Current-status survival analysis methodology applied to estimating sensory shelf life of ready-to-eat lettuce (Lactuca sativa)

Abstract

The objective of the present work was to develop a method for predicting sensory shelf life for situations in which each consumer evaluates only one sample corresponding to one storage time. This type of data is known as current-status data in survival analysis statistics. The methodology was applied to estimate the sensory sheaf life of ready-to-eat lettuce (Lactuca sativa var capitata cv. "Alpha"). For each of six storage times, 50-52 consumers answered yes or no to whether they would normally consume the presented sample. The results were satisfactory, showing that the methodology can be applied when necessary. The Weibull model was found adequate to model the data. Estimated shelf lives +/- 95% confidence intervals were 11.3 +/- 1.2 days and 15.5 +/- 0.9 days for a 25% and a 50% consumer rejection probability, respectively.