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: Chemistry & Salmonella. The organization has 1153 authors who have published 1189 publications receiving 14442 citations.

Spot test for aliphatic and aromatic cyanides: A contribution to the chemistry of specific, selective and sensitive reactions

Abstract: Studies of the pyrolytic behavior of cyanides (nitriles) have shown: 1. When aromatic and aliphatic cyanides (nitriles) are pyrolysed in the presence of sulfur, they split off thiocyanic acid. 2. Aliphatic cyanides yield hydrogen cyanide when the dry mixture with calcium oxide or carbonate is heated to 150°. 3. The detection of the thiocyanic acid or hydrogen cyanide produced in 1. and 2. forms the basis of new tests for cyanides. 4. The pyrolytic splitting off of thiocyanic acid is not specific for cyanides because this product also results with compounds which have a C=N group. 5. The test for aliphatic cyanides is specific.

Spontaneous melanotic lesions in axillary seabream, Pagellus acarne (Risso).

Abstract: In this article, we describe spontaneous melanotic lesions in the skin of axillary seabream, Pagellus acarne (Risso), from a defined area of the Portuguese Coast, located in Cabo da Roca and Foz do Arelho The lesions corresponded to the black pigmentation spots on the skin of the head, fins, lips and conjunctiva and, additionally, black nodules on the skin of the head and lips In some specimens, the nodular formations in the head changed their anatomical conformation Histologically, there were melanophores scattered along the basement membrane or forming aggregates in the dermis, infiltrating the subcutaneous tissue but not invading the adjacent muscle tissue The aim of this study was to characterize the macroscopic and microscopic features of the pigmented lesions These fish show sessile hyperpigmented lesions (spots) that correspond to proliferative lesions of melanophores in the dermis and nodular lesions that correspond to neoplastic lesions, melanophoromas The melanophores in such lesions showed high concentration of melanin in the cytoplasm, moderate pleomorphism and compact distribution throughout all of the dermis

Cinética de inativação de inibidores de tripsina e de insolubilização de proteínas de diferentes cultivares de soja

Abstract: A soja (Glycine max (L.) Merrill) e uma das leguminosas mais estudadas, em virtude de sua intensa utilizacao como fonte de oleo comestivel e proteina para alimentacao humana e animal. A presenca de inibidores de tripsina na soja limita sua utilizacao, tornando necessario o processamento termico para melhorar sua qualidade nutricional. Entretanto, o processamento termico excessivo ou inadequado pode reduzir a qualidade da proteina. Neste trabalho, foram utilizados cultivares de soja BR-36, com atividade normal de inibidores de tripsina, e cultivares BRM 95-5297 e BRM 95-5262, com baixas atividades de inibidores de tripsina. As farinhas com 10 e 16% de umidade foram aquecidas em banho a 95°C, com cinco intervalos (15, 25, 50, 75 e 100 minutos) de retencao; em seguida, foram determinados os respectivos parâmetros cineticos de inativacao de inibidores de tripsina e de insolubilizacao de proteinas. A partir da cinetica de primeira ordem para inativacao de IT e insolubilizacao de proteinas, observou-se que as constantes de velocidade de reacao de inibidores de tripsina aumentaram, com consequente reducao no tempo de processamento termico dos cultivares de soja BRM 95-5297 e BRM 95-5262 quando comparados ao cultivar BR-36. O acrescimo de 6% de umidade nas farinhas tambem aumentou as constantes de velocidade de inativacao de inibidores de tripsina e de insolubilizacao de proteinas.

Within-laboratory validation of a multiresidue method for the analysis of 98 pesticides in mango by liquid chromatography-tandem mass spectrometry.

Abstract: A within-laboratory validation procedure for a selective and sensitive method for the simultaneous determination of 98 pesticide residues in mango is presented. QuEChERS extraction was adapted to laboratory conditions. Mango samples (10 g) mixed with sodium sulfate (4 g) and sodium acetate (1 g) were extracted with acetonitrile/acetic acid (99/1 v/v), cleaned using dispersive solids, and subsequently identified and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pesticides were separated on a reversed-phase column using a gradient elution in conjunction with positive-mode electrospray ionisation. The analytical performance of the method was demonstrated by analysis of spiked mango samples at three concentration levels (0.01, 0.05 and 0.1 mg kg−1) for 3 different days, and the analysis was performed by three analysts. Calibration curves were statistically acceptable by the ordinary last-square method (OLSM), with a regression coefficient above 0.98 for all analytes. The method accu...