排序方式： 共有20条查询结果，搜索用时 421 毫秒
1.
Leonardo Velasco Elena García‐Navarro Begoña Pérez‐Vich José M. Fernández‐Martínez 《Plant Breeding》2013,132(6):694-700
Tocopherols are compounds present in oilseeds with major effect on nutritional and technological properties of seed oils. Brassica spp. mainly contain varying concentrations of α‐tocopherol, with high vitamin E value, and γ‐tocopherol, which contributes to oil stability. The objective of this research was to select for contrasting tocopherol content and profile in Ethiopian mustard (Brassica carinata A. Braun). A collection of 211 F4:5 lines was evaluated for tocopherol content and profile, and divergent selection was conducted till the S3:4 generation. Selection resulted in two lines with increased tocopherol content (244 and 243 mg/kg seed as average of four environments), one line with reduced tocopherol content (117 mg/kg), two lines with reduced α/γ‐tocopherol ratio (0.22 and 0.28) and two lines with increased α/γ‐tocopherol ratio (3.74 and 3.34). Control line C‐101 averaged 196 mg/kg with α/γ‐tocopherol ratio of 1.10. Reduced α/γ‐tocopherol ratio was controlled by recessive alleles at a single locus. Seed to plant correlation was high (r = 0.92), which suggests the feasibility of selecting at the single‐seed level. 相似文献
2.
《Journal of Crop Improvement》2013,27(1-2):309-344
Abstract Vegetable oils are one of the most valuable commodities in world trade. They are subject to specific quality requirements, both for food and non-food uses, there being a continuous demand for new oil types. Thus, plant breeders have made great efforts over the past four decades to develop those quality features demanded by the industry, mainly related to the fatty acid composition of the seed oil. Initially, breeders had to focus on the natural variation occurring within each oilseed crop and closely related species. From the 1970s onwards, the induction of mutations by treatment of seeds with mutagenizing agents was revealed as an effective system for modifying the fatty acid profile. In fact, mutagenesis has proved to be one of the most successful approaches for creating novel oil types. Nowadays, breeding for improved seed oil quality is in a transitional stage, both from a conceptual and a methodological point of view. First, the concept of oil quality is changing. It is not only defined by its fatty acid composition but also by other parameters, the most important being the triacylglycerol profile and the tocopherol content and composition. Second, molecular techniques for gene identification and manipulation are opening up new possibilities, much more powerful and less random than the traditional ones, for the modification of quality traits. In this review, we aim to offer an overview of seed oil quality as well as its genetic improvement by traditional and biotechnological means. 相似文献
3.
A. Surendraraj K. H. Sabeena Farvin R. Anandan 《Journal Of Aquatic Food Product Technology》2013,22(1):11-26
The aims of the present study were (a) to extract and quantify the main phenolic acids and tocopherols from the petiole, leaves, and flowers of Eichornia crassipes; (b) to evaluate the antioxidant capacity of the extracts in four in vitro systems (1,1-diphenyl-2-pycryl-hydrazyl [DPPH] radical scavenging ability, iron chelating activity, reducing power, and prevention of oxidation in a liposome model system); and (c) its effectiveness in retarding lipid peroxidation in fish oil by accelerated stability test. Significant differences were observed in total and individual phenolic contents and in the antioxidant activities of extracts from the various parts of E. crassipes. Out of the 11 phenolic acids analyzed, ethanolic extracts contained high amounts of gallic, protocatechuic, gentisic, and p-hydroxybenzoic acid, whereas, water extracts contained less amounts of a varied number of phenolic acids. Ethanolic extracts of flower, which contained the highest total phenolic content, were found to have high DPPH radical scavenging activity and reducing power. However, ethanolic extracts of leaf exerted a high Fe2+ chelating activity and also inhibited lipid peroxidation process both in liposomes and fish oil. Our results demonstrate that E. crassipes, an underutilized aquatic weed, could be a potential natural antioxidant source for food, feed, and pharmaceutical applications. 相似文献
4.
维生素E是一类人体所必需的脂溶性维生素,具有重要的生理功能。尿黑酸叶绿醇转移酶（HPT）、2-甲基-6．叶绿基-1,4-苯醌甲基转移酶（MPBQMT／VTE3）、1-生育酚甲基转移酶（γ-TMT／VTE4）是维生素E生物合成途径中的关键酶。本研究对来自拟南芥的HPT1,VTE3,VTE4三个基因启动子在低温、高盐及无光等逆境条件下的表达特性进行了分析,GUS组织化学染色结果表明：低温条件下,HPT1的表达降低明显,高盐条件下,HPT1的表达仅略有降低,无光条件下HPT1在茎中的表达升高,而根中的表达则降低;低温条件下VTE3的表达没有变化,高盐条件下则明显降低,无光条件下VTE3在茎中的表达显著降低;低温条件下VTE4表达略有升高,高盐条件下其表达明显降低,无光条件下VTTE4在茎中的表达有所降低。说明拟南芥维生素E合成途径中的酶的表达受外界环境条件的影响。 相似文献
5.
6.
Identification and genetic characterization of a safflower mutant with a modified tocopherol profile 总被引：1，自引：0，他引：1
Safflower (Carthamus tinctorius L.) seeds have a tocopherol fraction dominated by α‐tocopherol, which accounts for more than 95% of the tocopherols. α‐Tocopherol exerts a high vitamin E activity, but a low in vitro antioxidant action. For non‐food applications, replacement of high α‐tocopherol by γ‐tocopherol is preferred. Because of the limited variability found in germplasm of cultivated safflower, the objective of the present research was to search for variability for tocopherol profile in germplasm of wild safflower species. Bulk seed samples of 77 accessions from six species were analysed for total tocopherol content and profile. One accession of C. oxyacanthus showed increased γ‐tocopherol content (36%). Single‐seed analysis showed the existence of a bimodal distribution, which included high α‐tocopherol (>90%) and high γ‐tocopherol (HGT) seeds (>85%). Plants from the HGT seeds bred true for the trait and showed introgression of cultivated safflower, which allowed a rapid selection for cultivated safflower traits. Genetic analysis revealed that the HGT trait was controlled by partially recessive alleles at a single locus Tph1, which will facilitate the transference of the novel trait to diverse safflower germplasms. 相似文献
7.
Concentrations of retinol and tocopherols in the milk of cows supplemented with conjugated linoleic acid 
下载免费PDF全文
下载免费PDF全文 D. K. Gessner E. Most G. Schlegel K. Kupczyk F. J. Schwarz K. Eder 《Journal of animal physiology and animal nutrition》2015,99(6):1039-1046
This study was performed to investigate the hypothesis that supplementation of conjugated linoleic acid (CLA) changes the concentrations of retinol and tocopherols in the milk of cows. To investigate this hypothesis, Holstein cows received daily from 3 weeks ante‐partum to 14 weeks post‐partum either 172 g of a CLA‐free rumen‐protected control fat (control group, n = 20) or the same amount of a rumen‐protected CLA fat, supplying 4.3 g of cis‐9, trans‐11 CLA and 3.8 g of trans‐10, cis‐12 CLA per d (CLA group, n = 20). Milk samples (collected at weeks 1, 3, 5, 8 and 11 of lactation) were analysed for retinol, α‐ and γ‐tocopherol concentrations. Milk of cows supplemented with CLA had higher concentrations of retinol (+34%), α‐tocopherol (+44%) and γ‐tocopherol (+21%) than milk of control cows (p < 0.05). The daily output of these vitamins via milk was also greater in cows of the CLA group than in cows of the control group (+36, 50 and 24% for retinol, α‐tocopherol and γ‐tocopherol, respectively, p < 0.05). In agreement with higher concentrations of tocopherols, concentrations of thiobarbituric acid‐reactive substances, determined in milk of week 5, were lower in cows of the CLA group than in control cows, indicative of a lower susceptibility of milk lipids to peroxidation. Plasma concentrations of retinol and α‐tocopherol, determined at 1 and 5 weeks post‐partum, were not different between the two groups of cows. In conclusion, this study shows that supplementing dairy cows with a moderate amount of CLA causes an increase of the concentrations of vitamins A and E in the milk and results in an increased output of those vitamins via milk. These effects might be beneficial with respect to the nutritional value of dairy products and the susceptibility of milk fat to oxidative deterioration. 相似文献
8.
Hamed Safafar Jonathan van Wagenen Per M?ller Charlotte Jacobsen 《Marine drugs》2015,13(12):7339-7356
This study aimed at investigating the potential of microalgae species grown on industrial waste water as a new source of natural antioxidants. Six microalgae from different classes, including Phaeodactylum sp. (Bacillariophyceae), Nannochloropsis sp. (Eustigmatophyceae), Chlorella sp., Dunaniella sp., and Desmodesmus sp. (Chlorophyta), were screened for their antioxidant properties using different in vitro assays. Natural antioxidants, including pigments, phenolics, and tocopherols, were measured in methanolic extracts of microalgae biomass. Highest and lowest concentrations of pigments, phenolic compounds, and tocopherols were found in Desmodesmus sp. and Phaeodactylum tricornuotom microalgae species, respectively. The results of each assay were correlated to the content of natural antioxidants in microalgae biomass. Phenolic compounds were found as major contributors to the antioxidant activity in all antioxidant tests while carotenoids were found to contribute to the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferrous reduction power (FRAP), and ABTS-radical scavenging capacity activity. Desmodesmus sp. biomass represented a potentially rich source of natural antioxidants, such as carotenoids (lutein), tocopherols, and phenolic compounds when cultivated on industrial waste water as the main nutrient source. 相似文献
9.
Tocopherols are one of the most important bioactive compounds in vegetable oils. It is known that these antioxidants present a dilution like relationship with oil weight per grain but the mechanism underlying this relationship are unknown. The aim of this work was to analyze the dynamics of tocopherol accumulation in sunflower grains, its relationship with oil accumulation and its effects on final oil quality in genotypes with different fatty acid composition. Three field experiments were conducted with genotypes with different potential fatty acid composition (a traditional, a high oleic and a high stearic−high oleic) and treatments with different source (intercepted solar radiation) or sink (grains) during grain filling to obtain varied grain filling conditions and grains with different oil concentration and oil unsaturation. Intercepted solar radiation modified oil per grain but did not affect tocopherol per grain. The rate of accumulation explained 79% and 74% of the oil and tocopherol per grain variation, respectively. When intercepted solar radiation increased, the duration of the period of oil and tocopherols accumulation increased, being the first the most responsive. These differences in the duration of accumulation periods are reflected in a larger relative increase in oil than tocopherols per grain and thus a dilution of the latter in the oil. These differences in the dynamics of oil and tocopherol accumulation are common to genotypes with different level of unsaturation. These results help to understand the mechanism associated with the dilution curve of oil tocopherol concentration reported in the literature. 相似文献
10.
不同地域环境对栝楼籽和栝楼籽油营养成分的影响（英文） 总被引：1，自引：0，他引：1
为了研究和比较同一时间收获于不同区域(浙江长兴、河北安国、山西晋城和山东滨州)的栝楼籽的营养成分,将栝楼籽样本去皮压碎后,测定其蛋白质、氨基酸、脂质、脂肪酸、生育酚和矿物质.结果表明：栝楼籽的蛋白质质量分数为28.68％(长兴)～40.91％(安国);总氨基酸质量分数为686.9～863.3 mg/g 蛋白,其中亮氨酸是最丰富的必需氨基酸,谷氨酸和精氨酸是主要的非必需氨基酸;栝楼籽的总脂质量分数为22.81％(安国)～49.41％(长兴),其中石榴酸(9c ,11t ,13c‐C18：3)是最主要的脂肪酸(33.09％～50.75％),其次为 C18：2n‐6(亚油酸)、C18：1n‐9、C16：0、C18：0和 C14：0,而总脂含量和脂肪酸组成因地理位置不同而有差异;在栝楼籽中检测到α‐和γ‐生育酚,其中安国样本含α‐生育酚最低,为67.8μg/g ,而长兴的为350.7μg/g ;晋城的栝楼籽含有最高的铜(6.01 mg/kg)、铁(136.94 mg/kg)和硒(35.06μg/kg),而长兴的栝楼籽含有最低的铁(98.18 mg/kg)、锌(22.89 mg/kg)和硒(22.89 mg/kg).总之,栝楼籽营养丰富,含有脂质、蛋白质、石榴酸、多不饱和脂肪酸和硒,地理位置和气候可能影响栝楼籽中的营养素.从本实验数据看,在将栝楼籽应用于功能食品时,河北安国将是比较好的栝楼籽产地. 相似文献