Abstract
Nowadays, current practices at home and childcare
settings involved MW heating after powder infant formula
milk reconstitution. Microwave (MW) effectiveness for
Cronobacter sakazakii inactivation in reconstituted powder
infant formula milk was investigated. Power levels in the
range 400¿C900 W were tested during exposure times ranging
from 0 to 120 s. Power levels of 800 and 900Wreduced the C.
sakazakii initial population to undetectable levels (¡Ý8 log10
cycles), reaching maximum temperatures of 78.8¡À2.3 ¡ãC
and 88.1¡À1.5 ¡ãC, respectively. A post-treatment storage
study (5 ¡ãC, 24 h) was completed to determine the
recovery or death of C. sakazakii damaged and survival cells.
It was observed that lowest MW intensity treatments (power
level and treatment time) provide the highest percentages of
injured cells. Moreover, these high percentages of damaged
cells progressively die during refrigerated storage (up to 24 h).
Microbial reduction levels higher or equal to 5 log10 cycles
were reached due to the sublethal damaged cell death.
