STUDY OF CASEIN AS A FOAMING AGENT IN THE DRYING OF TOMATOES BY THE FOAM-MAT METHOD
Casein; foaming agent; drying tomato FOAM-MAT
The constant technological innovations in the food industry require industries to search for increasingly healthier products with high added value. In this scenario, fruit powders have great potential for application in healthy products, because they have nutrients and vitamins essential to the functioning of the immune system. Fruit powders are obtained by several drying methods, and one of them is the foam layer method, in which the material is submitted to air incorporation to form a foam. In the preparation of the foam it is common to use additives such as foaming agents and emulsifiers, which aid in both the formation and stability of the foam. The foaming agent studied in this work is casein, a natural protein obtained from the coagulation of skim milk, which adds nutritional value to the final product obtained. In this work the process to obtain casein will be the coagulation through the addition of microbial rennin (an enzyme), which forms casein and whey, and the subsequent separation of the two components. After beating the casein is transformed into foam and then incorporated into the tomato pulp. The experiments will be conducted based on a factorial experimental design of the 2³ type. The foams will be formed from raw tomato pulp and cooked tomato (without cooking and with 10 and 20 minutes of cooking), and different proportions of pulp (50, 60 and 70%) and submitted to drying in an air chamber with controlled temperature (60, 70 and 80ºC) until reaching a constant weight. Semi empirical and phenomenological mathematical models will be fitted to the drying kinetics data of the foams. The powders obtained will be submitted to analysis for humidity, water activity and hygroscopicity. Considering as response variables the physical-chemical characteristics of the powders and the drying time, from the statistical analysis of the results the best experimental condition will be defined. In the optimal experimental condition, experiments will be performed to produce powder in sufficient quantity for solubility, microbiological and centesimal composition analyses. In order to verify a subsequent industrial application, a sensory analysis of products such as cheese creams and pâtés flavored with tomato powder will be performed.