Increased thermal sensitivity of Escherichia coli O157:H7 in sous vide cooked ground beef supplemented with celery (Apium graveolens L.) seed oil or root powder

Abstract

Escherichia coli O157:H7, a major cause of foodborne illness, is primarily associated with undercooked ground beef. Celery root powder (CP) and celery seed oil (CSO), rich in bioactive compounds such as essential oils and phenolic compounds, can enhance bacterial susceptibility to heat treatments. This study aimed to assess the effectiveness of CP (3 g/100 g) and CSO (2 mL/100 g) in reducing the thermal resistance of Escherichia coli O157:H7 in sous vide-cooked ground beef. The D-values of E. coli O157:H7 at 55–62.5 °C in samples without CP or CSO ranged from 11.64 to 0.99 min. In samples with CP or CSO, D-values ranged from 10.59 to 0.35 min and 11.11 to 0.41 min, respectively. The effect of CP and CSO on D-values was temperature-dependent. The D-values at 55 °C reduced slightly by CP or CSO adding (p > 0.05); however, at temperatures equal to or higher than 57.5 °C, the D values reduced significantly (p < 0.05). The control samples had a z-value of 7.06 °C, whereas CP and CSO-added samples had z-values of 5.18 °C and 5.57 °C, respectively. These findings indicate that adding 3 g/100 g CP or 2 mL/100 g CSO to ground beef may shorten heating time or reduce the temperature needed to inactivate E. coli O157:H7.