The Influence of Temperature on Production of Organic Acids in Dough Fermentation with Lactobacillus brevis, Saccharomyces uvarum and Candida krusei (in Pure and Mixed Cultures)
S. Grba, Vesna Stehlik-Tomas, Đurđica Šehović and S. Romac
Faculty of Food Technology and Biotechnology, University of Zagreb
Received June 27, 1994
Accepted February 28, 1995
The conditions of dough fermentation with L. brevis bacteria in pure and mixed S. uvarum/C. krusei cultures have been explored in order to produce optimal quantities of lactic, acetic and other organic acids capable of improving dough properties. These acids give a more aromatic flavour to the bread, increase its durability and reduce bread crumbling and deterioration. It was found that dough souring with L. brevis and yield 200 (dough and wheat flour ratio x 200) produced the maximal quantity of lactic acid when fermentation occurred at 30 to 35 °C (0.76 %). In these conditions the fermentation temperature had no influence on the production of acetic acid. The greatest concentations of acetic and lactic acids were obtained with a mixed L. brevis/C. krusei culture at 30 °C (0.9 % lactic acid, and 0.2 % acetic acid). The best results in the production of organic acids were achieved in dough fermentation that was carried out with a mixed L. brevis/S. uvarum culture. When dough was soured at 25 to 35 °C, concentrations of i-butyric, valeric, i-valeric and unindentified acids, in addition to lactic acid (0.7 %) and acetic acid (0.2 %), have also been quantified.
Presented at the 2nd Croatian Congress of Food Technologists, Biotechnologists and Nutritionists, Zagreb, June15-17,1994