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排序方式: 共有704条查询结果,搜索用时 31 毫秒
31.
Mulinacci N Innocenti M La Marca G Mercalli E Giaccherini C Romani A Erica S Vincieri FF 《Journal of agricultural and food chemistry》2005,53(23):8963-8969
Solid olive residues (SOR) are byproducts of the olive-milling process, but they have an increasing importance in the pharmaceutical industry due to their rich content of biophenols. Such compounds are studied widely for their antioxidant and antimicrobial activities, but there is a lack of information about their quantitative recovery. This research highlighted the key role played both by the selection of the cultivar and by the degree of olive fruit ripening on the phenolic content on the SOR. The extraction methods were selected to reach the best quantitative results mainly using a safe food solvent. In light of the results the Soxhlet extraction with ethanol could be proposed as preferential for a higher recovery of verbascoside and its analogues. 相似文献
32.
Natera R Castro R de Valme García-Moreno M Hernández MJ García-Barroso C 《Journal of agricultural and food chemistry》2003,51(11):3345-3351
The phenolic composition, aroma compounds, and organic acid content of 83 vinegars have been determined. Multivariate analysis techniques have been used to classify these vinegar samples according to raw material (white wine, red wine, apple, honey, alcohol, balsamic, and malt) and production process (with and without aging in wood). Cluster analysis grouped the samples according to production process. Only apple and balsamic vinegars were separated from wine vinegars. Alcohol, honey, and malt vinegars were grouped with no aged wine vinegars. Linear discriminate analysis allowed a 88% differentiation according to raw material and 100% according to aging in wood. Besides, from the results obtained, a major role of the volatile compounds in the differentiation of the vinegar samples according to their aging period in wood can be seen. 相似文献
33.
Determination of antioxidant power of red and white wines by a new electrochemical method and its correlation with polyphenolic content 总被引:2,自引:0,他引:2
Alonso AM Domínguez C Guillén DA Barroso CG 《Journal of agricultural and food chemistry》2002,50(11):3112-3115
A new method for measuring the antioxidant power of wine has been developed based on the accelerated electrochemical oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). The calibration (R = 0.9922) and repeatability study (RSD = 7%) have provided good statistical parameters. The method is easy and quick to apply and gives reliable results, requiring only the monitoring of time and absorbance. It has been applied to various red and white wines of different origins. The results have been compared with those obtained by the total antioxidant status (TAS) method. Both methods reveal that the more antioxidant wines are those with higher polyphenolic content. From the HPLC study of the polyphenolic content of the same samples, it is confirmed that there is a positive correlation between the resveratrol content of a wine and its antioxidant power. 相似文献
34.
Determination of cadmium, copper, and lead in sodium chloride food salts by flame atomic absorption spectroscopy 总被引:1,自引:0,他引:1
M J Alvarez De Eulate R Montoro N Yba?ez M De La Guardia 《Journal of the Association of Official Analytical Chemists》1986,69(5):871-873
A method for determination of Cd, Cu, and Pb in sodium chloride food salt samples has been developed. It consists of extraction in 4-methyl-2-pentanone of the complexes formed with ammonium pyrrolidine dithiocarbamate and further analysis of the extracts by flame atomic absorption spectroscopy. Detection limits in ng/g salt were 0.2 for Cd, 0.7 for Cu, and 10.0 for Pb. The coefficients of variation of 12 independent analyses were 13% for Cd (at a level of 0.4 ppb), 18% for Cu (1.6 ppb), and 5% for Pb (40 ppb). The recoveries were 100 +/- 0% for Cd, 115 +/- 14% for Cu, and 100 +/- 13% for Pb. 相似文献
35.
36.
The production of agglutinins to Salmonella typhi was studied in the opossum embryo in the period immediately before and after the development of thymic and lymph node lymphoid tissue. Antibody was found only in embryos older than 8 days which corresponds to an 8- to 10-week human embryo in terms of organogenesis and is the earliest stage at which antibody production has been recorded. 相似文献
37.
38.
Myoglobin diffusion in bovine heart muscle 总被引:15,自引:0,他引:15
The rotational mobility of myoglobin in situ was determined by proton nuclear magnetic resonance line width measurements of a characteristic myoglobin resonance observed in bovine heart muscle spectra. The protein diffuses intracellularly at nearly half the rate observed in dilute solution. This high mobility allows the oxygenated form of myoglobin to contribute significantly to the overall diffusive flux of oxygen in respiring heart muscle. 相似文献
39.
喇国玮 《山东省农业管理干部学院学报》2002,(4)
学风问题是关系到中国共产党的兴衰和社会主义事业成败的重大问题。新时期,我们要进一步加强学风建设, 大力弘扬马克思主义学风,坚持理论联系实际,推动社会主义现代化建设事业不断发展。 相似文献
40.
Laü LJ 《Science (New York, N.Y.)》1976,194(4266):715-716