Influence of yeast extract enrichment on fermentative activity of Saccharomyces cerevisiae and technological properties of spelt bread

Considerable interest in the consumption of bread from ancient spelt wheat with superior nutritional properties, easy digestibility and pleasant taste and aroma, has arisen recently. Yeast extract (YE) is nowadays frequently used as natural flavor enhancer for improving organoleptic properties such as meaty, cheesy and savory attributes of different food products. YE is a natural product from baker?s yeast industry with high nutritional richness containing amino acids, peptides, nucleotides, vitamins and minerals. In this work the effect of YE, table salt and white sugar content on fermentative activity of yeast and technological properties of spelt bread was investigated by response surface methodology (RSM) aiming to define the optimal conditions for obtaining a new functional product. The addition of YE, salt and white sugar slightly decreased yeast fermentative activity, while CO2 retention in dough was found to depend more on its chemical composition. YE addition (up to 5%) was found to increase volume and decrease firmness of bread prepared from dough with sugar content up to 5%, while the opposite effect was established in bread with higher sugar content. Maximal bread elasticity was obtained for YE content of 1.57%, table salt content of 2.01% and sugar content of 7.15%.