Combined effect of sourdough lactic acid bacteria and additives on bread firmness and staling

The effect of various sourdoughs and additives on bread firmness and stalin g was studied. Compared to the bread produced with Saccharomyces cerevisiae 141, the chemical acidification of dough fermented by S. cerevisiae 141 or the use of sourdoughs increased the volume of the breads. Only sourdough f ermentation was effective in delaying starch retrogradation. The effect dep ended on the level of acidification and on the lactic acid bacteria strain. The effect of sourdough made of S. cerevisiae 141-Lactobacillus sanfrancis censis 57-Lactobacillus plantarum 13 was improved when fungal a-amylase or amylolytic strains such as L. amylovorus CNBL1008 or engineered L. sanfranc iscensis CB1 Amy were added. When pentosans or pentosans, endoxylanase enzy me, and L. hilgardii S32 were added to the same sourdough, a greater delay of the bread firmness and staling was found. When pentosans were in part hy drolyzed by the endoxylanase enzyme, the bread also had the highest titrata ble acidity, due to the fermentation of pentoses by L. hilgardii S32. The a ddition of the bacterial protease to the sourdough increased the bread firm ness and staling.