Validation of radio frequency assisted traditional thermal processing for pasteurization of powdered infant formula milk

Thermal inactivation of Cronobacter sakazakii ATCC 29544 in powdered infant formula milk using thermostatic radio frequency

“…Likewise, numerous non-thermal technologies are under development to pasteurize PIFM, such as high pressure processing (Wazed, Ismail, & Farid, 2020), intense pulsed light (Chen et al, 2018, gamma irradiation (Chen, Zhu, Qin, Qiu, & Zhao, 2018, pulsed electric field (Henry & Fouladkhah, 2019), ultrasounds (Chen et al, 2018), and cold plasma treatment (Oh et al, 2015). Among them, ohmic heating, microwave, high pressure processing, pulsed electric field, and ultrasounds are commonly used in liquid dairy products (Lin, Subbiah, Chen, Verma, & Liu, 2020). Irradiation is effective, fast and feasible for pasteurizing a variety of packaged foods, but is banned from PIFM.…”

“…However, most studies failed to achieve a constant material temperature, and the samples were continuously heated during pasteurization due to the dielectric heating mechanism (Chen, Wei, Irmak, Chaves, & Subbiah, 2019;Jeong, Baik, & Kang, 2017). Other studies used RF to rapidly heat a material to a target temperature, followed by conventional thermal treatments during holding period, such as hot air (Jiao, Zhong, & Deng, 2016;Lin et al, 2020;Zheng, Zhang, & Wang, 2017), hot water (Yang et al, 2019), or natural heat preservation (Liu, Ozturk, et al, 2018;Ozturk et al, 2019;Xu, Liu, & Tang et al, 2018). No systematic study has been reported on RF pasteurization kinetics of C. sakazakii.…”

“…It has been demonstrated that RF treatment can achieve desired lethal effect of C. sakazakii in PIFM in a shorter time than conventional thermal treatment due to the much shorter come-up time (CUT) (Lin et al, 2020). However, the non-thermal effects of RF energy on microorganism inactivation are still controversial.…”

Validation of process technologies for enhancing the safety of low‐moisture foods: A review

“…RF heating is a dielectric heating method operating in the range of 3 kHz–300 MHz. The heat is volumetrically generated due to the friction caused by ionic conduction and dipole rotation of water molecules (Boreddy et al., 2019; Lin et al., 2020; Piyasena et al., 2003; Wei et al., 2018). RF heating offers many advantages such as faster heating rate, better heating uniformity, and a higher penetration depth when compared to the conventional heating method (Jiao et al., 2014).…”

“…Therefore, it is critical to identify the cold spot in the sample prior to conducting the validation studies. The cold spot and hot spots can be identified by inserting the fiber optic sensors in different layers of the sample and acquiring the temperature data during RF heating (Chen et al., 2019; Lin et al., 2020; Liu et al., 2018; Wei et al., 2018). An inoculated pack method has been used by several researchers where the inoculated food product is packaged in a pouch and is placed in the cold spot (Chen et al., 2019; Lin et al., 2020; Liu et al., 2018; Wei et al., 2018).…”