Research – Effect of citral on the thermal inactivation of Escherichia coli O104:H4 in ground beef

Journal of Food Protection

The objective of the present study was to analyze the combined effect of heat treatment (55 to 62.5 °C) and citral (0 to 3%) on the heat resistance of Escherichia coli O104:H4 inoculated in ground beef. Inoculated meat packages were immersed in a circulating water bath stabilized at 55, 57.5, 60 and 62.5 °C for different times. The surviving microbial cells were counted in tryptic soy agar. A factorial design (4 x 4) was used to analyze the effect and interaction of heat treatment and citral. The results showed that heat and citral promoted E. coli O104:H4 thermal inactivation, suggesting a synergistic effect. At 55 °C, the incorporation of citral at 1, 2 and 3%, decreased D values (control: 42.75 min) by 85, 89, and 91%, respectively ( p < 0.05). Similarly, other evaluated temperatures exhibited a citral concentration-dependent effect ( P < 0.05). In conclusion, the findings could be a valuable tool for the food industry in designing a safe thermal process for inactivating E. coli O104:H4 in ground beef under similar thermal inactivation conditions.