Prediction of secondary shelf-life of croissants: Survival analysis and cata questions methodologies

The secondary shelf life of croissants made by frozen dough was estimated by using the survival analysis methodology. Check-all-that-apply (CATA) questions were also performed in order to evaluate sensory perception of the product by consumers. Two formulations of frozen butter croissant (A, B) were stored at -18 degrees C until experimental analysis. The samples were removed from the freezer and baked for 20 minute at 180 degrees C. Samples were stored for 3, 7, 16, 20, 23 and 27 hours at 25 degrees C and 65% of relative humidity (RH). Ninety-six subjects participated in the consumer test. They were asked to eat each sample, and answer the question:" Would you normally consume/buy this croissant? Yes or No?" and provide a sensory product characterization using check-all-that-apply (CATA) questions composed of 16 terms. Results showed that the survival analysis can be used to successfully determine the secondary shelf life of croissants. Weibull distribution was used to describe the rejection function. The shelf life was estimated as the storage time that corresponded to 50% consumers rejection in 22 +/- 2 h and 11 +/- 2 h, respectively for formulation A and B. Significant differences among samples were found in terms of both negative (stale, hard, dry) and positive (soft, fresh) attributes, and, as expected, frequency of use of the positive attributes decreased with storage time, whereas the contrary occurred for the negative ones.