Banca de DEFESA: CINTHIA MEIRELLY DE ARAÚJO ELPÍDIO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CINTHIA MEIRELLY DE ARAÚJO ELPÍDIO
DATE: 12/12/2020
TIME: 09:00
LOCAL: Sala Virtual
TITLE:

Drying of the plum by the foam mat method: optimization of parameters and product characterization.

KEY WORDS:

Prunus domestica L. Foam mat. Heat and mass transfer. Physicochemical properties. Bioactive compounds.

PAGES: 172
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

Plum is a seasonal fruit with low durability after harvest, requiring the application of techniques that prolong the shelflife of this food. Among the methods that can be applied is the drying in foam mat that consists of the transformation of liquids or semi-liquids into a stable foam from the addition of a foaming agent and application of agitation so that there is the incorporation of air. In this work, the plum foam was produced from the addition of egg albumin and the drying was carried out in an air recirculation oven with a speed of 2 m / s. The study of the drying of the plum in a foam layer was divided into stages, the first part of which is the investigation of the effects of the process variables, whipping time and albumin concentration, on the physical, thermal properties and drying time in order to optimize the operational conditions for the production of plum foam, whose values found were 3% albumin concentration and 12 minutes of whipping time. In the next step, the influence of temperature and foam mat thickness on the moisture, water activity and drying time of the plum foam was evaluated in order to define the best operational condition for drying this fruit, being observed that the higher temperature and less foam mat thickness are more suitable for the process, since they provided the best results for powder moisture (2.690 g water / g dry powder), water activity (0.245), drying time ( 70 minutes) and average drying rate (0.0631 g water / g dry powder / min). The last phase of this work investigated the influence of temperature on the physical-chemical properties, bioactive compounds and antioxidant activity and performed a comparison of the powders obtained by foam mat at four temperatures with the powder obtained by freeze drying, since the latter is widely used. known as the method capable of preserving the original characteristics of the fruit. The experiments were carried out using the foam in the previously optimized process condition (3% egg albumin in the formulation, 12 minutes of whipping and 0.8 cm layer thickness) and four drying temperatures: 50, 60, 70 and 80 ° C. For lyophilization, about 280 grams of pure plum pulp was used, without the addition of egg albumin (it was not foamed). The analysis of the produced powders showed that the higher temperature (80 ° C) provided a product with low cohesion between the particles (1.153) and good fluidity (13.235), in addition to low absolute density (0.637 g / cm³), important characteristics for particulate materials. All powders showed good solubility in the range of 75.737 and 76.842 g / 100 g and low water activity (0.245 to 0.386). The phenolic compounds were not impacted by the process conditions, the antioxidant activity was favored by the temperature, but the amount of ascorbic acid and carotenoids was greatly reduced by the action of this variable. Based on the results and because the lyophilization process is costly, the condition that provided the best results for both the drying process and the quality of the plum powder was the temperature of 80 ° C.

BANKING MEMBERS:
Presidente - 349802 - MARIA DE FATIMA DANTAS DE MEDEIROS
Interno - 1547970 - JACKSON ARAUJO DE OLIVEIRA
Externo ao Programa - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR
Externa ao Programa - 029.669.684-60 - KATIA CRISTINA BORGES - UFRN
Externo à Instituição - JOSILENE DE ASSIS CAVALCANTE - UFPB
Externo à Instituição - MARCELLO MAIA DE ALMEIDA - UEPB