The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Chang Y. Lee - One of the best experts on this subject based on the ideXlab platform.
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Effects of heat processing and storage on flavanols and sensory qualities of green tea beverage
Journal of Agricultural and Food Chemistry, 2000Co-Authors: Li Fei Wang, Dong Man Kim, Chang Y. LeeAbstract:This research was conducted to understand the effects of heat processing and storage on flavanols and sensory qualities of green tea extract. Fresh tea leaves were processed into steamed and roasted green teas by commercial methods and then extracted with hot water (80 degrees C) at 1:160 ratio (tea leaves/water by weight). Green tea extracts were heat processed at 121 degrees C for 1 min and then stored at 50 degrees C to accelerate chemical reactions. Changes in flavanol composition and sensory qualities of green tea extracts during processing and storage were measured. Eight major flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin Gallate, catechin Gallate, epigallocatechin Gallate, and gallocatechin Gallate) were identified in the processed tea extract. Among them, epigallocatechin Gallate and epigallocatechin appeared to play the key role in the changes of sensory qualities of processed green tea beverage. The steamed tea leaves produced a more desirable quality of processed green tea beverage than the roasted ones.
T W Wu - One of the best experts on this subject based on the ideXlab platform.
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evidence of trolox and some Gallates as synergistic protectors of erythrocytes against peroxyl radicals
Biochemistry and Cell Biology, 1998Co-Authors: J. Wu, Donald A.g. Mickle, L H Zeng, H. Sugiyama, T W WuAbstract:The peroxidation of human erythrocytes induced by peroxyl radical initiator and its inhibition by several Gallate esters (e.g., propyl, methyl, ethyl) and Trolox (a more polar analogue of vitamin E) have been studied. The antioxidant activity was determined on erythrocytes against hemolysis generated by a thermal activator, 2,2prime-azobis-(2-amidinopropane)dihydrogenchloride. It was found that propyl Gallate and its two analogues were more effective than Trolox in preventing cell lysis. However, the combination of Gallate esters and Trolox produced a protective effect exceeding the arithmetic sum of their individual contributions. These perceived synergisms occur at more than one level of Trolox at a given level of a Gallate ester.Key words: Trolox, Gallates, synergism, peroxyl radicals.
Ravindra Pandey - One of the best experts on this subject based on the ideXlab platform.
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electronic structure of spinel oxides zinc aluminate and zinc Gallate
Journal of Physics: Condensed Matter, 1999Co-Authors: Suresh K Sampath, D G Kanhere, Ravindra PandeyAbstract:The electronic structure of zinc aluminate (ZnAl2O4) and that of zinc Gallate (ZnGa2O4) were studied by the self-consistent tight-binding linearized muffin-tin orbital method with the atomic sphere approximation. The calculated results predict these zinc-based spinel oxides to be direct-gap materials. The direct gap at is found to be 4.11 eV for ZnAl2O4 and 2.79 eV for ZnGa2O4. With reference to the calculated band gap of 5.36 eV for MgAl2O4, the systematic decrease in the gap is attributed to the presence of 3d orbitals of Zn and Ga and the associated p-d hybridization in the upper valence band of zinc aluminate and Gallate. Comparison of the contour maps of the electron localization function of ZnAl2O4 and ZnGa2O4 with that of MgAl2O4 clearly shows the bonding to be less ionic in the zinc-based spinel oxides. Finally, the calculations yield a smaller electron effective mass for zinc Gallate as compared to that for zinc aluminate, suggesting a higher mobility of electrons in Gallate.
Susana Gorzalczany - One of the best experts on this subject based on the ideXlab platform.
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Potential usefulness of methyl Gallate in the treatment of experimental colitis
Inflammopharmacology, 2017Co-Authors: María Laura Anzoise, Angeles Rodríguez Basso, Julieta Sofía Mauro, Graciela López Ordieres, Aparicio Carranza, Susana GorzalczanyAbstract:Methyl Gallate is a gallotannin widely distributed in nature. Previous studies have demonstrated its antioxidant, anti-inflammatory, antimicrobial and anti-tumor activities. In the present study, the activity of methyl Gallate on experimental models of inflammatory bowel disease has been investigated. Experimental colitis was induced in Sprague–Dawley rats through the intracolonic instillation of an acetic acid solution (2 mL, 4% v/v). Methyl Gallate (100 and 300 mg/kg, p.o.) and the reference drug mesalazine (100 mg/kg, p.o.) were tested. Methyl Gallate induced a significant reduction in the colon weight/length ratio and macroscopic lesion score. Besides, the malondialdehyde content and the GSSG/GSH ratio were remarkably decreased. Furthermore, the administration of methyl Gallate reduced the expression of COX2, IL-6, TNFα and the severity of microscopic tissue damage induced by acetic acid, while the mean goblet cell density was significantly higher in both the group treated with methyl Gallate and the one treated with mesalazine, in comparison with untreated animals. The Na+K+ATPase pump activity was recovered in treated groups (control: 827.2 ± 59.6, colitis: 311.6 ± 54.8, methyl Gallate 100 mg/kg: 642.2 ± 175.0, methyl Gallate 300 mg/kg: 809.7 ± 100.6, mesalazine: 525.3 ± 81.7). Methyl Gallate was also found to induce a significant reduction in the castor oil-induced intestinal motility in Swiss mice, decreasing the peristalsis by 74.5 and 58.82% at 100 and 300 mg/kg p.o., respectively. This compound also antagonized the jejunum contractions induced by Ach and CaCl2. This study demonstrates that methyl Gallate exerts beneficial effects in a preclinical model of intestinal disorders.
Li Fei Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of heat processing and storage on flavanols and sensory qualities of green tea beverage
Journal of Agricultural and Food Chemistry, 2000Co-Authors: Li Fei Wang, Dong Man Kim, Chang Y. LeeAbstract:This research was conducted to understand the effects of heat processing and storage on flavanols and sensory qualities of green tea extract. Fresh tea leaves were processed into steamed and roasted green teas by commercial methods and then extracted with hot water (80 degrees C) at 1:160 ratio (tea leaves/water by weight). Green tea extracts were heat processed at 121 degrees C for 1 min and then stored at 50 degrees C to accelerate chemical reactions. Changes in flavanol composition and sensory qualities of green tea extracts during processing and storage were measured. Eight major flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin Gallate, catechin Gallate, epigallocatechin Gallate, and gallocatechin Gallate) were identified in the processed tea extract. Among them, epigallocatechin Gallate and epigallocatechin appeared to play the key role in the changes of sensory qualities of processed green tea beverage. The steamed tea leaves produced a more desirable quality of processed green tea beverage than the roasted ones.
