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.

Determination of ochratoxin A in green coffee by immunoaffinity column cleanup and liquid chomatography: collaborative study.

Abstract: A collaborative study was conducted to evaluate a method using immunoaffinity column cleanup with liquid chromatography (LC) for the determination of ochratoxin A (OTA) in green coffee at levels that could be included in possible future regulations of the European Union. The test portion was extracted with methanol-3% aqueous sodium hydrogen carbonate solution (50 + 50, v/v). The extract was filtered, and the filtrate was diluted with phosphate-buffered saline and applied to an immunoaffinity column containing antibodies specific for OTA. After washing, the toxin was eluted from the column with methanol and quantified by LC with fluorescence detection. Pairs of 4 homogeneous noncontaminated and naturally contaminated materials (mean levels of < 0.12, 2.44, 5.15, and 13.46 ng/g) and blank samples (< 0.12 ng/g) for spiking were sent to 20 participant laboratories from 8 countries. The materials were analyzed according to the method description and all difficulties encountered in the analysis were reported. Statistical analysis was carried out according to the Harmonized Protocol of the International Union of Pure and Applied Chemistry. The relative standard deviation for repeatability (RSDr) ranged from 7.42 to 20.94%, and the relative standard deviation for reproducibility (RSDR) ranged from 16.34 to 29.17%. The method showed acceptable within-laboratory and between-laboratories precision for green coffee materials, as evidenced by HorRat values of < or = 0.85, at the studied range, for spiked and naturally contaminated materials. The mean recovery was 92.8% for green coffee material spiked with OTA at a level of 4.82 ng/g.

Determining aflatoxins B1, B2, G1 and G2 in maize using florisil clean up with thin layer chromatography and visual and densitometric quantification

Abstract: A method for determining aflatoxins B1 (AFB1), B2 (AFB2),G1 (AFG1) andG2 (AFG2) in maize with florisil clean up was optimised aiming at one-dimensional thin layer chromatography (TLC) analysis with visual and densitometric quantification. Aflatoxins were extracted with chloroform: water (30:1, v/v), purified through florisil cartridges, separated on TLC plate, detected and quantified by visual and densitometric analysis. The in-house method performance characteristics were determined by using spiked, naturally contaminated maize samples, and certified reference material. The mean recoveries for aflatoxins were 94.2, 81.9, 93.5 and 97.3% in the range of 1.0 to 242 µg/kg for AFB1, 0.3 to 85mg/kg for AFB2, 0.6 to 148mg/kg for AFG1 and 0.6 to 140mg/kg for AFG2, respectively. The correlation values between visual and densitometric analysis for spiked samples were higher than 0.99 for AFB1, AFB2, AFG1 and 0.98 for AFG2. The mean relative standard deviations (RSD) for spiked samples were 16.2, 20.6, 12.8 and 16.9% for AFB1, AFB2, AFG1 and AFG2, respectively. The RSD of the method for naturally contaminated sample (n = 5) was 16.8% for AFB1 and 27.2% for AFB2. The limits of detection of the method (LD) were 0.2, 0.1, 0.1 and 0.1mg/kg and the limits of quantification (LQ) were 1.0, 0.3, 0.6 and 0.6mg/kg for AFB1, AFB2, AFG1 and AFG2, respectively.

An improved method for the detection and presumptive identification of Paenibacillus larvae subsp. larvae spores in honey

Abstract: SUMMARYOne of the most important diseases that attacks honey bees (Apis spp.) in the larval stage is American foulbrood (AFB), for which Paenibacillus larvae subsp. larvae is the causative agent. American foulbrood is considered an exotic bee disease in Brazil because it has not yet been detected in the country. Feeding honey containing spores of P. I. larvae to bee larvae can transmit AFB, hence imported honey could spread this disease to Brazil. Since the disease is widely spread in some Latin American countries, including one bordering Brazil, the Brazilian authorities, and beekeepers, are concerned about the risk of introduction of AFB to Brazil. Accordingly, an improved method of detecting spores of P. I. larvae in honey has been developed. The method is based on concentrating spores by centrifugation, inactivating vegetative cells and then inoculating onto a newly developed selective solid medium: Paenibacillus larvae subsp. larvae agar (PLA). Suspect colonies are then selected and cultures are conf...

Situação epidemiológica da brucelose bovina no Estado de Santa Catarina

Abstract: A study to characterize the brucellosis epidemiological situation in the State of Santa Catarina was carried out. The State was divided into five regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 7,801 serum samples from 1,586 herds were collected. In each herd, it was applied an epidemiological questionnaire regarding herd features and also husbandry and sanitary practices that could be associated with risk of infection. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal Test (RBT), and all RBT-positive sera re-tested by the 2-mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalences of infected herds and animals in Santa Catarina State were, respectively: 0.32% [0.10-0.69%] and 0.06% [0.0-0.17%]. The prevalence of infected herds in the regions were: region 1, 0.33% [0.0-0.99%]; region 2, 0.33% [0.0-1.0%]; region 3, 0.25% [0.0-0.75%]; region 4, 0.66% [0.08-1.84%]; and region 5, 0.33% [0.0-1.00%].

Nutrient Release, Plant Nutrition, and Potassium Leaching from Polymer-Coated Fertilizer

Abstract: The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots [...]