Experimental approach to optimize the use of α-amylases in breadmaking

α-Amylases from different origins (wheat, malted barley, fungi, and bacteria) are used extensively to improve breadmaking. However, the enzyme activities, in addition to the differences associated with their origins, are strongly affected by the process conditions and the presence of other compounds in the medium. The activity of different α-amylases was tested under different conditions (pH and temperature), and in the presence of some bread ingredients (salt and sugar), some breadmaking additives (ascorbic acid and sodium propionate), and some metabolites (organic acids and saccharides) generated during the fermentation step, to envisage the behavior of these α-amylases during the breadmaking process. The α-amylase activities were affected to a different extent by the addition of these compounds depending on the enzyme origin. In general, the α-amylases from cereals (wheat and malted barley) were less sensitive to the presence of some ingredients, additives, and metabolites. These results show the great variation of the α-amylase activity with the process conditions and the importance of its knowledge in the selection of the appropriate α-amylase for a specific breadmaking process.M. Haros thanks the René Hugo Thalmann Program of the Universidad de Buenos Aires, Argentine, for the postdoctoral grant