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

Download
index.pdf
2015
Didiş, Mert Cem
Show full item record
216
views
96
downloads
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.
Polyphenols., Catechin., Phenols., Cocoa., Antioxidants., High performance liquid chromatography.
http://etd.lib.metu.edu.tr/upload/12618765/index.pdf
https://hdl.handle.net/11511/24659
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Investigation of antioxidant capacity and phenolic contents of chocolates in the Turkish market
Övet, Başak; Bozoğlu, Faruk; Sağdıçoğlu Celep, Gülçin; Department of Food Engineering (2015)
Consumption of polyphenol rich foods is highly associated with human health, mainly with cardiovascular homeostasis. Chocolate is a very rich source of flavonoids, mainly (-)-epicatechin (EC), which has several reported bioactivities. Beneficial effects of polyphenols are usually attributed to their antioxidant potential. Therefore in this study, different chocolate samples commonly found in Turkish market were studied for their antioxidant capacities using DPPH• and ABTS• radicals scavenging methods. Total...
Evaluation of different coating materials for encapsulation of phenolic compounds extracted from onion (allium cepa) skin
Akdeniz, Büşra; Şümnü, Servet Gülüm; Şahin, Serpil; Department of Food Engineering (2016)
Encapsulation provides a protective barrier to some vulnerable food ingredients such as phenolic and antioxidant compounds against some external factors. Moreover, by the help of encapsulation the unwanted odor or taste of core the materials are masked. The main objective of the study was to evaluate the effects of different type of coating materials on encapsulation of phenolic compounds extracted from onion skin. Coating materials were maltodextrin, gum arabic, casein and whey protein concentrate (WPC). A...
Production of xylooligosaccharides from cotton and tobacco stalk
Akpinar, Ozlem; Erdogan, Kader; Ak, Ozlem; Bakir, Ufuk; Yılmaz, Levent (2007-09-01)
Xylooligosaccharides (XOs) are non digestible oligosaccharides which have many beneficial health effects. XOs are produced from xylan rich materials. For production of XOs, among the xylan rich materials, the residual origin such as forestal, agricultural or industrial wastes of lignocellulosic nature were special interest since utilization agricultural biomass as raw material provides economic and ecological benefits. The driving force of this study was to test the suitability of cotton and tobacco stalks ...
Phenolic compounds, carotenoids, and antioxidant capacities of a thermo-tolerant Scenedesmus sp. (Chlorophyta) extracted with different solvents
Bulut, Onur; Akin, Dilan; Sonmez, Cagla; Oktem, Aysegul; Yucel, Meral; Öktem, Hüseyin Avni (Springer Science and Business Media LLC, 2019-06-01)
The human body can fight against the adverse effects of chronic exposure to environmental pollutants and stress by consumption of a diet rich in antioxidants. Although fruits and vegetables are the predominant sources, alternative sources of antioxidants such as microalgae are also being explored. Here, we investigate the antioxidant capacity, total phenolic, flavonoid, and carotenoid contents of novel thermo-resistant green microalga Scenedesmus sp. ME02. This strain has previously been shown to have a hig...
Production and characterization of chickpea flour based biofilms containing gallic acid
Kocakulak, Seçil; Şümnü, Servet Gülüm; Şahin, Serpil; Department of Food Engineering (2019)
Chickpea is an easily accessible legume which has beneficial effects on human health. On the other hand, gallic acid is a widespread phenolic compound found in various plants. In this study, it was aimed to obtain chickpea flour based active films and to characterize this films. The effects of pH (9 and 11), glycerol concentration (1% and 3% w/v of film solution) and gallic acid concentration (5% and 10% w/w of total solid) on color, opacity, mechanical strength, water vapor permeability (WVP), microstructu...
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.
METU IIS - Integrated Information Service open@metu.edu.tr