scholarly journals Effects of mixtures of gallic acid, soya lecithin or catechin and ascorbic acid on the thermal decomposition of tocopherol in vegetable oils.

1991 ◽  
Vol 44 (1) ◽  
pp. 45-50
Author(s):  
Goro KAJIMOTO ◽  
Mariko SHIBATA ◽  
Yuki KANOMI ◽  
Hiromi YOSHIDA ◽  
Akira SHIBAHARA
Keyword(s):  
Thermal Decomposition ◽  
Ascorbic Acid ◽  
Gallic Acid ◽  
Vegetable Oils ◽  
Soya Lecithin

scholarly journals Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Helena Abramovič ◽  
Blaž Grobin ◽  
Nataša Poklar Ulrih ◽  
Blaž Cigić
Keyword(s):  
Ascorbic Acid ◽  
Chlorogenic Acid ◽  
Gallic Acid ◽  
Caffeic Acid ◽  
Sulfonic Acid ◽  
Epigallocatechin Gallate ◽  
The Other ◽  
Oh Groups ◽  
Standard Compound

Trolox, gallic acid, chlorogenic acid, caffeic acid, catechin, epigallocatechin gallate, and ascorbic acid are antioxidants used as standards for reaction with chromogenic radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) and 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS⋅+), and Folin–Ciocalteu (FC) reagent. The number of exchanged electrons has been analyzed as function of method and solvent. A majority of compounds exchange more electrons in FC assay than in ABTS and DPPH assays. In reaction with chromogenic radicals, the largest number of electrons was exchanged in buffer (pH 7.4) and the lowest reactivity was in methanol (DPPH) and water (ABTS). At physiological pH, the number of exchanged electrons of polyphenols exceeded the number of OH groups, pointing to the important contribution of partially oxidized antioxidants, formed in the course of reaction, to the antioxidant potential. For Trolox, small impact on the number of exchanged electrons was observed, confirming that it is more suitable as a standard compound than the other antioxidants.

Electrochemical Profile and Antioxidant Potential of Gallic Acid in Presence of Ascorbic Acid

2018 ◽  
pp. 171-180
Author(s):  
Dulce A. Flores-Maltos ◽  
Cristobal N. Aguilar ◽  
Ruth E. Belmares ◽  
Raúl Rodríguez ◽  
L. V. Rodríguez-Duran ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Gallic Acid ◽  
Antioxidant Potential

scholarly journals HPTLC method for simultaneous determination of ascorbic acid and gallic acid biomarker from freeze dry pomegranate juice and herbal formulation

2019 ◽  
Vol 27 (7) ◽  
pp. 975-980 ◽  
Author(s):  
Prawez Alam ◽  
Y.T. Kamal ◽  
Saleh Ibrahim Alqasoumi ◽  
Ahmed Ibrahim Foudah ◽  
Mohammed Hamed Alqarni ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Gallic Acid ◽  
Simultaneous Determination ◽  
Pomegranate Juice ◽  
Herbal Formulation ◽  
Hptlc Method

Thermal stability, antioxidant activity, and photo-oxidation of natural polyphenols

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Irina Volf ◽  
Ioana Ignat ◽  
Mariana Neamtu ◽  
Valentin Popa
Keyword(s):  
Thermal Stability ◽  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Gallic Acid ◽  
Vanillic Acid ◽  
Grape Seeds ◽  
Photo Oxidation ◽  
Degradation Rates ◽  
Ultraviolet C ◽  
Uv C

AbstractThe thermal stability (60°C, 80°C, 100°C), antioxidant activity, and ultraviolet C light (UV-C) stability of standard polyphenols solutions (catechin, gallic acid, and vanillic acid) and of vegetal extracts from spruce bark and grape seeds were investigated. Exposure of the standard solutions and vegetal extracts to high temperatures revealed that phenolic compounds were also relatively stable (degradations ranged from 15 % to 30 % after 4 h of exposure). The highest antioxidant activity was obtained for ascorbic acid and gallic acid followed by catechin and caffeic acid and the grape seeds. The results show that, after 3 h of UV-C exposure, approximately 40 % of vanillic acid, 50 % of gallic acid, and 83 % of catechin were removed. Similar degradation rates were observed for vegetal extracts, with the exception of the degradation of catechin (40 %) from grape seeds. In addition, the photo-oxidation of polyphenols in the presence of food constituents such as citric acid, ascorbic acid, sodium chloride, and sodium nitrate was assessed.

Thermal decomposition of ascorbic acid

1997 ◽  
Vol 305 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Gaston Vernin ◽  
Soundouss Chakib ◽  
Sonia M. Rogacheva ◽  
Tzvetan D. Obretenov ◽  
Cyril Párkányi
Keyword(s):  
Thermal Decomposition ◽  
Ascorbic Acid
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