|ZHOU, SIYUAN - Southwest University|
|ZHAO, GUOHUA - Southwest University|
|CHUANG, SHIHYU - National Taiwan University|
|HAN, LIN - Drexel University|
Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2020
Publication Date: 6/23/2020
Citation: Zhou, S., Sheen, S., Zhao, G., Chuang, S., Han, L., Liu, L.S. 2020. Inactivation of Salmonella in tomato by combination treatment of high pressure and trans-cinnamaldeyde. Food Control. https://doi.org/10.1016/j.foodcont.2020.107441.
Interpretive Summary: Salmonella outbreaks associated with produce have become a major food safety concern. Within the past 15 years, more than 20 fresh produce associated with Salmonella outbreaks were recorded and over 600 illnesses (including death) were caused by Salmonella contamination on tomato according to the Centers for Disease Control and Prevention (CDC). This study provided an effective means to enhance the inactivation of Salmonella in tomatoes using high pressure processing (HPP) and trans-cinnamaldehyde (a food grade ingredient). A cell reduction of 99.9999% can be achieved at 200-250 MPa (1 MPa = 147 psi = 10 ATM) which also satisfies the FDA requirement for non-thermal food processing operation to meet microbial food safety concern. Inactivation models (linear and nonlinear) were also developed for HPP to predict the microbial cell reduction/inactivation. These models can be applied to food safety risk assessment.
Technical Abstract: High pressure processing (HPP) is an effective non-thermal food operation means to reduce foodborne illness risks. Trans-cinnamaldehyde (TC) is a generally recognized as safe (GRAS) compound widely used in food applications for flavoring and recently found potential to enhance microbial inactivation with HPP. This research studied the effects of hydrostatic pressure level, operation time and TC concentration on Salmonella inactivation in tomato by using selective (XLT4 agar plates) and non-selective (Aerobic Petrifilms) media for microbial survival enumerations. We may be able to achieve more than 6 log inactivation of Salmonella if the parameters were properly selected. According to 4-Dimensional response surface plots, hydrostatic pressure played a major role in the inactivation. A synergistic inactivation effect between hydrostatic pressure and TC was observed, so the imposed pressure level and operation costs can be much reduced by the addition of TC. Linear and dimensionless non-linear regression models were developed from Central Composite Design for description and prediction of the inactivation effects. The model evaluation and validation results indicated good fittings between the experiment-observed values and predicted values from both types of models. The study provided useful information on the pathogen inactivation in the processing of tomato (and potentially other acidic fresh produce) by using HPP combined with TC.