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1.
K. Warner E. N. Frankel K. J. Moulton 《Journal of the American Oil Chemists' Society》1988,65(3):386-391
Reliable methods for evaluation of crude oils are needed to assist processing and to improve flavor quality of finished products.
The quality of crude oils from soybeans of different sources and treatments was determined by sensory evaluation and by capillary
gas chromatographic (GC) analyses of volatiles. Taste panelists were specially trained in using a new technique to evaluate
crude oils by dilution and comparison with freshly deodorized oils. The flavor quality of crude oils from untempered soybeans
was significantly poorer than that of oils from soybeans steam-tempered at 104 C for four min. Capillary GC analyses of total
volatiles and hexanal correlated well with differences in flavor quality and stability. Crude oils extracted from soybeans
damaged by storage at 45 C and 13% moisture received decreasing flavor scores with prolonged storage time. Similarlly, hexanal
and total volatile contents increased with storage times. Commercial crude oils from several geographic locations showed a
wide range in flavor scores. However, flavor scores of crude oils showed good agreement with flavor stabilities (decrease
in flavor scores after storage at 60 C) of the corresponding oils after refining, bleaching, and deodorization. Therefore,
the combined use, of sensory evaluations and GC-volatile analyses of crude oils can provide convenient, rapid, sensitive and
reliable screening methods to assist in improving the quality of finished soybean oils by controlling soybean storage and
processing. 相似文献
2.
C. D. Evans G. R. List R. E. Beal L. T. Black 《Journal of the American Oil Chemists' Society》1974,51(10):444-448
Analyses of commercial crude soybean oils showed a highly significant correlation of 0.74 between free fatty acid and iron content. Poor flavor characteristics exhibited by finished oils extracted from damaged beans may be caused in part by a higher free fatty acid and related higher iron content in crude oils. Source of the increased iron appears to be both damaged beams and steel processing equipment. Crude oil from damaged beans is 2–10 times higher in iron than crude oil extracted from sound beans. Iron appears loosely bound in soybeans, since autoclaving, spontaneous heating in storage, or treating with alcohol increased the level of iron in laboratory extracted crude oil from 0.2 to more than 1 ppm. Present data do not indicate that iron and phosphorus contents are associated statistically in extracted oils. 相似文献
3.
G. R. List C. D. Evans K. Warner R. E. Beal W. F. Kwolek L. T. Black K. J. Moulton 《Journal of the American Oil Chemists' Society》1977,54(1):8-14
Various processing steps were explored in an at-tempt to improve the quality of oil from field- and storage-damaged soybeans.
A crude soybean oil (5.7% free fatty acid) commercially extracted from damaged soybeans was degummed in the laboratory with
different reagents: water, phosphoric acid, and acetic anhydride. Two alkali strengths, each at 0.1 and 0.5% excess, were
used to refine each degummed oil. After vacuum bleaching (0.5% activated earth) and deodorization (210 C, 3 hr), these oils
were un-acceptable as salad oils. A flavor score of 6.0 or higher characterizes a satisfactory oil. Scores of water and phosphoric
acid degummed oils ranged from 4.5 to 5.1, while acetic anhydride degummed oils aver-aged 5.6. Flavor evaluations of (phosphoric
acid de-gummed) single- and double-refined oils (210 C deodorization) showed that the latter were signifi-cantly better. Flavor
scores increased from 5.0 to about 6.0. To study the effects of deodorization tem-perature, the crude commercial oil was alkali-refined,
water-washed and bleached with 0.5% activated earth, but the degumming step was omitted. Flavor evalua-tion of oil deodorized
at 210, 230, and 260 C showed that each temperature increment raised flavor scores significantly. Further evaluations of specially
proc-essed oils (water, phosphoric acid, and acetic anhy-dride degummed oils given single and double refinings and deodorized
at 260 C) showed that deodorization temperature is the most important factor affecting the initial quality of oil from damaged
beans. Flavor evaluations showed that hydrogenation and hydro-genation-winterization treatments produced oils of high initial
quality, but with poorer keeping proper-ties than oils from normal beans. No evidence was found implicating nonhydratable
phosphatides in the oil flavor problem. Iron had a deleterious effect in oils not treated with citric acid during deodorization.
Presented at AOCS Meeting, Philadelphia, September 1974. 相似文献
4.
E. N. Frankel K. Warner B. P. Klein 《Journal of the American Oil Chemists' Society》1988,65(1):147-150
The role played by lipoxygenase in the flavor quality of soybean oil was investigated by comparing the oil processed from
special soybeans lacking lipoxygenase-1 (Forrest x P.I. 408251) with the oil from normal (Century) beans. Quality assessment
was based on sensory evaluations and on capillary gas chromatographic (GC) analyses of volatiles of the extracted crude, partially
processed, and refined, bleached and deodorized oils. In direct comparisons of oil products from the two types of beans, no
significant differences were found in either flavor quality or in flavor stability based on total volatiles, and in analyses
for 2,4-decadienal. Although thermal tempering did not significantly affect the initial flavor scores of crude and degummed
oils from Century and low L-1 soybeans, the initial scores of refined and bleached oils from Century soybeans were significantly
improved by this treatment. Similarly, thermal tempering was just as important in producing good quality flour from the special
beans lacking lipoxygenase-1 as the flour from normal beans. Therefore, factors other than lipoxygenase-1 appear to affect
the food quality of soybean oils and meals. 相似文献
5.
T. L. Mounts K. Warner G. R. List W. E. Neff R. F. Wilson 《Journal of the American Oil Chemists' Society》1994,71(5):495-499
Oil was hexane-extracted from soybeans that had been modified by hybridization breeding for low-linolenic acid (18∶3) content.
Extracted crude oils were processed to finished edible oils by laboratory simulations of commercial oil processing procedures.
Oils from three germplasm lines N83-375 (5.5% 18∶3), N89-2009 (2.9% 18∶3) and N85-2176 (1.9% 18∶3) were compared to commercial
unhydrogenated soybean salad oil with 6.2% 18∶3 and two hydrogenated soybean frying oils, HSBOI (4.1% 18∶3) and HSBOII (<0.2%
18∶3). Low-18∶3 oils produced by hybridization showed significantly lower room odor intensity scores than the commercial soybean
salad oil and the commercial frying oils. The N85-2176 oil with an 18∶3 content below 2.0% showed no fishy odor after 10 h
at 190°C and lower burnt and acrid odors after 20 h of use when compared to the commercial oils. Flavor quality of potatoes
fried with the N85-2176 oil at 190°C after 10 and 20 h was good, and significantly better at both time periods than that of
potatoes fried in the unhydrogenated oil or in the hydrogenated oils. Flavor quality scores of potatoes fried in the N89-2009
oil (2.9% 18∶3) after 10 and 20 h was good and equal to that of potatoes fried in the HSBOI oil (4.1% 18∶3). Fishy flavors,
perceived with potatoes fried in the low-18∶3 oils, were significantly lower than those reported for potatoes fried in the
unhydrogenated control oil, and the potatoes lacked the hydrogenated flavors of potatoes fried in hydrogenated oils. These
results indicate that oils with lowered linolenic acid content produced by hybridization breeding of soybeans are potential
alternatives to hydrogenated frying oils. 相似文献
6.
L. A. Baumann D. G. McConnell Helen A. Moser C. D. Evans 《Journal of the American Oil Chemists' Society》1967,44(11):663-666
Results of 4-year storage tests are reported for crude and refined soybean oils held in 50-gal drums under conditions simulating
field tank operations. Once-refined oils stored in filled drums without breathers showed lower peroxide values and lower dimer
contents than oil stored in full drums with breathers. Refined oils in half-filled drums exhibited higher storage temperatures
and, consequently, higher peroxide values and dimer contents than any other storage condition. Nondegummed and degummed crude
oils held in drum storage had lower peroxide values and lower dimer contents than refined oils stored under similar conditions.
Relationships are significant not only between storage peroxide values and dimer contents, but also each of these with flavor
scores. Evidently, stored crude or stored refined soybean oils with peroxide values under 60 could be deodorized to produce
salad-grade oils with initial flavor quality equal to that of oils processed from stocks having considerably lower initial
peroxide values. The relative rate of peroxide increase for field tank storage can be estimated from linear regression analysis
on data from stor-age of soybean oil in drums. Once-refined soybean oil held under large field tank storage conditions would
not be expected to reach peroxide levels of 60 until after 3-4 years, even in warm areas.
ARS, USDA.
No. Utiliz. Res. Dev. Div.. ARS, USDA. 相似文献
7.
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
8.
G. R. List T. L. Mounts K. Warner A. J. Heakin 《Journal of the American Oil Chemists' Society》1978,55(2):277-279
A lot of commercially extracted crude soybean oil was water degummed with and without a phosphoric acid pretreatment. The
degummed oils were bleached and then deacidified-deodorized in a single step to yield physically (steam) refined soybean salad
oils. Their flavor and oxidative stability were compared to caustic-refined oils given otherwise identical processing treatments.
Physically refined oils without a phosphoric acid pretreatment were of poor initial quality compared to those given the phosphoric
acid pretreatment. However, caustic- and steam-refined oils processed with the phosphoric pretreatment were of comparable
quality.
Presented in part at the AOCS-AACC Symposium, Current Concepts of Food Ingredients, Chicago, March 1977. 相似文献
9.
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
10.
G. R. List T. L. Mounts A. J. Heakin 《Journal of the American Oil Chemists' Society》1978,55(2):280-284
The first paper in this series described the effect of refining and degumming methods on the quality of steam- and caustic-refined
soybean oils. Flavor evaluations demonstrated that phosphoric acid-pretreated oils were superior to water-degummed oils particularly
in the steam-refining mode. The present study reports observations on the function of the phosphoric acid pretreatment. The
effects of iron on the flavor and oxidative stability are reviewed. Data on phosphatide and iron removal during caustic and
steam refining are presented and the results discussed. The poor initial quality of the water-degummed, steam-refined oil
is attributed to oxidation resulting from incomplete iron removal during the prerefining stage. Significant correlations were
obtained between the initial flavor scores of processed oils and their iron contents. Phosphoric acid pretreatment apparently
alters iron compounds in crude soybean oil and facilitates their removal during subsequent processing.
Presented in part at the AOCS-AACC Symposium, Current Concepts of Food Ingredients, Chicago, March 1977. 相似文献
11.
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
12.
Mohamed Fawzy Ramadan Jrg‐Thomas Mrsel 《European Journal of Lipid Science and Technology》2004,106(1):35-43
Information on stability of edible oils is important for predicting the quality deterioration of the oil during storage and marketing. Stripping of crude oils removes most of non‐triacylglycerol components, including polar lipids and phenolics. Oxidative stability of black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) crude and stripped seed oils was investigated and compared. The factors influencing the oxidative stability of different seed oils were also discussed. Oil samples were stored under accelerated oxidation conditions for 21 d. The progress of oxidation at 60 °C was followed by recording the ultraviolet absorptivity and measuring the formation of oxidative products (peroxide and p‐anisidine values). Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by p‐anisidine value and stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. In general, oxidative stabilities of crude oils were stronger than their stripped counterparts and the order of oxidative stability was as follows: coriander > black cumin > niger seed. Levels of polar lipids in crude oils correlated with oxidative stability. Thus, the major factor that may contribute to the better oxidative stability of crude oils was the carry‐over of their polar lipids. 相似文献
13.
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
14.
D. R. Erickson 《Journal of the American Oil Chemists' Society》1983,60(2):351-356
The growth and present stature of soybeans and soybean oil production and utilization in the world and in the USA is presented.
Compositions of soybeans and soybean oil are compared with other common vegetable oils. The current and optimal processing
practices of extraction, degumming, neutralization (caustic and physical), hydrogenation, and deodorization are discussed.
Where appropriate, new and innovative approaches are introduced. Utilization of soybean oil is covered, followed by a historical
and present view on the subject of soybean oil flavor and present and future nutritional considerations of soybean oil. 相似文献
15.
The state of soybeans prior to extraction affected the tocopherol content of crude soybean oils. Soybean flakes with a thickness
of 0.16–0.33 mm had higher extracted oil yield but a slightly lower tocopherol content of the oils than did cracked beans
and thicker bean flakes. Highmoisture content and long storage of soybeans resulted in lower tocopherol content in the crude
oils, with moisture content being more important than storage time at decreasing the tocopherol content of oils. Soybean oil
from stored beans with 15±1% moisture content led to a more significant decrease in the tocopherol content than did oil from
stored beans with low (12%) or high (18%) moisture contents. Soybean flakes contaminated with oxidized oil had a significant
effect on the decrease of the tocopherol content in crude oils. The high amount of phospholipids in crude soybean oil might
result in a smaller decrease in the tocopherol content of oil during heating. 相似文献
16.
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
17.
Color reversion in soybean oil can be prevented by reducting the enzyme activity of soybeans before cracking and flaking.
Soybean oil extracted from steamed, intact soybeans (18% moisture) had lower Rm (max. red) values in RBD oil, higher amounts
of γ-tocopherol, plus its isomers, in both crude and RBD oil, and also higher amounts of hydratable phosphatides in crude
oil than those in the oils from the same beans without steam treatment. For soybean pretreatments, a toasting process is less
effective than the steaming process for the inhibition of color reversion of soybean oil. To prevent the occurrence of color
reversion in RBD soybean oil, the amount of γ-tocopherol and γ-TED (5-[tocopheryloxy]-γ-tocopherol) should be above 550 ppm
in crude oil. 相似文献
18.
The oxidative stabilities of one canola oil and six soybean oils of various fatty acid compositions were compared in terms
of peroxide values, conjugated dienoic acid values and sensory evaluations. Two of the soybean oils (Hardin and BSR 101) were
from common commercial varieties. The other four soybean oils were from experimental lines developed in a mutation breeding
program at Iowa State University that included A17 with 1.5% linolenate and 15.2% palmitate; A16 with 2% linolenate and 10.8%
palmitate; A87-191039 with 2% linolenate and 29.6% oleate; and A6 with 27.5% stearate. Seed from the soybean genotypes was
cold pressed. Crude canola oil was obtained without additives. All oils were refined, bleached and deodorized under laboratory
conditions with no additives and stored at 60°C for 15 days. The A17, A16, A87-191039 and A6 oils were generally more stable
to oxidation than the commercial soybean varieties and canola oil as evaluated by chemical and sensory tests. Canola oil was
much less stable than Hardin and BSR 101 oils by both chemical and sensory tests. The peroxide values and flavor scores of
oils were highly correlated with the initial amounts of linolenate (r=0.95, P=0.001). Flavor quality and flavor intensity
had negative correlations with linolenate, (r=−0.89, P=0.007) and (r=−0.86, P=0.013), respectively. 相似文献
19.
Ultrasonic energy has been applied to continuous degumming for the efficient removal of phospholipids from crude soybean oil.
The crude oil and water (2.0% by weight) were pumped through an ultrasonic processing cell, oil and hydrated gums were separated
by centrifugation, and the recovered oil was vacuum bleached. The degummed and bleached oil had a residual phosphorus content
of less than 10 ppm and was subsequently deacidified-deodorized in all-glass laboratory deodorization equipment. Odor and
flavor evaluation indicated that the salad oil produced by the process of ultrasonic degumming/deodorization-deacidification
was equivalent in quality and stability to a conventionally processed salad oil. 相似文献
20.
A. M. Nash E. N. Frankel W. F. Kwolek 《Journal of the American Oil Chemists' Society》1984,61(5):921-923
Oils from both properly stored and damaged soybeans were degummed with a series of 4 nonionic, 2 cationic and 5 anionic surfactants
and with lecithins as amphoteric emulsifiers. Efficiency of phosphatide removal in the presence or absence of citric acid
was determined by colorimetric analysis of phosphorus in the degummed oils. For normal oils, efficiency of citric acid degumming
was improved by the addition of fatty alkyl oxazoline, polymeric sulfonate, alkyl sulfate and crude or purified lecithin.
Success in degumming of oils from partially damaged soybeans was limited; however, the average phosphorus content was lowest
for those solutions degummed with alkyl sulfate. Aqueous citric acid degumming of oils from severely damaged soybeans indicated
high levels of nonhydratable phosphatides (NHP). When added to the oil from severely damaged beans, several nonionic and anionic
surfactants showed statistically significant improvements in degumming efficiency. However, the nonhydratable phosphorus contents
of the degummed oils were still too high, indicating the need for special processing of damaged oils. Crude lecithin was effective
in removing NHP from oil of fresh soybeans, but was ineffective on oils of stored and severely damaged beans.
Biometrician, North Central Region, ARS, USDA, stationed at the Northern Regional Research Center, Peoria, Illinois 61604. 相似文献