UTILIZATION OF SPROUT-DAMAGED WHEAT AS RAW-MATERIAL FOR SOUR DOUGH PRE-FERMENTS WITH MIXED CULTURES OF LACTIC AND PROPIONIC-ACID BACTERIA

The utilization of sprout-damaged wheat flour in pre-fermentation for sour dough bread-baking increased lactic acid formation and titratable acidity several fold in comparison to the use of baker's wheat flour, and also resulted in a lactic acid to acetic acid molar ratio accepta ble for sour dough bread. Further, enzymic treatment of the sprout-dam aged wheat flour with malted grain flour appared to be necessary for a properly balanced acid formation although the alpha-amylase activity of sprout-damaged wheat flour was quite high. The accumulation of lact ic acid in the pre-ferment decreased in the presence of yeast, and thu s the molar ratio of lactic to acetic acid could be adjusted suitable for sour bread-baking even with homofermentative lactic acid bacteria. Finally, when using mixed culture pre-ferments of Lactobacillus brevi s and Propionibacterium jensenii, at least 0.1% of propionic acid (bas ed on flour weight), sufficient to prevent mold growth in the final br ead, was obtained.