بررسی تأثیر استفاده از خمیرترش بر کاهش بیاتی نان بربری

This study was intended to use the sourdough LAB containing specific starter cultures for Barbari bread production and reduction of its staling. For sourdough preparation, fresh microbial cells were collected by centrifugation from LAB cultures. Then 1.5% of flour (w/w) from these washed cells with the same amounts of wheat flour and tap water and 0.25% (w/w) active dry yeast extract, containing Saccharomyces cerevisiae were mixed. The effects of fermentation time (8, 16 and 24 hours), fermentation temperature (28, 32 and 36 ºC) and type of starter culture (Lactobacillus sanfransicencis, Lactobacillus plantarum and a mixture of both LAB) were analyzed in a completely randomized design with factorial experiment with 4 replications. Bread staling was determined by its measuring crumb hardness and specific volume in 1, 24, 48 and 72 hours after baking. Correlation between variables was obtained by multivariate regression, and regression models were exhibited. The results showed that sourdough had significant effect (p≤0.05) on reduction of Barbari bread staling at 1, 24, 48 and 72 hours after baking in comparison with control sample. Moreover, the sample prepared with Lactobacillus plantarum (24 h fermentation time and 32 ºC fermentation temperature) had the maximum specific volume and the least staling, 72 hours after baking.