Impact of Saccharomyces cerevisiae metabolites produced during fermentation on bread quality parameters: A review

Saccharomyces cerevisiae and its industrial applications

Saccharomyces cerevisiae is the best studied eukaryote and a valuable tool for most aspects of basic research on eukaryotic organisms. This is due to its unicellular nature, which often simplifies matters, offering the combination of the facts that nearly all biological functions found in eukaryotes are also present and well conserved in S. cerevisiae. In addition, it is also easily amenable to genetic manipulation. Moreover, unlike other model organisms, S. cerevisiae is concomitantly of great importance for various biotechnological applications, some of which date back to several thousands of years. S. cerevisiae's biotechnological usefulness resides in its unique biological characteristics, i.e., its fermentation capacity, accompanied by the production of alcohol and CO2 and its resilience to adverse conditions of osmolarity and low pH. Among the most prominent applications involving the use of S. cerevisiae are the ones in food, beverage -especially wine- and biofuel production industries. This review focuses exactly on the function of S. cerevisiae in these applications, alone or in conjunction with other useful microorganisms involved in these processes. Furthermore, various aspects of the potential of the reservoir of wild, environmental, S. cerevisiae isolates are examined under the perspective of their use for such applications.

Relation between the Recipe of Yeast Dough Dishes and Their Glycaemic Indices and Loads

The aim of the study was to evaluate the glycaemic indices (GI) and glycaemic loads (GL) of four food dishes made from yeast dough (steamed dumplings served with yoghurt, apple pancakes sprinkled with sugar powder, rolls with cheese and waffles with sugar powder), based on their traditional and modified recipes. Modification of the yeast dough recipe consisted of replacing wheat flour (type 500) with whole-wheat flour (type 2000). Energy value and the composition of basic nutrients were assessed for every tested dish. The study was conducted on 50 people with an average age of 21.7 ± 1.1 years, and an average body mass index of 21.2 ± 2.0 kg/m2. The GI of the analysed food products depended on the total carbohydrate content, dietary fibre content, water content, and energy value. Modification of yeast food products by replacing wheat flour (type 500) with whole-wheat flour (type 2000) contributed to the reduction of their GI and GL values, respectively.

Evaluation of Quality Parameters in Gluten-Free Bread Formulated with Breadfruit (Artocarpus altilis) Flour

Flour from the fruit of breadfruit trees (Artocarpus altilis) holds the potential to serve as a wheat flour replacement in gluten-free product formulations. This study evaluated the impact of breadfruit flour and leavening agent on gluten-free bread quality. Breadfruit flour was first milled and characterized by the researchers prior to being used in this study. Experimental formulas were mixed with varying breadfruit flour inclusion (0%, 20%, 35%, and 50%) and leavening agent (yeast and baking powder). Quality parameters including density, specific volume, pH, water activity, color, and texture were assessed, and proximate analysis was performed to characterize the nutritional value of the bread. Significant differences (p<0.05) were found in loaf density, specific volume, color (crust L∗ and b∗; crumb L∗, a∗, and b∗), pH, water activity, and crumb firmness. Additionally, a consumer sensory study was performed on the most well-liked formulations. Consumer testing yielded significant differences (p<0.05) between the yeast-leavened control (0% breadfruit flour) and yeast-leavened breadfruit bread (20% breadfruit flour). Nonceliac consumers rated the breadfruit treatment as significantly less acceptable than the control for all sensory characteristics assessed. These results indicate that breadfruit flour can be used at ≤20%, when leavened with yeast, to produce quality gluten-free bread. Future studies should be conducted to assess the impact of breadfruit variety and milling practices on breadfruit flour properties before further attempts are made to investigate how breadfruit flour impacts the gluten-free bread quality.