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1.
Hiromi Yoshida Mikiko Tatsumi Goro Kajimoto 《Journal of the American Oil Chemists' Society》1991,68(8):566-570
Effects of microwave heating on the oxidative stability ofd-tocopherols were studied in relation to the production of fatty acids in oils. During microwave heating, the stability of
tocopherols decreased in the orderδ>β>γ>α. This order did not depend on the types of ethyl esters of fatty acids or oils present. But, the shorter the chainlength
and the lower the degree of unsaturation of the fatty acid ethyl esters, the greater was the reduction in amount of individual
tocopherols. A similar tendency was observed when tocopherol-stripped vegetable oils, with equimolar mixtures of tocopherols
added, were treated under the same conditions. The reduction in tocopherols became greater with increasing levels of free
fatty acids. 相似文献
2.
The main biochemical function of the tocopherols is believed to be the protection of polyunsaturated fatty acids (PUFA) against
peroxidation. A critical question that must be asked in reference to this is whether there is a biochemical link between the
tocopherol levels and the degree of unsaturation in vegetable oils, the main source of dietary PUFA and vitamin E. We used
a mathematical approach in an effort to highlight some facts that might help address this question. Literature data on the
relative composition of fatty acids (16:0, 16:1, 18:0, 18:1, 18:2, and 18:3) and the contents of tocopherols (α-, β-, δ-,
and γ-tocopherol) in 101 oil samples, including 14 different botanical species, were analyzed by principal-component analysis
and linear regression. There was a negative correlation between α- and γ-tocopherols (r=0.633, P<0.05). Results also showed a positive correlation between linoleic acid (18:2) and α-tocopherol (r=0.549, P<0.05) and suggested a positive correlation between linolenic acid (18:3) and γ-tocopherol. 相似文献
3.
S.?M.?NolascoEmail author L.?A.?N.?Aguirrezábal G.?H.?Crapiste 《Journal of the American Oil Chemists' Society》2004,81(11):1045-1051
Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological
activities. Significant variations (389 to 1873 μg g oil−1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to
determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling
and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed.
Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two
contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling
in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the
tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration
stabilized for oil weight per seed higher than 23 mg oil seed−1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil−1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted
independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols. 相似文献
4.
Atsuyoshi Nishina Kohji Kubota Hiromu Kameoka Toshihiko Osawa 《Journal of the American Oil Chemists' Society》1991,68(10):735-739
A substance with antioxidant properties was obtained from the hexane extract of roots ofRumex japonicus Houtt. The active component of the hexane extract was isolated and characterized as 2-acetyl-1,8-dihydroxy-3-methyl naphthalene,
trivially named musizin (MUS). The antioxidant activities of MUS in six types of fats and oils were higher than that of butyl
hydroxyanisole (BHA) and δ-tocopherol (δ-TOC). Together, TOC and MUS have a synergistic effect, because comparable amounts
of either had lower antioxidant activity than various combinations of the two antioxidants. When we studied the antioxidant
properties of a mixture of MUS and δ-TOC with methyl linoleate (MeLH), we found that the rates of destruction of the two antioxidants
were comparable, but that their destruction occurred sequentially, with MUS first followed by δ-TOC, after which the oxidation
of MeLH quickly occurred. Comparison of the antioxidant activity of MUS and its analogs suggests that only one of the two
hydroxyl groups in MUS is involved in its antioxidant activit. Intermolecular hydrogen bonding may be involved. 相似文献
5.
Yuen May Choo Ah Ngan Ma Hawari Yahaya Y. Yamauchi M. Bounoshita M. Saito 《Journal of the American Oil Chemists' Society》1996,73(4):523-525
Successful separation of triglycerides, diglycerides, free fatty acids, carotenes, tocopherol, and tocotrienols from crude
palm oil has been achieved by supercritical fluid chromatography (SFC) with a combination of a C18 and a silica gel column.
The separation was carried out by the programmed extraction elution method. Free fatty acids were separated into five components
by gas-liquid chromatography; tocopherol and tocotrienols were also separated into four components by SFC analysis, and the
pure fractionated carotenes were obtained by preparative SFC. Thus, by using supercritical fluid chromatography, crude palm
oil components can be separated and fractionated, based on differences in their functional groups. 相似文献
6.
ABSTRACT: Fish- and peanut-containing half-products were obtained by extruding and drying tocopherol- and retinyl palmitate-fortified mixtures of tapioca starch and minced fish or partially defatted peanut flour (PDPF 60:40, wet basis). Half-products were puffed by deep-fat frying. Vitamins were determined simultaneously at each step of snack production using a direct solvent extraction method. Extrusion significantly reduced the content of tocopherols and retinyl palmitate in both products. Reduction of retinyl palmitate in fish and peanut extrudates during snack production was 48% and 27%, respectively. Final products contained more tocopherol than intermediates because of the high tocopherol content in the frying oil and its uptake. 相似文献
7.
8.
本研究应用柱色谱预分离、气相色谱与质谱联用技术,在国内首次对野生植物沙棘果油中所含的维生素E类组份进行了系统的分析鉴定.除分析出了α、β、γ、δ——生育酚外,还用质谱碎片解析法推断出了四种未有报道的新组份,为沙棘果油在化妆品及医药方面的应用提供了可靠的依据. 相似文献
9.
核桃的营养保健功能及药用价值研究进展 总被引:6,自引:0,他引:6
核桃中所含的有益健康的成分如ω-3系多不饱和脂肪酸、生育酚、抗氧化剂及褪黑素等,对心脏病、动脉硬化、癌症、糖尿病、肥胖等慢性非传染性疾病的预防发挥积极的独到作用.本文就核桃的营养价值、保健功能及对与疾病预防方面的研究进展进行了综述. 相似文献
10.
Semra Turan Ihsan Karabulut Halil Vural 《Journal of the science of food and agriculture》2007,87(1):90-97
The oxidative stability of structured lipids (SLs) synthesised by specific sn‐1,3‐lipase catalysed interesterification of soybean oil (SBO) with caprylic acid (CA) in a stirred batch reactor was studied. SLs contained considerable amounts of tocopherol (TOH) isomers, although they lost almost 25% of endogenous TOHs during production. The effects of the addition of different TOH homologues (α, β, γ, δ), ascorbyl palmitate (AP, 200 ppm), lecithin (Le, 1000 ppm), butylated hydroxytoluene (BHT, 100 ppm) and butylated hydroxyanisole (BHA, 100 ppm) on the oxidative stability of SLs were investigated. Induction time (IT) of SBO, determined by the Rancimat method, decreased from 8.4 to 5.8 h at 110 °C after the modification. On the other hand, purified SLs and purified SBO had the same IT due to the tocopherol reduction during silica purification. No significant difference was observed between IT of SLs and SLs plus different α‐tocopherol concentrations (50, 100, 150, 200, 300, 500 and 1000 ppm) (P > 0.05). However, the addition of Le and/or AP significantly improved oxidative stability of purified SLs and SBO. The ternary blend containing δ‐TOH, AP and Le had higher IT than ternary blends of α‐TOH, β‐TOH or γ‐TOH. Furthermore, ternary blend containing BHA, AP and Le had higher IT than ternary blends of BHT, AP and Le. In addition, there was an increase in peroxide value (PV), conjugated diene (CD) content and p‐anisidine value (AV) during oxidation of oils at 60 °C. Antioxidant mixtures of α‐TOH (50 ppm) and δ‐TOH (500 ppm) with AP and Le decreased PV, CD and AV effectively. Copyright © 2006 Society of Chemical Industry 相似文献