ABSTRACT Blueberry farming can be considered an excellent alternative to diversify the family income. In addition, the fruits have several health benefits thanks to the presence of phenolic compounds and anthocyanins, however blueberries chemical composition is affected by edaphoclimatic conditions and bud position within the shoot. Therefore, the objective of the study was to evaluate the influence of the bud position on the total phenolic content, anthocyanins, antioxidant capacity, and other quality parameters of blueberry fruits of three cultivars (Climax, Bluegem, and Powderblue) grown in the mesoregion of Pelotas, Brazil. Fruits of these cultivars were harvested from three shoot position. The fruits were evaluated for their total soluble solids content, pH, total titratable acidity, total soluble solids/total titratable acidity ratio, fruit color, phenolic compounds, anthocyanins, and antioxidant potential against the 2,2-diphenyl-1-picryl-hydrazyl radical. The bud position in the shoots influenced the physicochemical parameters of the blueberry fruits of all cultivars. Fruits harvested from apical levels had higher content of soluble solids, pH, phenolic compounds, anthocyanins, and antioxidant potential, demonstrating that studies aiming at evaluating fruits from different shoot levels are important, as they directly impact the quality of the fruits as well as their biological potentials.

O sistema de degradação utilizando ferro metálico e peróxido de hidrogênio (reação de Fenton) foi empregado para a degradação do herbicida diurom. Visando obter as melhores condições de degradação, foram otimizados parâmetros que influenciam no processo, como pH, concentração de peróxido de hidrogênio (H2O2) e quantidade de ferro. A degradação do herbicida foi acompanhada por cromatografia líquida com detecção por arranjo de diodos (CLAE-DAD) e cromatografia líquida com detecção por espectrometria de massas sequencial (LC-ESI-MS/MS), além da determinação de carbono orgânico total (COT). Nas melhores condições de degradação, pH = 2,5; 2 g de ferro e 2 mmol L-1 de H2O2, uma solução aquosa de diurom comercial (10 mg L-1), alcançou valores não detectáveis ao tempo de 10 min, para diurom e para o metabólito monitorado, 3,4-DCA. Ainda os valores de COT foram reduzidos, chegando a valores menores que 5 mg L-1, mostrando a eficiência e rapidez do sistema.

A degradation system using metallic iron and hydrogen peroxide (Fenton reaction) was employed for the degradation of the diuron herbicide. In order to obtain the maximum degradation the main conditions such as pH, hydrogen peroxide concentration and iron amount, were optimized. Herbicide degradation was evaluated by liquid chromatography with diode array detection (HPLC-DAD) and liquid chromatography tandem mass spectrometric detection (LC-ESI-MS/MS) and total organic carbon analysis (TOC). In the best degradation condition, pH = 2.5, 2 g of iron and 2 mmol L-1 of hydrogen peroxide, after 10 min a commercial diuron solution (10 mg L-1) had no detection values for diuron and its metabolic, 3,4-dichloroaniline (3,4-DCA). The TOC was reduced to values lower than 5 mg L-1 showing the efficiency of the system.

Pesticides can be quite useful in agricultural production, however, some pesticides after application can reach and contaminate the hydric resource. Pesticide monitoring must be careful because it is expensive and lengthy. Thus, in this work, a theoretical prediction was made using the approaches suggested by EPA-USA, the Groundwater Ubiquity Score index (GUS) and the Goss method associated with physicochemical properties of 27 pesticides used in a region in the south of Brazil. The results of this work led to the identification of the pesticides that should be prioritized in the environmental monitoring due to their high potential for contaminating water resources.