Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Comparison of Cronobacter sakazakii thermal death kinetics in powdered infant formula milk using hot water and combined radio frequency and hot air treatment

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:  2016 ASABE Annual International Meeting  162459966.(doi:10.13031/aim.20162459966)
Authors:   Lu Wang, Juming Tang, Yawen Lin, Yucen Xie, Shaojin Wang, Zhenjiang Gao, Yanhong Liu
Keywords:   . thermal death kinetics, Cronobacter sakazakii, powdered infant formula milk, hot water, radio frequency


Powdered infant formula milk is prone to Cronobacter sakazakii (C. sakazakii) contamination, which is fatal to infants. In order to explore effective thermal inactivation applications of powdered infant formula milk, this research studied the thermal death kinetics of C. sakazakii in powdered infant formula milk using hot water and radio frequency energy. D-values and z-values were determined for powdered infant formula milk with water activity of 0.2, 0.3 and 0.4 inoculated with approximately 108 CFU/g C. sakazakii vegetative cells and sealed in TDT cells which were completely immersed in a circulating water bath and held at prescribed temperatures for predetermined time periods. D-values for sample with water activity of 0.3 at 60, 65, 70 and 75 °C were 77.9, 50.3, 29.9 and 15.6 min, respectively, which were too harsh for quality retention of powdered infant formula milk because under these conditions, protein was denatured. The z-value was 21.5 °C. When inoculated powdered infant formula milk sealed in Petri dish was exposed to combined radio frequency and hot air treatment, one log reduction of C. sakazakii was obtained during come up time of 70 °C. Under such condition, quality of powdered infant formula milk was well retained. With increase of sample water activity, D and z values decreased for both treatments. This study demonstrated that radio frequency technology may serve as an effective way to inactivate C. sakazakii in packaged powdered infant formula milk.

(Download PDF)    (Export to EndNotes)