Secagem e armazenamento de folhas de guaçatonga (Casearia sylvestris Swartz var. língua): caracterização de folhas e extratos aquosos Colina natural na nutrição de frangos de corte

Abstract

Casearia sylvestris Swartz var. língua, popularly known as guaçatonga, has anti inflammatory, anti-rheumatic, anti-arthritic, cardiotonic, anti-obesic properties, among other medicinal characteristics.Medicinal plants, when collected, need to be dried and stored correctly, in order to preserve the quality of the chemical constituents present, allowing their use for long periods in addition to maintaining their therapeutic action. However, despite being essential steps for the conservation of plant material, when not carried out correctly, they can lead to the degradation of compounds of medicinal interest. The experiment was conducted at the Laboratory of Physical Properties of Agricultural Products, Faculty of Agricultural Sciences, Federal University of Grande Dourados and CERNA Laboratory, State University of Mato Grosso do Sul. Freshly harvested guaçatonga leaves were dried in an experimental dryer at temperatures of 40, 50, 60 and 70 ºC and drying air speeds of 0.4 and 0.8 m s-1. Mathematical models traditionally used to estimate the drying curves of agricultural products were fitted to the drying data. The water reduction rate, the effective diffusion coefficient, the activation energy and the influence of drying temperatures on the color and medicinal characteristics were also determined, which were determined by the total content of phenolic compounds, flavonoids and potential antioxidant. The storage was carried out after drying the leaves for 180 days in different types of packaging, and every 60 days the effect of storage time and the type of packaging on the color and chemical composition of the leaves were evaluated. For the analysis of the chemical composition, the aqueous extract obtained from the dried leaves of C. sylvestris was used. For drying, the results allowed us to conclude that: the Midilli model satisfactorily represented the drying curves of the leaves; the increase in temperature and drying air velocity resulted in an increase in the water reduction rate and in the values of the effective diffusion coefficient; the increase in drying air speed promotes an increase in the magnitudes of activation energy; the increase in temperature and drying air speed resulted in a decrease in the total levels of phenolic compounds, flavonoids and DPPH.There was an influence of drying temperatures as well as the storage period on the color of dry leaves when compared to fresh leaves. The drying and storage processes evaluated maintained the leaf quality standards and chemical composition throughout the evaluation period.