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Determination of nutritional values and antioxidant capacity of different edible roots
Ciffrová, Karolína ; Bendová, Agáta (referee) ; Němcová, Andrea (advisor)
This bachelor thesis deals with selected edible roots, their nutritional composition, antioxidant capacity and use in healthy eating. Eight selected edible roots were analyzed: type A, B and C potatoes, red potatoes, sweet potatoes, and purple potatoes were selected as representatives of potatoes. Jerusalem artichoke and cassava represent the other two root crops. The theoretical section of the thesis describes the basic characteristics of root crops, as well as the description and composition of the nutritional substances they contain, i.e. proteins, carbohydrates, fats, vitamins and antioxidant properties. The general characteristics of the methods used for analysis are also described here. The experimental part is based on specific analyses, procedures, results, chemicals and laboratory equipment used to determine the basic nutritional values and antioxidant capacity of these selected root vegetables. First, the total dry matter content was established to be about 23 % in the selected root crops. Higher dry matter content was determined for the cassava at 35 %. Crude protein content determined by the Kjeldahl method ranges from 6.5-9.9 %. The gravimetrically determined fiber in the given root crops was in the range of 0.27–0.91 %. The starch content is significantly higher in the cassava (46 %) than in other root crops. The inulin content was determined in sweet potatoes and Jerusalem artichokes instead of starch content; this value is significant for the Jerusalem artichoke (258.58 g/kg). Fat content in grams per 100 grams of dry matter was determined by Soxhlet extraction. Significant fat content was determined for sweet potatoes (12.6 g/100 g). From the extracted fats, the fatty acid profile was determined for individual root vegetables, such as the content of saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Total and reducing carbohydrates, determined by the spectrophotometric method, were measured separately in the peel and pulp of the root crops. Antioxidant capacity was determined using antioxidant activity values, polyphenol and flavonoid concentrations. Of the vitamins, vitamin C was determined, vitamin E only in type B, C and purple potatoes. For sweet potatoes, beta-carotene was determined to be 540.56 g/g. The measured and calculated results are plotted in graphs. Finally, there is a discussion of the conclusions of the individual methods.
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