how do i measure the enthalpy change of a type of food?

Answer 1

I've seen this done. The problem is that the food after cooking or freezing has temperature gradients within it so you can't just check its temperature.

The solution is to use an insulated container. A foam minnow bucket works with a known quanity of water in it, at a uniform temperature. Dump in a known quantity of food.

mass x heatcapacity x temp change (of the Water ) = mass x heat capacity x temp change (Food)

The accuracy will depend on how well the container is insulated. Good luck.