超临界二氧化碳萃取亚麻籽油工艺的可视化分析

对采用超临界二氧化碳技术萃取亚麻籽油进行较为系统的研究.选择萃取压力、萃取温度、萃取时间、分离压力4个主要影响因素,运用多因素多水平可视化设计法(m2VD)安排试验.选择分离釜1中产物的质量为试验指标,用自主提出的多因素多水平试验结果可视化分析方法(m2VA)对多维空间试验数据进行分析.得出最佳工艺范围为萃取压力20～ 30 MPa、萃取温度30～46℃、萃取时间77～90 min、分离压力4.0 ～4.7和5.7～5.9 MPa.根据优化工艺范围,在萃取压力为25 MPa、萃取温度40℃、萃取时间83 min、分离压力4.3 MPa下重新试验得到22.87％的得率,对应于质量为34.3 g.     

亚麻籽油的营养特性研究进展

亚麻籽油的营养价值已得到普遍认可,对于其功效及作用机制分别以人或动物为实验对象开展了广泛的研究.本文首先对油脂风味、脂肪酸组成、微量营养成分和氧化稳定性四个影响亚麻籽油营养价值的因素进行了阐述,在此基础上重点综述了亚麻籽油在降血脂、降血压、降血糖、改善认知功能和改善眼睛疾病等方面的最新研究进展.     

亚麻籽油中亚麻酸的提取与纯化

研究采用尿素-硅胶和氯化亚铜-硅胶两次层析亚麻籽油,结果表明:尿素-硅胶层析后,亚麻籽油中只含有油酸、亚油酸和亚麻酸;氯化亚铜-硅胶层析后得到了纯度高于90%的亚麻酸产品。运用外标定量法,以亚麻酸甲酯为标准品,样品总亚麻酸在0. 045～0. 677 mg/m L范围内回归方程为:Y=782 59x-686 8(R2=0. 999 9)。本研究为今后亚麻酸的纯化研究及工业生产提供相关的理论依据和新的思路。     

Degradation of Linseed Oil Vapors by Soil Bacteria in Trickling Biofilters

Oxidation products of linseed oil were produced by impinging a stream of air onto the surface of pure linseed oil and injecting the vapor-laden air into soil percolation columns to enrich the population of bacteria capable of degrading linseed oil vapors. As the populations of bacteria increased, the linseed oil vapors were consumed by these organisms, and the air that emerged from the columns was free of linseed oil contaminants. Five different kinds of bacteria capable of growing on the linseed oil oxidation products as sole source of carbon and energy were found and isolated in pure culture. Chromatographic analyses showed that individual organisms removed specific components of the vapor at specific rates, but none was able to remove them all within a 30-day period of time. When the five were grown together and presented the linseed oil vapor, all vapor constituents were utilized, and the rate of utilization was greater than that seen when the isolates were tested in pure culture. This indicated that the five organisms operated as a bacterial consortium in the degradation of linseed oil vapors. Trickling biofilters prepared from pregrown populations of the five organisms challenged with linseed oil vapors were able to remove all volatile constituents found in linseed oil vapor. Bioremediation of the air was complete and it was accomplished in a single pass of the air through the filter.

This work shows that bacteria found in the soil are capable of degrading linseed oil vapors and that they can be grown in the laboratory and used successfully in bench scale trickling biofilters.     

植物弱光逆境生理研究综述

弱光是目前影响设施生产的重要不利环境因素之一。本文综述了弱光对植物生长发育和光合特性的影响及其信号转导途径,并在此基础上讨论了植物对弱光的适应途径和今后植物弱光逆境生理的研究方向。     

植物弱光逆境生理研究综述

弱光是目前影响设施生产的重要不利环境因素之一。本文综述了弱光对植物生长发育 和光合特性的影响及其信号转导途径,并在此基础上讨论了植物对弱光的适应途径和今后植 物弱光逆境生理的研究方向。     

Physico-Chemical Properties of Linseed Oil as Affected by Various Seed-Borne Fungi

The effect of six seed-borne fungi on linseed oil was studied. Alternaria alternate, Aspergillus flavus, Aspergillus repens, Fusarium culmorum and Torula allii reduced oil content while Cladosporum herbarum slightly increased it. All fungi increased the free fatty acid content and saponification number linseed oil. Iodine number was decreased except in Cladosporium herbarum and Fusarium culmorum. Aspergillus flavus was the most destructive parasite in altering quantity and quality of linseed oil.     

Effect of Sugars and Sugar Analogs on Autoxidation of Methyl Linoleate and Safflower Oil

The antioxidative and prooxidative activities of sugars and sugar analogs were investigated on the autoxidation of methyl linoleate and safflower oil. Autoxidation of methyl linoleate was conducted in either the dry state or aqueous emulsion state. Although all sugars and sugar analogs inhibited the autoxidation of methyl linoleate in the dry system, the reducing sugars accelerated oxidation in the aqueous emulsion system. When glyceraldehyde, dihydroxyacetone and glycerol were added in the oxidation system, glyceraldehyde and dihydroxyacetone with water accelerated the formation and decomposition of methyl linoleate monohydroperoxide. On the other hand, glycerol inhibited the formation and decomposition of hydroperoxide. These results indicate that the carbonyl group of sugars accelerates lipid peroxidation and the hydroxy group of sugars and sugar analogs inhibits the oxidation. The effect of sugars in the safflower oil-sugar-cellulose oxidation system was also examined. Sugars at low humidity inhibited the autoxidation of safflower oil, but reducing sugars at high humidity accelerated the oxidation.     

黄瓜苗期低温弱光下MDA含量主基因-多基因联合遗传分析

选取耐低温弱光性不同的2份黄瓜材料9507、9517及其配制的BC1、BC2、F1、F2等6个世代,进行低温弱光处理,每天光照处理7.5 h,强度为30 μmol·m-2·s-1,约合2 000 lx,白天12℃,晚上8℃,共处理14 d.运用主基因-多基因联合遗传模型方法研究丙二醛(MDA)含量的遗传规律,并估算遗传参数.结果表明MDA含量的遗传受2对加性-显性-上位性主基因+加性-显性多基因控制,2对主基因的加性效应均为负向效应,其显性效应也均为负向,差异不大.总加性效应与总显性效应均为较大的负向效应.分离世代中,主基因的遗传率均比多基因的遗传率高,环境方差对表型方差的影响占有绝对优势,即低温弱光条件下环境对MDA含量的遗传起很大作用,对于这个性状适于晚代选择.     

弱光对樱桃叶片膜脂过氧化的影响

以无性繁殖的一年生莱阳矮樱桃 (PrunuspseudocerasusL .“Laiyang”)幼苗为试材 ,研究了弱光对樱桃叶片膜脂过氧化的影响。结果表明 :随着光照强度的减弱 ,樱桃叶片的净光合速率降低 ;而MDA含量和膜保护酶活性在弱光下也发生明显变化 ,其中MDA含量和POD活性上升 ;CAT活性下降 ;SOD在 36 6 μmol·m-2 ·s-1和 5 33.8μmol·m-2 ·s-1光强下活性升高 ,而在 2 2 8.8μmol·m-2 ·s-1和 83.9μmol·m-2 ·s-1光强下活性下降。     

弱光对樱桃叶片膜脂过氧化的影响

以无性繁殖的一年生莱阳矮樱桃( Prunus pseudocerasus L. "Laiyang")幼苗为试材,研究了弱光对樱桃叶片膜脂过氧化的影响.结果表明:随着光照强度的减弱,樱桃叶片的净光合速率降低;而MDA含量和膜保护酶活性在弱光下也发生明显变化,其中MDA含量和POD活性上升;CAT活性下降;SOD在366 μmol*m-2*s-1和533.8 μmol*m-2*s-1光强下活性升高,而在228.8 μmol*m-2*s-1和83.9 μmol*m-2*s-1光强下活性下降.     

New Insights into the Ageing of Linseed Oil Paint Binder: A Qualitative and Quantitative Analytical Study

This paper presents an analytical investigation of paint reconstructions prepared with linseed oil that have undergone typical 19th century treatments in preparation for painting. The oil was mechanically extracted from the same seed lot, which was then processed by various methods: water washing, heat treatments, and the addition of driers, with and without heat. A modern process lead white (Dutch source, Schoonhoven) and a commercially available vine black were used as pigments. The reconstructions were prepared in 1999, and naturally aged from then onwards. We compared thermogravimetric analysis (TG), which yields macromolecular information, with gas chromatography-mass spectrometry (GC-MS) and direct exposure mass spectrometry (DEMS), which both provide molecular information. The study enabled us to quantitatively demonstrate, for the first time, that the parameters used to identify drying oils are deeply influenced by the history of the paint. In particular, here we show that the ratio between the relative amounts of palmitic and stearic acid (P/S), which is used as an index for differentiating between drying oils, is extremely dependent on the pigments present and the age of the paint. Moreover the study revealed that neither the P/S parameter nor the ratios between the relative amounts of the various dicarboxylic acids (azelaic over suberic and azelaic over sebacic) can be used to trace the sorts of pre-treatment undergone by the oil investigated in this study. The final results represent an important milestone for the scientific community working in the field, highlighting that further research is still necessary to solve the identification of drying oils in works of art.     

Autoxidation of Sodium Linoleate in the Protein Solution

The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for treating inflammatory diseases. The effects on OVA-induced asthmatic mice of an Inulae Flos extract (IFE) were evaluated in this study. The anti-asthmatic effects of IFE were determined by observing eosinophil recruitment, airway hyper-responsiveness (AHR), Th2 cytokine and IgE levels, and lung histopathology. The IFE treatment effectively reduced the percentage of eosinophils and Th2 cytokines in the bronchoalveolar lavage fluid (BALF) when compared to the levels in OVA-induced mice. IFE also suppressed AHR induced by aerosolized methacholine in OVA-induced mice. The results of the histopathological studies indicate that inflammatory cell infiltration and mucus hypersecretion were both inhibited by the IFE administration when compared to the effect on OVA-induced mice. The IFE treatment also suppressed the serum IgE levels and decreased Th2 cytokines in the supernatant of cultured splenocytes. These results suggest that IFE may have therapeutic potential against asthma.     

黄瓜苗期耐低温性及相关生理指标遗传分析

选取耐低温弱光性不同的6份黄瓜材料9504、9507、9506、9517、9511、9514按Griffing方法Ⅱ配制完全双列杂交组合,对亲本及F1进行低温弱光处理(昼/夜温度12℃/8℃,每天光照7.5 h,光照强度30μmol·m-2·s-1)14 d后调查幼苗耐低温性、保护酶(POD和SOD)活性、渗透调节物质(可溶性蛋白质和脯氨酸)含量等生理指标,分析其遗传规律.结果显示,黄瓜亲本9504、9507及其组合F1幼苗的耐寒性较强,保护酶活性和脯氨酸含量较高,黄瓜幼苗耐寒性与其保护酶活性和渗透调节物质含量关系密切;黄瓜幼苗耐低温性、POD和SOD活性、可溶性蛋白质和脯氨酸含量所有性状的遗传符合加性-显性模型,它们的广义遗传力分别达82.133%、93.351%、97.368%、59.230%、93.460%,狭义遗传力达73.170%、53.191%、26.316%、58.587%、45.963%.研究表明,黄瓜耐低温性、POD和SOD活性、脯氨酸含量适于早代选择;幼苗可溶性蛋白质含量受生长环境的影响较大,可晚代选择.     

The Use of Morphological and AFLP Markers in Diversity Analysis of Linseed

Different methods of genetic diversity measures could give better judgment of differentiating important accessions for growers, germplasm curators and plant breeders. Data of 60 accessions of linseed, mainly from Ethiopia, were used to assess their genetic diversity, employing morphological and amplified fragment length polymorphism (AFLP) methods. Analyses of genetic distance, principal components and clusters showed the presence of a wide range of diversity among the studied accessions. The mean for genetic distance estimates of the entire 1770 pairwise accessions was 0.6684 for morphology, while that of AFLP was 0.5734. These genetic distances varied from zero to one for morphology in contrast to 0.29 to 0.71 of the AFLP. Morphological and AFLP based clusters and their accompanying analyses showed different hierarchical patterns of genetic diversity among the accessions. Despite their disparity, the two diversity measures were found independently useful for assessing the degree of relatedness and the overall patterns of genetic variation among the analysed linseed accessions.     

A Spectroscopic View of Some Recent Advances in the Study of Blue Light Photoreception*

The blue to UV-A region of the spectrum, spanning the region of about 320–520 nm, strongly influences the growth and development of plants and fungi. Photomorphogenesis in plants is, to a great extent, controlled by phytochrome, but there are unique contributions of the blue region, which cannot be duplicated by any amount of red light. Phototropism is, with few exceptions, a purely blue light response. In fungi, the blue region dominates the photocontrol of growth and development, though some red light effects have been reported. Many blue light action spectra fit the definition of cryptochrome, a pigment class defined by its UV-A and blue peaks. The action spectrum, if measured to sufficient resolution, displays several minor maxima or shoulders in the blue region which call to mind the vibrational levels of carotenoids and flavins. Recent molecular genetic studies, as well as photobiological work, have shown that some cryptochromes are related to the DNA repair enzyme photolyase, while others appear genetically and spectroscopically distinct. In this review, we have applied established criteria from photobiology, in particular, comparison of action spectra with absorption spectra, to these recent results. It is apparent that photolyase homologs such as CRY1 can explain the blue light portion of the action spectrum for hypocotyl elongation, assuming participation of the oxidized flavin. In fungi, the photoreceptor question remains open. Identification of the nph1 gene in Arabidopsis may soon lead to a photoreceptor for higher plant phototropism. Also, we present a possible solution to the most recent version of the long-standing flavin-carotenoid controversy, the zeaxanthin hypothesis for higher plant phototropism. In conclusion, there appear to be at least three classes of cryptochromes.     

Kinetic Analysis of Temperature-Programmed Autoxidation of Ethyl Eicosapentaenoate and Ethyl Docosahexaenoate

On the basis of an autocatalytic and a first order reaction kinetics, a nonisothermal oxidation reaction model was developed for n-3 polyunsaturated fatty acid (PUFA) under temperature-programmed linear heating conditions. With this model, the activation energy of oxidative reaction can easily be obtained with at least three linear heating conditions. The temperature-programmed oxidation experiments of ethyl eicosapentaenoate and ethyl docosahexaenoate were done under linear heating conditions of 4 to 12 K/h. The activation energies and the frequency factors obtained were in good agreement with those by the isothermal oxidation experiments reported previously.     

Mode of Loss of Phosphatidyl-ethanolamine in Autoxidation

This report identifies and describes the chemical structure of granular material that accumulates in the cytoplasm of Selenomonas ruminantium grown in glucose or lactate medium. The granular material was identified to be glycogen. Its molecular weight was about 2 x 10⁷ daltons. Conversion into maltose with α-amylase, β-amylase, and isoamylase was 61%, 37%, and 15%, respectively. The glycogen was digested completely by joint action of β-amylase and isoamylase, and its conversion into maltose was 103%. The average chain length of the glycogen was 23.5. The maximum absorption of the iodine complex of the glycogen was at 520 nm. These results led us to conclude that the chemical structure of this glycogen was similar to that of plant amylopectin, unlike normal Microbiol or animal glycogen so far known. When S. ruminantium was grown in glucose medium, the amount of glycogen in cells reached about 260 µg/mg dry weight of cells during late exponential phase and early stationary phase.     

Adaptation of the Photosynthetic Apparatus of Scenedesmus obliquus to Strong and Weak Light Conditions

Homocontinuous cultures of the unicellular green alga Scenedesmus obliquus were grown under strong (28 W/m²～28,000 lux) and weak (5 W/m²～5000 lux) light conditions to simulate the conditions of ‘sun’ and ‘shade’ plants. As in higher plants the cells adapted to strong light had less chlorophyll but demonstrated a higher photosynthetic capacity and a higher respiration rate, so that their compensation point was reached at three times higher energy than in the cells grown under low light intensities. The CO₂ fixation rate and the RuDP carboxylase activity under saturating light intensities were both higher in the cells grown in strong light. In spite of the differences in the pigment content and in the light saturated photosynthetic capacities for both cultures, the quantum yields of photosynthetic oxygen evolution were equal. As documented for some species of higher plants Scenedesmus is not genetically determined to be either a ‘sun’ or ‘shade’ organism but can adapt its photosynthetic apparatus to the different light intensities.