Express Method for Colorimetric Determination of Wheat Flour Contamination with Bac. Subtilis Spores

Abstract

The causative agents of potato disease are spore-forming bacteria belonging to the subspecies Bacillus subtilis ssp. mesentericus (potato bacillus), common in nature (soil, air, plants). The causative agent of potato bread disease (Bacillus subtilis ssp. mesentericus) develops in the wheat bread crumb. The affected bread loses its natural taste and aroma first, then a peculiar sweet smell appears. The crumb becomes sticky, while breaking there are mucous, stretching threads. The crumb color changes: yellow-brown and pinkish-dirty spots. When the disease develops, the bread turns into a dark layered mass with a sharp specific smell and unpleasant taste. To prevent potato bread disease (PBD), it is necessary to control raw materials and finished products in order to detect their microbiological contamination. To determine the presence of bacteria that causes potato bread disease, a man can use different methods, which are usually divided into four groups: 1) bacteriological; 2) technological; 3) biochemical and 4) physical. In all four groups of methods, there is no single method for analyzing the PBD pathogens detection, that would be easily reproduced in any laboratory and would have the correctness of evaluating the results obtained. The workers of the Food Technology Department of the Ural State University of Economics have developed an express method for colorimetric determination of wheat flour contamination with Bac. Subtilis spores based on the erythrodextrins content in it, which give a red-brown staining when interacting with an iodine solution. The advantages of the improved method for determining PBD are: a) speed and expressiveness; b) the possibility of both qualitative and quantitative determination of Bac. Subtilis in flour in order to predict the PBD occurrence in wheat flour bread.