable oils provided a sensitive
index of linoleate and linolenate oxidation, respectively. Our evaluations demonstrated that all-cis oil compositions of improved oxidative stability can be formulated by blening soybean, canola and corn oils with different
proportions of HOSO. On the basis of peroxide values, a partially hydrogenated soybean oil containing 4.5% linolenate was
more stable than the mixture of soybean oil and HOSO containing 4.5% linolenate. However, on the basis of volatile analysis,
mixtures of soybean and HOSO containing 2.0 and 4.5% linolenate were equivalent or better in oxidative stability than the
hydrogenated soybean oil. Mixtures of canola oil and HOSO containing 1 and 2% linolenate had the same or better oxidative
stability than did the hydrogenated canola oil containing 1% linolenate. These studies suggest that we can obviate catalytic
hydrogenation of linolenate-containing vegetable oils by blending with HOSO.
Presented at the AOCS/JOCS joint meeting, Anaheim, CA, April 25–29, 1993. 相似文献
3.
Nuo Shen Walter Fehr Lawrence Johnson Pamela White 《Journal of the American Oil Chemists' Society》1997,74(3):299-302
Oils from soybean lines, developed to contain different amounts of palmitate (16:0) and linolenate (18:3), were evaluated
for oxidative stability. Oils were extracted in the laboratory from the soybean seeds and refined, bleached, and deodorized.
Two replications, separated at the point of conditioning, were evaluated for each genotype, including Hardin 91 (normal beans),
P9322 (10.6% 16:0 and <2.6% 18:3), A91-282036 (26.3% 16:0 and 9.8% 18:3), and HPLL (23.2% 16:0 and 3.5 % 18:3). Elevating
16:0 and/or lowering 18:3 increased the oxidative stability of soybean oils as measured by peroxide values. Soybean oils with
elevated 16:0 had higher solidification temperatures than did oils with normal 16:0 content, and soybean oils with low 18:3
content had higher solidification temperatures than did oils with normal 18:3 contents. 相似文献
4.
Pilot plant-processed samples of soybean and canola (lowerucic acid rapeseed) oil with fatty acid compositions modified by
mutation breeding and/or hydrogenation were evaluated for frying stability. Linolenic acid contents were 6.2% for standard
soybean oil, 3.7% for low-linolenic soybean oil and 0.4% for the hydrogenated low-linolenic soybean oil. The linolenic acid
contents were 10.1% for standard canola oil, 1.7% for canola modified by breeding and 0.8% and 0.6% for oils modified by breeding
and hydrogenation. All modified oils had significantly (P<0.05) less room odor intensity after initial heating tests at 190°C than the standard oils, as judged by a sensory panel.
Panelists also judged standard oils to have significantly higher intensities for fishy, burnt, rubbery, smoky and acrid odors
than the modified oils. Free fatty acids, polar compounds and foam heights during frying were significantly (P<0.05) less in the low-linolenic soy and canola oils than the corresponding unmodified oils after 5 h of frying. The flavor
quality of french-fried potatoes was significantly (P<0.05) better for potatoes fried in modified oils than those fried in standard oils. The potatoes fried in standard canola
oil were described by the sensory panel as fishy. 相似文献
5.
The carbonyl compounds in five oxidized soybean oils (SBO) of various fatty acid compositions were determined. Three were
from common normal soybean varieties, and two were from lines developed from new mutant varieties. One mutant line had a linolenate
(18:3) content of 3.5% (A5), and one had a stearate (18:0) content of 24% (A6). SBO were stored at 28 C and 60 C. Trichlorophenylhydrazones
(TCPH) of carbonyls formed during oxidation were quantified and tentatively identified by gas chromatography. The storage
temperature and the composition of the oils affected the types and amounts of volatiles produced. Hexanal was the major volatile
in the oils in both storage tests. After 60 C storage, 2- and/or 3-hexenal was present only in the oil with the highest 18:3
content (BSR 101, 18:3=9%). The amounts of the carbonyls formed in A5 were 2 to 5 times less than the amounts formed in BSR
101. The amounts of many of the carbonyls were converted into relative flavor potency by using reported data. Hexanal was
the major contributor to flavor. After storage at 28 C, 2- and/or 3-hexenal was the second most intense flavor compound regardless
of the 18:3 content of the oil. The amount of a compound and the threshold value did not always predict its flavor importance
according to the flavor potency data. 相似文献
6.
Four soybean oils (SBO) with different fatty acid (FA) compositions were tested for stability during intermittent heating
and frying of bread cubes. None of the oils was hydrogenated or contained any additives. Two of the oils were from common
commercial varieties. The other two oils were from seed developed in a mutation breeding program and included the line A5,
which contained 3.5% linolenate, and the line A6, which contained 20% stearate. Each oil (450 g) was heated to 185 C in a
minifryer. Bread cubes were fried at the beginning of heating, and half were stored at −10 C to preserve freshness. The second
half was stored at 60 C for 14 days. Heating was continued for 10 hr/day for four days. After 40 hr of heating, an additional
30 g of bread cubes were fried. According to sensory evaluations of the fried bread cubes, peroxide values of oil extracted
from the cubes and conjugated diene values of the oils, the A5 and A6 oils were more stable than those from the commercial
varieties. Small differences occurred in the flavor and oxidative stability of the cubes fried after 40 hr of heating the
oils. Large differences between A5 and A6 and the commercial varieties occurred after storage of bread cubes for 14 days. 相似文献
7.
K. Warner P. Orr L. Parrott M. Glynn 《Journal of the American Oil Chemists' Society》1994,71(10):1117-1121
Potato chips were fried in six canola (low-erucic acid rape-seed) oils under pilot-plant process settings that represented
commercial conditions. Oil samples included an unmodified canola oil and oils with fatty acid compositions modified by mutation
breeding or hydrogenation. Chips were fried for a 2-d, 18-h cycle for each oil. Chips and oil were sampled periodically for
sensory, gas-chromatographic volatiles and chemical analyses. Unmodified canola oil produced chips with lower flavor stability
and oxidative stability than the other oils. The hydrogenated oil imparted a typical hydrogenation flavor to the chips that
slightly affected overall quality. the modified canola oil (IMC 129) with the highest oleic acid level (78%) had the lowest
content of total polar compounds and the lowest total volatile compounds at most of the storage times; however, the sensory
quality of the potato chip was only fair. The potato chip with the best flavor stability was fried in a modified/blended oil
(IMC 01-4.5/129) with 68% oleic acid, 20% linoleic acid and 3% linolenic acid. 相似文献
8.
It is generally agreed that the high linolenate (18:3) content of soybean oil (SBO) contributes to its flavor instability.
In this study, the oxidative stability of five SBO of various fatty acid (FA) compositions was compared by using peroxide
values, conjugated dienoic acid values and sensory panel scores. Three of the oils were from common commercial varieties representing
the range of 18:3 content normally found in SBO. The other two oils were from seed developed in a mutation breeding program.
One of these oils from the line A5 had an 18:3 content of 3.5%, and the other from the line A6 had a stearate (18:0) content
of 24%. Seed from the five soybean varieties was cold pressed, refined and deodorized without additives under laboratory conditions.
Two oxidation experiments were conducted. In the first, the oils were stored at 28 C for 67 days. In the second, the oils
were stored at 60 C for eight days. Sensory comparisons were done by using the AOCS Flavor Intensity Scale. The A5 and A6
oils were more stable than the commercial varieties as measured by chemical tests, but the sensory data were inconclusive.
Oils with similar 18:3 contents did not have similar rates of oxidation. The differences between the oils were not as distinct
in the 60 C test as in the 28 C test. 相似文献
9.
W. E. Neff E. Selke T. L. Mounts W. Rinsch E. N. Frankel M. A. M. Zeitoun 《Journal of the American Oil Chemists' Society》1992,69(2):111-118
The oxidative stability of soybean oil triacylglycerols was studied with respect to composition and structure. Crude soybean
oils of various fatty acid and triacylglycerol composition, hexane-extracted from ground beans, were chromatographed to remove
non-triacylglycerol components. Purified triacylglycerols were oxidized at 60°C, in air, in the dark. The oxidative stability
or resistance of the substrate to reaction with oxygen was measured by determination of peroxide value and headspace analysis
of volatiles of the oxidized triacylglycerols (at less than 1% oxidation). The correlation coefficients (r) for rates of peroxide
formation (r=0.85) and total headspace volatiles (r=0.87) were related positively to oxidizability. Rate of peroxide formation
showed a positive correlation with average number of double bonds (r=0.81), linoleic acid (r=0.63), linolenic acid (r=0.85).
Rate of peroxide formation also showed a positive correlation with linoleic acid (r=0.72) at the 2-position of the glycerol
moiety. A negative correlation was observed between rate of peroxide formation and oleic acid (r=−0.82). Resistance of soybean
triacylglycerols to reaction with oxygen was decreased by linolenic (r=0.87) and increased by oleic acid (r=−0.76)-containing
triacylglycerols. Volatile formation was increased by increased concentration of linolenic acid at exterior glycerol carbons
1,3 and by linoleic acid at the interior carbon 2. Headspace analysis of voltiles and high-performance liquid chromatography
of hydroperoxides indicated that as oxidation proceeded there was a slight decrease in the linolenic acid-derived hydroperoxides
and an increase in the linoleic acid-derived hydroperoxides. The oxidative stability of soybean oil triacylclycerols with
respect to composition and structure is of interest to the development of soybean varieties with oils of improved odor and
flavor stability.
Presented at the 81st Annual American Oil Chemists' Society Meeting, Baltimore, MD, April 18–21, 1990. 相似文献
10.
E. N. Frankel K. Warner K. J. Moulton Sr. 《Journal of the American Oil Chemists' Society》1985,62(9):1354-1358
Soybean oil was continuously hydrogenated in a slurry system to investigate the effects of linolenate content and additives
on cooking oil performance. Room odor evaluations carried out on oils heated to 190 C after frying bread cubes showed that
the oils hydrogenated with Cu catalyst to 2.4% linolenate (Cu-2.4) and with Ni catalyst to 4.6 linolenate (Ni-4.6) had a significantly
lower odor intensity score than the unhydrogenated soybean oil (SBO). Other hydrogenated oils (Cu-0.5 and Ni-2.7) were not
significantly better than SBO. Oil hydrogenated with Ni (Ni-0.4) scored poorly because of its strong “hydrogenated-paraffin”
odor. The performance of all partially hydrogenated oils (2.4, 2.7 and 4.6% linolenate) was improved by adding methyl silicone
(MS), but the most hydrogenated oils (0.5 and 0.4% linolenate) were not improved. Although with tertiary butyl hydroquinone
(TBHQ) no improvement was obtained, with the combination of TBHQ + MS all odor scores were lower, indicating a synergistic
effect. Evaluations of bread cubes after intermittent heating and frying showed that the breads fried in most hydrogenated
oils (Ni-0.4, Cu-2.4 and Ni-2.7) were rated significantly better in flavor quality than breads fried in SBO. The bread cubes
fried in MS-treated oils had significantly higher flavor quality scores than breads fried in SBO or SBO containing TBHQ. Dimer
analyses by gel permeation chromatography and color development after heat treatments also did not correlate with sensory
analyses. 相似文献
11.
T. L. Mounts K. Warner G. R. List 《Journal of the American Oil Chemists' Society》1981,58(7):A792-A794
The efficacy of tertiary butyl hydroquinone (TBHQ) treatment for enhancement of the storage stability of soybean oil has been
studied by flavor evaluation and chemical analysis. Soybean oils (I) unhydrogenated (IV=137.7; % linolenate=8.3), (II) hydrogenated
with nickel catalyst (IV=109.1; % linolenate=3.3), and (III) hydrogenated with copper-chromium catalyst (IV=112.8, % linolenate=0.4)
were each deodorized. In the cooling stage of the deodorizer, each oil was treated with citric acid plus TBHQ. These freshly
deodorized oils were compared to separate batches of each oil treated with citric acid alone or with citric acid plus butylated
hydroxyanisole and butylated hydroxytoluene. An analytical taste panel performed sensory evaluations by a paired sample test
using an intensity rating scale system. The oils were also evaluated after being subjected to accelerated storage tests (4
days and 8 days at 60 C) and a fluorescent light exposure test (4 hr, ambient temperature). Peroxide development during storage
was beneficially reduced in oils treated with TBHQ. The flavor stability of the three oils was not enhanced by treatment with
TBHQ under any test conditions.
Presented at ISF-AOCS Meeting, New York, NY, April 27–May 1, 1980. 相似文献
12.
An AOCS collaborative study was conducted to determine the effectiveness of sensory analysis and gas chromatographic analyses
of volatile compounds in measuring vegetable oils for levels of oxidation that ranged from none to high. Sixteen laboratories
from industry, government, and academia in Canada and the United States participated in the study to evaluate the flavor quality
and oxidative stability of aged soybean, corn, sunflower, and canola (low-erucic acid rapeseed) oils. Analytical methods included
sensory analyses with both flavor intensity and flavor quality scales and gas-chromatographic volatiles by direct injection,
static headspace, and dynamic headspace (purge and trap) techniques. Sensory and volatile compound data were used to rank
each of the oils at four levels of oxidation—none, low, moderate, and high. For soybean, canola, and sunflower oils, 85–90%
of laboratories correctly ranked the oils by either analysis. For corn oil, only 60% of the laboratories ranked the samples
according to the correct levels of oxidation by either analysis. Variance component estimates for flavor scores showed that
the variation between sensory panelists within laboratories was lowest for the unaged oils. As storage time increased, the
variance also increased, indicating that differences among panelists were greater for more highly oxidized oils. Between-laboratory
variance of sensory panel scores was significantly lower than within-laboratory variance. 相似文献
13.
J. C. Cowan C. D. Evans Helen A. Moser G. R. List S. Koritala K. J. Moulton H. J. Dutton 《Journal of the American Oil Chemists' Society》1970,47(12):470-474
The use of copper catalyst to reduce selectively the linolenate in soybean oil improves its flavor stability. As previously
shown, the copper must be removed or properly inactivated to obtain an oil of high initial quality. In oven and heat tests,
odor and flavor development in the hydrogenated soybean oil samples correlate surprisingly well with actual levels of linolenate,
but there were some differences in overall responses among cottonseed oil, copper-reduced (0.0% linolenate) and nickel-reduced
(3.0% linolenate) soybean oils. The taste panel generally scored the last three oils in the following order: cottonseed oil,
copper-reduced and nickel-reduced soybean oil.
One of 10 papers to be published from the Symposium “Hydrogenation”. presented at the AOCS Meeting, New Orleans, April 1970.
No. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献
14.
15.
Yasushi Endo Hiromi Endo Kenshiro Fujimoto Takashi Kaneda 《Journal of the American Oil Chemists' Society》1991,68(10):769-771
Edible refined, bleached and deodorized (RBD) soybean oil was fractionated by silicic acid column chromatography to identify
minor components responsible for flavor reversion. Minor components from oil eluted with diethyl ether/n-hexane (1:1) were
compared with those from corn and canola oils. All vegetable oils contain free fatty acids, diglycerides and sterols as major
ingredients in this fraction. However, unusual triglycerides consisting of 10-oxo-8-octadecenoic acid and 10-and 9-hydroxy
octadecanoic acids were detected in RBD and crude soybean oils. 相似文献
16.
W. E. Neff T. L. Mounts W. M. Rinsch H. Konishi 《Journal of the American Oil Chemists' Society》1993,70(2):163-168
The photooxidation of soybean oil was determined and correlated with triacylglycerol composition and structure. Purified triacylglycerols
were photooxidized at room temperature under fluorescent light. Rates of peroxide formation and total headspace volatiles
were related positively (P<0.5 significance) to oxidizability (r=0.75, r=0.76); content of linolenic acid (r=0.80, r=0.85) and linoleic acid (r=0.61,
r=0.57); linoleic acid on carbon 2 (r=0.64, r=0.64); and average number of double bonds (r=0.76, r=0.76). Negative correlations
were observed with respect to oleic acid (r=−0.70, r=−0.70). Soybean oil stability was decreased by linolenic acid-containing
triacylglycerols and increased by oleic acid-containing triacylglycerols. Trilinoleoylglycerol and dilinoleoyl-oleoylglycerol
were the most important oxidation product precursors. However, for high-linolenic acid soybean oil, dilinoleoyl-linolenoylglycerol
and trilinoleoylglycerol were the most important oxidation product precursors. The most abundant volatile produced from thermal
decomposition at 140°C of photooxidized triacylglycerols was 2-heptenal, except for high-linolenic acid oils, where the most
abundant volatile was propanal. The photooxidative stability of soybean oil triacylglycerols with respect to composition and
structure is of interest for the development of soybean varieties with oils of improved odor and flavor stability.
Presented at the 20th ISF World Congress 83rd Annual American Oil Chemists’ Society Meeting, May 10–14, 1992, Toronto, Canada. 相似文献
17.
Soybeans produced by induced mutation breeding and hybridization were cracked, flaked and hexane-extracted, and the recovered
crude oils were processed to finished edible oils by laboratory simulations of commercial oil-processing procedures. Three
lines yielded oils containing 1.7, 1.9 and 2.5% linolenic acid. These low-linolenic acid oils were evaluated along with oil
extracted from the cultivar Hardin, grown at the same time and location, and they were processed at the same time. The oil
from Hardin contained 6.5% linolenic acid. Low-linolenic acid oils showed improved flavor stability in accelerated storage
tests after 8 d in the dark at 60°C and after 8h at 7500 lux at 30°C, conditions generally considered in stress testing. Room
odor testing indicated that the low-linolenic oils showed significantly lower fishy odor after 1 h at 190°C and lower acrid/pungent
odor after 5 h. Potatoes were fried in the oils at 190°C after 5, 10 and 15 h of use. Overall flavor quality of the potatoes
fried in the low-linolenic oils was good and significantly better after all time periods than that of potatoes fried in the
standard oil. No fishy flavors were perceived with potatoes fried in the low-linolenic oils. Total volatile and polar compound
content of all heated oils increased with frying hours, with no significant differences observed. After 15 h of frying, the
free fatty acid content in all oils remained below 0.3%. Lowering the linolenic acid content of soybean oil by breeding was
particularly beneficial for improved oil quality during cooking and frying. Flavor quality of fried foods was enhanced with
these low-linolenic acid oils. 相似文献
18.
Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development 总被引:2,自引:4,他引:2
David Dolde Chris Vlahakis Jan Hazebroek 《Journal of the American Oil Chemists' Society》1999,76(3):349-355
As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the
range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols
were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of
economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics,
and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal-phase
high-performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples
ranged from 1947 to 4082 μg g−1. Total tocopherol concentration ranges varied from 534 to 1858 μg g−1 in sunflower, 504 to 687 μg g−1 in canola, and 1205 to 2195 μg g−1 among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was
stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean
oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated
in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered
storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently
did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed
among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured
under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level
and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature
effects on the biosynthesis of both compounds. 相似文献
19.
Xin-Qing Xu Viet Hung Tran Martin Palmer Keith White Philip Salisbury 《Journal of the American Oil Chemists' Society》1999,76(9):1091-1099
The performance of three high-oleic canola oils with different levels of linolenic acid [low-linolenic canola (LLC), medium-linolenic
canola (MLC), and high-linolenic canola (HLC)], a medium-high-oleic sunflower oil, a commercial palm olein and a commercial,
partially hydrogenated canola oil, was monitored by chemical and physical analyses and sensory evaluation during two 80-h
deep-frying trials with potato chips. Linolenic acid content was a critical factor in the deep-frying performance of the high-oleic
canola oils and was inversely related to both the sensory ranking of the food fried in the oils and the oxidative stability
of the oils (as measured by color index, free fatty acid content, and total polar compounds). LLC and sunflower oil were ranked
the best of the six oils in sensory evaluation, although LLC performed significantly better than sunflower oil in color index,
free fatty acid content, and total polar compounds. MLC was as good as palm olein in sensory evaluation, but was better than
palm olein in oxidative stability. Partially hydrogenated canola oil received the lowest scores in sensory evaluation. High-oleic
canola oil (Monola) with 2.5% linolenic acid was found to be very well suited for deep frying. 相似文献
20.
K. Warner C. D. Evans G. R. List H. P. Dupuy J. I. Wadsworth G. E. Goheen 《Journal of the American Oil Chemists' Society》1978,55(2):252-256
Samples of commercially processed soybean, cottonseed, and peanut oils were stored under controlled conditions then evaluated
for flavor by a 20-member trained, experienced oil panel and for pentanal and hexanal contents by direct gas chromatography.
The oils, which contained citric acid and/or antioxidants, were either aged from 0 to 16 days at 60 C or exposed to fluorescent
light for 0 to 16 hr. The simple linear regressions of flavor score with the logarithm of pentanal or hexanal content in aged
soybean oil gave correlation coefficients of −0.96 and −0.90, respectively; for cottonseed oil, −0.60 and −0.85; and for peanut
oil −0.74 and −0.75. Addition of peroxide values to the linear regressions increased the correlation coefficients. Flavor
scores of cottonseed and peanut oil can be predicted from pentanal and hexanal contents, but the technique is slightly more
reliable for soybean oil based on the treatments used for these oils.
Presented at the AOCS Meeting, Chicago, September 1973. 相似文献