Investigation of natural and processed cocoa and cocoa containing products for their antioxidant capacity and phenolic compounds

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2015
Didiş, Mert Cem
Cocoa is one of the richest sources of polyphenols which have positive effects on cardiovascular health. (-)-Epicatechin(EC) and (+)-Catechin(C) are flavanols with several biological activities, particularly known for their high antioxidant potential. They scavenge free radicals in human body and prevent lipid peroxidation, which otherwise damage the cells. Food processing techniques may reduce the polyphenol contents and antioxidant capacity of food products substantially. Therefore, in this study natural and processed (alkaline) cocoa samples obtained from industry were investigated for their antioxidant capacities using DPPH• and ABTS• radical scavenging methods. EC and C contents of the cocoa samples and cakes prepared by these samples were evaluated using RP-HPLC. IC50 for DPPH• radical scavenging activity for natural and alkalized cocoa samples were determined as 0.047±0.001 mg/mL, and 0.064±0.001 mg/mL, respectively. Trolox equivalence data for natural and alkali samples were determined as 188.51±4.19 µmol TE/g and 71.84±2.99 µmol TE/g, respectively. Both total phenol and total flavonoid content analysis have shown that natural cocoa has the highest phenolic and flavonoid contents with 4883.84±382.72 mg GAE/100g and 3155.30±120.70 mg QE/100g, respectively. The HPLC results indicated that natural cocoa has the highest EC content with 0.936±0.17 mg/g and the alkalized cocoa has the highest C content 0.327±0.18 mg/g. Natural cocoa and its products have much greater antioxidant activity, phenolic and flavonoid contents than alkali cocoa and their products. Further studies are necessary to improve the properties of natural cocoa and formalize polyphenol rich functional foods with significant health claims.
Citation Formats
M. C. Didiş, “Investigation of natural and processed cocoa and cocoa containing products for their antioxidant capacity and phenolic compounds,” M.S. - Master of Science, Middle East Technical University, 2015.