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1.
Flavor and oxidative stability of soybean,sunflower and low erucic acid rapeseed oils 总被引:2,自引:0,他引:2
K. Warner E. N. Frankel T. L. Mounts 《Journal of the American Oil Chemists' Society》1989,66(4):558-564
Three samples each of soybean, sunflower and low erucic acid rapeseed (LEAR) oils were evaluated for flavor and oxidative
stability. The commercially refined and bleached oils were deodorized under identical conditions. No significant differences
were noted in initial flavor quality. After storage at 25°C or 60°C in the dark, soybean oils—with or without citric acid—were
more stable than either sunflower or LEAR oils. However, in the presence of citric acid, soybean oils were significantly less
stable to light exposure than either LEAR or sunflower oils. In contrast, in the absence of citric acid, soybean oils were
significantly more light stable than LEAR oils. In either the presence or absence of citric acid, sunflower oil was significantly
more stable to light than soybean oil. Analyses by static headspace gas chromatography showed no significant differences in
formation of total volatile compounds between soybean and LEAR oils. However, both oils developed significantly less total
volatiles than the sunflower oils. Each oil type varied in flavor and oxidative stability depending on the oxidation method
(light vs dark storage, absence vs presence of citric acid, 100°C vs 60°C).
Presented at the annual meeting of the Canadian Section of AOCS, held in October 1987 in Winnipeg, Manitoba, Canada. 相似文献
2.
T. L. Mounts K. A. Warner G. R. List J. P. Fredrich S. Koritala 《Journal of the American Oil Chemists' Society》1978,55(3):345-349
Flavor and oxidative stabilities were studied by organoleptic evaluation and chemical analysis of three different samples
of soybean oil: unhydrogented (I); hydrogenated with nickel catalyst (II); and hydrogenated with copper-chromium catalyst
(III). Analyses for these oils were: I II III iodine Value 138 109 113 Linolenate, % 8.3 3.3 0.4 Each oil was deodorized with
the addition of either citric acid alone or citric acid plus BHA and BHT antioxidants. Addition of antioxidants did not improve
the flavor stabilities of the oils in accelerated storage tests but did improve the flavor stabilities of II and III in light
exposure tests. All three oils that received the same additive treatment had equivalent flavor stability in both accelerated
storage and light exposure tests. However, both hydrogenation and antioxidant treatment improved oxidative stability as measured
by the Active Oxygen Method. There was good correlation between flavor score and the logarithm of the peroxide value determined
at the time of tasting.
Presented at the AOCS Meeting, New York, May 1977. 相似文献
3.
G. R. List J. W. King J. H. Johnson K. Warner T. L. Mounts 《Journal of the American Oil Chemists' Society》1993,70(5):473-476
A hexane-extracted crude soybean oil was degummed in a reactor by counter-currently contacting the oil with supercritical
CO2 at 55 MPa at 70°C. The phosphorus content of the crude oil was reduced from 620 ppm to less than 5 ppm. Degummed feedstocks
were fed (without further processing,i.e., bleaching) directly to a batch physical refining step consisting of simultaneous deacidification/deodorization (1 h @ 260°C
and 1–3 mm Hg) with and without 100 ppm citric acid. Flavor and oxidative stability of the oils was evaluated on freshly deodorized
oils both after accelerated storage at 60°C and after exposure to fluorescent light at 7500 lux. Supercritical CO2-processed oils were compared with a commercially refined/bleached soybean oil that was deodorized under the same conditions.
Flavor evaluations made on noncitrated oils showed that uncomplexed iron lowered initial flavor scores of both the unaged
commercial control and the CO2-processed oils. Oils treated with .01% (100 ppm) citric acid had an initial flavor score about 1 unit higher and were more
stable in accelerated storage tests than their uncitrated counterparts. Supercritical CO2-processed oil had equivalent flavor scores, both initially and after 60°C aging and light exposure as compared to the control
soybean oil. Results showed that bleaching with absorbent clays may be eliminated by the supercritical CO2 counter-current processing step because considerable heat bleaching was observed during deacidification/deodorization. Colors
of salad oils produced under above conditions typically ran 3Y 0.7R. 相似文献
4.
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
5.
β-Carotene was added to soybean salad oils to study its effect in inhibiting flavor deterioration due to light exposure. Flavor
evaluations indicated that (a) when oils treated with citric acid were exposed to light (7535 lux) for 8 to 16 hr, oils containing
5 to 10 ppm β-carotene showed improved flavor stability compared to oils containing 0 to 1 ppm β-carotene; and (b) when oils
were not treated with citric acid, only oils containing 20 ppm β-carotene were more stable to light. Capillary gas chromatographic
analysis showed that the addition of 1 to 20 ppm of β-carotene significantly decreased formation of 2-heptenal and 2,4-decadienal
in the absence or presence of citric acid. Determination of peroxide values showed the same trends as gas chromatographic
analyses of volatiles. In the presence of 15 and 20 ppm β-carotene, some off-flavors, as well as poor ratings for color quality,
were reported by panelists. Therefore, flavor deterioration initiated by light can be inhibited effectively in soybean oil,
without affecting color quality, by addition of β-carotene at concentrations from 5 to 10 ppm to oils treated with citric
acid. 相似文献
6.
C. D. Evans G. R. List Helen A. Moser J. C. Cowan 《Journal of the American Oil Chemists' Society》1973,50(6):218-222
Commercially prepared and packaged soybean and cottonseed salad oils from several different processors were evaluated periodically
during storage for 12 months. Partially hydrogenated and winterized soybean oils, as well as unhydrogenated soybean salad
oils, were stored in bottles and cans at 78 and 100 F. Control samples of all oils were held at 0 F during the entire test.
Some lots in bottles and cans were packaged under nitrogen to improve storage stability. Agreement was good between organoleptic
and oxidative evaluation of aged oils. After 26 weeks of storage at 100 F, the flavor of partially hydrogenated-winterized
oils packaged under nitrogen showed a minimum loss. These same oils did not exhibit much, if any, reduction in their oxidative
stability as indicated by storage peroxide values (active oxygen method). Soybean oil not protected with nitrogen demonstrated
progressive flavor deterioration at 100 F. After 10 weeks of storage, the deterioration became marked and the flavor score
was below 5. From limited observations, bottled oils appear to have a better stability than oils packaged in screw-cap tin
cans. Hydrogenated oils packaged under nitrogen in cans had good oxidative stability, but some lowering of the flavor score
was observed. Nonhydrogenated soybean oils packaged in tin cans not under nitrogen exhibited the most rapid flavor deterioration
of all lots of oil investigated.
Presented in part at the AOCS meeting, New York, October 1968
ARS, USDA 相似文献
7.
8.
T. L. Mounts K. Warner G. R. List R. Kleiman W. R. Fehr E. G. Hammond J. R. Wilcox 《Journal of the American Oil Chemists' Society》1988,65(4):624-628
During the last 15 years, hybridization and induced mutation breeding of soybeans have been successful in producing an altered
fatty acid composition in the extracted oil. The objective of those investigations was to produce a low-linolenic acid soybena
oil. Crude oils extracted from the seeds of three such genotypes were processed in laboratory simulations of commercial procedures
to finished deodorized oils. Analysis of the fatty acid composition of the three oils showed the linolenic acid content to
be 3.3%, 4.2% and 4.8%. The stability of these finished oils was compared to that of oil from a soybean variety having a linolenic
acid content of 7.7% and of a commercial hydrogenated-winterized soybean oil (3.0% linolenic acid). Test and control oils
were evaluated by a trained sensory panel initially, after accelerated storage at 60 C and during use at 190 C in room tests.
Peroxide values were determined at the time of sensory evaluation. Results indicated there was no significant difference in
flavor stability during storage between test and control oils. There was no significant difference, between the oils, in peroxide
development during accelerated storage. Compared to control oils, the test oils had improved overall room odor intensity scores
and lacked the fishy odors of non-hydrogenated soybean oil and the hydrogenated odors of commercial cooking oil.
Presented at the AOCS meeting in Honolulu, HI in May 1986. 相似文献
9.
J. M. King L. K. Svendsen W. R. Fehr J. M. Narvel P. J. White 《Journal of the American Oil Chemists' Society》1998,75(9):1121-1126
Soybeans that lack or contain three lipoxygenase (LOX) isozymes, LOX-1, LOX-2, and LOX-3, were evaluated for oxidative and
flavor stability at 60°C in the dark and at 35°C in the light. Although the two types of soybeans had a similar genetic background,
there were significant differences (P ≤ 0.01) in fatty acid percentages between the lipoxygenase-free and normal oils before and after storage at both temperatures.
The linolenic acid content of oil from LOX-free germplasm before storage averaged 7.2%, while normal lines averaged 6.6%.
The linoleic acid content after storage averaged 6.9% for LOX-free and 6.6% for normal oils. LOX-free oil was not significantly
different from normal oil in flavor, as judged by a sensory panel, or in concentrations of volatiles during storage at either
storage condition. LOX-free oil had less hexanal than normal oil before storage, but had significantly greater (P ≤ 0.05) levels after storage for two weeks at 35°C. Peroxide values of oil from LOX-free soybeans were significantly greater
(P ≤ 0.01) than oil from the normal soybean after storage at 60 and 35°C. LOX-free oil had significantly greater (P ≤ 0.01) levels of α-, β-, and γ-tocopherols. In general, oil from LOX-free soybeans did not have improved flavor or oxidative
stability. Differences between the two oil types in peroxide value and in production of a few volatiles were probably a result
of the differences in initial fatty acid composition. 相似文献
10.
J. M. King L. K. Svendsen W. R. Fehr J. M. Narvel R. J. White 《Journal of the American Oil Chemists' Society》1998,75(12):1121-1126
Soybeans that lack or contain three lipoxygenase (LOX) isozymes, LOX-1, LOX-2, and LOX-3, were evaluated for oxidative and
flavor stability at 60°C in the dark and at 35°C in the light. Although the two types of soybeans had a similar genetic background,
there were significant differences (P≤0.01) in fatty acid percentages between the lipoxygenase-free and normal oils before and after storage at both temperatures.
The linolenic acid content of oil from LOX-free germplasm before storage averaged 7.2%, while normal lines averaged 6.6%.
The linoleic acid content after storage averaged 6.9% for LOX-free and 6.6% for normal oils. LOX-free oil was not significantly
different from normal oil in flavor, as judged by a sensory panel, or in concentrations of volatiles during storage at either
storage condition. LOX-free oil had less hexanal than normal oil before storage, but had significantly greater (P≤0.05) levels after storage for two weeks at 35°C. Peroxide values of oil from LOX-free soybeans were significantly greater
(P≤0.01) than oil from the normal soybean after storage at 60 and 35°C. LOX-free oil had significantly greater (P≤0.01) levels of α-, β-, and γ-tocopherols. In general, oil from LOX-free soybeans did not have improved flavor or oxidative
stability. Differences between the two oil types in peroxide value and in production of a few volatiles were probably a result
of the differences in initial fatty acid composition. 相似文献
11.
Herbert J. Dutton Helen A. Moser John C. Cowan 《Journal of the American Oil Chemists' Society》1947,24(8):261-264
Summary The future of the soybean oil industry depends in part upon increasing the flavor stability of edible soybean oil. A procedure,
which is reported to have been used by the German soybean oil refiners for combating flavor instability, has been tested on
laboratory scale and appears to have distinct merit. Oils subjected to a particularly thorough degumming operation and to
the subsequent addition of a small amount of citric acid during deodorization possessed a significantly higher flavor stability
than did those subjected to a conventional type of refining.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献
12.
The effects of linolenic acid (18∶3) concentration, combined with TBHQ addition, temperature, and storage time, on the oxidative
and flavor stabilities of soybean oils (SBO) were evaluated. During storage under fluorescent light at both 21 and 32°C, the
SBO with ultra-low-18∶3 concentration (1.0%, ULSBO) generally had greater oxidative stability than did SBO with low-18∶3 concentration
(2.2%, LLSBO). The ULSBO had about half the p-anisidine value of LLSBO throughout storage. Although the ULSBO initially had significantly greater PV and poorer (lower)
sensory scores for overall flavor quality than did LLSBO, significant differences disappeared with storage. The ULSBO had
a lower content of polar compounds and greater oil stability indices than did LLSBO when TBHQ was present. All oils were more
oxidatively stable with TBHQ addition, but the TBHQ addition did not result in improved flavor stability early in storage.
In all tests, oils stored at 32°C were less stable than oils stored at 21°C. The TBHQ had a better antioxidant capacity when
the 18∶3 concentration was lower. The retardation effect of TBHQ on lipid oxidation and the improved stability of ULSBO over
LLSBO were more easily detected when the storage temperature was higher. 相似文献
13.
Although previous research showed that volatile compounds detected by gas chromatography (GC) correlated well with flavor
scores, no instrumental or chemical method has been available to predict flavor stability of vegetable oils reliably. A direct
GC method was tested to predict flavor stability of soybean oil by measuring induction periods based on the time required
for rapid formation of volatile compounds. By this technique, induction periods of 9, 5 and 0 days were obtained with oils
containing a combination of tertiary butylhydroquinone (TBHQ) and citric acid (CA), CA only and no additives, respectively.
Addition of methyl silicone to the oils containing CA or CA+TBHQ did not increase their stability. Prominent peaks identified
by gas chromatography-mass spectrometry included: pentane, hexanal, 2-heptanal, 2,4-heptadienal, 2-decenal and 2,4-decadienal.
Measures of total volatile compounds, pentane and 2,4-decadienal were best related to deteriorative changes. High correlation
coefficients were obtained between individual and total volatiles with flavor scores. This study showed that flavor stability
of oils can be predicted by determining induction periods based on the formation of volatile compounds. 相似文献
14.
C. D. Evans Patricia M. Cooney C. R. Scholfield H. J. Dutton 《Journal of the American Oil Chemists' Society》1954,31(7):295-297
Summary The addition prior to deodorization of 0.1% of either crude phosphatides, or the alcohol-soluble, or the alcohol-insoluble
fraction all improved the oxidative stability and the initial flavor of soybean salad oil. However all three additives caused
significant darkening of the oils and the introduction of undesirable storage flavors when added at levels which improved
the oxidative stability.
High-sugar fractions from the crude phosphatides did not darken the oil nor did they confer improved oxidative or flavor characteristics.
Cadmium-precipitated lecithin and inositol-phosphatidic acids containing no amino nitrogen gave lower color to salad oils
upon deodorization than did the amino-nitrogen-containing phosphatides.
Purified cadmium-precipitated lecithin had little effect upon the oxidative stability when added at levels below 0.02%. A
significant improvement results from the addition of 0.05%, and oxidative stability shows further improvement by raising the
level to 0.1%; however no increase in stability was obtained by raising of the concentration above this level.
At concentrations of 0.01 and 0.05%, cadmium-precipitated lecithin had little effect on the color of the oil. At levels of
0.1 and 0.2%, significant darkening of the oils occurred though much less than with the amino-nitrogen-containing phosphatides.
Based on the flavor responses of oils to which these phosphatides were added, it appears that phosphatides constitute the
precursors for the melony, bitter, cucumber flavors frequently encountered in aged soybean salad oils. These flavor responses
are the same as those obtained from added phosphoric acid.
Presented at fall meeting of American Oil Chemists’ Society, Nov. 2–4, 1953, in Chicago, Ill.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Service, U. S. Department
of Agriculture. 相似文献
15.
C. D. Evans Helen A. Moser Patricia M. Cooney J. E. Hodge 《Journal of the American Oil Chemists' Society》1958,35(2):84-88
Summary Amino-hexose-reductones were evaluated as antioxidants in soybean, cottonseed, and corn oils and were shown to be highly effective
by all oxidative and chemical tests. The activity of the eight different reductones was approximately the same in any one
substrate. Slightly higher activities were given by reductones of lower molecular weight. Activity was demonstrated at concentrations
as low as 0.001% and was shown to be a linear function of the concentration up to 0.02%, the approximate limit of solubility.
Out-standing features of the reductone-treated oils were long induction periods, slow absorption of oxygen, and low rates
of peroxide development. Reductones are believed not to react directly with peroxides but to prevent peroxide formation by
reacting with some precursor.
The combination of reductones with other antioxidants showed synergistic effects in only one sample of corn oil. The activity
of combinations in soybean and cottonseed oils was for the most part strictly additive. In soybean oil, citric acid-reductone
combinations with each at the 0.01% level gave a slight improvement over the expected activity. Oils stabilized with multiple-component,
antioxidant mixtures in which an amino reductone replaced propyl gallate showed less peroxide development and were equally
acceptable according to organoleptic scores. Aged oils did not show the organoleptic improvement that would be expected from
the marked improvement observed in the oxidative stability. Significant improvements in flavor stability could be observed
with reductones only when they were used in combination with an-other antioxidant. Reductone-treated soybean and cottonseed
oils did not show an appreciable improvement in flavor stability. Only the di-n-butylamino-and diallylamino-reductones contributed
foreign flavors to the oil. Atypical flavors are believed associated with the amine moiety of the reductone.
At high temperatures and at higher concentrations of reductones a brown melanoid color develops in the oil. The anhydro derivatives
developed more color than the normal reductone. The reductones do not withstand oil deodorization conditions.
Presented at the meeting of the American Oil Chemists' Society, Chicago, Ill. September 23–26, 1956. 相似文献
16.
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
17.
K. J. Moulton Sr. S. Koritala K. Warner 《Journal of the American Oil Chemists' Society》1985,62(12):1698-1701
Soybean oil was partially hydrogenated in a continuous system with copper and nickel catalysts. The hydrogenated products
were evaluated for flavor and oxidative stability. Processing conditions were varied to produce oils of linolenate contents
between 0.4 and 2.7%, as follows: oil flow, 0.6–2.2 liters/hr; reaction temperature, 180–220 C; hydrogen pressure, 100–525
psig, and catalyst concentration, 0.5–1% copper catalyst or 0.1% nickel catalyst.Trans unsaturation varied from 8 to 20% with copper catalyst and from 15.0 to 27% with nickel catalyst. Linolenate selectivity
was 9 with copper catalyst and 2 with nickel catalyst. Flavor evaluation of finished oils containing 0.01% citric acid (CA),
appraised initially and after accelerated storage at 60 C, showed no significant difference between hydrogenated oils and
nonhydrogenated oil. However, peroxide values and oxidative stability showed that hydrogenated oils were more stable than
the unhydrogenated oil. CA+TBHQ (tertiary butylhydroquinone) significantly improved the oxidative stability of test oils over
oils with CA only, but flavor scores showed no improvement. Dimethylpolysiloxane (MS) had no effect on either flavor or oxidative
stability of the oils. 相似文献
18.
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
19.
C. D. Evans E. N. Frankel Patricia M. Cooney Helen A. Moser 《Journal of the American Oil Chemists' Society》1960,37(9):452-456
Summary Oxidation prior to deodorization was shown to be detrimental to the flavor and oxidative stability of soybean oil. The increase
in the nonvolatile carbonyl content of freshly deodorized oils was proportional to the peroxide value of the oils before deodorization.
Rate of loss of flavor and oxidative stability of the oil were related to the extent of carbonyl development. All oils, whether
or not they had been submitted to any known oxidation, contained some nonvolatile carbonyls. The loss in stability was not
due to a loss of the antioxidant tocopherol.
Oxidized soybean oil methyl esters were shown to develop nonvolatile carbonyl compounds upon heating at deodorization temperatures.
The addition of isolated methyl ester peroxide decomposition products to deodorized soybean oil reduced its flavor and oxidative
stability in proportion to the amount added. The results obtained were parallel and similar to those obtained by oxidizing
soybean oil prior to deodorization.
Flavor deterioration and undesirable flavors were typical of aging soybean oil whether or not the oils were oxidized before
deodorization or whether an equivalent amount of nonvolatile thermal decomposition products was added to the oil. These oxidatively
derived, nonvolatile carbonyl materials are believed to enter into the sequence of reactions that contribute to flavor instability
and quality deterioration of soybean oil. The structure of these materials is not know.
This work indicates the importance of minimizing autoxidation in soybean oil particularly before deodorization to insure good
oxidative and flavor stability.
Presented at fall meeting, American Oil Chemists’ Society, October 20–22, 1958, Chicago, Ill.
This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department
of Agriculture. 相似文献
20.
Herbert J. Dutton Arthur W. Schwab Helen A. Moser John C. Cowan 《Journal of the American Oil Chemists' Society》1948,25(11):385-388
Summary A study has been made of the effectiveness of various polycarboxylic acids and polyhydric alcohols in improving the stability
of soybean oil. Certain observations have been made regarding the structural groups required and the possible mechanism of
reaction. Since salts and esters of organic acids are inactive, free carboxyl groups are required. Among the four carbon atom
dicarboxylic acids activity increases with the number of hydroxyl groups. Within the polyalcohols activity increases with
the increase in number of hydroxyl groups. Steric immobility and loss of hydroxyl groups by dehydration reduces activity.
Evidence is presented which attributes to citric acid and certain polyhydric alcohols the role of metal scavenger. For example,
it has been demonstrated that the addition of citric acid and sorbitol to soybean oil containing prooxidant metallic salts
effectively increases the oxidative and flavor stability of the oil. By using a sample of treated soybean oil with no detectable
tocopherols, in order to eliminate synergistic effects of citric acid, it has been shown that the prooxidant effect of iron
stearate is counteracted by the presence of citric acid. The demonstration that polyhydric alcohols increase the flavor and
oxidative stability is compatible with their known metal complexing properties. Evidence is presented which indicates a relationship
between flavor stability and oxidative stability.
Presented at the 39th Annual Meeting of the American Oil Chemists' Society, May 4–6, 1948, in New Orleans, Louisiana.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献