The aim of the diploma thesis was to prepare model bread using different yeast strains of Saccharomyces cerevisiae and to compare the technological and sensory properties of different bread samples. We baked bread using three different yeast strains (a strain that has good maltose exploitation and has been isolated from cider in the Koroška region, a wine strain from the Dolenjska wine-growing region and commercial baker's yeast). The experiment was performed in two replicates for each yeast strain. We compared the pH of the dough immediately after kneading, after fermentation, and the pH of the bread. Small differences between samples were observed, and the lowest pH was measured in the dough after fermentation. The color of the bread crust was measured with a Minolta chromometer. Bread prepared with commercial yeast had the least colored crust. We also measured the specific volume of different bread samples and confirmed statistically significant differences between the samples. Bread made with commercial yeast had the highest specific volume. The hardness of the bread crumb was monitored immediately after baking, after 1 day and 2 days of storage. We measured it with the Texture Analyzer TA XT plus. Measurements showed that the changes in core hardness of bread prepared with commercial yeast were significantly the smallest. Bread prepared with commercial yeast got the highest sensory evaluation score, followed by bread made with ZIM 3704, which had a very pleasant aroma. Technological and sensory properties of bread prepared with strain ZIM 3704 were relatively similar to the properties of bread prepared with the commercial yeast.
|
