Effect of high-pressure processing on the microbial load and functionality of sugar-cookie dough

Background and objectives: Refrigerated dough products have the potential to be a safety hazard to consumers because they could be consumed raw or undercooked. The objectives of this study were designed to evaluate the microbial and functionality changes in high pressured sugar-cookie dough as a function of a_w (0.80–0.87), pressure level (100–600 MPa), and holding time (1–6 min). Findings: Endogenous microbial populations were marginally reduced (0.2–0.5 log CFU/g) by pressure treatments. However, treating the dough at 600 MPa for 6 min significantly reduced counts of inoculated Escherichia coli by as much as 2.0 log CFU/g. Increasing the a_w of cookie dough from 0.80 to 0.87 did not play a significant role in the reduction of microbial counts; however, it yielded a softer and thicker cookie when baked. Dough and cookie physical characteristics did not differ significantly among HPP-treated and control doughs within the same a_w level. Conclusions: The results of this study suggest that pressure treatment has the potential to improve the microbiological quality of wheat-based cookie doughs. However, variations in food matrix composition must be considered because some food constituents, such as sugar and fat, may protect microorganisms against pressure-induced inactivation. Significance and novelty: The results reported here have practical implications for the food industry and contributes to understand the effects of high-pressure processing on wheat-based cookie doughs and their microbial loads.