Purpose: The purpose of this study was to evaluate the microbiological profile of dough systems during routine production conditions from a food safety standpoint.
Methods: Dough samples were collected from a commercial pretzel facility. Two types of dough: (1) regular pretzel dough and (2) peanut butter containing pretzel dough were evaluated for the study. Dough samples were individually inoculated with multiple strains of S. aureus to achieve a target level of 102 CFU/g. Following inoculation, samples were stored at 25 and 35°C. Samples were analyzed following storage at several time points between 0 and 7 days. Baird-Parker agar, deMan-Rogosa-Sharpe agar, Potato Dextrose agar supplemented with Chlortetracycline and Tryptic Soy agar were used as plating media for S. aureus, Lactic acid bacteria, Yeasts and Total Plate counts, respectively. The experiment was performed in triplicate. In accordance with FDA published guidance, the limit of food safety was defined as 105 CFU/g for S. aureus. ANOVA analysis was performed to understand the effect of storage temperature and time on the growth profile of S. aureus. The level of significance used was 5%.
Results: Growth of S. aureus did not exceed (P<0.05) the limit of food safety at both temperatures in all the evaluated dough types. This may be attributed to ‘competitive inhibition’ due to the presence native flour microflora.
Significance: The study findings indicate no significant food safety risk associated with the current production practices. The data generated in this study also provide scientific basis for the facility’s food safety plan in compliance with anticipated FSMA guidelines.