Ministry of Agriculture

About: Ministry of Agriculture is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Biology & Chemistry. The organization has 1153 authors who have published 1189 publications receiving 14442 citations.

Profiling of dynamic changes in non-volatile metabolites of shaken black tea during the manufacturing process using targeted and non-targeted metabolomics analysis

Abstract: Shaken black tea (SBT) is a new type of black tea that combines the traditional black tea processing technology with the shaking process of oolong tea. In this study, non-targeted metabolomics analysis based on ultra-high-pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was applied to comprehensively analyze the non-volatile metabolites of SBT during the manufacturing process. Using multivariate statistical analysis, 93 compounds were screened as differential compounds. During the whole process of SBT, amino acids, dipeptides, theaflavins and lipids contents showed significant increases, while that of catechins and procyanidin C1 significantly decreased. Compared with fresh leaves, the content of proteinaceous amino acids (PAAs) in the dried black tea increased 1.61-fold, and total catechins decreased to 7.25%. The results of hierarchical clustering analysis (HCA) showed that fermentation is the key process that causes the variations of these metabolites, followed by drying and shaking. The biosynthesis metabolism of amino acids, flavonoids and linoleic acid are abundant, mainly due to the stress response of fresh tea leaves to dehydration and mechanical damage during shaking processing. It is beneficial to explore the quality formation during the production of SBT through comprehensive analysis of the changes in metabolites.

Erodibilidade entressulcos e atributos de solos com B Textural e B Latossólico do sul de Minas Gerais

Abstract: The objectives of this work were to assess soil and water losses and determine interrill erodibility (Ki) of three soils with clayey texture: Typic Rhodudult (PE), a Typic Hapludult (PV) and a Rhodic Hapludox (LR) for the application of the WEPP (Water Erosion Prediction Project) model in Lavras, Minas Gerais, Brazil and to evaluate the relationship between Ki and some physical, chemical and mineralogical soil properties and surface characteristics. The experiment was set in a completely randomized block design, consisting of three clayey soils, four slopes (15, 25, 35 and 45%), five simulated rainfall intensities (50, 60, 70, 90 and 120 mm h-1 ) and five replicates, and carried out under prewetted conditions. The Ki values were determined from the simulated rain intensities, plot declivities and interrill erosion rates across each simulated rain. The results showed that the PV had the highest interrill erodibility (Ki) followed by the PE and LR. The interrill erodibibity rates determined were: 4,67 x 105 kg s m-4 for PE; 6,85 x 105 kg s m-4 for PV and 3,38 x 105 kg s m-4 for LR. The soil parameters that showed the best correlation with interrill erodibility were iron oxide, caulinite, water dispersible clay, total volume of pores, bulk density, particle density, organic matter and aggregates < 0,105 mm.

Chemometric evaluation of darifenacin hydrobromide using a stability-indicating reversed-phase lc method

Abstract: A set of chemometric tools including in silico simulation and design of experiments (DOE) was used to develop and validate an RP-LC/UV method for darifenacin hydrobromide. Retention factor (k′) from darifenacin and resolution (R) between darifenacin and degradation product were assessed by an exploratory study using organic modifier type, organic modifier content, mobile phase pH, flow rate, and column oven temperature as factors in a full factorial 25 design. The significant factors (organic modifier content, mobile phase pH, and column oven temperature) were selected and applied in a central composite design (CCD) with axial points positioned in α = 1.681. The optimum condition was obtained with Derringer's desirability. The validation was performed with a C8 (150 mm × 4.6 mm, 5 µm) column, wavelength 205 nm, 1.1 mL · min−1 flow rate, mobile phase with acetonitrile (MeCN) and orthophosphoric acid (OPA) 0.01% (v/v) pH 3.0 in a ratio 28:72 and column maintained at room temperature (25 ± 1°C). Forced decom...