Secagem da folha do manjericão (Ocimum basilicum L.) pelo método de camada de espuma

Abstract

The species Ocimum basilicum L., popularly known as basil, basil, basilicão, among others, is a plant that has great economic value, being used as a medicinal, ornamental, aromatic plant in the food, pharmaceutical and cosmetics industry. Basil leaf is highly perishable, not being able to keep for many days. To preserve existing plant properties, the foam-mat drying method presents a simple, low-cost alternative capable of increasing shelf life. In this way, the objective of this work was to obtain and evaluate the quality of the basil leaf by drying in a foam layer using a foaming agent. The foam was analyzed. The control operation of choosing an experiment 3 midpoints, making 3 midpoints, making 11 experiments complete, for an influencing agent 3, experimental, 5% of the independent influences (4.5 and total independent factors) 6) and drying temperature (50, 60 and 70 °C) on the dependent variables (final drying time) and on the characteristics of the powder obtained (theoretical time, water activity, solubility, moisture content, ash content), pH and SST) through statistical analysis. With the drying data they were plotted as kinetic and drying rate curves. The results showed a typical drying curve, represented by two periods, the constant period and the decreasing rate period. It was observed that the increase of the drying temperature provided a reduction in the drying time, being the smallest time obtained in the experiment of maximum conditions of the experimental design. The highest drying rates were also presented in the experiments at a temperature of 70 °C and the lowest at a temperature of 50 °C. The mathematical model with the best fit for the experimental data was the Page model. The powders resulted in a slightly acidic pH, around 6.02. Average water activity of 0.360 within the parameters required by legislation. The powder moisture varied between 6.98 and 9.02%. The basil leaf powder showed ash content with an average of 12.35%, soluble solids below 2.5 ºBrix and water solubility index between 20.55 ± 0.07% and 54.58 ± 0.14% . When comparing the powder obtained by drying in a foam layer with the powder obtained by lyophilization, we have products with similar characteristics. The characteristics of the basil leaf were preserved, indicating that the foam layer drying technique is a viable process for obtaining its powder form.