Description:
The properties of instant coffee and their analogues are much less known than roasted coffee beans, but the interest of people and the desire to take care of their health promotes the investigation of the characteristics of these beverages and the amount that is recommended of these powders to prepare the coffee with higher antioxidant performance, which would have a beneficial effect on human health. Antioxidant substances have anti-bacterial, pain-suppressant, tonic effects. In the final bachelor thesis, it is analysed what is the antioxidant activity of the 5 sorts of selected instant coffee and their substitutes when increasing the concentration: chicory powder (Estonia); the essence of barley, rye, chicory and sugar beet (Poland); soluble coffee from India and two types of aromatic coffee (Germany, the Netherlands). The first part of the work presents the theoretical part about the beverage with a large amount of phenolic compounds that act as natural antioxidants: the types of instant coffee production, the chemical composition, and the influence of the positive and negative sides of this drink on human health. The second part describes the research progress and results. Three objectives were set for the study: 1) Describe the chemical composition of instant coffee and their analogues, its production methods and their effects on human health; 2) Determine the antioxidant soluble coffee and their substitutes activity; 3) Estimate the dependence of phenolic compounds on the concentration of instant coffee and their analogues. The total phenolic compounds of aqueous extracts of instant coffee were evaluated using the Folin – Ciocalteu spectrophotometric method and the antiradical efficiency by DPPH· radical interconnection method. The total determination of the phenolic compounds showed that increasing concentrations of soluble coffee increased the content of phenolic compounds in decaffeinated solutions, while in the case of caffeinated coffee it was not significant. An antioxidant evaluation study showed that increasing the concentration of antiradical effects decreases and the coffee beverages start to act as an oxidizing agent, therefore it is recommended to take 1-2 teaspoons of instant coffee powder.
