Effect of Cultivar, Year Grown, and Cropping System on the Content of Tocopherols and Tocotrienols in Grains of Hulled and Hulless Barley

In a three-year period (2000–2002) total tocols (tocopherols and tocotrienols), content of vitamin E and its isomers (α-, β+γ-, δ-tocopherols and tocotrienols) were assessed in grain of 13 barley genotypes. The highest content of tocols (60.3–67.6 mg kg⁻¹) and content of vitamin E (Vitamin E equivalent—18.0–20.1 mg kg⁻¹) were determined in the waxy varieties Wanubet, Wabet, and Washonubet. Standard varieties, i.e. of a malting type (Krona and Kompakt), had statistically significantly lower content of tocols (49.9 and 53.6 mg kg⁻¹) and vitamin E (15.7–16.1 mg kg⁻¹) compared to the waxy varieties. The hulless waxy variety Washonubet had statistically significantly higher total content of tocols (67.6 mg kg⁻¹) and α- tocotrienols isomer (42.1 mg kg⁻¹) versus all other genotypes in the set. Chemical treatment and fertilization statistically significantly increased the content of tocols (by 4.7 mg kg⁻¹), vitamin E (by 1.9 mg kg⁻¹), isomer α-tocopherol (by 0.9 mg kg⁻¹) and isomer α- tocotrienols (by 3.3 mg kg⁻¹). The average values of α-tocopherols and α-tocotrienols in the set were 6.7 mg kg⁻¹ and 29.7 mg kg⁻¹, respectively. Some of the reciprocal lines created by us from the malting and waxy varieties are suitable for food use for high contents of all tocopherols and α-tocotrienols.     

树莓(Rubus idaeus)种子油的性质研究

研究了空气干燥树莓种子、溶剂提取和室温压榨提取种子油的物理性质和化学性质以及维生素E组成和含量。结果表明，树莓种子出油率为9．04％；10％（v/v)树莓种子油的正己烷溶液叶绿素和类胡萝卜素的吸光度分别为0．804和0．0406；树莓种子油的皂化值为192，对甲氧基苯胺值为8．2，过氧化值为5．63mequiv/kg，粘度为25．2mPs。树莓种子油仅含有α-，γ-和δ-烷链维生素E，树莓种子油的主要维生素E为γ－烷链维生素（79％）和α－烷链维生素E（20％）。     

植物脂质过氧化研究进展

脂质过氧化反应在生物体内普遍存在,对生物的危害最大。生育酚是一种脂溶性抗氧化剂,保护生物膜免受脂质过氧化损伤。该研究综述了脂质过氧化物的产生、危害以及生育酚抗氧化机制。     

Chemical composition and profile characterisation of pumpkin (Cucurbita maxima) seed oil

Seeds of a Tunisian variety (Béjaoui) of pumpkin (Cucurbita maxima) were analysed for their main chemical composition and for their oil properties. Expressed on dry weight basis, seed moisture was 8.46%, whereas contents of proteins, fibre, ash, fat, and total sugars established at 33.92%, 3.97%, 21.97%, 31.57%, and 0.11% respectively. Gas chromatography revealed that the major fatty acids were oleic, linoleic, and palmitic acids (44.11%, 34.77%, and 15.97% respectively). Seed oil was also found to be rich in tocopherols with a predominance of δ-tocopherol (42.27%). The sterol marker β-sisosterol accounted for 39.6% of total sterols contained in seed oil of this variety. Six phenolic acids (protocatechuic, caffeic, syringic, vanillic, p-coumaric and ferulic) were detected, the syringic acid being predominant (7.96 mg/100 g). As a whole, based on its seed oil features, pumpkin may be considered as a valuable source for new multi-purpose products for industrial, cosmetic, and pharmaceutical utilisation.     

Tocochromanol content and composition in Jatropha curcas seeds

Physic nut (Jatropha curcas L.) is a promising seed oil source for biodiesel production. Natural antioxidants play a major role in maintaining oxidative stability of oils and they also have important food and industrial applications. Among them, tocochromanols are the most abundant in seeds. The objective of this research was to evaluate the variation for tocochromanol content and profile in a germplasm collection of 52 accessions of J. curcas. Seeds collected in two different periods, August and November of 2009, were analysed for tocochromanol content. Additionally, the dynamics of tocochromanol accumulation in developing seeds was studied. Total seed tocochromanol content averaged 307.2 mg kg⁻¹ in August and 303.7 mg kg⁻¹ in November, whereas total oil tocochromanol content averaged 507.4 mg kg⁻¹ in August and 500.8 mg kg⁻¹ in November. The tocochromanol fraction was made up of 15.4% gamma-tocopherol, 83.8% gamma-tocotrienol, and 0.8% delta-tocotrienol in August and 18.0% gamma-tocopherol, 80.4% gamma-tocotrienol, and 1.6% delta-tocotrienol in November. Genotype × environment effects were identified for tocochromanol content but not for the proportion of major tocochromanol homologues, which showed a high positive correlation between both environments. Developing seeds contained primarily alpha-tocopherol and gamma-tocopherol at early stages of development, with gamma-tocotrienol and delta-tocotrienol being practically undetectable. Gamma-tocotrienol content remained practically undetectable till 66 DAP and then increased pronouncedly to final levels of 177.1 mg kg⁻¹ (74.8% of the total tocochromanol content). The powerful antioxidant and health-promoting properties of gamma-tocotrienol encourages further studies on selection for the tocopherol/tocotrienol ratio in Jatropha and on the potential of tocochromanols as high added-value products derived from Jatropha seed oil production.     

Influence of cultivar and site of cultivation on levels of lipophilic and hydrophilic antioxidants in virgin olive oils (Olea Europea L.) and correlations with oxidative stability

Oxidation stability is an important property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by cultivar, year and place of production. Polyphenols, tocopherols, carotenoids, chlorophylls and fatty acids levels were correlated to oxidative stability in olive oils from three experiments: cultivar influence (18 cultivars assessed for 4 years in the same place); environmental influence by mesoclimatic (4 cultivars from 17 sites in a single region for 4 years) and macroclimate conditions (3 cultivars from 3 different regions for 3 years). Total polyphenols and saturated on polyunsaturated fatty acids ratio were shown to be the major factors in oil antioxidant stability, according to multivariate regression models. Among the surveyed cultivars, oils from ‘Leccino’ and from three ‘local’, minor cultivars (‘Miniol’, ‘Regina’ and ‘Rossanello’) resulted in higher oxidative stability and oils from cultivars grown in Tuscany (central Italy) showed the highest oxidative stability by comparison with northern and southern regions.     

不同基因型大麦品种大麦油及其母育酚含量的变异规律

为了探讨不同基因型大麦品种大麦油及其母育酚含量的变异规律,采用超临界萃取法及HPLC法提取并测定了30个大麦品种的大麦油及其母育酚含量和成分.结果表明,大麦油含量存在显著的基因型和环境效应(P＜0.05),裸大麦的大麦油含量(平均为4.16%)高于皮大麦(平均为2.96%),蜡质裸麦品种(Sumire mochi)含量最高(6.15%).与去皮籽粒相比,全麦的大麦油含量较高;与麦芽相比,制啤后的大麦原料仍有较高的母育酚含量.大麦油的母育酚组成成分主要为α-生育酚(占总生育酚的65.4%)和α-生育三烯酚(占总生育三烯酚的70.7%).试验表明,大麦油及其母育酚含量既受基因型的控制,又受生长环境条件的影响;大麦种皮部分可能是大麦油的主要储存组织之一,制啤后的大麦原料有可能作为母育酚提取的资源加以利用,从而提高大麦的附加值.     

Comparative advantages of chemical compositions of specific edible vegetable oils

As important supplementary to major edible oils, comparative chemical advantages of minor edible oils decide their development and usage. In this study, chemical composition of 13 kinds of specific edible vegetable oils were investigated. The comparative advantages of chemical compositions of these edible oils were obtained as follows: (1) camellia, tiger nut and almond oil were rich in oleic acid, the contents of which accounted for 79.43%, 69.16% and 66.26%, respectively; (2) safflower oil contained the highest content of linoleic acid (76.69%), followed by grape seed (66.85%) and walnut oil (57.30%); (3) perilla seed, siritch, peony seed and herbaceous peony seed oil were rich in α-linolenic acid (59.61%, 43.74%, 40.83% and 30.84%, respectively); (4) the total phytosterol contents of these oils ranged from 91.46 mg/100 ​g (camellia oil) to 506.46 mg/100 ​g (siritch oil); and (5) The best source of tocopherols was sacha inchi oil (122.74 mg/100 ​g), followed by perilla seed oil (55.89 mg/100 ​g), peony seed oil (53.73 mg/100 ​g) and herbaceous peony seed oil (47.17 mg/100 ​g). The comparative advantages of these specific edible oils indicated that they possess the high potential nutritional values and health care functions.