Leafy kale (Brassica oleracea L.) is a biannual leafy vegetable, of the Brassicacea family that is cultivated all over the world. It is popular for it`s undemanding cultivation, as it can even be grown on less fertile soil and is tolerant on low temperatures and frost. Leafy kale is important nutritional food, because it is rich in nutrients and bioactive substances as vitamins, minerals, glucosinolates and phenolic compounds. In the Master`s thesis, we wanted to identify sugars and glucosinolates in leafy kale plants and to determine the differences in their content among different leafy kale genetic resources. We also tried to find out if there are differences in the content of sugars and glucosinolates among plants grown in optimal conditions and plants exposed to frost. We found out that all genetic resources of leafy kale contained four sugars: sucrose, glucose, fructose and galactose. Sugar content significantly differed between frosted and non-frosted plants. Total sugar content was from 201,2 to 338,1 g/kg dry weight (DW) before frost and from 223,9 to 388,3 g/kg DW after frost. We identified eleven glucosinolates, which were divided into three groups. Glucobrassicanapin, sinigrin, gluconapin, glucoiberin, glucoraphanin and progoitrin were present among the aliphatic glucosinolates. Glucobrassicin, 4-hydroxyglucobrassicin and neoglucobrassicin were presented among the indole glucosinolates and gluconasturtiin was presentend among aromatic glucosinolates. The contents of most glucosinolates significantly differed among non-frosted and frosted plants, however for some glucosinolates the difference between non-frosted and frosted palnts could not ne demonstrated.
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