Method for determining a characteristic value for the freshness and/or the loss of freshness of a food sample containing at least one first starting product, wherein the first starting product decomposes and at least one first metabolite is formed upon the occurrence of a first type of loss of freshness, wherein a first actual starting-product concentration value is measured for the concentration of the first starting product and a first actual metabolite concentration value is measured for the concentration of the first metabolite, wherein the first actual starting-product concentration value and the first actual metabolite concentration value are measured simultaneously, characterized in that the food sample contains a second starting product different from the first starting product, in that the second starting product decomposes and at least one second metabolite is formed upon the occurrence of a second type of loss of freshness, in that a second actual starting-product concentration value is measured for the concentration of the second starting product and a second actual metabolite concentration value is measured for the concentration of the second metabolite, in that the actual starting-product concentration values and the actual metabolite concentration values are measured simultaneously, in that the first type of loss of freshness is provided with first reference value combinations which have in each case a first reference ratio value dependent on the ratio between the starting-product concentration value for the first starting product and the metabolite concentration value for the first metabolite as well as a first reference shelf-life value assigned thereto, in that a first actual ratio value dependent on the ratio between the first actual starting-product concentration value and the first actual metabolite concentration value is formed, in that a first shelf-life value is ascertained depending on the first reference value combinations and the first actual ratio value for the first type of loss of freshness, in that the second type of loss of freshness is provided with second reference value combinations which have in each case a second reference ratio value dependent on the ratio between the starting-product concentration value for the second starting product and the metabolite concentration value for the second metabolite as well as a second reference shelf-life value assigned thereto, in that a second actual ratio value dependent on the ratio between the second actual starting-product concentration value and the second actual metabolite concentration value is formed, in that a second shelf-life value is ascertained depending on the second reference value combinations and the second actual ratio value for the second type of loss of freshness, in that a nominal value for the shelf life of the food sample is provided, in that each type of loss of freshness has determined therefor a difference value for the difference between the shelf-life value ascertained for said type of loss of freshness and the nominal value, in that an interaction value for the influence which the loss of freshness of the type of loss of freshness for which the largest difference value has been ascertained has on the loss of freshness of the other type of loss of freshness is provided, and in that the characteristic value for freshness is formed in such a way that all difference values, with the exception of the largest difference value, are each multiplied by an interaction value assigned thereto, and in that the result of this multiplication or the results of these multiplications as well as the largest difference value are subtracted from the nominal value for shelf life.