Predictive Modeling of Bacillus cereus on Carrot Treated with Slightly Acidic Electrolyzed Water and Ultrasonication at Various Storage Temperatures

Abstract

This study was conducted to develop predictive models for the growth of Bacillus cereus on carrot treated with slightly acidic electrolyzed water (SAcEW) and ultrasonication (US) at different storage temperatures. In addition, the inactivation of B. cereus by US with SAcEW was investigated. US treatment with a frequency of 40 kHz and an acoustic energy density of 400 W/L at 40°C for 3 min showed the maximum reduction of 2.87 log CFU/g B. cereus on carrot, while combined treatment of US (400 W/L, 40°C, 3 min) with SAcEW reached to 3.1 log CFU/g reduction. Growth data of B. cereus on carrot treated with SAcEW and US at different temperatures (4, 10, 15, 20, 25, 30, and 35°C) were collected and used to develop predictive models. The modified Gompertz model was found to be more suitable to describe the growth data. The specific growth rate (SGR) and lag time (LT) obtained from the modified Gompertz model were employed to establish the secondary models. The newly developed secondary models were validated using the root mean square error, bias factor, and accuracy factor. All results of these factors were in the acceptable range of values. After compared SGR and LT of B. cereus on carrot, the results showed that the growth of B. cereus on carrot treated with SAcEW and US was slower than that of single treatment. This result indicates that shelf life of carrot treated with SAcEW and US could be extended. The developed predictive models might also be used to assess the microbiological risk of B. cereus infection in carrot treated with SAcEW and US.

Control Measures of Pathogenic Microorganisms and Shelf-Life Extension of Fresh-Cut Vegetables

“…Microbial reduction effects of combined treatments were not significantly different regardless of temperature or volume of washing solution ( p < 0.05) ( Table 2 ). Previous studies have reported that higher temperature of treatment solution (25~60 °C) is more effective for reducing pathogenic bacteria in fresh-cut carrot, potato, and bell pepper [ 21 , 29 , 30 ]. However, potatoes washed at 60 °C with US treatment have shown color changes [ 29 ].…”

Combination of ultrasonic waves and dielectric barrier discharge plasma for the viable reduction in human norovirus while retaining the quality of raw sea squirt

“…(Jin, Kim, Ding, & Oh, 2009; Ugarte‐Romero, Feng, & Martin, 2007; Zhou, Feng, & Luo, 2009). However, UW are usually combined with many other technologies such as chemical and physical processing, as it is limited to the extinction of microorganisms when used alone (Chung, Ko, & Shin, 2015; Kim & Oh, 2014; Park et al, 2016; Park, Song, & Ha, 2014). The combined treatment technology (hurdle technology) can be applied sequentially to the properties of the hurdle factors by using a combination technologies to maximize the sterilization and storage effects (Ding, Rahman, Purev, & Oh, 2010; Huang et al, 2006; Rahman, Ding, & Oh, 2010).…”