Every year, one third of global food production -1.3 billion tons of food- is thrown away, partially due to the “best before” dating system. <font color=#FF6700><b>iGEM Groningen 2012</b></font> seeks to provide an alternative method of assessing edibility: <font color=#FF6700><b>the Food Warden</b></font>. It uses an <font color=#FF6700><b>engineered strain of Bacillus subtilis</b></font> to detect and report volatiles in spoiling meat. The introduced <font color=#FF6700><b>genetic construct</b></font> uses a promoter to trigger a pigment coding gene coding gene. This promoter, <font color=#FF6700><b>identified by microarray analysis</b></font>, is significantly up-regulated in the presence of <font color=#FF6700><b>volatiles from spoiled meat</b></font>. The activity of the <font color=#FF6700><b>promoter</b></font> regulates the expression of the <font color=#FF6700><b>pigment reporter</b></font> and will be visible to the naked eye. For safe usage of the system, spores of our engineered strain are placed into one half of a semi-permeable <font color=#FF6700><b>capsule</b></font>, the second containing a calibrated amount of nutrients. Breaking the barrier between the two compartments allows <font color=#FF6700><b>germination and growth</b></font>, thereby activating the <font color=#FF6700><b>spoiling meat sensor</b></font>.<br><br>