Dados do Trabalho

Título

EFFECT OF DRYING ON BIOACTIVE COMPOUNDS IN Eugenia uniflora FRUIT

Introdução

Eugenia uniflora is a tropical species rich in bioactive compounds that are sensitive to processing conditions, especially when heat is used. Drying is a common method of preserving fruit pulp which can affect these compounds. The aim of
this study was to assess the impact of drying at different temperatures on the preservation of phenolic compounds and carotenoids present in the pulp of E. uniflora, with a view to optimize the drying process to preserve the quality of the pulp.

Material e Métodos

The E. uniflora pulp was dried in an oven with air circulation at three temperatures (45°C, 65°C and 85°C) and at different intervals of time, determining the moisture and the concentration of phenolics, β-carotene and lycopene over time. Several drying models were tested in order to represent the moisture content over time and the degradation process of bioactive compounds.

Resultados e Discussão

These results shows that drying E. uniflora pulp at higher temperatures and for longer periods of time leads to greater degradation of phenolic compounds. However, when the moisture reaches around 15%, the concentrations of these compounds tend not to differ significantly regardless of the temperature, suggesting that the time is a crucial factor in the preservation of phenolics. The degradation of phenolic compounds followed a second-order kinetics, but the adjustments at 65° C and 85° C were not satisfactory in statistical terms. β-carotene and lycopene showed a similar degradation behavior to phenolic compounds, i.e., high temperatures and exposure time lead to the degradation of carotenoids. Both β-carotene and lycopene degradation followed first-order kinetics, with good adherence to
experimental data. With respect to the adjustment of drying models, the Page model and the Midilli model presented equivalent statistical results for the drying kinetics of the E. uniflora pulp, with excellent agreement between calculated values and the experimental data.

Conclusão

Obtaining the activation energy for the degradation reactions of β-carotene (4388.94 J/mol) and lycopene (5379.25 J/mol) allowed the generation of simulated degradation surfaces (including time and temperature as operational variables), which can be useful in further studies on the optimization of drying processes in order to minimize degradation effects.