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Composition of phenolic compounds and antioxidant activity of commercial aqueous smoke flavorings
No full textThe antioxidant activity of 12 aqueous commercial smoke flavorings used in the food industry was
determined by two methods: bleaching of the carotenoid crocin and scavenging of the DPPH radical.
The reaction with the DPPH radical was evaluated by calculating the effective concentration (EC50)
and the antiradical efficiency (AE). A gas chromatography-mass spectrometry method was, moreover,
used for the determination of 2-methoxyphenols, 2,6-dimethoxyphenols, and dihydroxybenzenes.
The methoxyphenols were extracted from the aqueous smoke by dichloromethane, and also the
residue aqueous phase was analyzed to determine the more water-soluble dihydroxybenzenes. The
recovery and the repeatability of the method are reported. The total phenolic concentrations of the
smoke flavorings showed a wide range, from about 1000 to 25000 mg/kg. Considering the three
classes of compounds, the concentrations were about 300–3000 mg/kg for the 2-methoxyphenols,
200–11000 mg/kg for the 2,6-dimethoxyphenols, and 140–10000 mg/kg for the dihydroxybenzenes.
The range of the antioxidant activities of the smoke flavorings was wide, reflecting the wide range of
the phenolic concentrations. Good correlations were obtained between the total phenolic concentration
and the antioxidant activities determined by both the DPPH and crocin assays
Comparative Evaluation of the Antioxidant Capacity of Smoke Flavouring Phenols by Crocin Bleaching Inhibition, DPPH Radical Scavenging and Oxidation Potential
No full textThe antioxidant capacity of the main phenolic compounds present in wood smoke and smoke flavourings used in the food industry was
investigated by three methods, based on a kinetic and thermodynamic approach: the bleaching of the carotenoid crocin, the scavenging of
the DPPHradical, and the determination of the oxidation potential. The reaction with the DPPH radical was evaluated calculating the effective
concentration (EC50) and the antiradical efficiency (AE). The compounds tested were 2-methoxyphenols (guaiacol, 4-methylguaiacol,
4-ethylguaiacol, 4-vinylguaiacol, 4-propylguaiacol, eugenol, isoeugenol, vanillin, acetovanillone, 2-propiovanillone), 2,6-dimethoxyphenols
(syringol, 4-methylsyringol, 4-allylsyringol, syringaldehyde, acetosyringone) and dihydroxybenzenes (catechol, 3-methylcatechol, 4-methylcatechol,
3-methoxycatechol and hydroquinone). The trend in antioxidant capacity was similar in all the three methods, with dihydroxybenzenes
> 2,6-dimethoxyphenols > 2-methoxyphenols, although some discrepancies in the ranking within the groups were present.
Considering the overall ranking, isoeugenol was amongst the most active compound, like dihydroxybenzenes, evidencing the role of a
conjugated double bond at para position for the stabilization of the phenoxyl radical in the radical scavenging process
EVOLUTION OF CHEMICAL AND SENSORY BITTERNESS DURING AGEING OF TOP FERMENTED AND BOTTLE CONDITIONED BEER
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Studies of toxic and hazardous compounds biodegradation utilizing a CO2 respirometric method
No full textA respirometric method based on carbon dioxide detection by titration for the evaluation of hazard compounds degradation is described. The mineralization of substrates has been done in a ''biometer flask'', a close system where athmospheric carbon dioxide contamination is avoided by the use of an Ascarite filter. Enrichment microbial cultures and strain isolation have been performed with particular techniques from different organic matter. Catabolic activities of some bacterial strains on degradation of naphthalene, phenanthrene, byphenil and nicotine have been tested by this respirometric method
Valutazione dell’attività antiossidante di composti fenolici nei fumi per affumicatura.
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