共查询到8条相似文献,搜索用时 15 毫秒
1.
Hiromi Yoshida Sachiko Takagi Hiroyuki Ienaga Chiharu Tsuchiya 《Journal of the American Oil Chemists' Society》1998,75(7):767-774
Seed coat, axis, and sections of cotyledons in three soybean cultivars were analyzed by high-performance liquid chromatography
for tocopherols, and by gas-liquid chromatography for acyl lipids. Tocopherols were predominantly detected in axis, followed
by cotyledons and seed coat. With a few exceptions, dominant components were γ- and δ-tocopherols, with much smaller amounts
of α- and β-tocopherols. However, α-tocopherol was higher (P<0.05) for the Mikawajima cultivar than for Okuhara and Tsurunoko in all tissues. Triacylglycerols (TAG) were the major fraction
of total lipids, representing 70% in axis and coat and 94% in cotyledons. A small difference (P<0.05) occurred in fatty acid composition of TAG when comparing seed coat to the axis. The fatty acid composition of phosphatidylinositol
(PI) differed (P<0.05) from phosphatidylethanolamine (PE) and phosphatidylcholine (PC) in each tissue. Principally, the percentage of palmitic
acid was higher, especially in axis and coat. In PE and PC, linoleic was greater, followed by palmitic, in all samples except
for seed coat tissue in Mikawajima. The percentages of palmitic acid in both phospholipids were significant higher in the
seed coat tissue from this cultivar than in cotyledon or axis of the other varieties. These results suggest that the differences
in soybean cultivars could be appreciable, based on the distribution of tocopherols and fatty acids in each component part
within soybean seeds. 相似文献
2.
Whole soybeans were exposed to microwave roasting for 6, 12, and 20 min at a frequency of 2,450 MHz and were studied not only
for phospholipid composition but also for positional distribution of the fatty acids. During microwave roasting, the greatest
rate of phospholipid losses (P<0.05) was observed in phosphatidylethanolamine (PE), followed by phosphatidylcholine (PC) and phosphatidylinositol (PI),
respectively. Therefore, the effects of microwave roasting on the composition and positional distribution of the fatty acids
are likely clearer in PE than in PC or PI. However, the principal characteristics for the positional distribution of fatty
acids are still retained during microwave roasting: unsaturated fatty acids, especially linoleic, are predominantly concentrated
in the 2-position, and saturated fatty acids, especially palmitic, primarily occupy the 1-position after 12 or 20 min of roasting.
The results suggest that unsaturated fatty acids located in the 2-position are significantly protected from microwave roasting. 相似文献
3.
C. Adhikari H. E. Snyder T. W. Kwon P. K. Clark 《Journal of the American Oil Chemists' Society》1992,69(11):1141-1145
By varying the extracting conditions, it may be possible to produce high-quality, low-phosphorus and low-free fatty acid (FFA)
oil extracted from water or mechanically damaged soybeans. The variability in phospholipids and FFA was studied in oil extracted
by an alternative process from undamaged, damaged and aged soybeans subjected to various changes. Forrest and Hutcheson cultivars
were used, and extractions were from finely ground flour rather than from flakes. Freezing caused the maximum increase in
FFA and phosphorus levels compared to other levels in damaged or undamaged soybeans, but the levels were reasonable compared
to flake extraction. Phosphorus and FFA increased when storage temperatures went from 25 to 45°C, extraction temperatures
from 25 to 50°C and moisture of the flour from 6 to 10%. However, the storage time of soybeans with initially high moisture
(20%) did not have a marked influence on FFA and phosphorus levels. Immediately after grinding moisture of the flour elevated
or lowered the phosphorus level to a great extent, although it had little influence on the FFA level. Phosphatidic acid and
phosphatidylcholine were identified as the main phospholipids present when total phosphorus was low in extracted oil. The
time taken for the flour to dry to 6% moisture (after grinding and before it was extracted) was critical. The alternative
extraction process moderated the expected increase in FFA and phospholipids as the result of soybean damage. 相似文献
4.
Hiromi Yoshida Sachiko Takagi Sayaka Mitsuhashi 《Journal of the American Oil Chemists' Society》1999,76(8):915-920
Whole soybeans (Glycin max L.) were roasted by exposure to microwaves at a frequency of 2,450 MHz, and their hypocotyls were separated from other tissues
(seed coat and cotyledons). The quality characteristics and composition in the hypocotyl oils were studied in relation to
their tocopherol distributions and were evaluated as compared to an unroasted oil sample. Only minor increases (P<0.05) in chemical and physical changes of the oils, such as carbonyl value, anisidine value and color development, occurred
with increased roasting time. Significant decreases (P<0.05) were observed in the amounts of phospholipids in the oils after microwave roasting. Nevertheless, compared to the original
level, more than 80% tocopherols still remained after 20 min of roasting. These results suggest that the exposure of soybeans
to microwaves for 6 to 8 min caused no significant loss or changes in the content of tocopherols and polyunsaturated fatty
acids in the hypocotyls. Therefore, a domestic microwave oven would be useful as a simple and quick means for preparing hypocotyl
oil of good quality. 相似文献
5.
Hiromi Yoshida Yuki Hirakawa Sayaka Abe 《European Journal of Lipid Science and Technology》2001,103(4):201-207
Whole sunflower seeds were exposed to microwave roasting for 6, 12, 20 or 30 min at a frequency of 2450 MHz. The kernels were then separated from the sunflower seeds, and the lipid components and the positional distribution of fatty acids in triacylglycerols (TAGs) and phospholipids (PLs) were investigated. Major lipid components were TAGs and PLs, while steryl esters, free fatty acids and diacylglycerols were also present in minor proportions. The greatest PL losses (p < 0.05) were observed in phosphatidyl ethanolamine, followed by phosphatidyl choline or phosphatidyl inositol. Significant differences (p < 0.05) in fatty acid distributions occurred (with few exceptions) when sunflower seeds were microwaved for 20 min or more. Nevertheless, the principal characteristics for the positional distribution of fatty acids still remained after 20 min of microwave roasting; unsaturated fatty acids, especially linoleic, were predominantly concentrated in the sn‐2‐position and saturated fatty acids, especially stearic and palmitic acids, primarily occupied the sn‐1‐ or sn‐3‐position. These results indicate that no significant changes in fatty acid distribution of TAGs and PLs would occur within 12 min of microwave roasting, ensuring that a good‐quality product would be attained. 相似文献
6.
Microwave roasting effects on the physico-chemical composition and oxidative stability of sunflower seed oil 总被引:1,自引:0,他引:1
Fozia Anjum Farooq Anwar Amer Jamil M. Iqbal 《Journal of the American Oil Chemists' Society》2006,83(9):777-784
The purpose of the present study was to explore the influences of microwave heating on the composition of sunflower seeds
and to extend our knowledge concerning the changes in oxidative stability, distribution of FA, and contents of tocopherols
of sunflower seed oil. Microwaved sunflower seeds (Helianthus annuus L.) of two varieties, KL-39 and FH-330, were extracted using n-hexane. Roasting decreased the oil content of the seeds significantly (P<0.05). The oilseed residue analysis revealed no changes in the contents of fiber, ash, and protein that were attributable
to the roasting. Analysis of the extracted oils demonstrated a significant increase in FFA, p-anisidine, saponification, conjugated diene, conjugated triene, density, and color values for roasting periods of 10 and
15 min. The iodine values of the oils were remarkably decreased. A significant (P<0.05) decrease in the amounts of tocopherol constituents of the microwaved sunflower oils also was found. However, after
15 min of roasting, the amount of α-tocopherol homologs was still over 76 and 81% of the original levels for the KL-39 and
FH-330 varieties, respectively. In the same time period, the level of σ-tocopherol fell to zero. Regarding the FA composition
of the extracted oils, microwave heating increased oleic acid 16–42% and decreased linoleic acid 17–19%, but palmitic and
stearic acid contents were not affected significantly (P<0.05). 相似文献
7.
Zeynep Aksoylu Özbek Kıvılcım Yıldız Pelin Günç Ergönül Elif İyilikeden Türkan Uzlaşır 《European Journal of Lipid Science and Technology》2023,125(10):2300024
The tomato processing industry generates a significant amount of a by-product (pomace), which is a mixture of peels and seeds. The purpose of this study was to compare the effects of conventional oven-roasting (at 120°C, 150°C, and 180°C for 25 min) and innovative microwave-roasting (at 240, 388, and 536 W for 3 min) pretreatments on the physicochemical properties, fatty acid profiles, bioactive contents, and aroma profiles of tomato seeds and their hexane-extracted oils. The total flavonoids contents (TFCs) of the seeds decreased from 258.40 to 141.20 mg quercetin equivalent (QE) per kg after roasting. All roasting treatments improved the extractability of both α- and γ-tocopherols. The amounts of total tocopherols in the seeds increased from 917.61 to 1256.25 mg kg–1 after pretreatment. Luteolin was found to be the most abundant phenolic in seed oils, increasing from 10.68 to 91.72 mg kg–1, followed by quercetin, ferulic acid, and catechin. Within each roasting technique, the ones treated at 150°C and 338 W yielded the oils with the highest concentrations of aroma compounds, 418 and 92 mg kg–1, respectively. The detrimental effect of microwave-roasting on these compounds was more pronounced. In conclusion, microwave-roasting at shorter times than conventional roasting produced tomato seed oils with well-preserved bioactive components and few unfavorable changes. Industrial relevance: Conventional oven-roasting has been widely applied to oilseeds to improve oil yield as well as to obtain desirable sensory characteristics of extracted oils for years. However, longer roasting times may also cause detrimental changes in the properties of oils. On the other side, microwave-assisted applications as an emerging technology provide homogenous and well-controlled heat distribution, shorter treatment times, and considerable energy savings for the processing of various foods. Microwave technology has been easily scaled up and is currently employed for sterilization, drying, pasteurization, precooking, and extraction by the food and chemistry industries. Therefore, the present research suggests the use of microwaves for comparatively short roasting times to produce edible oils with enhanced physicochemical attributes and bioactives contents, and well-maintained sensory properties. This promising innovative technology has the potential to be industrialized for a cost-effective seed roasting process. 相似文献
8.
G. R. List T. L. Mounts A. C. Lanser R. K. Holloway 《Journal of the American Oil Chemists' Society》1990,67(11):867-871
The impact of enzyme activity on the nonhydratable phospholipid content of crude soybean oil has been evaluated. A radiochemical
method was used to assay phospholipase D activity in whole and flaked soybeans stored under a variety of storage and enzyme
inactivating conditions. The crude enzyme was isolated and incubated with a mixture of14C-labeled and unlabeled phosphatidylcholine. The amount of liberated radioactive choline was used as a measure of enzyme activity.
whole soybeans with moisture contents of 8–18% were stored at 40°C and sampled weekly for up to four weeks. Although the enzyme
was active in all samples, the optimum moisture content for enzyme activity was about 14%. Flaking and flake thickness were
shown to increase phospholipas D activity. At moisture levels above 10%, flakes at .012″ showed about twice the activity of
whole beans. As flake thickness was increased, enzyme activity decreased.
Whole soybeans with moisture contents of 12–18% were treated by microwave heating under controlled conditions. During the
early stages of heating, the enzyme was activated, and then was gradually destroyed by the time the temperature of the beans
reached 115–120°C. Approximately 8–10 min of microwave heating was required to completely destroy enzymatic activity. The
inactivation of phospholipase D in soyflakes treated with live steam was also evaluated. The enzyme is rapidly destroyed at
temperatures of about 110°C. Evaluations of flakes subjected to live steam and whole beans treated by microwave heating to
inactivate phospholipase D suggest that heat, moisture and enzyme activity are important factors contributing to the formation
of nonhydratable phospholipid in extracted crude oils.
Presented at Annual Meeting of the American Oil Chemists' Society, May 3–7, 1989. 相似文献