Microwave heating of infant formula: A dilemma resolved

Microwave heating of infant formula is a common practice despite concerns of infant scalding. Beyond the issue of physical safety, little is known about the effects on nutrient content of microwave heating of infant formula. Casein-predominant infant formula in 120- and 240-mL glass and plastic nursing bottles of varying colors were heated for 40 seconds and 60 seconds, respectively. Temperature profiling was monitored during the heating cycle. Analysis of riboflavin and vitamin C was made prior to and after heating. Topmost portions reached a mean temperature of 44.7 ± 1.7°C and 43.0 ± 2.4°C for all types of 240-mL and 120-mL bottles, respectively. Topmost temperatures were significantly hotter than temperatures reached at other sites. Routine mixing resulted in formula temperatures which could safely be fed to infants (35.4 ± 0.3°C and 33.9 ± 0.2°C for 240-mL and 120-mL bottles, respectively). There was no significant loss of either riboflavin or vitamin C. Protocols for microwave heating are given.