My teammate David and me managed to test a range of spoiled foods recently. We packages various kinds (milk, fruit juices, fruits, bread, prepared meal (risotto)) into sealed containers and left them outside the fridge.

Now what sounds pretty disgusting is neccessary as we need to test if the gas sensors can actually pick it up. The methane sensor successfully detected spoiled milk and spoiled fruit. The fruit could also be detected using alcohol sensors, which are particularily helpful with detecting spoilage and decomposition of high-energy foods.

A video showing the tests is to follow very soon...