Study the Preservation Properties and Microbial Quality of Bread and Flour Produced in Tikrit City

Abstract

The study involved collecting samples of flour and bread from five specialized bakeries produced five kind of local bread In the city of Tikrit. Tests follow-up phenomenon of Staling of bread types were studied during periods 2, 24,48,72 hours. Microbial tests were also conducted to identify the total numbers of bacteria and fungi in the flour and bread. Results of follow-up staling revealed increasing the degree of hardness for all the types of bread, the were between 12.417-19.500 mm. Swelling Power test showed range of 1.207-1.694%. The results of moisture content in the crumb and the crust showed difference in moisture content between the crumb and crust of fresh bread. This difference was continued during stale bread, because the sharp decline in the moisture content of crumb at storage while there was a slight increase in moisture crust, and the extent of the difference in the crumb was between 25.498 -38.870 %, and in the crust between 29.955 - 33.496%. Using of pH in estimation of staling but did not show significant differences between the types of bread during staling.The test of volume of sediment showed range between 37.500-47.667 ml. The results of sensory evaluation showed lower values averages for all types of bread studied with increasing storage period, the have been confined to the averages of sensory evaluation values between 2.871 - 5.199 degrees. And other methods that have been used in the following-up staling of bread is a method of measuring electrical conductivity and estimation of turbidity has proven the success of these methods in a following-up staling in the types of bread, where it was noted the possibility use them efficiently comparing to the other methods used in the follow-up to the phenomenon of staling. The values of conductivity electrical were between 2,383 - 3.813 ms / cm while the values of turbidity were between 234.93 - 890.75 FTU.The results of microbial tests have shown that all types of bread were completely free of all microorganisms after process baking directly.The Coli form bacteria did not show any growth of these bacteria in samples of bread and flour. Numbers of molds were between 1 x102-6 x102 in bread and between 3 x102 - 13 x102 in flour. The number of yeasts was confined to bread between 1 x102 - 3 x102 and in flour between 2 x102-7 x102. About Spore former bacteria in the bread the numbers were between 7 x102-39 x102 and in flour confined ratio between 15x102 -31x102 .The number of Staphylococcus aureus was confined to bread between 11 x102 - 45 x102 .