Polyphenolic content and composition and antioxidative activity of different cocoa liquors
2009
Radojcic Redovnikovic, I.,University of Zagreb (Croatia). Faculty of Food Technology and Biotechnology | Delonga, K.,University of Zagreb (Croatia). Faculty of Food Technology and Biotechnology | Mazor, S.,Kras, Food Industry, Zagreb (Croatia) | Dragovic-Uzelac, V.,University of Zagreb (Croatia). Faculty of Food Technology and Biotechnology | Caric, M.,Kras, Food Industry, Zagreb (Croatia) | Vorkapic-Furac, J.,University of Zagreb (Croatia). Faculty of Food Technology and Biotechnology
Cocoa liquor used in the confectionery industry comes from a wide range of geographical areas and may have different chemical compositions, sensory properties, and nutritional values. We found it interesting to study the polyphenolic content and composition of cocoa liquors for their potential use in industrial production. Six defatted samples originating from different countries were extracted with aqueous methanol (70%, v/v), and the polyphenolic profiles were determined using RP-HPLC method. According to our results, all samples of cocoa liquors have similar polyphenolic profiles, however, quantitatively varied. About 13 compounds were identified by comparison of their retention times and UV spectra. The quantified peaks were (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin, caffeic acid derivative, caffeine, and theobromine. Several peaks were identified as oligomeric procyanidins. The free-radical scavenging activity was determined by the DPPH* (1,1'-dipheny-2-picrylhydrazyl) and Oxygen Radical Antioxidant Capacity (ORAC) assays. The order of antioxidant activity of the cocoa liquors studied was the same with both methods (Madagascar more than Mexico more than Ecuador more than Venezuela more than Sao Tome more than Ghana samples). High correlation coefficients were determined between the antioxidant capacity and polyphenolic concentrations by both methods (R2 = 0.9868 for DPPH, and 0.9375 for ORAC).
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