It is rarely that bakery products are tainted by microbiological contamination. While biscuits, cookies and other low moisture products with low water activity may be immune to proliferation of bacteria and other microorganisms, bread and allied products with about 35-40% moisture can be right candidates for microbial growth under favorable conditions. It is true that use of anti fungal agents like propionates, sorbates and other preservatives confer some protection for limited periods and generally manufacturers do not give safety guarantee beyond a week for such products. Sandwich bread produced for use as a base of many products will have to be scrupulously clean and free from pathogens as they never undergo toasting as in the case of normal bread products. The reported occurrence of pathogens in some of the equipment in bread plants does raise an alarm which needs to be addressed to.
"Bread feeding machines, slicers, conveyor belts and water hoses are the areas most at risk for contamination by L. monocytogenes and continuous monitoring of plant equipment and environment can provide an early warning system for processors, finds a new study on a sandwich plant.The researchers, in a study published in Food Control said that they investigated the occurrence and genetic diversity of L. monocytogenes in a Swiss sandwich-producing plant over a 12-month period, with the goal of evaluating the potential persistence of L. monocytogenes there in order to identify possible contamination sources. L. monocytogenes as a food-borne pathogen has significant public health and economic impacts with manufacturers of ready-to-eat foods required, under EU regulation, to examine the processing environment for microbe as part of their hazard analysis critical control point (HACCP) approach and sampling schemes".
Production of sandwich bread in India is confined to the organized sector and commercial production of ready to eat sandwich products with longer shelf life is practically non-existent. But the possibility of presence of pathogens like L.monocytogenes in some parts of the plant should make the bakers more alert in maintaining the plant hygiene scrupulously.