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31.
The present study was undertaken to establish micromorphological standards of Daphne mucronata Royle and Myrtus communis (L.). Daphne mucronata Royle is a xerophytic perennial shrub while, Myrtus communis is an evergreen shrub or small tree. Micromorphological investigation is one of the cheapest methods. It will be helpful in the accurate identification of these plants from other species. Results of macroscopic evaluation showed various organoleptic features. Anatomy of the selected plant parts was carried out. It showed a typical dicot structure as it revealed the presence of epidermal cells, crystals, trichomes, cuticle, mesophyll tissues, xylem, phloem, paracytic, and dicytic stomata. Anatomical study facilitates the detection of adulteration with inferior commercial varieties, exhausted drugs, cheaper natural substances, and chemicals. Stomatal number, types, and size of stomata, and palisade ratio of Myrtus communis were observed. These observations will be helpful in the preparation of taxonomic key for the identification of selected species. Powder drug study [scanning electron microscopy (SEM)] showed characteristics histological differentiation. The methods cited here can be measured as characteristics to identify and validate these drugs. 相似文献
32.
Fluorescence shell: a novel view of sclereid morphology with the Confocal Laser Scanning Microscope 总被引:1,自引:0,他引:1
Confocal Laser Scanning Microscopy (CLSM) was used to observe sclereids from stems of Avicennia germinans and from fruits of two species of pear (Pyrus calleryana "Bradford" and P. communis "Red Bartlett"). The images obtained from thick (25 to 100 microm) free-hand sections were, in certain respects, far superior to those obtained by other, more invasive and time-consuming microscopic techniques upon which previous reports of sclereid morphology were based. The cell wall surfaces, including the "internal" surfaces of the branched pit canals and cell lumens, were much accentuated with the techniques we describe, resulting in a "fluorescence shell" image, meaning the cell wall did not stain all the way through but instead only at the inner and outer wall surfaces, including the edges of ramiform pits. By controlling the time of staining with 1% aqueous Safranin O, or by changing the number of optical sections used in extended focus images, it was possible to get either a conventional view of the cell wall structure or a unique, three-dimensional view of the elaborate cell interconnections. Similar fluorescence shell images of sclereids were also obtained using a periodic-Schiff (PAS) staining system, but the stain was not as specific to sclereid cell walls as was the Safranin O stain. Particularly with the use of a narrow range band pass emission filter of 505-530 nm, the Safranin O staining may be more specific to lignin than reported in the literature. 相似文献
33.
采用正交设计优化鸭跖草多糖提取工艺.蒽酮-硫酸法测定不同生长环境鸭跖草茎、叶部位多糖的含量.试验结果表明,此方法简便,精密度及重现性较好,结果令人满意. 相似文献
34.
The influence of distillation parameters on the extraction of flavour compounds from the gin botanical Juniperus communis L. using vapour infusion was investigated. The optimum mix of conditions to extract the highest levels of certain compounds was established using a 33-factorial design. Quantification using solid-phase microextraction and gas chromatography coupled mass spectrometry, was performed measuring nine common flavour compounds. The greatest influence was the botanical ratio, whilst the least influential parameter was ethanol concentration for all compounds except terpinen-4-ol. Density functional theory calculations of quantitative structure–activity relationship properties for the flavour compounds were also undertaken to test for molecular influence on solvent extraction. The quantitative structure–activity relationship model showed the highest dipole moment for terpinen-4-ol and the lowest for γ-terpinene. © 2020 The Institute of Brewing & Distilling 相似文献
35.
大孔树脂分离纯化芦根中总酚酸的研究 总被引:1,自引:0,他引:1
目的:研究大孔树脂分离纯化芦根中总酚酸的工艺条件。方法:以芦根总酚酸的洗脱效果为考察指标,研究大孔树脂分离纯化的吸附性能及洗脱参数。结果:HPD500大孔树脂适宜芦根总酚酸的分离纯化,其再生能力良好,吸附过程符合Langmuir方程,洗脱液为pH8的80%体积分数乙醇溶液,获得纯度为0.98mg/g的总酚酸样品。结论:HPD500大孔树脂可用于芦根总酚酸的分离纯化。 相似文献
36.
鸭跖草抗氧化成分提取及其活性研究 总被引:3,自引:0,他引:3
采用1:2的氯仿:甲醇超声提取鸭跖草成分,并用石油醚、乙酸乙酯和正丁醇依次进行萃取,利用DPPH法、α-脱氧核糖法和铁氰化钾还原法进行抗氧化实验。同时与BHT和没食子酸(GA)2种合成抗氧化剂进行对照。结果显示乙酸乙酯提取物(EAF)具有较高的抗氧化活性。对其进行硅胶柱层析分离,得到6种纯化的组分(EAF1~EAF6),其中EAF4具有最高的抗氧化活性,在实验所测4个浓度下,清除DPPH自由基能力均比BHT强,在10μg/ml和50μg/ml浓度时,比GA强。其清除羟自由基能力在所有测定浓度下均比2种人工合成抗氧化剂强。其还原能力在所有测定浓度下均比BHT强,但比GA弱。 相似文献
37.
Olga Gortzi Stavros Lalas Ioanna Chinou John Tsaknis 《European Food Research and Technology》2008,226(3):583-590
The antioxidant and antimicrobial activity of Myrtus communis extract was determined before and after its encapsulation in liposomes of different composition. Evaluation of the sunflower
oil oxidation by the Rancimat stability test and malondialdehyde formation by HPLC were used to measure the antioxidant action
in comparison with common commercial antioxidants, such as butylated hydroxytoluene and α-tocopherol. The thermal-oxidative
decomposition of the samples, the modification of the main transition temperature for the lipid mixture and the splitting
of the calorimetric peak in the presence of the antioxidants were studied by differential scanning calorimetry. The size and
the surface charge of liposomes were also studied. The extract showed antioxidant and antimicrobial activity. Αt concentrations
up to 160 ppm, the extract showed superior activity than α-tocopherol. When the extract was encapsulated in liposomes, its
antioxidant as well as its antimicrobial activity proved to be superior from that of itself in pure form. 相似文献
38.
39.
Physical Properties, Sensory Attributes, and Consumer Preference of Pear Fruit Leather 总被引:1,自引:0,他引:1
ABSTRACT: Pear fruit leathers were prepared by drying a mixture of pear juice concentrate, pectin, corn syrup, and water at 70°C for 8 h. The effects of ingredients on texture, color, microbial growth, moisture content (MC), water activity (aw ), glass transition temperature (Tg ), and sensory attributes were investigated. Pectin was the most significant independent variable that affected the properties of interest. This was followed by initial moisture content and corn syrup. Glass transition temperature (Tg ) was not useful for predicting microbiological attributes but had strong correlations with instrumental and sensory hardness and chewiness. The results from partial least squares analysis (PLS) indicate instrumental hardness, chewiness, and cohesiveness could be used to predict their corresponding sensory attributes. The consumer liking of pear fruit leather could be increased by raising their fruit aroma, sweetness, tartness, and shininess. 相似文献
40.
1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase, the enzyme that catalyzes the final step in ethylene biosynthesis, was
recovered from pear (Pyrus communis L. cv. Blanquilla) fruit tissues with maximum activity at pH 6.5. The enzyme eluted as a single hydrophobic protein with
an estimated molecular weight of 37.9 kDa in a three-step FPLC chromatographic procedure. The sensitivity of the pear ACC
oxidase against a range of chemicals known by their inhibitory action on ethylene biosynthesis in vivo has been studied. Among
them, and in contrast to a previous proposal, α-(p-chlorophenoxy)isobutyric acid, a substance possessing antiauxin properties, did not inhibit the in vitro enzyme activity.
The significance of the results is discussed in terms of the nature and mechanism of the enzyme reaction.
Received: 12 May 1999 / Revised version: 7 July 1999 相似文献