Effects of Yeast, Fermentation Time, and Preservation Methods on Tarhana

Abstract

The physicochemical properties of tarhana soup produced with different dough treatments, fermentation times, and preservation methods were examined. Tarhana doughs were prepared with yogurt (control) or baker's yeast (Saccharomyces cerevisiae) and fermented for 3 days. Samples were taken at 24, 48, and 72 hr. Samples were then preserved via one of four methods: sun dried, dried in the shade, vacumn dried, and frozen. Frozen samples produced lower organic acid levels after 72 hr of fermentation in both control (0.68 g/100 g) and yeast (0.61 g/100 g) applications than samples that were dried (0.94 g/100 g control samples; 0.81 g/100 g samples with yeast). Increasing fermentation time resulted in a significant effect on the formation of organic acid in the tarhana (p < .01). At 72 hr of fermentation, total acidity increased 11%, 17%, and 23% for tarhana samples vacumn-dried, sun-dried, and dried in the shade, respectively. Preservation methods also affected the moisture, ash, crude protein, total acidity, pH, salt, fat, reducing sugar levels, and the sensory assestment of tarhana soup (p < .01). Sensory characteristics were not significantly affected by baker's yeast in any of the preservation methods used (p > .01). However, sensory scores for tarhana prepared from the samples dried in a sheltered area showed a reduction in color desireablilty as the fermentation time increased. The soup prepared from frozen tarhana (72 hr fermentation, with yeast) had the highest scores with respect to color, mouth feel, flavor, and overall acceptability. Vacuum-dried samples' scores in these areas were also high in comparison to the two other drying methods.

Influence of starter culture on the physicochemical properties of rice bran sourdough and physical quality of sourdough bread

“…Higher lactic acid content recorded for the sourdough fermented with L. brevis, L. plantarum, and L. sanfranciscencis starter culture could be ascribed to improved activities of LAB, which resulted in the rapid production of lactic acid in the sourdoughs. This result was in agreement with the findings of Gurbuz et al (2010), who reported that LAB grows and produce lactic acid more slowly in mixtures containing yeasts than in pure culture. Sourdough with high acid will have improved proteolysis and protein solubility.…”

“…Rice bran sourdough fermented with yeast (control sample) had the highest glucose (1.1 g/100g) and maltose content (1.06 g/100g) compared to the sourdoughs fermented with mixed culture or L. brevis, L. plantarum, and L. sanfranciscencis. This could be because yeasts and LAB have different kinetics for soluble carbohydrate uptake (Gurbuz et al, 2010). This observation was in agreement with the report of Colla et al (1996).…”

“…This could be due to the effect of yeast fermentation on carbohydrate, in which glucose is converted into ethanol (Gurbuz et al, 2010). This result is in agreement with the previous report on headspace flavour profile of dough, in which ethanol is the most prominent compound in dough fermented with yeast while diacetyl is prominent in dough fermented with LAB (Colla, 1996).…”

“…It could also be due to competition between baker's yeast and LAB for carbohydrate source (Gurbuz et al, 2010).…”

Inhibition of quorum sensing virulente factors of Pseudomonas aeruginosa PAO1 by Ferulago macedonica and Echinophora sibthorpiana extracts and essential oils

“…It was proven that this species stimulates the fermentation of tarana by affecting lactic acid bacteria and yeast Saccharomyces cerevisiae. In traditional medicine, it is used as a fungicide for the treatment of wounds and stomach ulcers, also, as digestive and anti-spasm agent (Baser et al, 1998;Cakilcioglu and Turkoglu, 2010;Degirmencioglu et al, 2005;Gurbuz et al, 2010;Ozdemir et al, 2007). In addition, the seeds and the roots of this taxon have been effectively applied in the treatment of epilepsy (Eadie, 2004).…”