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1.
Nongnuch Sutivisedsak Bryan R. Moser Brajendra K. Sharma Roque L. Evangelista Huai N. Cheng William C. Lesch Robert R. Tangsrud Atanu Biswas 《Journal of the American Oil Chemists' Society》2011,88(2):193-200
Four common beans (black, kidney, great northern, and pinto) were extracted with hexane and found to contain about 2% triacylglycerols.
The fatty acids in these bean oils were mainly linolenic (41.7–46 wt%), linoleic (24.1–33.4 wt%), palmitic (10.7–12.7 wt%)
and oleic (5.2–9.5 wt%). Because of the high levels of polyunsaturated fatty acids, the bean oils had iodine values between
174 and 177 g/100 g (compared to 130 g/100 g for soybean oil). Yet, the bean oils exhibited high oxidative stability due to
the presence of high amounts of tocopherols (2,670–2,970 ppm). The bean oils had lower pour points (−18 to −11 °C) compared
to −9 °C for soybean oil. Among the four bean oils, kidney bean oil had the highest acid value (15.4 mg KOH/g) and kinematic
viscosities over a wide range of temperatures. 相似文献
2.
Facile purification of tocopherols from soybean oil deodorizer distillate in high yield using lipase 总被引:16,自引:0,他引:16
Yuji Shimada Seiichi Nakai Masaharu Suenaga Akio Sugihara Motohiro Kitano Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2000,77(10):1009-1013
Tocopherols have been purified from deodorizer distillate produced in the final deodorization step of vegetable oil refining
by a process including molecular distillation. Deodorizer distillate contains mainly tocopherols, sterols, and free fatty
acids (FFA); the presence of sterols hinders tocopherol purification in good yield. We found that Candida rugosa lipase recognized sterols as substrates but not tocopherols, and that esterification of sterols with FFA could be effected
with negligible influence of water content. Enzymatic esterification of sterols with FFA was thus used as a step in tocopherol
purification. High boiling point substances including steryl esters were removed from soybean oil deodorizer distillate by
distillation, and the resulting distillate (soybean oil deodorizer distillate tocopherol concentrate; SODDTC) was used as
a starting material for tocopherol purification. Several factors affecting esterification of sterols were investigated, and
the reaction conditions were determined as follows: A mixture of SODDTC and water (4∶1, w/w) was stirred at 35°C for 24 h
with 200 U of Candida lipase per 1 g of the reaction mixture. Under these conditions, approximately 80% of sterols was esterified, but tocopherols
were not esterified. After the reaction, tocopherols and FFA were recovered as a distillate by molecular distillation of the
oil layer. To enhance further removal of the remaining sterols, the lipase-catalyzed reaction was repeated on the distillate
under the same reaction conditions. As a result, more than 95% of the sterols was esterified in total. The resulting reaction
mixture was fractionated to four distillates and one residue. The main distillate fraction contained 65 wt% tocopherols with
low contents of FFA and sterols. In addition, the residue fraction contained high-purity steryl esters. Because the process
presented in this study includes only organic solvent-free enzymatic reaction and molecular distillation, it is feasible as
a new industrial purification method of tocopherols.
This work was presented at the Biocatalysis symposium in April 2000, held at the 91st Annual Meeting and Expo of the American
Oil Chemists Society, San Diego, CA. 相似文献
3.
J. C. Evans D. R. Kodali P. B. Addis 《Journal of the American Oil Chemists' Society》2002,79(1):47-51
The optimal concentration for tocopherols to inhibit soybean oil oxidation was determined for individual tocopherols (α-,
γ-, and δ-tocopherol) and for the natural soybean oil tocopherol mixture (tocopherol ratio of 1∶13∶5 for α-, γ-, and δ-tocopherol,
respectively). The concentration of the individual tocopherols influenced oil oxidation rates, and the optimal concentrations
were unique for each tocopherol. For example, the optimal concentrations for α-tocopherol and γ-tocopherol were ∼100 and ∼300
ppm, respectively, whereas δ-tocopherol did not exhibit a distinct concentration optimum at the levels studied (P<0.05). The optimal concentration for the natural tocopherol mixture ranged between 340 and 660 ppm tocopherols (P<0.05). The antioxidant activity of the tocopherols diminished when the tocopherol levels exceeded their optimal concentrations.
Above their optimal concentrations, the individual tocopherols and the tocopherol mixture exhibited prooxidation behavior
that was more pronounced with increasing temperature from 40 to 60°C (P<0.05). A comparison of the antioxidant activity of the individual tocopherols at their optimal concentrations revealed that
α-tocopherol (∼100 ppm) was 3–5 times more potent than γ-tocopherol (∼300 ppm) and 16–32 times more potent than δ-tocopherol
(∼1900 ppm). 相似文献
4.
Sakina Khatoon R. G. Raja Rajan A. G. Gopala Krishna 《Journal of the American Oil Chemists' Society》2010,87(3):321-326
The deodoriser distillate (DOD) of Indian soybean oil obtained from two industries processing soybean oil was investigated
for its physicochemical characteristics, its composition of tocopherols, phytosterols, fatty acids and recovery of phytosterols
for use in nutraceutical products. It was found that the two DOD samples studied were dark in color and had higher amounts
of free fatty acids (22.7 and 49.9%), unsaponifiable matter (11.8 and 21.9%) (5–10 times found in soybean oil), total tocopherols
(1957–2256 mg/100 g) (20 times the amount in soybean oil), and 6–10% of phytosterols (12–20 times the soybean oil). The fatty
acids found were palmitic (23.2–25.5%), stearic (1.4–2.4%), oleic (23.8–26.1%), linoleic (40.4–41.1%) and linolenic (2.7–3.2%)
acids. The unsaponifiable matter (21.9%) and phytosterols (8.7%) content of DOD-2 were higher than in DOD-1 and hence was
more suited for isolation of phytosterols. Using hexane and water for crystallisation, the DOD-2 yielded a phytosterol fraction
with lower recovery of 13.2–17.8% while treatment with alkali to remove FFA and the glycerides followed by organic solvent
extraction yielded unsaponifiable matter containing phytosterols with a recovery of 74.6%. Later the unsaponifiable matter
was purified by double crystallisation into a mixture of phytosterols of 87% purity containing β-sitosterol (34.3%), stigmasterol
(3.1%) and campesterol (50.1%). The product may find use in foods, pharmaceuticals, cosmetics and allied industries probably
as a nutraceutical. 相似文献
5.
Keito Boki Hidehito Mori Naohito Kawasaki 《Journal of the American Oil Chemists' Society》1994,71(6):595-601
Efficiencies of synthetic adsorbents and attapulgites in bleaching alkali-refined rapeseed and soybean oils ranged from 13–53%
and 93–97%, respectively. The Freundlich equation was more applicable than the Langmuir equation to the experimental adsorption
isotherms of β-carotene on attapulgites. Bleaching with attapulgites reduced tocopherols by 12.5–29.5% in rapeseed oil and
by 18.9–44.8% in soybean oil. Cosmetic-grade attapulgite was superior to the others in bleaching efficiency, equilibrium amount
adsorbed and removal of free fatty acids. 相似文献
6.
Reaction gas chromatography was found to be helpful in elucidating structures of tocopherol dimers. By this method γ- and
δ-tocopherols were determined as monomers derived from tocopherol dimers, after isolation of the latter compounds from soybean
oil. It was shown that gas chromatographic determination of tocopherols, as performed by injection of total unsaponifiables
from soybean oil, will give results too high; the eluted tocopherols will account for both tocopherol monomers and dimers. 相似文献
7.
Jill Kristine Winkler-Moser Steven Francis Vaughn 《Journal of the American Oil Chemists' Society》2009,86(11):1073-1082
A distillate was obtained by molecular distillation of oil extracted from distillers dried grains (DDG). The distillers dried
grain oil distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was
tested for its impact on the oxidative stability index (OSI) at 110 °C of soybean, sunflower, and high-oleic sunflower oils,
as well as the same oils that were stripped of their natural tocopherols and phytosterols. In addition, the impact of added
DDGD on the stability of stripped sunflower oil during an accelerated storage study conducted at 60 °C was also determined.
DDGD (0.5–1% w/w) had little impact on the OSI of soybean, sunflower, and high-oleic sunflower oil, but at levels of 0.1–1%
it significantly increased the OSI for stripped soybean, sunflower, and high-oleic sunflower oil in a dose-dependent manner.
DDGD also delayed peroxide value, conjugated diene, and hexanal formation during accelerated storage of stripped sunflower
oil. The antioxidant activity is probably due to the combination of tocopherols, tocotrienols, and steryl ferulates. 相似文献
8.
Analysis of free and esterified sterols in vegetable oils 总被引:2,自引:6,他引:2
T. Verleyen M. Forcades R. Verhe K. Dewettinck A. Huyghebaert W. De Greyt 《Journal of the American Oil Chemists' Society》2002,79(2):117-122
In vegetable oils, phytosterols occur as free sterols or as steryl esters. Few analytical methods report the quantification
of esterified and free sterols in vegetable oils. In this study, esterified and free sterols were separated by silica gel
column chromatography upon elution with n-hexane/ethyl acetate (90∶10 vol/vol) followed by n-hexane/diethyl ether/ethanol (25∶25∶50 by vol). Both fractions were saponified separately and the phytosterol content was
quantified by GC. The analytical method for the analysis of esterified and free sterols had a relative standard deviation
of 1.16% and an accuracy of 93.6–94.1%, which was comparable to the reference method for the total sterol analysis. A large
variation in the content and distribution of the sterol fraction between different vegetable oils can be observed. Corn and
rapeseed oils were very rich in phytosterols, which mainly occurred as steryl esters (56–60%), whereas the majority of the
other vegetable oils (soybean, sunflower, palm oil, etc.) contained a much lower esterified sterol content (25–40%). No difference
in the relative proportion of the individual sterols among crude and refined vegetable oils was observed. 相似文献
9.
Isolation and separation of tocopherols from olive by-products with supercritical fluids 总被引:1,自引:0,他引:1
E. Ibáñez J. Palacios F. J. Señoráns G. Santa-María J. Tabera G. Reglero 《Journal of the American Oil Chemists' Society》2000,77(2):187-190
Supercritical fluid extraction of olive pomace, the semisolid residue obtained using two-phase olive oil production systems,
and supercritical fluid chromatographic separation of the extracts were performed to study the content of tocopherols, a group
of compounds of interest for the food industry owing to their antioxidant activity. The developed method consists of supercritical
CO2 extraction at pilot plant scale and subsequent fractionation by two successive depressurizations. Enrichment of α-, β-, and
γ-tocopherol was achieved in separator 2 when working at low densities in the first separator. Fractions obtained using high
densities in separator 1 contained major proportions of triglycerides, waxes, and sterols. Tocopherols from olive by-products
were separated and quantified in an environmentally friendly way by using supercritical fluid chromatography with packed capillary
columns coated with polyethylene glycol and neat CO2 according to a method previously optimized in our laboratory. The studied olive by-products can be considered a natural source
of antioxidants because substantial concentration of tocopherols have been obtained in the extracts. The isolation and separation
of tocopherols from olive pomace by applying supercritical fluid technology provides an interesting approach to exploit such
by-products in an environmentally friendly way. 相似文献
10.
H. W. Rawlings Noel H. Kuhrt J. G. Baxter 《Journal of the American Oil Chemists' Society》1948,25(1):24-26
Summary A method for the analysis of the total tocopherols in soybean oil has been presented, and judged by distillation and other
procedures is estimated to be accurate to within 10%. A discussion is made of the tocopherol to within 10%. A discussion is
made of the tocopherol losses in various steps of soybean oil refining.
Communication No. 115 from the Research Laboratories of Distillation Products, Inc., Rochester, New York. (Presented at The
American Oil Chemists Society meeting in New Orleans, May 20–22, 1947.) 相似文献
11.
Isolation of tocopherol and sterol concentrate from sunflower oil deodorizer distillate 总被引:10,自引:0,他引:10
The isolation of tocopherols and sterols together as a concentrate from sunflower oil deodorizer distillate was investigated.
The sunflower oil deodorizer distillate was composed of 24.9% unsaponifiable matter with 4.8% tocopherols and 9.7% sterols,
28.8% free fatty acid (FFA) and 46.3% neutral glycerides. The isolation technology included process steps such as biohydrolysis,
bioesterification and fractional distillation. The neutral glycerides of the deodorizer distillates were hydrolyzed byCandida cylindracea lipase. The total fatty acids (initial FFA plus FFA from neutral glycerides) were converted into butyl esters withMucor miehei lipase. The esterified product was then fractionally distilled in a Claisen-vigreux flask. The first fraction, which was
collected at 180–230°C at 1.00 mm of Hg for 45 min, contained mainly butyl esters, hydrocarbons, oxidized products and some
amount of free fatty acids. The fraction collected at 230–260°C at 1.00 mm Hg for 15 min was rich in tocopherols (about 30%)
and sterols (about 36%). The overall recovery of tocopherols and sterols after hydrolysis, esterification and distillation
were around 70% and 42%, respectively, of the original content in sunflower oil deodorizer distillate. 相似文献
12.
Analysis of tocopherols and phytosterols in vegetable oils by HPLC with evaporative light-scattering detection 总被引:1,自引:5,他引:1
Methods were developed for the separation, detection, and quantification of tocopherols and phytosterols by high-performance
liquid chromatography with an evaporative light-scattering detector. Four tocopherols— α, β, γ and δ—and four phytosterols—campesterol,
β-sitosterol, brassicasterol, and stigmasterol—were analyzed in soybean, sunflower, low-erucic acid rapeseed (LEAR) and corn
oils. The use of an evaporative light-scattering detector, in conjunction with modification of methods from the literature
to prepare and analyze tocopherols and phytosterols by HPLC, showed consistent results between trials and levels of these
minor constituents.
Presented at the Annual American Oil Chemists' Society Meeting, May 3–7, 1989, Cincinnati, OH. 相似文献
13.
Enzymatic pretreatment of deodorizer distillate for concentration of sterols and tocopherols 总被引:15,自引:7,他引:15
Separation of sterols and tocopherols from fatty acids in deodorizer distillate was facilitated through lipase-catalyzed modification
of fatty acids in canola, mixed and soya deodorizer distillates. The fatty acid esterification with methanol catalyzed by
SP-382 (an immobilized nonspecific lipase) proceeded rapidly, with conversion of fatty acid to methyl ester in 5 h being 96.5,
83.5 and 89.4%, respectively. A model mixture of pure oleic acid and dl-α-tocopherol was used to study any potential side
reactions that may lower the tocopherol content during the esterification reaction. Under the conditions employed, the loss
of tocopherol was less than 5%. Simple vacuum distillation (1–2 mm Hg) was employed to remove the volatile fraction (methyl
esters of fatty acids, some fatty acids and other volatiles) of the esterified deodorizer distillate, leaving behind sterols,
sterol esters and tocopherols. Sterols and tocopherols were almost completely retained in the residue fraction with recoveries
in the range of 95%. Overall recoveries of sterols and tocopherols after esterification and distillation were over 90% for
all the deodorizer distillate samples. 相似文献
14.
Anita Rani Vineet Kumar Sandeep K. Verma Arvind K. Shakya G. S. Chauhan 《Journal of the American Oil Chemists' Society》2007,84(4):377-383
Plant seed oils, including soybean seed oil, represent the major source of naturally derived tocopherols, the antioxidant
molecules that act as free radical quenchers preventing lipid peroxidation in biological systems and vegetable oil products.
All four isomers of tocopherols, i.e. α, β, γ, δ tocopherols that exist in nature are found in soybean seeds. The biological
activity and the contribution of these isomers in improving the oxidative stability of vegetable oil are in reverse order.
Because of the nutritive value and the importance for oil stability, enhancement of tocopherol content, through breeding programs,
in soybean seeds has become a new and an important objective. Genotypic variability, which is the basis of every breeding
program, is scarcely reported for tocopherol content and profile in soybean seeds. In the present investigation, the tocopherol
content and profile in seed samples of 66 genotypes of Indian soybean were determined. The ratios observed between the lowest
and the highest values for α, β, γ, δ, total tocopherol content were 1:13.6, 1:10.4, 1:7.5, 1:9.1, 1:7.9, respectively. The
mean contents for α, β, γ, δ and total tocopherols were 269, 40, 855, 241 and 1,405 μg/g of oil, respectively. Total tocopherol
content was the highest in ‘Co Soya2’ followed by ‘Ankur’. Concentration of α-tocopherol was the highest (27%) in ‘Ankur’
followed by ‘MACS124’ (26%) whereas gamma tocopherol concentration was the highest (69%) in ‘VLS1’ and ‘PK327’ followed by
‘MACS13’ (67%). In view of the fact that levels of unsaturated fatty acids, apart from tocopherols, also determine the oxidative
stability of vegetable oils, the relationship of four isomers of tocopherols with each other as well as with different unsaturated
fatty acids and oil content was also investigated in the present study. All the four isomers of tocopherols exhibited highly
significant correlations with each other (p < 0.001) whereas γ-tocopherol and total tocopherol content showed a significant relationship with linoleic acid (p < 0.05). 相似文献
15.
Minor constituents of vegetable oils during industrial processing 总被引:6,自引:10,他引:6
R. Ap. Ferrari E. Schulte W. Esteves L. Brühl K. D. Mukherjee 《Journal of the American Oil Chemists' Society》1996,73(5):587-592
We report the effects of individual steps of industrial refining, carried out in Brazil, on the alteration of selected minor
constituents of oils, such as corn, soybean, and rapeseed oils. Total sterols, determined by capillary gas chromatography
(GC), decreased by 18–36% in the fully refined oils, compared with the crude oils. The total steradienes, dehydration products
of sterols, were determinedvia a simple clean-up on a short silica gel column, followed by high-performance liquid chromatography (HPLC) with ultraviolet
detection. The level of steradienes, normally not present in crude oils, increased after each refining step, especially after
deodorization. Thus, the content of steradienes increased after deodorization by about 15- to 20-fold in corn and soybean
oils, and by about 2-fold in rapeseed oil. The total steryl esters were also determinedvia clean-up on a short silica gel column, followed by HPLC with evaporative light scattering mass detection. A minor decrease
in the level of steryl esters was observed after complete refining. The individual tocopherols and tocotrienols were determined
by HPLC with a fluorescence detector. The level of total tocopherols and tocotrienols decreased by about 2-fold after complete
refining of corn oil and by about 1.5-fold in soybean and rapeseed oils. In all three cases, maximum reduction of tocopherols
was observed after the deodorization step. The level of polymeric glycerides, determinedvia clean-up on a short silica gel column followed by size-exclusion HPLC, increased to some extent (0.4–1%) during refining.
The level oftrans fatty acids, determined by capillary GC, also increased to a substantial extent (1–4%) after refining.
Part of doctoral thesis of Roseli Ap. Ferrari to be submitted to Faculdade de Engenharia de Alimentos, Universidade de Campinas,
Campinas, Brazil. 相似文献
16.
Effects of processing steps on the contents of minor compounds and oxidation of soybean oil 总被引:4,自引:0,他引:4
The processes of degumming, alkali refining, bleaching and deodorization removed 99.8% phospholipids, 90.7% iron, 100% chlorophyll,
97.3% free fatty acids and 31.8% tocopherols from crude soybean oil. The correlation coefficient between the removals of phosphorus
and iron in soybean oil during processing was r = 0.99. The relative ratios of α-, β -, γ- and δ-tocopherols in crude oil,
degummed oil, refined oil, bleached oil and deodorized soybean oil were almost constant, γ- and δ -tocopherols represented
more than 94% of tocopherols in soybean oil. The order of oxidation stability of oil is crude > deodorized > degummed > refined
> bleached oil. 相似文献
17.
Oxidative stabilities of crude soybean oils obtained by different extraction solvents such as hexane, water and Folch's solvent
(mixture of two volumes of chloroform and one volume of methanol) were determined by gas chromatographic analyses of headspace
and peroxide value of oil samples. For the determination of oxidative stability of oil samples, total volatile compounds formation,
molecular oxygen disappearance in the headspace and peroxide value of oil samples were measured. Iodine value (133–136), saponification
value (195–198), unsaponifiable matters (0.3–0.4%), iron (0.6 ppm), sterols content (2,400–2,590 ppm), tocopherols content
(1,250–1,520 ppm) and fatty acid composition of crude oils obtained by different solvent extraction were not significantly
different. Acid value of Folch-extracted oil was the highest as 1.3, whereas those of hexane-and aqueous-extracted oils were
0.5 and 0.4, respectively. Crude soybean oil extracted by Folch's method was found to contain the most phosphorus, while hexane-
and aqueous-extracted oils contained similar amounts of phosphorous. Crude soybean oil obtained by Folch extraction was most
stable in oil oxidation, and oxidative stabilities of oils obtained by hexane and aqueous extraction, which were significantly
much less stable than Folch-extracted oil, were not significantly different during ten weeks storage. 相似文献
18.
Steven J. Britz Diane F. Kremer William J. Kenworthy 《Journal of the American Oil Chemists' Society》2008,85(10):931-936
Controlled environment studies show α-tocopherol (αT) in soybean seeds increases several fold as a result of warmer temperature
or drought during seed maturation, but total tocopherols (Ttot) stay approximately constant. To determine if natural variation in weather or climate affect T under field conditions, we
analyzed soybean seeds grown at several locations in Maryland between 1999 and 2002. Weather was relatively normal during
1999–2001, whereas warmer temperatures and extreme drought were characteristic of 2002. Comparing 18 lines, there were small
but significant differences in Ttot as well as 2- to 3-fold differences in αT during 1999–2001. Seeds from locations on the Eastern Shore of Maryland (full season
crops) had higher absolute and relative levels of αT compared to seeds from a (cooler) central Maryland location or seeds
from a later planting (double crop) on the Eastern Shore. Effects of location or planting date were small compared to that
of genetic line when considering the normal years 1999–2001. In 2002, however, several fold increases in αT/Ttot were observed in Maturity Group III and IV seeds, especially from full season crops grown at two locations on the Eastern
Shore of Maryland. We conclude weather and climate are significant factors affecting soybean seed T content. 相似文献
19.
Carlos F. Torres Tiziana Fornari Guzmán Torrelo F. Javier Señoráns Guillermo Reglero 《European Journal of Lipid Science and Technology》2009,111(5):459-463
Enzymatic esterification and supercritical fluid extraction was used to produce phytosterol esters from soybean oil deodorizer distillates. The raw material was first subjected to a two‐step enzymatic reaction; the product obtained mainly comprised fatty acid ethyl esters, tocopherols and phytosterol esters, together with minor amounts of squalene, free fatty acids, free sterols and triacylglycerols. The phytosterol esters were then purified from this mixture using supercritical carbon dioxide. Experimental extractions were carried out in an isothermal countercurrent column (without reflux), with pressures ranging from 200 to 280 bar, temperatures of 45–55 °C and solvent‐to‐feed ratios from 15 to 35 kg/kg. Using these extraction conditions, the fatty acid esters were completely extracted and, thus, the fractionation of tocopherols and phytosterol esters was studied. At 250 bar, 55 °C and a solvent‐to‐feed ratio of 35, the phytosterol esters were concentrated in the raffinate up to 82.4 wt‐% with satisfactory yield (72%). 相似文献
20.
Sodeif Azadmard-Damirchi Paresh C. Dutta 《Journal of the American Oil Chemists' Society》2007,84(3):297-304
Free and esterified forms of sterols provide detailed information on the identity and the quality of vegetable oils. In this
study, 4,4′-dimethylsterols in free and esterified forms were investigated in hazelnut and virgin olive oils. Moreover, a
sample of solvent-extracted hazelnut oil was refined at the laboratory to monitor the effects of processing on the levels
of 4,4′-dimethylsterols. Generally, the level of total 4,4′-dimethyslterols was higher in the esterified form (49–68%) compared
with that in free form (32–51%) of these compounds in the hazelnut oil. In virgin olive oil samples, cycloartenol and 24-methylenecycloartanol
were present in higher amounts in free forms (70–80%) than in esterified forms (20–30%). Among the refining processes, degumming,
deodorization, neutralization and bleaching, only neutralization and bleaching considerably reduced 4,4′-dimethylsterols.
In fully refined hazelnut oil, 18 and 37% of lupeol and an unknown compound X in the esterified form were lost, respectively.
The loss of these two compounds in the free form was considerably higher, 26 and 72%, respectively. GC–MS analysis showed
that adulteration of olive oil with a sample of fully refined hazelnut oil could be detected at a level as low as 2% by tracing
lupeol in total or only in esterified forms of 4,4′-dimethylsterols. Further studies on the levels of free and esterified
4,4′-dimethylsterols and their retention during refining processes are anticipated in hazelnut cultivars from different origins. 相似文献