Descripció del contingut i pla d'activitats:
Aquess TFG és desenvoluparà en el departament d'alimentació dolça de l'empresa Dallant, S.A. continuant un conveni de pràctiques curricular.
L'objectiu del treball és estudiar la vida útil de farcits i cremes emprats en pastisseria quan es substitueix els additius conservants usuals en la seva formulació per extractes vegetals amb acció antimicrobiana.
Es vol determinar com afecta l'addició d'aquest extractes a la vida útil del producte, aixó com a nivell de la quantitat sensorial (flavor textura).
Overview (resum en anglès):
The aim of this work is to determine the dose of natural extract that acts as a preservative agent in pastry filling creams. To achieve this, a search and tests must be carried out to determine which one is the most suitable. In a preliminary phase, a study was made of the possible extracts (turmeric, cilantro, cumin, thyme and Serval berries) that could be used and through sensory analysis tests, Serval berry extract was chosen as it did not contribute any off flavors. The rest are discarded as they do not pass this first phase.
This extract is tested at different doses (0.2-0.3% or 0.4-0.6%) and applied to two products: cream and cocoa cream. Shelf life is monitored for three months at three different storage temperatures (4±1°C, 20±2°C, 35±1°C). During this period, physicochemical, microbiological and organoleptic characteristics were analyzed. In the former, pH, water activity (aw), total soluble solids (TSS (°Brix)), viscosity and humidity are evaluated. In the microbiological tests, a plate count of different types of micro-organisms is made. For cream, mesophilic aerobes, fungi, yeasts and enterobacteria are analyzed. For cocoa cream, aerobic and anaerobic lactobacillus counts are also studied. In the organoleptic test, a preference test is carried out where the creams are evaluated by temperature with a panel of 9 tasters.
Finally, all the tests carried out were analyzed and it was concluded that the Serval berry extract at a dose of 0.4-0.6% is more effective and has an effect more similar to a synthetic preservative. In the microbiological results, it has been verified that the extract has performed its function, and this is confirmed in the physicochemical and sensory results. It must be said that the dose applied at this concentration was higher than the lower extract concentration, although lower than the control according to the liquid chromatography HPLC (High-Performance Liquid Chromatography) tests. Both in the cream and in the cocoa cream, the results after three months of stability are in accordance with the product specifications, although the content of sorbic acid in the product is lower.