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Extract Components (extract + component)
Selected AbstractsEnhanced coloration reveals high antioxidant potential in new sweetpotato cultivarsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2003Martin Philpott Abstract Sweetpotato is one of the world's most important food crops, particularly in developing countries. The storage roots have high carbohydrate and vitamin A contents and possess strong antioxidant potential, previously attributed to their hydroxycinnamic acid content. We report on several new purple sweetpotatoes developed for their high anthocyanin content. Although the antioxidant activity of purple sweetpotato extracts was greater than that of sweetpotato lacking anthocyanins, anthocyanins alone could not account for all the activity. Extract components were separated by 2D paper chromatography, and their relative contributions to antioxidant activity were determined. The antioxidant activity of the extracts from sweetpotato was shown to be due to both anthocyanins and hydroxycinnamic acids, additively. Neither the anthocyanin content nor the antioxidant activity of sweetpotato flesh was affected by common cooking methods. These findings may be important in the light of the health-protective properties attributed to both antioxidants and anthocyanins. Copyright © 2003 Society of Chemical Industry [source] Comparison of conventional and ultrasound-assisted extraction of carvone and limonene from caraway seedsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2004Smain Chemat Abstract Extraction experiments with hexane were carried out at atmospheric pressure in Soxhlet, conventional and ultrasound extractions of ,aked caraway seeds, and detailed results are given for two major plant extract components, carvone and limonene. The results indicate that carvone yield and plant extract quality are better in ultrasound extraction compared to those given by conventional methodology. Extraction rates of carvone and limonene reported that ultrasound-assisted extraction was 1.3,2 times more rapid, depending on temperature, than a conventional system, according to the rate constant obtained during the initial 10 minutes of extraction. Moreover, the SEM micrographs provided more evidence for the mechanical effects of ultrasound, mainly appearing on cell walls and shown by the destruction of cells, faulitating the release of their contents, in contrast to conventional maceration or extraction, which involve diffusion of plant extracts across glandular walls and causing cell rupture over longer time periods. Copyright © 2004 John Wiley & Sons, Ltd. [source] Inhibition of 304 stainless steel corrosion in acidic solution by Ferula gumosa (galbanum) extractMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2009M. Behpour Abstract The inhibition effect of the extract of galbanum (Ferula gummosa Boiss.) on the corrosion of 304 stainless steel in 2 M HCl solution was studied by weight loss measurements, Tafel polarization, and electrochemical impedance spectroscopy (EIS) methods. It was found that the inhibition efficiency (IE) increases as the extract concentration is increased. Tafel polarization method revealed the mixed mode inhibition of galbanum extract (GE) with predominant control of anodic reaction. The effect of temperature on the corrosion behavior of steel indicates that inhibition efficiency of the natural substance increases with the rise in temperature. At all temperatures, the adsorption of the extract components onto the steel surface was found to follow the Temkin adsorption isotherm. [source] Biological characterization of glutaraldehyde-modified Parietaria judaica pollen extractsCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2004I. Ibarrola Summary Background Allergoids are widely used in specific immunotherapy (SIT) for the treatment of IgE-mediated allergic diseases, but all techniques for standardization of conventional allergic extracts may not be appropriate for standardization of a glutaraldehyde (GA)-modified extract because of the unique characteristics of these extracts. Objective To assess an accurate methodology for standardization of chemically modified extracts. Methods GA-modified extracts from Parietaria judaica pollen were purified by diafiltration. Biochemical properties were investigated by determination of amino groups, chromatography, and SDS-PAGE. The IgE-binding activity was determined by skin prick test, enzyme allergosorbent test inhibition, basophil activation, and histamine release tests. Peripheral blood mononuclear cells (PBMCs) from P. judaica pollen-allergic subjects were stimulated with either native or allergoid extracts, and proliferation was measured. Results Biochemical data indicated a high degree of allergen polymerization resulting in extract components higher than 100 kDa. IgE-binding activity, both in vivo and in vitro, was reduced by more than 99.8%. Both allergen and allergoid induced PBMC proliferation and synthesis of blocking IgG antibodies at similar rates. Moreover, no evidence of introduction of new determinants by chemical modification was found. Conclusions The preparation of GA-modified extracts by diafiltration is faster and more reliable than previous chromatographic methods. These modified extracts have drastically reduced their allergenicity while maintaining their immunogenicity, and therefore they can be used in safer and shortened schedules of SIT. [source] | ||||||||||