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The present study was conducted to develop subcritical water extraction (SWE) of Echinacea purpurea flowers. The influence of temperature and extraction time on quality of extracts considering total phenols content, total flavonoids content, antioxidant capacity and extraction yield, was determined. Optimized extraction parameters for maximised investigated responses were as follows: 147.56 °C and 8.43 min. The experimental values agreed with the values predicted, thus indicating the adequacy of central composite experimental design for modelling the SWE of bioactive compounds from E. purpurea. Results of the study also highlighted the potential application of E. purpurea subcritical water extracts as a source of valuable bioactive compounds. 相似文献
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Shmuel Borenstain Gil Bar-Haim Keren Goldshtein Gili Cohen-Taguri 《Color research and application》2020,45(6):1153-1169
Investigation of ink formulation options with the purpose to obtain color-gamut-optimal set of Cyan Magenta and Yellow CMY inks is reported. Implementation of the thickness dependent Kubelka-Munk model on multiple ink layers having different and well-defined thicknesses, provides characteristic absorption and scattering (K, S ) spectra of the ink ingredients. These data enable accurate computation of the reflectance spectrum and thus the L*a*b* color coordinates for any given ink thickness or substrate. Pigment materials investigated are quinacridone as magenta, copper-phthalocyanine as cyan, and arylide yellow. Scaling the peak of the absorption band to the number of molecules per unit area for the specific pigments studied in this article provides the molar extinction coefficients, 1.21 × 104 , 4.7 × 104 , and 3.3 × 104 cm2/millimole respectively, regardless of the different ink formulations used, in accord with Avogadro's principle. Having a set of three pairs of K, S spectra is used to compute the color gamut of any CMY color combination in the L*a*b* space as a function of ink layer thickness and formulation. Using an iterative algorithm, a color-gamut-optimal set of CMY inks is obtained. 相似文献
25.
Effect of chitosan on Bacillus cereus inhibition and quality of cooked rice during storage 下载免费PDF全文
Chitsiri Rachtanapun Juthamas Tantala Phatthranit Klinmalai Savitree Ratanasumawong 《International Journal of Food Science & Technology》2015,50(11):2419-2426
Improper cooling of cooked rice at an inappropriate temperature or leaving cooked rice at room temperature can cause food poisoning attributed to Bacillus cereus. Natural food preservative of either squid or crab polymer chitosan solution was added to examine their antibacterial properties against Bacillus cereus in cooked rice during storage at 37 and 4 °C. Both types of chitosan could retard the growth of B. cereus and total aerobic counts in cooked rice stored at 37 °C up to 1 day. In addition, the effect of chitosans on the physical and textural properties of cooked rice during storage was studied. Both chitosans slightly increased the moisture content of cooked rice. However, chitosans had no effect on the whiteness and hardness of cooked rice during storage (P > 0.05). Therefore, both chitosans have a potential to be used as food preservative for cooked rice with no negative effects on rice quality. 相似文献
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《Ceramics International》2022,48(21):31265-31272
Bismuth layer structured Na0.5Bi4.5Ti4O15 (NBT) ferroelectric is one of the most promising materials for potential applications at high temperature. However, it is challenged to achieve a balance between high Curie temperature piezoelectric coefficient and excellent thermal stability for NBT piezoceramics. Here, through chemical modification at the A site of NBT with Ca2+, novel (Na0.5Bi0.5)1-xCaxBi4Ti4O15 piezoceramics with excellent properties fabricated by solid state reaction were studied. After doping of Ca2+, the Curie temperature TC increased from 648 °C to 662 °C while the piezoelectric coefficient d33 increased from 14 pC/N to 22 pC/N which can be attributed to the intrinsic contribution of TiO6 octahedral lattice distortion (tilting and rotation) and the extrinsic contribution of the increased density of domain walls. The composition of (Na0.5Bi0.5)0.95Ca0.05Bi4Ti4O15 ceramics with x = 0.05 has the optimal performance with high TC of 655 °C, large d33 of 22 pC/N, high electrical resistivity ρ close to 107 Ω cm at 500 °C and especially excellent thermal stability of d33 only about 5% reduction after being annealed at 625 °C. The work effectively reveals the great potential of CNBT-5 ceramics for high-temperature piezoelectric applications. 相似文献
27.
Pierre Santucci Christina Dedaki Alexandros Athanasoulis Laura Gallorini Anaïs Munoz Dr. Stéphane Canaan Dr. Jean-François Cavalier Dr. Victoria Magrioti 《ChemMedChem》2019,14(3):349-358
In the quest for new antibacterial agents, a series of novel long- and medium-chain mono- and disubstituted β-lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus, M. marinum, and M. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β-lactones synthesized, only 3-hexadecyloxetan-2-one (VM005) exhibited promising activity against M. abscessus, whereas most of the β-lactones showed interesting activities against M. marinum, similar to that of the classical antibiotic, isoniazid. Regarding M. tuberculosis, six compounds were found to be active against this mycobacterium, with β-lactone VM008 [trans-(Z)-3-(hexadec-7-en-1-yl)-4-propyloxetan-2-one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents. 相似文献
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Supaluk Krittanai Hathairat Buraphaka Seiichi Sakamoto Waraporn Putalun 《International Journal of Food Science & Technology》2021,56(11):5843-5852
Licorice is an herbal plant in the Leguminosae family, and its roots and rhizomes are used as sweeteners in food and confectionery products. Moreover, it has a distinct inflammatory activity. In the present study, a sample pre-treatment method to induce the deglycosylation of active metabolites in callus cultures of Glycyrrhiza inflata (GI) and Glycyrrhiza glabra (GG) was developed. The results of the method evaluation showed the biotransformation of ononin to formononetin, a rare flavonoid found in trace amounts in licorice. The magnitude of enhancement was 3- and 19-fold in the GI and GG samples, respectively. Moreover, the anti-inflammatory activity assay showed that the potency of the sample pre-treatment group was higher than that of the untreated group because it exerted an enhanced suppression of cyclo-oxygenase 2 (COX-2), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) gene expression. This is the first report on the anti-inflammatory activity of licorice callus, which has the potential to be utilised as a functional food for health promotion. These findings support the idea of using sample preparation to impart nutraceutical properties to plant products. 相似文献
30.
Kamalesh Pal Amitava Mukherjee Md. Motin Seikh Parthasarathi Bera Arup Gayen 《Ceramics International》2021,47(10):14798-14808
Synthesis of nanocrystalline pristine and Mn-doped calcium copper titanate quadruple perovskites, CaCu3?xMnxTi4?xMnxO12 (x = 0, 0.5, and 1.0) by modified citrate solution combustion method has been reported. Powder X-ray diffraction patterns attest the phase purity of the perovskite materials. Average particle sizes of all the materials obtained from the Scherrer's formula are in the range of 55–70 nm. The specific surface areas for all the perovskites obtained from BET isotherms are found to be low as expected for the condensed oxide systems and fall in the range of 13–17 m2 g?1. Transmission electron microscopy studies show a reduction in particle size of CaCu3Ti4O12 with increase in Mn doping. Ca and Ti are present in +2 and +4 oxidation states in all the materials as demonstrated by X-ray photoelectron spectroscopy analyses. Cu2+ gets reduced in CaCu3Ti4O12 with higher Mn content. Mn is observed to be present only in +3 oxidation state. All the materials have been examined to be active in CO oxidation as well as H2 production from methanol steam reforming. CaCu3Ti4O12 with ~14 at.% Mn is found to show best catalytic activities among these materials. A comprehensive analysis of the catalytic activities of these perovskites toward CO oxidation and H2 production from MSR reveal the cooperative activity of copper-manganese in the doped perovskites and it is more effective at lower manganese content. 相似文献