Shelf life determination using sensory evaluation scores: A general Weibull modeling approach

Sensory evaluations to determine the shelf life of food products are routinely conducted in food experimentation as a part of each product development program. In such experiments, trained panelists are asked to judge food attributes by reference to a scale. The “failure time” associated to a product unit under test is usually defined as the time required to reach a cut-off point previously defined by the food company. Due to the destructive nature of these evaluations, one never knows the exact “failure time” of a given unit. Consequently, data arising from these studies are either left or right censored. This article deals with the problem of modeling such kind of data for shelf life determination and develops a general Weibull model (GWM). Simulations indicate a good performance of the parameter estimates obtained though the GWM. The modeling approach is applied to a real data set.