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1.
Hazelnuts from 19 cultivars collected during 3 consecutive-year crops, in 2 different geographical localities, for a total of 79 samples, were evaluated for their contents in tocopherols and tocotrienols by normal-phase high-performance liquid chromatography coupled to a series arrangement of a diode array and a fluorescence detector. Seven compounds were identified and quantified. All samples presented alpha-, beta-, gamma-, and delta- tocopherols and beta-tocotrienol; alpha- and gamma-tocotrienols were detected in some of the studied samples. alpha-Tocopherol was the major compound in all samples, ranging from 105.9 to 226.8 mg/kg of hazelnut. Considering the generality of the obtained results, an identical qualitative and quantitative pattern was found, which can define a chemical fingerprint that may be helpful in the assessment of identity and quality of hazelnut oils. Statistical analyses were carried out in order to check for differences among cultivars, year crops, and geographical localities. Although some differences were observed when different-year crops and geographical localities were considered, neither of these factors seemed to produce considerable differences in terms of tocopherol and tocotrienol contents. Some minor differences were observed among cultivars.  相似文献   

2.
A total of 26 walnut (Juglans regia L.) samples from 9 cultivars (Arco, Franquette, Hartley, Lara, Marbot, Mayette, Mellanaise, Parisienne, and Rego) harvested in the 2001, 2002, and 2003 crop years and grown in two geographical origins (Braganca and Coimbra, Portugal) were evaluated with regard to their triacylglycerol composition. The methodology employed was reversed-phase high-performance liquid chromatography coupled to an evaporative light-scattering detector (RP-HPLC-ELSD) after extraction of the lipidic fraction of the nuts. Nine compounds were separated, identified, and quantified. All samples presented an identical qualitative profile composed by LLnLn, LLLn, LLL, OLLn, OLL, PLL, OOL, and PLO (P = palmitoyl; O = oleoyl; L = linoleoyl; Ln = linonenoyl). Trilinolein (LLL) was the major triglyceride, followed by dilinoeoyl-oleoyl-glycerol (OLL) and dilinoleoyl-linolenoyl-glycerol (LLLn), with mean values of 37.7, 18.5, and 18.4%, respectively. Significant differences in composition were found between cultivars, and these differences were also significant when cultivars were grouped by year of production, showing that besides genetic factors, the triacylglycerol composition can be strongly influenced by environmental factors.  相似文献   

3.
Three different HPLC detection systems were compared for the determination of tocopherols and tocotrienols in olive oil: fluorescence and diode array connected in series, ultraviolet, and evaporative light scattering. The best results were obtained with the fluorescence detector, which was successfully applied in the quantification of tocopherols and tocotrienols in 18 samples of Portuguese olive oils. To support the validity of the method, the parameters evaluated were linearity, detection limits, repeatability, and recovery. All of the studied samples showed similar qualitative profiles with six identified compounds: alpha-T, beta-T, gamma-T, delta-T, alpha-T3, and gamma-T3. Alpha-tocopherol (alpha-T) was the main vitamin E isomer in all samples ranging from 93 to 260 mg/kg. The total tocopherols and tocotrienols ranged from 100 to 270 mg/kg. Geographic origin did not seem to influence the tocopherol and tocotrienol composition of the olive oils under evaluation.  相似文献   

4.
alpha-Tocopherol, the main tocopherol homologue found in olive oil, was determined using normal phase HPLC. Ninety Greek virgin olive oils, selected according to a designed sampling protocol from different cultivars and regions all over Greece for three successive crop years, were analyzed. For a specific olive cultivar, which is widely used for the production of olive oil in Greece, additional measurements were made to study the effect of milling conditions on alpha-tocopherol concentration. Finally, a significant number of commercial olive oil samples (25) obtained from the retail market were analyzed. High concentrations of alpha-tocopherol were observed in most of the samples selected from various regions. Values ranging between 98 and 370 mg/kg were found (>200 mg/kg in 60% of samples). Extraction conditions were not found to influence alpha-tocopherol level. alpha-Tocopherol content of retail market samples was high, ranging from 120 to 250 mg/kg of oil (>180 mg/kg in 60% of samples). Storage of samples under domestic conditions for two years showed that good handling is quite important for retaining high alpha-tocopherol levels and for increasing, thus, the storage life and nutritional value of this exquisite oil.  相似文献   

5.
The concentration of the different tocopherol homologues in almond kernel oil was determined in 17 almond cultivars grown in two different experimental orchards, in Spain and Morocco. The three main homologues showed a large variability, ranging from 210.9 to 553.4 mg/kg of oil for α-tocopherol, from 4.64 to 14.92 mg/kg for γ-tocopherol, and from 0.2 to 1.02 mg/kg for δ-tocopherol. The year effect was significant, independent of the experimental site, for all homologues and total tocopherol, the values of α-tocopherol, γ-tocopherol, and total tocopherol being higher in 2009 than in 2008, whereas the value of δ-tocopherol was higher in 2008. The location effect was also significant, the values of γ- and δ-tocopherol being higher in Spain than in Morocco, whereas for α-tocopherol the location effect was dependent on the genotype. These effects could not be explained by the temperature differences between sites, but probably other undetermined environmental factors might explain the effect of the location, such as rainfall and irrigation supplementation during fruit growing and ripening.  相似文献   

6.
Phytosterols (PS) lower low density lipoprotein (LDL) levels by as much as 10–14% in normal and hypercholesteromic people. High LDL levels in the blood are associated with an increased risk of coronary heart disease. Wheat germ and bran contain significant amounts of PS. The main objective of this study was to evaluate the effect of genotype and environment on PS content and composition in whole wheat grain. Protein and ash contents and mineral composition of the samples were also determined. Grain samples were collected from three cultivars, Jagger, Trego, and Intrada, grown at three locations, Alva, Balko, and Goodwell, OK in 2005. Irrigated and dryland samples were obtained from Goodwell. Total PS content and composition in the grain samples were determined using a gas chromatography system. Whole wheat grain samples varied in PS content from 202 mg/kg to 355 mg/kg. β‐Sitosterol, campesterol, and stigmasterol were the major PS compounds found in all the samples. PS exhibited a significant location‐by‐cultivar random effect (P < 0.048), indicating the presence of genotype‐by‐location interaction. Within each location, a significant cultivar effect was also observed. Protein and ash contents and mineral composition of the samples, except those collected from Goodwell‐dryland, were within the range published in the literature for other wheat cultivars. A fundamental understanding of compositional variation in wheat grain requires multi‐environment testing of genotypes, perhaps over several years. This study is a first step for achieving this goal.  相似文献   

7.
Six strawberry cultivars grown on the same commercial plantation in Brazil were evaluated for their chemical composition and quality attributes at the ripe stage. The profiles of the main soluble sugars, ascorbic acid, and anthocyanins were also obtained during the developmental stages. Results showed significant differences among cultivars in all of the investigated parameters. Cv. Campineiro showed an average value for texture of 0.63 N, half the value found for cv. Oso Grande. Anthocyanin content ranged from 13 (cv. Campineiro) to 55 (cv. Mazi) mg/100 g. Total ascorbic acid found for cv. Campineiro (85 mg/100 g) was twice the amount found in cv. Dover (40 mg/100 g). Fructose was the predominant soluble sugar in almost all cultivars. The proportion among the main soluble sugars (fructose, sucrose, and glucose) was similar for Oso Grande and Toyonoka cultivars. The flavonol content (quercetin plus kaempferol derivatives) ranged from 2.7 to 7.1 mg/100 g, with a mean value of 6.1 mg/100 g, whereas free ellagic acid ranged from 0.9 to 1.9 and total phenolics varied from 159 to 289 (mean 221) mg/100 g.  相似文献   

8.
The production of fusaproliferin (FUS), a recently described mycotoxin, and beauvericin (BEA), a mycotoxin recently reported to co-occur with FUS in Fusarium-infected corn, by South African isolates in the Fusarium section Liseola, was investigated. Five isolates each of F. verticillioides, F. proliferatum, F. subglutinans, and F. globosum were cultured on corn kernels. Four each of the five South African isolates of F. proliferatum and F. subglutinans produced FUS (10-1725 and 330-2630 mg/kg, respectively). BEA was produced by four of the F. proliferatum strains (310-1130 mg/kg) and three of the F. subglutinans strains (140-700 mg/kg). The isolates of F. verticillioides failed to produce significant levels of either of these secondary metabolites. F. globosum was a weak producer of both in that one isolate of five produced 25 mg/kg FUS and five out of five produced BEA at levels ranging between 10 and 110 mg/kg. To further characterize these strains, their production of fumonisins B(1), B(2), and B(3), as well as moniliformin, was investigated. Of the four species investigated, fumonisins were produced by all except F. subglutinans, which in turn was the only species whose isolates in this study produced moniliformin (four of five isolates, ranging from 155 to 2095 mg/kg). Analysis of visibly Fusarium-infected home-grown corn collected in the Transkei region of the Eastern Cape Province of South Africa showed that nine of the ten samples contained low levels of FUS (up to 62 microg/kg), whereas all ten samples showed BEA contamination ranging from 8 to 1734 microg/kg with a mean of 258 microg/kg.  相似文献   

9.
The lycopene content of 50 commercial cultivars of seeded and seedless red-fleshed watermelons was determined. Scanning colorimetric and spectrophotometric assays of total lycopene were used to separate watermelon cultivars into low (<50 mg/kg fw), average (50-70 mg/kg fw), high (70-90 mg/kg fw), and very high (>90 mg/kg fw). Cultivars varied greatly in lycopene content, ranging from 33 to 100 mg/kg. Most of the seeded hybrid cultivars had average lycopene contents. Sixteen of the 33 seedless types had lycopene contents in the high and very high ranges. All-trans-lycopene was the predominant carotenoid (84-97%) in all watermelon cultivars measured by high-performance liquid chromatography, but the germplasm differed in the relative amounts of cis-lycopene, beta-carotene, and phytofluene. Red-fleshed watermelon genotypes vary extensively in carotenoid content and offer opportunities for developing watermelons with specifically enhanced carotenoids.  相似文献   

10.
This study reports quali-quantitative analyses on isoprenoids, phospholipids, neutral lipids, phytosterols, and proteins in purified plastids isolated from fresh fruits of traditional (Donald and Incas) and high-pigment (Kalvert and HLY-18) tomato cultivars at four ripening stages. In all of the investigated cultivars, lycopene, β-catotene, lutein, and total carotenoids varied significantly during ripening. Chromoplasts of red-ripe tomato fruits of high-pigment cultivars accumulated twice as much as lycopene (307.6 and 319.2 μg/mg of plastid proteins in Kalvert and HLY-18, respectively) than ordinary cultivars (178.6 and 151.7 μg/mg of plastid proteins in Donald and Incas, respectively); differences in chlorophyll and α-tocopherol contents were also evidenced. Phospholipids and phytosterols increased during ripening, whereas triglycerides showed a general decrease. Regardless of the stage of ripening, palmitic acid was the major fatty acid in all cultivars (ranging from 35 to 52% of the total fatty acids), followed by stearic, oleic, linoleic, linolenic, and myristic acids, but their relative percentage was affected by ripening. Most of the bands detected on the SDS-PAGEs of plastid proteins were constantly present during chloroplast-to-chromoplast conversion, some others disappeared, and only one, with a molecular weight of ~41.6 kDa, was found to increase in intensity.  相似文献   

11.
文山植烟土壤有效锌含量及其影响因素研究   总被引：1，自引：0，他引：1  
谭军  刘晓颖  李强  周冀衡  陈丽娟  宾俊  邱永健 《土壤》2017,49(4):719-724
为探明文山烟区植烟土壤有效锌分布情况及其影响因素,并为烤烟合理施用锌肥提供理论依据,运用GPS定位技术采集了276份土样,测定其有效锌含量,采用经典统计学方法和GIS技术,对其基本特征、空间分布状况及影响因素进行了分析。结果表明:(1)文山烟区植烟土壤有效锌平均含量为1.93 mg/kg,变幅为0.20~8.17 mg/kg,变异系数为70.47%,属于中等变异强度。全烟区有70.12%的区域土壤有效锌在适宜范围内(1.00~5.00 mg/kg)。(2)县域间植烟土壤有效锌平均含量从高到低排序为:麻栗坡西畴县文山县马关县砚山县丘北县广南县。(3)土壤中有效锌含量随着有机质增加而增大,随海拔升高呈抛物线变化;不同海拔组和有机质组间有效锌含量差异均达极显著水平。有效锌含量在土壤p H为6.5~7.5时最低,在偏酸和偏碱的环境中含量较高。(4)文山烟区分布最广的是红壤,其次是黄壤。不同土壤类型有效锌含量差异达极显著水平,含量最高的是水稻土,最低的是紫色土。因此,文山烟区植烟土壤有效锌含量总体满足优质烟叶生产的需求,部分缺锌区域应加强锌肥、有机肥的施用以提高土壤中有效锌含量。  相似文献   

12.
The following organic acids (glutamic, oxalic, pyruvic, malic, tartaric, citric, and fumaric), pungency, Brix degree, acidity, and pH were determined in onion cultivars (Texas, Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo, and Masca) harvested in the same agroclimatic conditions. Glutamic acid was the most abundant organic acid (325 +/- 133 mg/100 g) followed by citric acid (48.5 +/- 24.1 mg/100 g) and malic acid (43.6 +/- 10.4 mg/100 g). There were significant differences between the onion cultivars in the mean concentrations of all of the analyzed parameters. The San Juan de la Rambla and Masca cultivars presented, in general, higher concentrations of the organic acids than the other cultivars. Significant differences in most of the analyzed parameters were observed between the two seed origins for the Masca and San Juan de la Rambla cultivars. The onion samples tended to be classified according to the cultivar and, in the case of San Juan de la Rambla cultivar, according to the precedence of the seeds after applying discriminant analysis.  相似文献   

13.
Oil content and fatty acid composition were determined for two years in the kernel oil of eight cultivars and 47 advanced self-compatible almond genotypes developed in an almond breeding program. Considerable variation between genotypes was found for all parameters. Oil content ranged from 48% to 67% of the total kernel dry weight but was consistent over the two years. Fatty acid composition was also very variable, with significant differences between genotypes, even in genotypes of the same progeny. Oleic acid, ranging from 63% to 78%, and linoleic acid, ranging from 12% to 27%, were the major fatty acids, showing higher values in some selections than in their parents. The large variability observed for all fatty acids and the presence of selections with higher oil and fatty acid contents than the commercial cultivars represents a very promising base to obtain new almond cultivars with oil of higher quality, satisfying the industrial and consumer sectors.  相似文献   

14.
Root dry weight and the relationship between shoot and root characteristics for 119 white clover (Trifolium repens L.) cultivars and breeding lines were examined at five (40, 120, 200, 400, and 500 mg P/kg soil) phosphorus (P) levels. There were significant (P<0.01) differences among cultivars for root dry weight and root/shoot ratio. Instantaneous root/shoot ratio decreased with increasing P supply up to 200 mg P/kg, and then increased again from 400 to 500 mg P/kg soil. Allometric analysis indicated that root growth relative to shoot growth increased with increasing P supply. There was a significant (P<0.01) cultivar x P level interaction such that for the cultivars, the root/shoot ratio was either unaffected, increasing, or decreasing with increasing level of P supply. However, root/shoot ratio appeared to be unrelated to the functions used to describe the P response of the 119 cultivars studied. Shoot characters such as dry weight, leaf number, and stolon length were most closely correlated with root dry weight at the moderately low P levels of 120 and 200 mg added P/kg, where average P response was 9 and 24% of yields at 500 mg P/kg soil, respectively, rather than at the higher P levels. Root/shoot ratio was significantly correlated (r>0.6) with root dry weight over all P levels but not with any of the measured shoot characters (‐0.2> r <0.3).  相似文献   

15.
Intake of phytosterols (and -stanols) has been shown to decrease the level of low-density lipoprotein cholesterol and thus protect against development of cardiovascular diseases. Therefore, studies on the cultivar and year-to-year variation in phytosterol content in rye grains have been performed. The phytosterol content and composition of different rye cultivars, grown under identical conditions on the same field in three consecutive years, were analyzed. Both cultivar and year-to-year variation in sterol content were statistically significant (p < 0.0001). The total sterol content varied from 1007 +/- 21 mg/kg in the highest yielding cultivar, Tsulpan 3, to 761 +/- 10 mg/kg in the lowest yielding cultivar (Amando in the 1999 harvest). Because the meteorological conditions varied substantially between the different years, it was possible to deduce the impact of varying weather conditions on phytosterol content in the different cultivars. The studied cultivars had all the lowest phytosterol contents in the dry and warm harvest season of 1999. Although there were statistically significant cultivar and year-to-year variations in the sterol composition (p < 0.0001), these were only between 2 and 4% of the total sterol content.  相似文献   

16.
三峡库区消落区土壤重金属污染调查与评价   总被引：18，自引：1，他引：18  
通过对三峡重庆库区16个区县，183个土壤样品的分析，表明三峡库区消落区土壤重金属含虽均达到国家土壤环境标准3级以上。其中Cu含量范围为10.7～80.2mg／kg，均值为37.0mg／kg；Pb含量范围为14.6～51.8mg／kg，均值为29.3mg／kg；Zn含量范围为47.5～93.3mg／kg，均值为72.7mg／kg；Cd含量范围为0.081～0.864mg／kg，均值为0.321mg／kg；Hg含量范围为0.032～0.204mg／kg，均值为0.059mg／kg；As含量范围为4.63～12.7mg／kg，均值为8.65mg／kg。Cu、Cd之间存在极显著正相关关系，其余各重金属之间相关性不明显，pH值对重金属含量的影响不大。三峡库区消落区土壤主要受Cd、Cu污染。通过系统聚类分析，土壤重金属有明显的地域分布，即水库上游区、中游区和下游区。  相似文献   

17.
固定态铵是土壤氮素的一种重要形态，对植物生长具有十分重要的作用；然而，风沙土中固定态铵的含量及其影响因素目前并不清楚，限制着对沙地土壤肥力来源及其维持机制的认识。该研究测定了毛乌素沙地裸沙地、沙柳（Salix psammophila）和油蒿（Artemisia ordosica）林地风沙土固定态铵的含量，并分析了土壤粒径及矿物组成对其的影响。结果显示：1）研究区土壤固定态铵平均含量为18.63 mg/kg，占土壤氮库的8.77%，不同植被下土壤中固定态铵含量存在明显差别，油蒿林地土壤固定态铵含量（23.03±1.88 mg/kg）显著高于裸沙地（16.63±0.61 mg/kg）和沙柳林地（16.82± 1.25 mg/kg）；2）风沙土粒径组成与固定态铵含量显著相关，粒径越细，固定态铵含量越高，粒径越粗，含量越低；3）风沙土矿物组成与固定态铵含量间无显著关系。研究表明，毛乌素沙地风沙土中固定态铵含量取决于土壤物理构成而非矿物化学组成，植被主要通过影响粒径组成而影响其含量。固定态铵是荒漠土壤肥力的重要组成部分，通过植被建设增加土壤细粒物质，有利于提高固定态铵含量，对土地荒漠化治理和生物生产力的提高具有十分重要的意义。  相似文献   

18.
Perchlorate accumulation in forage and edible vegetation   总被引：8，自引：0，他引：8  
The accumulation of perchlorate in vegetation is becoming a concern, with increasing numbers of sites reporting the presence of perchlorate in groundwater and surface water. This study investigated potential perchlorate uptake and distribution by a variety of forage and edible crops in both the laboratory and the field. Perchlorate concentrations in soybean leaves grown in the greenhouse were significantly higher than perchlorate concentrations in soybean seeds and pods. Perchlorate concentrations in alfalfa grown in sand were significantly lower than those in alfalfa grown in soil. The concentration of perchlorate in tomato was lower in the fruit than the leaves. Commercially grown wheat and alfalfa samples all contained perchlorate, 0.72-8.6 mg/kg of fresh weight (FW) in the wheat stems, 0.71-4.4 mg/kg of FW in the wheat heads, and 2.9 mg/kg of FW in alfalfa. All field garden samples tested (including cucumber, cantaloupe, and tomato) that were irrigated with perchlorate-tainted water contained perchlorate at various concentrations ranging from 0.040 to 1.65 mg/kg of FW. Bioconcentration factors (BCF), ratios of plant fresh weight concentrations to estimated or measured groundwater concentrations [(microg/kg of FW)/microg/L], were all in the same order of magnitude ranging from 215 +/- 126 for wheat stems to 233 +/- 264 for wheat heads and to 380 +/- 89 for alfalfa. BCF for garden fruit samples were much lower (0.5-20). Results from this study highlight the potential for perchlorate exposure by routes other than drinking water.  相似文献   

19.
Fresh juices of four Italian cultivars of lemons (Citrus limon Burm) have been analyzed by headspace solid phase microextraction coupled to gas chromatography and gas chromatography-mass spectrometry (GC-MS). The best results have been obtained with the 2 cm 50/30 microm divinylbenzene/carboxen on poly(dimethylsiloxane) fiber, using a homogenization time of 1 h at 40 degrees C and a sampling period of 30 min. A total of 35 volatile compounds have been identified by GC-MS, and their relative amounts have been calculated by adding internal standard to the samples. Differences in composition of lemon juices volatile components have been observed. Verdello Siracusano lemon juice has the highest amount of volatile compounds (50.28 mg/L), followed by Interdonato (8.39 mg/L), Primo Fiore Capo d'Orlando (5.75 mg/L), and Femminello Siracusano (2.62 mg/L) juices. Volatile compounds mainly consist of mono- and sesquiterpene hydrocarbons and oxygenated molecules (aldheydes, monoterpene alcohols, and monoterpene esters). Headspace solid phase microextraction coupled to a gas chromatograph equipped with a specific sulfur detector, a sulfur chemiluminescence detector, let us detect and quantify dimethyl sulfide compound at the microgram/liter level in lemon juices.  相似文献   

20.
Twelve selected pepper (Capsicum annuum L.) cultivars, bred for mechanical harvesting (grouped ripeness) and adaptation to different cultivation cycles (short to long), have been characterized by their carotenoid pigment content and composition with the aim of producing high-quality paprika. A detailed analysis of the carotenogenesis was performed throughout the ripening process, but with special emphasis on the ripe stage, with the aim of selecting the best cultivar for paprika production. The MA1 cultivar (with grouped ripeness and very short cultivation cycle) showed the highest carotenoid content (12697.58 mg/kg dwt), followed by DN5 and RN2 cultivars with 11086.88 and 10393.29 mg/kg dwt, respectively. Most of the cultivars (MA3, RN1, LR2, LR7, DN3, DR6, Datler, and Mulato) showed a total carotenoid content in the range of 7000-9700 mg/kg dwt. In general, chlorophyll-retaining character was related to high carotenoid content (cultivars DN3, DN5, MA3, Mulato, RN1, and RN2). The general trend of the cultivation cycle was that the shorter the cycle, the higher the total carotenoid content (as exemplified by the cultivar MA1). The lowest total carotenoid content was found for the RR1 cultivar (4856.77 mg/kg dwt), which showed the longest cultivation cycle. Carotenogenic capacity of the cultivars has been discussed relative to total carotenoid content and the R/Y and Caps/Zeax ratios, the main quality traits for breeding cultivars for production of high-quality paprika. The cultivar MA1, with the highest total carotenoid content, high R/Y (2.11) ratio, and highest Caps/Zeax (9.85) ratio, was found to be the most suitable cultivar for paprika production in terms of carotenoid pigment biosynthesis capacity. Moreover, this cultivar has a short cultivation cycle and grouped ripeness, which are both important characteristics for a proper application of mechanical harvesting. The potential improvement of other varieties is also discussed.  相似文献   

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