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Evaluation of coffee and coffee substitute beverages from the perspective of sensory and antioxidant properties
HONYSZOVÁ, Tereza
The aim of the thesis was to evaluate selected coffee and coffee substitutes in terms of sensory properties and chemical properties with a focus on antioxidant properties and polyphenolic substances. The thesis was divided into two parts. The first, theoretical part, deals with the cultivation and processing of coffee, consumption of coffee and coffee substitutes, legislative definition of this issue. It also characterizes the most important chemical substances in coffee. The second, practical part, deals with the sensory analysis of selected coffee and coffee substitutes samples. The physical and chemical properties of the selected samples were determined. Subsequently, the antioxidant activity of the samples and the total polyphenol content were determined. Statistical analysis evaluated differences between the samples and correlation analysis was performed. The last part of the thesis was a questionnaire that focused on the consumption of coffee and coffee substitutes. Statistically significant differences were found for six of ten descriptors when evaluating sensory attributes of the samples. The samples differed significantly also in the physicochemical analyses. The Standard coffee sample had the highest pH value, and among the coffee substitutes it was the Organic Hemp coffee. The coffee samples had higher soluble solids than the coffee substitutes samples. When colour was measured, the coffee samples were found to be darker than the coffee substitutes. From the measurements of antioxidant activity and polyphenol content, the sample of the coffee substitute Red espresso was evaluated as the best.
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