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1.
Hiromi Yoshida Yuki Hirakawa Yoshiyuki Mizushina Tomoko Tanaka 《European Journal of Lipid Science and Technology》2002,104(6):347-352
Whole sunflower seeds (Helianthus annuus L.) were exposed to microwaves for 6, 12, 20 or 30 min at a frequency of 2450 MHz. The hulls were then stripped from the seeds. Molecular species and fatty acid distributions of triacylglycerols (TAGs), isolated from total lipids in the hulls, were analyzed by a combination of argentation thin‐layer chromatography (TLC) and gas chromatography. A modified argentation TLC procedure, developed to optimize the separation of the TAGs, provided 10 different groups of TAGs, based on both the degree of unsaturation and the total fatty acid chain‐length. Dilinoleolein (29.5—30.2 wt‐%), trilinolein (18.2—24.2 wt‐%), dilinoleopalmitin and dilinoleostearin (17.0—18.1 wt‐%), palmitoleolinolein and stearoleolinolein (11.4—14.0 wt‐%) and dioleolinolein (7.5—8.6 wt‐%) were the main TAGs detected after microwave roasting. However, roasting caused a significant decrease (p < 0.05), not only in TAG molecular species containing more than four double bonds, but also in the amounts of diene species present in TAGs. These results suggest that microwaves should affect TAGs in the hulls more significantly (p < 0.05) than those in the sunflower kernels. 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.
Hiromi Yoshida Yuki Hirakawa Yuka Tomiyamaa Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2003,105(7):351-358
Peanut seeds (Arachis hypogaea) were roasted for 6, 12, 20, or 30 min at a frequency of 2450 MHz using a microwave oven. The quality characteristics and the compositions of the oils, i.e. their tocopherol distributions and the molecular species of the triacylglycerols (TAGs) were investigated. These results were compared with those of an unroasted oil sample. Only minor increases (p <0.05) in chemical and physical properties of the oils, such as the carbonyl value, the p‐anisidine value and the color development occurred after a prolonged roasting period. Compared to the original level, more than 92 wt‐% tocopherols remained after 30 min of roasting. A modified thin‐layer chromatography argentation procedure provided 12 different groups of TAGs, based on both the degrees of unsaturation and the total fatty acid chain‐length. Although significant increases (p <0.05) generated in these chemical and physical changes of the oils after 20 min of roasting, no significant loss (p >0.05) was observed in the molecular species of the TAGs during microwave roasting. These results indicate that phospholipids may be attributed to the quality characteristics of peanut oils during microwave roasting. 相似文献
4.
Hiromi Yoshida Yuki Hirakawa Sayaka Abe Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2002,104(2):116-122
Sunflower seeds ((Helianthus annuus were roasted for 6, 12, 20 or 30 min at a frequency of 2450 MHz using a domestic microwave oven. After the kernels were separated from the sunflower seeds, the quality characteristics and the compositions of the oils were investigated in relation to their tocopherol distributions, and they were further evaluated as compared with an unroasted oil sample. Only minor increases (p < 0.05) in chemical and physical changes of the oils, such as the carbonyl value, the p‐anisidine value and the color development, occurred at a prolonged roasting period. Significant decrease (p < 0.05) was observed in the amounts of phospholipids in the oils after microwave roasting. Nevertheless, compared to the original level, more than 92 wt‐% tocopherols still remained after 30 min of roasting. With a few exceptions, these results indicate that the exposure of sunflower seeds to microwaves for 12 min caused no significant (p < 0.05) loss or change in the content of tocopherols and polyunsaturated fatty acids in the kernels. 相似文献
5.
S. Kermasha S. Kubow M. Safari A. Reid 《Journal of the American Oil Chemists' Society》1993,70(2):169-173
Triacylglycerol (TAG) standards were separated by analytical high-performance liquid chromatography (HPLC) with laser light-scattering
detection (LLSD). A high sensitivity for TAGs was observed with LLSD whereas poor sensitivity was observed with ultraviolet
detection. The HPLC-LLSD analytical separation of butterfat TAGs showed that the TAGs were eluted according to increasing
carbon number. Preparative HPLC-LLSD was used to characterize butterfat TAGs that contained hypercholesterolemic fatty acids
(laurate, myristate, palmitate) with carbon chainlengths of 12 or greater. These TAG fractions accounted for 29.2% of the
total butterfat TAGs. Analysis of the positional distribution of fatty acids of selected butterfat TAGs containing hypercholesterolemic
fatty acids showed the presence of positional isomers in each of these fractions. These butterfat TAGs also showed the predominant
presence of hypercholesterolemic fatty acids at thesn-2 position. The characterization of the positional distribution of hypercholesterolemic fatty acids in butterfat TAGs is
the first step for the determination of the metabolic role of the positional distribution in the hypercholesterolemic effects
of butter. 相似文献
6.
Hiromi Yoshida Yuka Tomiyama Yuki Hirakawa Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2004,106(2):101-109
Whole pumpkin seeds (Cucurbita spp.) of two cultivars were exposed to microwaves for 6, 12, 20 or 30 min at a frequency of 2450 MHz. The kernels were separated from the whole seeds, and were investigated not only for the different acyl lipids and their fatty acid compositions, but also for the molecular species of triacylglycerols (TAGs). A modified argentation TLC procedure, developed to optimize the separation of the complex mixture of total TAGs, provided 11 different groups of TAGs, based on both the degree of unsaturation and the chain‐length of fatty acid groups. With a few exceptions, dioleopalmitin (5.8–18.8 wt‐%), dipalmitolinolein (8.1–8.8 wt‐%), triolein (6.3–20.5 wt‐%), palmitoleolinolein (15.0–16.1 wt‐%), dioleolinolein (16.7–23.0 wt‐%), dilinoleopalmitin (4.6–15.4 wt‐%) and dilinoleolein (6.7–19.4 wt‐%) were the main TAG components. When pumpkin seeds were microwaved for 20 min or more, significant differences (p <0.05) occurred in the acyl lipids as well as their fatty acid distributions with a few exceptions. Therefore, microwave roasting caused a significant decrease (p <0.05), not only in TAGs molecular species containing more than 4 double bonds, but also in the amounts of diene species present in triacylglycerols. These results contribute to the study of the functional properties of pumpkin seed products. 相似文献
7.
Carlos A. Álvarez Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2015,92(7):1003-1014
A structured lipid (SL) with a substantial amount of palmitic acid at the sn‐2 position and enriched with capric acid (C), was produced in two enzymatic interesterification stages by using immobilized lipase, Lipozyme® TL IM (Novozymes North America Inc., Franklinton, NC, USA). The substrates for the reactions were high melting point palm stearin, high oleic sunflower oil and tricaprin. The SL was characterized for total and positional fatty acid profiles, triacylglycerol (TAG) molecular species, free fatty acid content, melting and crystallization profiles. The final SL contained 20.13 mol% of total palmitic acid, of which nearly 40 % was located at the sn‐2 position. The total capric acid content was 21.22 mol%, mostly at the sn‐1 and sn‐3 positions. The predominant TAGs in the SL were oleic–palmitic–oleic, POP and CLC. The melting completion and crystallization onset temperatures of the SL were 27.7 and 6.1 °C, respectively. The yield for the overall reaction was 90 wt%. This SL might be totally or partially used in commercial fat blends for infant formula. 相似文献
8.
Yasuhiro Ando Kazuhiko Nishimura Naoki Aoyanagi Toru Takagi 《Journal of the American Oil Chemists' Society》1992,69(5):417-424
Stereospecific analysis of fish oil triacyl-sn-glycerols was carried out by novel high-performance liquid chromatography on a chiral stationary phase. The positional distributions
of fatty acids were determined without accumulation of errors in a particular position and preferential hydrolysis for a particular
fatty acid. High-resolution gas-liquid chromatography on an open tubular column detailed the distribution of unsaturated fatty
acid isomers having olefinic bonds in different positions. The distribution of fatty acids was not independent of other fatty
acids. The distribution of long-chain highly unsaturated fatty acids 22:6(n-3), 22:5(n-3) and 20:5(n-3) was governed by total
amounts of 20:1 and 22:1 in triacyl-sn-glycerols. Long-chain monounsaturated acids 20:1 and 22:1 were influenced by the position of the olefinic bond in 20:1 occurring
in triacyl-sn-glycerols. Shorter-chain C14-C18 fatty acids seemed to be influenced by total fatty acid composition. These results introduce
a concept of mutual interaction between fatty acids to the investigation of positional distribution of fatty acids. 相似文献
9.
The positional distribution of fatty acids has been determined for the milk triacylglycerols of the Antarctic fur seal,Arctocephalus gazella. Of particular interest was the positional distribution of the polyunsaturated n−3 fatty acids in milk triacylglycerols (TG).
In adipocytes of pinnipeds, TG are synthesized with the n−3 fatty acids primarily in thesn-1,3 positions. To determine the positional distribution, extracts of enzymatically digested lipids were separated by thin-layer
chromatography, and the constituent fatty acids were separated and quantified by gas-liquid chromatography. Monoenoic and
saturated fatty acids comprised over 75% of the total, the ratio of monoenoic to saturated fatty acids being 2∶1. The percent
content of the long-chain n−3 fatty acids, 20∶5, 22∶5 and 22∶6, ranged between 15–20%. The positional analyses revealed that
at thesn-2 position of milk TG, saturated fatty acids were in excess (57%), and the content of n−3 fatty acids was less than 5%. More
than 80% of the n−3 fatty acids in milk were located in thesn-1,3 positions. The data indicate that in pinnipeds TG are synthesized in the mammary gland and adipose tissue with fatty
acids having similar positional distributions. 相似文献
10.
Hiromi Yoshida Naoko Yoshida Yuka Tomiyama‐Sakamoto Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2012,114(7):787-793
Extracted lipids obtained from Jack beans (white and red) were fractionated by TLC into nine subfractions. The major components were TAGs (TAG: 43.8–45.7 wt%) and phospholipids (PL: 46.7–47.0 wt%), while other components were also present in minor proportions (0.3–2.7 wt%). The principal fatty acids (FA) are generally palmitic (18.8–28.8%), stearic (0.7–6.8%), oleic (42.0–51.8%), linoleic (16.2–22.8%), and α‐linolenic (3.0–8.2%) acids, the distribution of which differs according to these lipid classes. There were no significant differences (p>0.05) in the positional distribution of FA in the TAG; unsaturated FA (97.5%) were predominantly concentrated in the sn‐2 position while saturated FA (33.3%) primarily occupied the sn‐1 position or sn‐3 position. However, significant differences (p<0.05) in FA distribution existed when the individual PL were compared between the white and red beans. Based on the FA composition of these lipids, it seems that the two cultivars of Jack beans are very similar to each other with a few exceptions. The results could be useful to both producers and consumers for our daily diet to improve value of the Japanese diet. Practical applications : The lipid composition suggests that these beans could be a good source of nutraceuticals with providing heath benefits. The white and red beans may be well incorporated into our daily Japanese diets to improve nutritional value. The data obtained in this study provide valuable information for manufacturing functional drinks such as Jack bean tea in Japan. 相似文献
11.
Kotte Sagar Rao Pradosh Prasad Chakrabarti B. V. S. K. Rao R. B. N. Prasad 《Journal of the American Oil Chemists' Society》2009,86(2):197-200
Jatropha curcus L. oil has emerged as one of the most important raw materials for biodiesel production. However, no detailed study has been
reported on characterizing the lipid constituents of jatropha oil. The present study revealed that the total oil content of
jatropha seeds was 32% with a composition of 97.6% neutral lipids, 0.95% glycolipids and 1.45% phospholipids. The fatty acid
composition of total lipids, neutral lipids, phospholipids and glycolipids was also determined and found to contain oleic
acid (18:1) and linoleic acids (18:2) as major fatty acids. The phospholipids fraction was further characterized and quantified
and found to contain phosphatidyl choline (PC) 60.5%, phosphatidyl inositol (PI) 24% and phosphatidyl ethanolamine (PE) 15.5%.
The fatty acid composition and the positional distribution of the fatty acids of individual phospholipids were also reported. 相似文献
12.
Interesterification or the randomization reaction changes fatty acid positional distribution and solid fat content of fats, which may consequently affect fat absorption and metabolism. It is well established that saturated fatty acids in the sn‐2 position of triacylglycerols (TAG) have better digestibility and lower postprandial chylomicron clearance compared to those in the sn‐1,3 positions in animal experiments. TAG structure is also shown to affect fasting lipid level and atherosclerosis in animals, but fat interesterification it has been shown to not affect fasting lipid level in human adults. However, its effect on postprandial responses is controversial. In this review, the complex results of studies of interesterification and lipemia were briefly discussed. More importantly, the confounding of two factors that are both changed by interesterification, TAG structure and solid fat content as the main limitation on understanding how interesterification affects lipemia is emphasized. Separation of the two factors is possible using paired fats as demonstrated. This paper also discusses some intriguing effects of fats having saturated fatty acids in the sn‐2 position and the need for future research. 相似文献
13.
The pattern of accumulation of triacylglycerols, their fatty acid compositions and the positional distribution of the fatty
acids at thesn-2- andsn-1,3-positions of the triacylglycerol molecules at progressive stages of oil palm fruit development were determined. There
was an exponential rate of increase of triacylglycerols and their fatty acids toward the end of fruit development. The fatty
acid composition of the triacylglycerols in the early stages of development, prior to active accumulation, was more or less
similar, but differed appreciably from the later stages, and the transition of fatty acid composition toward that of normal
palm oil occurred at around 16 wk after anthesis (WAA) and stabilized at 20 WAA. All fatty acids increased in terms of absolute
quantity. There was an overall consistency in fatty acid positional distribution, irrespective of development stage. More
saturated fatty acids were found to be esterified at thesn-1,3-positions and more unsaturated fatty acids at thesn-2-position of triacylglycerol. Higher rate of incorporation of 16:0 at the 1,3-positions during the active phase of triacylglycerol
synthesis was observed, while 18:1 acid exhibited a reverse trend. 相似文献
14.
Johanna Reske Jodi Siebrecht Jan Hazebroek 《Journal of the American Oil Chemists' Society》1997,74(8):989-998
Changes in composition were examined in oils extracted from genetically modified sunflower and soybean seeds. Improvements
were made to the analytical methods to accomplish these analyses successfully. Triacylglycerols (TAG) were separated on two
300 mm × 3.9 mm 4μ Novapak C18 high-performance liquid chromatography (HPLC) columns and detected with a Varex MKIII evaporative
light-scattering detector. Peaks were identified by coelution with known standards or by determining fatty acid composition
of eluted TAG by capillary gas chromatography (GC). Stereospecific analysis (fatty acid position) was accomplished by partially
hydrolyzing TAG with ethyl magnesium bromide and immediately derivatizing the resulting diacylglycerols (DAG) with (S)-(+)-1-(1-naphthyl)ethyl isocyanate. The derivatized sn-1,2-DAG were completely resolved from the sn-2,3-DAG on two 25 mm × 4.6 mm 3 μ silica HPLC columns. The columns were chilled to −20°C to obtain baseline resolution of
collected peaks. The distribution of fatty acids on each position of the glycerol backbone was derived from the fatty acid
compositions of the two DAG groups and the unhydrolyzed oil. Results for the sn-2 position were verified by hydrolyzing oils with porcine pancreatic lipase, isolating the resulting sn-2 monoacylglycerols by TLC, and determining the fatty acid compositions by GC. Results demonstrated that alterations in the
total fatty acid composition of these seed oils are determined by the concentration of TAG species that contain at least one
of the modified acyl groups. As expected, no differences were found in TAG with fatty acid quantities unaffected by the specific
mutation. In lieu of direct metabolic or enzymatic assay evidence, the authors’ positional data are nevertheless consistent
with TAG biosynthesis in these lines being driven by the mass action of available acyl groups and not by altered specificity
of the acyltransferases, the compounds responsible for incorporating fatty acids into TAG. 相似文献
15.
Mohammad Hojjati Leontina Lipan Ángel A. Carbonell-Barrachina 《Journal of the American Oil Chemists' Society》2016,93(9):1211-1220
Roasting enhances sensory quality of wild almonds (Amygdalus scoparia). The aim of the study was to evaluate the use of microwaves (480 W for 3 or 4 min) in roasting of wild almonds in comparison with traditional Spanish (165 °C for 20 min) and Iranian (soaking in 20 % NaCl in water for 30 min, drying at 60 °C for 2 h and roasting at 135 °C for 20 min) hot‐air processes. The influence of roasting wild almonds on moisture and oil contents, crispness, fatty acid profile, volatile compounds, and odour intensity was investigated. Roasting causes changes in appearance, texture and flavour, due to dehydration, browning, lipid oxidation, and diverse structural changes. The moisture content and hardness of the samples significantly decreased with all roasting methods. Roasting resulted in higher amounts of characteristics aroma compounds and only microwave roasting increased the oil content. The final recommendation is that microwave roasting at 480 W for 4 min led to roasted almonds of high physicochemical [dark and intense colour (L*44.9, a*8.4, and b*19.6), the highest content of total volatile compounds (132 mg kg?1), 85.2 % of unsaturated fatty acids], and sensory (high intensity of “roasted almond” aroma) quality. Microwaves can be used for roasting wild almond as a quick, safe, and economical method. 相似文献
16.
Ebenezer A. Ifeduba Silvana Martini Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2016,93(1):61-67
The objective of this study was to produce low saturated, zero‐trans, interesterified fats with 20 or 30 % saturated fatty acids (SFA) such as C16:0 or C18:0. Tripalmitin (TP) or tristearin (TS) was blended with high oleic sunflower oil (HOSO) at different ratios (0.1:1, 0.3:1, and 0.5:1 [w/w]). Total C16:0 and C18:0 compositions of the resulting TP/HOSO and TS/HOSO blends, respectively, were plotted against blending ratios. Linear interpolation was used to estimate blending ratios that would yield physical blends (PB) with 20 or 30 % SFA. Interesterified blends (IB) were then synthesized from the customized PB using Lipozyme TL IM as the biocatalyst. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability of PB and IB were compared. The total fatty acid compositions of PB and IB were similar but fatty acid positional distributions and TAG molecular species composition differed. IB contained 5–10 % more SFA at the sn‐2 position than corresponding PB. Furthermore, interesterification generated mono‐ and disaturated TAG species which resulted in broader melting profiles for IB. However, IB had lower oxidative stability than PB. The reformulation of food products with zero‐trans interesterified fats may be advantageous to the reduction of cardiovascular disease burden in the population. 相似文献
17.
A. N. Sibbald J. R. Carney A. G. Marangoni 《Journal of the American Oil Chemists' Society》2016,93(11):1441-1452
Molecular compound formation between multicomponent triacylglyceride (TAG) mixtures was characterized using palm oil mid fraction enriched in sn‐1,3‐dipalmitoyl‐2‐oleoylglycerol (cPOP) and a commercial fraction enriched in sn‐1,3‐dioleyl‐2‐palmitoylglycerol containing a wide range of TAGs (cOPO). Compound formation occurred at a 1:1 (w/w) ratio of cPOP to cOPO corresponding to an equal parts ratio of two different families of TAGs. One family of TAGs consisted of a grouping of all TAGs composed of a saturated–oleic–saturated (StUSt) positioning of fatty acids. The second family consisted of a grouping of all TAGs composed of all oleic–saturated–oleic and saturated–saturated–oleic fatty acids (UStU, StStU). An increase in solid fat content, peak melting temperature, and crystalline domain size and a change in crystalline microstructure were observed at this ratio corresponding to an overall equality in the amount of cPOP to cOPO. This indicates that it is possible to achieve that same level of solid fat content and hardness as a mixture containing more saturates, simply by slightly decreasing the saturates and substituting an oleic monounsaturated fatty acid containing TAG mixture such that a molecular compound is formed. The increase in full‐width at half‐maximum indicated a decrease in crystalline order and/or decrease in crystal domain size. The characteristic spherulitic crystalline microstructure of OPO changed to small granular crystals upon addition of cPOP. This discovery may allow for the incorporation of a larger proportion of healthy monounsaturated fats into foods while decreasing the use of saturated and trans fats. 相似文献
18.
Hiromi Yoshida Yuka Tomiyama Naoko Yoshida Yoshiyuki Mizushina 《European Journal of Lipid Science and Technology》2009,111(4):386-391
Regiospecific distributions of fatty acids of triacylglycerols (TAG) and phospholipids (PL) separated from broad beans (Vicia faba) of four cultivars (Minpo, Sanuki, Nintoku and Sanren) were investigated. The major lipid components were PL (47.5–50.5 wt‐%) and TAG (47.7–50.1 wt‐%), while steryl esters, hydrocarbons, free fatty acids, diacylglycerols and monoacylglycerols were present in minor proportions (1.6–2.4 wt‐%). The PL components isolated from the four cultivars were phosphatidylcholine (56.4–58.4 wt‐%), phosphatidylethanolamine (20.3–21.7 wt‐%) and phosphatidylinositol (16.6–18.6 wt‐%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among these PL. The principal characteristics of the fatty acid distribution in the TAG and PL were evident in the beans: Unsaturated fatty acids were predominantly concentrated in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in these lipids. The lipid components and fatty acid distributions were almost the same in the four cultivars and were not influenced by genetic variability and planting location. These results could be useful information to both consumers and producers for the manufacture of traditional broad bean foods in Japan. 相似文献
19.
Six oils of marine, algal, and microbial origin were analyzed for stereospecific distribution of component fatty acids. The
general procedure involved preparation ofsn-1,2-(2,3)-diacylglycerols by partial deacylation with ethylmagnesium bromide or pancreatic lipase, separation of X-1,3- andsn-1,2(2,3)-diacylglycerols by borate thin-layer chromatography, resolution of thesn-1,2- andsn-2,3-enantiomers by chiral phase high-performance liquid chromatography following preparation of dinitrophenylurethane derivatives,
and determination of the fatty acid composition by gas chromatography. Unexpected complications arose during a stereospecific
analysis of triacylglycerols containing over 33% of either 20∶4 or 22∶6 fatty acids. Thesn-1,2(2,3)-diacylglycerols made up of two long-chain polyunsaturated acids migrated with the X-1,3-diacylglycerols and required
separate chiral phase resolution. Furthermore, the enzymatic method yieldedsn-1,2(2,3)-diacylglycerols, overrepresenting the polyenoic species due to their relative resistance to lipolysis, but prolonged
digestion yielded correct composition for the 2-monoacylglycerols. The final positional distribution of the fatty acids was
established by pooling and normalizing the data from subfractions obtained by norman- and chiral-phase separation of diacylglycerols.
The molecular species of X-1,3-,sn-1,2- andsn-2,3-diacylglycerol dinitrophenylurethanes were identified by chiral-phase liquid chromatography/mass spectrometry with electrospray
ionization, which demonstrated a preferential association of the paired long-chain acids with thesn-1,2- andsn-2,3-diacylglycerol isomers. 相似文献
20.
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