On the nature and reactivity of active oxygen species formed from O2 and N2O on VOx/MCM-41 used for oxidative dehydrogenation of propane

There are active oxygen species that contribute to oxidative coupling or the partial oxidation during the oxidative dehydrogenation of methane when using solid oxide catalysts, and those species have not been definitively identified. In the present study, we clarify which of the active oxygen species affect the oxidative dehydrogenation of methane by employing photo-catalysts such as TiO2 or WO3, which generate active oxygen from UV-LED irradiation conditions under an oxygen flow. These photo-catalysts were studied in combination with Sm2O3, which is a methane oxidation coupling catalyst. For this purpose, we constructed a reaction system that could directly irradiate UV-LED to a solid catalyst via a normal fixed-bed continuous-flow reactor operated at atmospheric pressure. Binary catalysts prepared from TiO2 or WO3 were either supported on or kneaded with Sm2O3 in the present study. UV-LED irradiation clearly improved the partial oxidation from methane to CO and/or slightly improved the oxidative coupling route from methane to ethylene when binary catalysts consisting of Sm2O3 and TiO2 are used, while negligible UV-LED effects were detected when using Sm2O3 and WO3. These results indicate that with UV-LED irradiation the active oxygen of O2− from TiO2 certainly contributes to the activation of methane during the oxidative dehydrogenation of methane when using Sm2O3, while the active oxygen of H2O2 from WO3 under the same conditions afforded only negligible effects on the activation of methane.

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Characterization and functional properties of new everbearing strawberry (Fragaria x ananasa Duch.) cultivar, ‘Summertiara’ berries

Functional Foods in Health and Disease ◽

10.31989/ffhd.v4i1.27 ◽

2014 ◽

Vol 4 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Takeshi Nagai ◽

Misuzu Tamai ◽

Masato Sato ◽

Yasuhiro Tanoue ◽

Norihisa Kai ◽

...

Keyword(s):

Vitamin C ◽

Sensory Evaluation ◽

Functional Properties ◽

Active Oxygen Species ◽

Active Oxygen ◽

Antihypertensive Activity ◽

Oxygen Species ◽

Total Anthocyanins ◽

Strawberry Cultivar ◽

The Stability

Background: In recent years, a new everbearing strawberry cultivar, ‘Summertiara’ was cultivated to supply the strawberries in pre-harvest season from July to October in Japan. For highly research and development of processing of this cultivar, ‘Summertiara’ berries, the objective of this study was to characterize these berries, with relation to chemical parameters, total phenols, total flavonoids, total vitamin C, and total anthocyanins, and was to investigate the solubility and the stability of anthocyanins from the berries. Moreover, the functional properties such as antioxidative activity, active oxygen species scavenging activity, and antihypertensive activity were also evaluated.Methods: Chemical analysis, colour measurement, and sensory evaluation of new everbearing strawberry cultivar, ‘Summertiara’ berries were performed. Next, the solubility of anthocyanins from the berries and stability of these against pH, temperature, and an incandescent lighting were investigated. Moreover, functional properties of the extracts prepared from berries were elucidated using 5 different methods.Results: The contents of water, proteins, lipids, carbohydrates, and ash were the same as those of other cultivar berries. The sugar-acid ratio in the berries was low; these were acidulous. By sensory evaluation, the main factors were vivid red colour, aroma, and acidity. The berries were rich in phenols, flavonoids, vitamin C, and anthocyanins. The anthocyanins of the berries became unstable by heat treatment and light exposures such as visible rays. On the other hand, the extracts prepared from the berries showed the functionalities such as antioxidant activity, active oxygen species scavenging activities, and antihypertensive activity. Conclusions: The strawberry cultivar, ‘Summertiara’ berries were the most suitable for processing ingredient of strawberry-derived products with superior health promoting functionalities.Keywords: Summertiara, everbearing strawberry cultivar, characterization, sensory evaluation, color and storage, functional property

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