Abstract: The invention relates to a measuring device (1; 30) for measuring a surface coating (18) on an object to be measured (19; 24) such as a foodstuff, particularly for the measurement of metabolic products from bacteria on meat intended for consumption, said measuring device having at least one excitation source (3-6) for the excitation of luminescence in the surface coating (18) on the object to be measured (19; 24), such that the surface coating (18) emits a luminescent radiation and having at least one optical sensor (10) for detecting the luminescent radiation emitted by the surface coating (18). According to the invention, the measuring device (1; 30) measures the luminescent radiation from the surface coating (18) at a plurality of measuring points spaced at a distance from one another (M1-M4) on the foodstuff to be monitored (19; 24), particularly at four measuring points (M1-M4).