The aim of this master's thesis was to determine how different sweeteners affect the quality of rosehip spread and to what extent certain primary and secondary metabolites are lost during the thermal treatment of the fruit. In the experiment, four variations of rosehip spreads were examined – sweetened with stevia, fructose and sucrose, as well as a control spread without added sweetener. The objective was to identify which sweetener resulted in the best chemical quality parameters for the rosehip spread. We analyzed the content of phenols, ascorbic acid, sugars and organic acids. Our findings indicated that the thermal treatment of the fruit led to a 25% reduction in the total phenol content. The ascorbic acid content decreased by 41% and the total sugar content by 50%, while the organic acid content increased 1.5-fold. The use of different sweeteners led to a reduction in the total phenol content of the spread. The analysis of the rosehip spreads revealed that sweetening with sucrose resulted in a 44% reduction and sweetening with stevia resulted in a 38% reduction in total phenolic content compared to the control. Sweetening the rosehip spreads also affected the ascorbic acid content, with fructose sweetening leading to a 28% decrease in ascorbic acid content, while sweetening with sucrose resulted in a 33% decrease. Sweetening with sucrose reduced the organic acid content by 28%, and sweetening with stevia resulted in a 30% decrease in the total organic acid content compared to the control. Sweetening the spreads led to an increase in the total sugar content. Sweetening with stevia led to a 2.3-fold increase in total sugar content, while sweetening with fructose resulted in a 2.1-fold increase in total sugar content. We concluded that the rosehip spread without added sweetener had the best chemical quality, as the addition of sweeteners led to a decrease in the content of primary and secondary metabolites, with the exception of total sugars, which increased with sweetening.
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