EFFECT OF LEAVENING MICROFLORA ON PIZZA DOUGH PROPERTIES

Fourteen different starter cultures containing one strain of Saccharom yces cerevisiae with and without individual or combinations of lactic acid bacteria (Lactobacillus plantarum, Lact. sanfrancisco, Enterococc us faecium, Leuconostoc mesenteroides) were employed to investigate th e role of leavening microflora on the properties of pizza doughs. Micr obiological, chemical and physical characteristics of doughs prepared with the same flour and under the same processing conditions were dete rmined. Leavening times and acidification properties depended on the m icrobial association used. The proportions of lactic and acetic acid p roduced by lactic acid bacteria were consistent with the metabolic pro perties of the strains employed. The bacteria/yeast ratios arising fro m microbial counts at the end of the leavening process were always lon -er in comparison to sour- or bread-doughs. The size of the yeast popu lation did not change much, while bacteria showed from one to four dup lications. Rheologically, the fermented doughs could only be significa ntly distinguished from the control dough with regard to the elastic m odulus. Principal Component Analysis was applied to the acidimetric da ta. The scattergram of the two principal components effectively discri minated 13 of the 14 pizza dough types.