Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

Authors: CHIEN, SHIH YUNG - National Taiwan University; Sheen, Shiowshuh - Allen; Sommers, Christopher; SHEEN, LEE-YAN - National Taiwan University

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2016
Publication Date: 9/10/2016
Citation: Chien, S., Sheen, S., Sommers, C.H., Sheen, L. 2016. Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral. Food Control. 73:672-680.

Interpretive Summary: High pressure processing (HPP), is a green and sustainable non-thermal means to reduce the levels of harmful bacteria in foods, and has been demonstrated to be an effective method to inactivate pathogenic Escherichia coli. Some natural antimicrobial compounds are “consumer friendly” and can help sensitize E. coli to the HPP treatment. In this study the capability of HPP to inactivate the intestinal pathogenic E. coli O157:H7 versus Uropathogenic E. coli (UPEC) commonly found in beef meat, with and without citral essential oil as a natural antimicrobial, were determined. Mathematical models to predict E. coli inactivation based on HPP, citral concentration, and process time were developed. These models will assist meat processors to achieve a 5 log reduction (100,000 E. coli/g of meat) and provide regulatory agencies with valuable information for the control of E. coli O157:H7 and UPEC in ground beef and meat products.

Technical Abstract: Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing (HPP) with and without citral (essential oil) as a sensitizer. UPEC was found more resistant than E. coli O157:H7 at 450MPa and 500 MPa. A central composite experimental design was used to evaluate the effect of hydrostatic pressure (250-350 MPa), citral concentration (0.75–1.25%, w/w), and pressure-holding time (10-20 min) on the inactivation of E. coli O157:H7 and UPEC in ground beef. The quadratic equations were developed to predict the impact on E. coli O157:H7 (R2 = 0.93) and UPEC (R2 = 0.92), as well as dimensionless nonlinear models. Both linear and non-linear models were validated with data obtained from separated experiment points. The results provide useful information of both E. coli O157:H7 and UPEC in regard to how they may survive HPP in the presence or absence of citral. The models may further assist regulatory agencies and food industry to assess the potential risk of E. coli O157:H7 and UPEC in ground beef.