In the master's thesis, we analyzed the content of sugars, organic acids, ascorbic acid and total phenolics in apples of the cultivars 'Idared', 'Golden Delicious' and 'Granny Smith', which we bought in spring and autumn in stores. We compared the content of the analyzed compounds between cultivars and between the two seasons. The content of individual sugars, organic acids and ascorbic acid was analyzed using high–performance liquid chromatography (HPLC). The content of total phenolics was analyzed using a spectrophotometer. The total sugar content of the apples did not differ between the seasons. In autumn, 'Granny Smith' apples had the lowest total sugar content. Fructose was the most abundant sugar in all cultivars and in both seasons, followed by sucrose, glucose and sorbitol. 'Golden Delicious' apples had the highest fructose content in both seasons. The total organic acid content did not differ between seasons. The lowest total organic acid content in autumn was found in 'Golden Delicious'. In all cultivars and in both seasons, malic acid was the most abundant organic acid, followed by citric, shikimic and fumaric acid. 'Idared' and 'Granny Smith' had the highest malic acid in both seasons. Apples in spring had a significantly higher content of citric and shikimic acid. The ascorbic acid content did not differ between cultivars. The ascorbic acid content in apples was significantly higher in the autumn than in the spring. The content of total phenolics did not differ between seasons, with the highest content found in 'Idared' apples.
|
