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排序方式: 共有771条查询结果,搜索用时 984 毫秒
61.
Yasodha Sivasothy Wong Keng Chong Abdul Hamid Ibrahim M. Eldeen Shaida Fariza Sulaiman Khalijah Awang 《Food chemistry》2011
The essential oils obtained by hydrodistilation of the leaves and rhizomes of Zingiber officinale var. rubrum Theilade were analysed by capillary GC and GC–MS. Forty-six constituents were identified in the leaf oil, while 54 were identified in the oil from the rhizomes. The leaf oil was clearly dominated by β-caryophyllene (31.7%), while the oil from the rhizomes was predominantly monoterpenoid, with camphene (14.5%), geranial (14.3%), and geranyl acetate (13.7%) the three most abundant constituents. The evaluation of antibacterial activities using the micro-dilution technique revealed that both the leaf and rhizome oils were moderately active against the Gram-positive bacteria Bacilluslicheniformis, Bacillus spizizenii and Staphylococcus aureus, and the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Pseudomonas stutzeri. 相似文献
62.
Mohsen Gavahian Asgar Farahnaky Mahsa Majzoobi Katayoun Javidnia Mohammad Jamal Saharkhiz Gholamreza Mesbahi 《International Journal of Food Science & Technology》2011,46(12):2619-2627
Ohmic‐assisted hydrodistillation (OAHD) is a combination of ohmic heating and distillation, and could be considered as a novel method for the extraction of essential oils. Major problems with traditional methods are long extraction time and lower purity of the extract. In this study, OAHD was applied as an economic and green technology for the extraction of essential oils from Zataria multiflora Boiss. (Shirazi thyme) aerial parts and the results were compared to those obtained from hydrodistillation (HD) as a conventional method. The results showed that OAHD method had the extraction time of 32.21 ± 2.59 min while this value was about 57.21 ± 2.33 min for hydrodistillation (HD). Scanning electron micrographs of thyme leaves showed a sudden eruption of essential oil glands and their surrounding area for OAHD samples. GC–MS analysis indicated that both methods of OAHD and HD can extract the same compounds. 相似文献
63.
Chemical composition and antifungal activity of essential oils from three Himalayan Erigeron species
Three Himalayan Erigeron (Asteraceae) species viz Erigeron mucronatus, Erigeron annuus and Erigeron karwinskianus growing in sub-alpine region revealed occurrence of isomeric polyacetylenic constituents viz., matricaria and lachnophyllum esters which accounted for 83.3%, 69.3% and 30.1% of the essential oils from these species, respectively, in addition to mono- and sesquiterpenoids as minor constituents. The antifungal activity tested by poisoned food (PF) techniques against Fusarium oxysporum, Helminthosporium maydis, Rhizoctonia solani, Alternaria solani and Sclerotinia sclerotiorum demonstrated significant inhibition of the mycelial growth of all strains (p < 0.05). The oils (500 μg/mL) showed significant antifungal effect against tested fungi in the growth inhibition range of 37.6–85.5% with respective IC50 values ranging from 88.8 to 660.0 μg/mL as compared to standard fungicides (100% inhibition) with IC50 value in the range of 32.2–129.4 μg/mL. Significant inhibition of spore germination was noticed for F. oxysporum, Curvularia lunata and Albugo candida which were highly susceptible to E. annuus oil with their IC50 values 120.7, 253.5 and 300.4 μg/mL, respectively. Thus, the results obtained in this study demonstrate the potential of essential oils from Himalayan Erigeron species as non-toxic, eco-friendly and biodegradable natural fungicides. 相似文献
64.
Vivek K. Bajpai Atiqur Rahman Ung Kyu Choi Sun Joo Youn Sun Chul Kang 《Food chemistry》2007,105(3):1061-1066
The aim of this work was to examine the chemical composition of the essential oil and various solvent extracts isolated from the floral cone of Metasequoia glyptostroboides Miki ex Hu and to test their efficacy against a diverse range of organisms comprising food spoilage and food-borne pathogenic bacteria. The chemical composition of essential oil isolated by hydrodistillation was analysed by GC-MS. It was determined that 59 compounds, which represented 97.06% of total oil, were present in the oil. The oil contains mainly α-pinene (29.54%), totarol (9.37%), α-thujene (8.63%), bornylene (8.63%), β-caryophyllene (4.40%), totarol acetate (3.98%), δ-3-carene (3.19%) and 2-β-pinene (2.25%). The oil was found containing mainly the oxygenated mono- and sesquiterpenes and their respective hydrocarbons. Antibacterial activity of essential oil, methanol extract and various organic sub-fractions of methanol extract of M. glyptostroboides was determined in vitro using agar diffusion method and MIC determination test against eleven (four Gram-positive, seven Gram-negative) bacterial strains including food spoilage and food-borne pathogens. The essential oil (5 μl/ml, corresponding to 1000 ppm/disc), methanol extract and various organic sub-fractions (7.5 μl/ml, corresponding to 1500 ppm/disc) of M. glyptostroboides exhibited great potential of antibacterial activity against four Gram-positive bacteria such as Bacillus subtilis (ATCC 6633), Listeria monocytogenes (ATCC 19166), Staphylococcus aureus (KCTC 1916), S. aureus (ATCC 6538) and one Gram-negative bacterium, Pseudomonas aeruginosa (KCTC 2004). The zones of inhibition of different concentrations of essential oil, methanol extract and its derived various organic sub-fractions against the tested bacteria were found in the range of 10 ∼ 20 mm and the MIC values were recorded between 125 and 1000 μg/ml. This study shows that M. glyptostroboides mediated essential oil and extracts can be applied in food industries as a natural preservatives or flavoring additives to control food spoilage and food-borne pathogenic bacteria causing severe destruction in food. 相似文献
65.
The aerial parts of Satureja hortensis, cultivated in Iran (Research Station of Alborz, Karaj), were collected at the full-flowering stage and dried by three different drying methods (sun-drying, shade-drying and oven-drying at 45 °C). The essential oils of every treatment were obtained by hydro-distillation of the aerial parts. In addition, the essential oil of shade-dried sample was obtained by two other distillation methods (water- and steam-distillation and direct steam-distillation). The oils were analyzed by capillary GC and GC–MS. Statistical analysis showed no significant difference between oil yield (w/w) of the oven-dried sample (1.06%) compared to shade-dried (0.94%) and sun-dried (0.87%). The oil content of the shade-dried sample, obtained by hydro-distillation, was higher (0.94%) than that of the steam-distilled (0.27%). Twenty-three components were identified in the oil of S. hortensis in the different drying methods, including carvacrol (46.0–48.1%) and γ-terpinene (37.7–39.4%) as main components. Seventeen compounds were characterized in the oils of different distillation methods, including carvacrol (12.3–46%) and γ-terpinene (37.7–70.4%). Although the drying methods had no significant effect on oil composition of S. hortensis, the distillation changed the percentage of main components sharply (significant at 1%). The steam-distillation method produced the lowest amount of carvacrol and highest amount of γ-terpinene. The results showed that extraction by hydro-distillation gave the best results for S. hortensis, based on oil yield and carvacrol percentage. 相似文献
66.
67.
福建闽中土堡作为中国传统防御性乡土建筑的一种形式,是中华民族的先民在历史长河中营造实践的结晶。本文把尤溪县聚奎堡作为研究对象,通过对其因地制宜的布局形式、独特得建筑造型、独具匠心的防御体系以及富有层次的空间变化,来展示土堡建筑独特的文化底蕴和艺术内涵,并提出传统闽中土堡建筑作为一种宝贵的历史遗存,势必要得到保护和继承,创造适应于现代生活的环境,延续文脉,弘扬地域特色。 相似文献
68.
James R. Chambers Joshua Gong 《Food research international (Ottawa, Ont.)》2011,44(10):3149-3159
Salmonella control has been one of the major tasks in poultry production to ensure poultry food safety. Effective control is difficult due to the numerous potential sources of Salmonella infection and product contamination in integrated poultry enterprises. In addition, the lack of clinical symptoms of infection in poultry further increases the challenge of achieving proper control. The chicken intestinal microbiota plays an important role in the host health and its modulation has achieved considerable success in the past to reduce Salmonella contamination at the farm level. The use of pro/prebiotics has been the major approach in modulating the microbiota. There is increased consumer pressure demanding the reduction of antibiotics in feed and elimination of Salmonella from poultry and their products. Modulation of the chicken intestinal microbiota continues to offer an attractive option for natural control and sustainable chicken production. In this article, the role of intestinal microbiota in chicken health and the progress in microbiota modulation for Salmonella control have been reviewed. Major technologies for modulating intestinal microbiota, such as the use of probiotics, prebiotics, or phytobiotics (essential oils) and phage therapy that have either received much attention in research and application or demonstrated promise in the development of novel techniques for Salmonella control, are discussed. The potential and drawbacks of each of these are also critically reviewed. 相似文献
69.
Objective
To investigate blood lead level and its relationship to copper, zinc, calcium, magnesium and iron in the children aged 0 to 14 years old from Beijing, China.Methods
We classified 3181 children into one of the four groups: Group A (n = 783, < 1 year old); Group B (n = 1538, 1-3 years old); Group C (n = 443, 3-7 years old); and, Group D (n = 417, 7-14 years old). All these metal elements were determined by atomic absorption spectrometry.Results
The blood lead level was 0.207 ± 0.105 μmol/L. There was a significant gender difference for zinc (P < 0.05) in Group C, and there was also a significant gender difference for copper (P < 0.05) and lead (P < 0.05) in Group D. Controlling for gender and age, we observed that there was a negative correlation of lead with zinc (r = − 0.052, P < 0.01), magnesium (r = − 0.042, P < 0.05) and iron (r = − 0.031, P < 0.05), respectively. Furthermore, in the children aged 1-7 years old, we also found there was a negative linear correlation of lead with zinc, magnesium and iron, respectively (P < 0.01).Conclusion
Blood lead level in children from Beijing was markedly decreased. And deficiency of zinc, magnesium and iron is related to the elevated blood lead level in the children aged 1-7 years. 相似文献70.
肉味及海鲜味香精调香中常用的香原料 总被引:7,自引:0,他引:7
本文综述了各种单体香料、辛香料、精油及增香剂在肉味及海鲜味香精中的应用。 相似文献