Determinação da vida útil de diversos produtos de pastelaria utilizando a microbiologia preditiva

Abstract

The study of the product’s shelf-life determines the time period during which the food will remain safe and without significant changes in the quality, meeting the needs and demands of consumers. The objective of this study was to determine the shelf-life of pastry products of the company AIPAL using the predictive microbial growth by ComBase computer program as well as the sensory attributes of each of the cakes studied in four different moments. The sample consisted of six of the top selling cakes within each of the categories specified by the company: dry cakes (Croissant and Fogaça) sliced pies (Sublime de chocolate and Tarte de amêndoa) and cakes with cream (Napoleão de caramelo and Noivo). Data collection was performed by conducting physical and chemical analisys of products in order to determine their pH and aw, allowing to conduct the study of predictive microbiology, to verify the possibility of microbiological growth. It was also performed the sensory analysis in order to verify the level of acceptance of products with different lifetimes by a panel of testers, not trained, but with knowledge about the products evaluated. The study of the predictive microbiology was conducted using the ComBase computer software. To process the data basic descriptive measures were used (mean, standard deviation, relative frequencies and absolute values) and also the Friedman test to analyze the data of sensory analysis. The level of significance was set at p≤0,05. With regard to physical-chemical analysis, it was found that some products feature favorable conditions for the growth of microorganisms, yeasts and molds. However, results of predictive microbiology, for the microorganisms tested, indicate that there is no growth, since the binomial pH/aw does not show favorable conditions for its development. The shelf-life of the products was defined through sensory analysis, establishing the validity of Croissant and Fogaça in one day after production, of Tarte de amêndoa and Napoleão de caramelo in two days after its manufacture and Sublime de chocolate and Noivo in three days after its confection.

Date of Award	16 May 2016
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Paula Teixeira (Supervisor)