**5. Controlling of the** *Enterobacteriaceae* **foodborne pathogens**

At present, food pollution and poisoning caused by foodborne pathogens have attracted extensive attention. In the food industry, technologies such as irradiation, pulsed light treatment, microwave sterilization, slightly acid electrolytic water and fumaric acid treatment, algae extract treatment, *Bacillus* antimicrobial peptide treatment is usually used to control foodborne pathogens.

## **5.1 Irradiation**

In more and more countries, ionizing radiation processing is the most common method of food purification, and in the short run, a growing number of

#### *Foodborne Pathogens of Enterobacteriaceae, Their Detection and Control DOI: http://dx.doi.org/10.5772/intechopen.102086*

radiation-purified foods are presumed to be approved for production. It is a secure, smart, environmentally clean, and energy-efficient process, and it is especially valuable as a purification process for the final product. Due to the availability of irradiation in handling packaged foods, irradiation is regarded by most food safety officers and scientists as an effective critical control point in the processing of meat and poultry hazard analysis and critical control point (HACCP) system.

The high-energy photons or free radicals generated by ionizing radiation can break the DNA chain and generate reactive oxygen free radicals, and can also cause protein denaturation and cell membrane damage. Hesham reported that an irradiation dose of 4 kGy can effectively control the bacterial pathogens in meat by destroying *Salmonella*, significantly reducing *E. coli* [55]. They found the number of *Enterococcus faecalis* and *Enterobacteriaceae* was reduced by more than 1.8 log units and 5 log units, respectively, when treated with 4 kGy of irradiation, and no *Salmonella* was detected in the meat samples [55], which could prolong the cold storage shelf life without any significant impact on the sensory quality of meat.

#### **5.2 Pulsed-light treatment**

Nucleic acids are easily destroyed by pulsed light (PL). Pyrimidine bases form dimers the DNA of bacteria, viruses, and other pathogens through photochemical intervention and block DNA replication, and if there is not enough repair mechanism, it will ultimately lead to the death of microorganisms [56]. Xu et al. [57] investigated the inactivation effect of PL on *Salmonella* and *E. coli* in fresh raspberries. It was found that the pulsed light treatment of 28.2 J/cm2 for 30 s could reduce them by 4.5 and 3.9 lgCFU/g, respectively. However, considering the adverse effects on raspberry color and ground, the recommended dosage of PL is 5.0 J/cm2 . Rajkovic et al. [58] found that PL can kill *E. coli* in meat products, but the sterilization effect becomes worse with the extension of pulse interval. Ozer et al. [59] used pulsed ultraviolet light to treat *E. coli* on the surface of seafood. The results showed that the irradiation distance was 5 cm and the treatment time was 30 s, reducing 0.86 lgCFU/g; When the irradiation distance was 8 cm and treated for 60 s, 1.09 lgCFU/g was reduced [60]. This shows that under the condition of a long irradiation distance, the sterilization rate can be improved by prolonging the treatment time, but the surface temperature of the sample increases significantly with the extension of the treatment time.

However, in the sterilization process of fruits and vegetables, if the PL intensity is too high, due to the effect of PL on protein structure, it will improve the activity of polyphenol oxidase (PPO) to a certain extent and cause browning [61]. In the process of meat sterilization, PL has a poor sterilization effect on uneven surfaces [62], and the sterilization only stays on the surface.

#### **5.3 Microwave sterilization**

Microwave sterilization is that microwave constantly changes the direction of electromagnetic field, changes the ion and electron density around microbial cell membrane, destroy the permeability of cell membrane, lead to protein degeneration in cells, destroy cell metabolism, and microbial death [63].

De La Vega-Miranda observed that under 950 W water-assisted microwave treatment, *Salmonella typhimurium* on pepper and coriander foliage decreased by 5.12 log and 4.45 log after being treated at 63°C for 25 s and 10 s, respectively, and finally reached 3× 108 CFU/g [64]. The sterilization effect of microwave sterilization under

the same conditions (power and temperature) varies due to different objects. The high-voltage pulsed electric field sterilization technology to treat liquid food shows that it can effectively eliminate *E. coli*, *Salmonella*, *E. coli* O157:H7, et al. reaching the level of pasteurization. The cold source plasma has a significant sterilization effect on *Salmonella* and *B. subtilis* in pepper, and the cavitation jet technology also has a significant sterilization effect on *E. coli* and *K. pneumonia*.
