According to the aluminum industry,the aluminum tray microwavable;
however,cooking instructions in food packages say to remove food from the foil container
and put into an appropriate container for microwaving.
Oven manufacturers warn against the use of aluminum foil containers in microwaving.
And food processors are switching their aluminum oven ware
to dual-oven-proof paperboard or plastic containers.
Potential disadvantages of foil containers in microwaving are potential damage of
the magnetron from microwaves reflected on the aluminum foil surface,
uneven or slow heating of food contained or limitation of depth of food because of lower heating efficiency
by microwaves entering only from the top opening of container,
and arcing,which is a sparking phenomenon between the foil container and the oven walls when micro waving.
The AfCMA developed cook-in-the-carton to start a reeducation campaign proving the safety and effectiveness of aluminum container
for consumers and food processors.
Steps of cook-in-the-carton are open the outer paperboard carton and remove foil container,
remove lids,put foil container back into the outer carton,and place the carton in microwave oven and heat.
Advantages of the cooking-in-the-carton technique,according to AFCMA,
are eliminating any arcing by protecting the foil container from direct contact with oven walls,
and promoting the heating effect by steaming in the carton,which gives even heating of food contained,
decreases of heat loss,and prevents dehydration when microwaving.
The AFCMA studied concluded that there was no effect on the magnetron tube from
the microwave cooking with an aluminum foil container.