Microbiological and biochemical studies on Gergoush fermentation.
According to the results obtained, three steps in Gergoush fermentation were identified. Step one is the primary starter preparation and comprises a 12-15 h propagation of the natural thermotolerant bacterial flora of the legume ingredient of Gergoush using the legume and boiled milk as a propagation medium. This primary starter is then used in step two to inoculate a wheat flour dough to produce the adapted starter in a 1-2-h fermentation time. The adapted starter is finally used in step three to raise the main Gergoush dough. In all of the three steps of Gergoush fermentation, three genera of bacteria dominated. They were tentatively identified as lactic acid bacteria, Bacillus spp. and Clostridium spp. Their counts reached a maximum in the primary starter stage of 2.2 x 10(7), 2.8 x 10(8) and 7.3 x 10(7) CFU/g, respectively. These bacteria produced lactic, acetic and butyric acids. The concentrations of the acids were maximum in the primary starter and reached values of 0.6%, 0.4% and 0.5%, respectively, and the pH decreased from 6.1 to 4.1. Baked Gergoush has a pH of about 5 and contains about 59% starch, 16% protein, 18% fat, 6.5% water and 0.5% ash.
Sherfi
S A
SA
Faculty of Agriculture, University of Khartoum, Sudan.
Hamad
S H
SH
D019342:Acetic Acid / Q000378:metabolism; D000818:Animals; D001407:Bacillus / Q000302:isolation & purification; D020148:Butyric Acid / Q000378:metabolism; D003013:Clostridium / Q000302:isolation & purification; D015169:Colony Count, Microbial; D007887:Fabaceae / Q000737:chemistry / Q000382:microbiology*; D005285:Fermentation; D005433:Flour / Q000382:microbiology*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000302:isolation & purification; D008892:Milk / Q000382:microbiology*; D010946:Plants, Medicinal; D013397:Sudan; D014908:Triticum
D020148:Butyric Acid; D019344:Lactic Acid; D019342:Acetic Acid