SEASONALITY OF THE BARK TANNINS CONTENT OF FIVE-YEAR-OLD Acacia mangium TREES GROWN IN NORTHEAST BRAZIL

Abstract

This study aimed to assess the influence of the seasonality on the bark tannins content of Acacia mangium trees grown in the Northeastern Brazilian Region and the effect of soil preparation on the results. Two experimental plots of 1.0 ha each were submitted to different soil preparation methods, with two different intensities. The experimental design consisted of four treatments, two types of soil preparation and, two different bark collection seasons (end of the rainy and dry seasons). The bark of the trees was collected in each treatment and the contents of condensed tannins were determined. For each experimental treatment, 15 trees were harvested and debarked. Bark material was submitted to extraction with hot water, obtaining the total solids content (TSC), Stiasny index (I), and the condensed tannins content (CTC). There was no influence of the soil preparation method on the TSC, I, and CTC. However, there was a significant difference in these parameters for tree bark collected in the rainy season, with higher values. The less intensive soil preparation method is recommended due to its lower cost, and bark should be collected at the end of the rainy season for the best yield of condensed tannins.

PROPERTIES OF CROSS-LAMINATED TIMBER BONDED WITH AN ADHESIVE BASED ON TANNINS FROM THE BARK OF Mimosa tenuiflora TREES

“…This comparison shows that M. tenuifl ora has real potential as a source of tannins, so it can help reduce the overexploitation of A. colubrina in Brazil. It is important to note that the diff erences found between the values in the studies mentioned here for TS, I, and CT in the bark also can be related to diff erences in the age of the trees, time of the year when the bark was collected, the position of collection in the trees and mainly the site quality (Paes et al, 2010;Souza et al, 2021).…”

Tannin-rich tree bark extracts inhibit the development of bacteria associated with bovine mastitis

“…Regarding the concentration of TF present in the bark extract, Mimosa tenuiflora was the only species that presented a value greater than 100 mg GAE/g. These variations between the values for the different parameters used in this study can be justified by the difference between the tree species, bark collection period, solvents used in the extraction method, and soil and climatic conditions of the trees' original environment (Naima et al 2015;Souza et al 2021).…”