Felipe Machado Trombete

Chemical, Technological and Sensory Properties of Wheat Grains (Triticum aestivum L) as Affected by Gaseous Ozonation

Gaseous ozonation, an emerging technology, is applied to microbiological decontamination and to the degradation of residues and contaminants in wheat grains. However, due to its high oxidizing capacity, ozone may cause undesirable effects on the quality of grains or in their derivatives. This study aimed to evaluate the influence of ozone gas on wheat grain quality when exposed to different levels of ozone concentration, exposure time, and grain mass, using a full 23 factorial design. After the milling of ozonized grains, two fractions were evaluated: flour (A) and bran plus germ (B). In fraction A, the quality of the wheat flour was analyzed by both alveography and farinography. The flour extraction rate, falling number and gluten contents were also measured. The chemical and mineral profiles were determined in both fractions. A sensory evaluation, using the difference-from-control test, was applied to investigate the possible differences in aroma or in overall appearance of the flour obtained from the ozonized grains. The results showed that ozone concentration (60 mg/L) positively affected (p < 0.05) the toughness and the falling number of the flour. The other parameters of alveography, as well as farinography, gluten content, chemical composition, mineral, and sensory profiles were not affected (p > 0.05) by ozonation. This study demonstrated that gaseous ozonation, when applied under the conditions of 10 to 60 mg/L, from 2 to 5 h of exposure, grain mass from 2 to 5 kg, does not cause any negative impact on the wheat quality.

In-house validation of a method for determining aflatoxins B1, B2, G1 and G2 in wheat and wheat by-products

Aflatoxins are naturally occurring carcinogenic substances, extremely toxic to humans, which have been identified in wheat and wheat by-products. The use of reliable analytical methods to evaluate and monitor such contaminants is extremely important. This study aimed to in-house validate a methodology to determine aflatoxins B 1 , B 2 , G 1 and G 2 in wheat grains using pre-column derivatization and quantification by High Performance Liquid Chromatography with fluorescence detection (HPLC-FLD). Three methods were evaluated and the most suitable one was the method based on the extraction with chloroform, removal of interfering chemicals by filtration, liquid-liquid partition with hexane-methanol-water and methanol-water-chloroform and pre-column derivatization with trifluoroacetic acid. The method showed a Relative Standard Deviation lower than 15% and recovery values in the 70-110% range, with limits of detection and quantification (0.6 µg kg -1 and 1.2 µg kg -1 , respectively) below the maximum level of aflatoxins allowed in wheat and wheat by-products by the European Commission (4.0 µg kg -1 ) and by the Brazilian legislation (5.0 µg kg -1 ). Using the validated method, aflatoxins were quantified in 20 commercial samples of wheat grains, wheat bran, whole wheat flour and refined wheat flour intended for direct human consumption. Six samples (30%) were positive for aflatoxins and all samples presented levels below the maximum limit stipulated by the Brazilian legislation.

Residuos de antibióticos en la leche comercializada en Brasil: una revisión de los estudios publicados en los últimos años

Los antibioticos se utilizan ampliamente para el tratamiento de las vacas lecheras y los residuos de estos medicamentos pueden permanecer en la leche y los productos lacteos, los que pueden ser una amenaza potencial para la salud humana. La exposicion a bajos niveles de antibioticos se considera un problema de salud publica ya que pueden resultar en el desarrollo de cepas resistentes de bacterias humanos. De acuerdo con la legislacion brasilena, los antimicrobianos deben ser utilizados de acuerdo con las Buenas Practicas Agricolas. Sin embargo, estudios recientes han informado de la contaminacion de la leche comercializada en el pais. Este trabajo tuvo como objetivo revisar los estudios publicados en los ultimos 10 anos, que describen residuos de antimicrobianos en la leche comercializada en Brasil. Se discuten los limites maximos de residuos, los metodos para la cuantificacion y los resultados de los estudios publicados por autores y agencias gubernamentales

Aflatoxin M1 contamination in grated parmesan cheese marketed in Rio de Janeiro - Brazil

This study aimed to determine the occurrence of AFM 1 contamination in the samples of grated parmesan ch eese marketed in the Metropolitan Region of Rio de Janei ro - Brazil. Thirty samples representing 10 major b rands marketed in the region were analyzed by High Perfor mance Liquid Chromatography with fluorescence detec tion (HPLC-FLD) after purification with immunoaffinity cThe method showed recovery values within the range of 70-90%, with RSD lower than 15% and limits of de tection and quantification below the maximum level allowed by the European Commission for the presence of AFM 1 in cheeses. The mycotoxin was identified in 18 (60% ) of the grated cheese samples tested. The highest value cor responded to 0.69 ± 0.02 μg/kg and the mean for all the analyzed samples was 0.16 μg/kg. All the samples were lower than the limit est ablished by the Brazilian legislation (2.5 μg/kg) for AFM 1 in cheeses in general. However, eight samples (26. 7%) presented AFM 1 levels above the tolerance limit of 0.25 μg/kg adopted by the European Commission. These results i ndicated that AFM 1 levels in the grated cheese consumed in Rio de Janeiro - Brazil w ere relatively high and it could provide a potentia l hazard for the public health.

Aflatoxinas y tricotecenos en trigo y derivados: incidencia de la contaminación y métodos de determinación

Trichothecenes and aflatoxins are natural contaminants produced by filamentous fungi and they are widely present in wheat. The presence of these mycotoxins a...

Contaminação de queijos por aflatoxina M1: uma abordagem sobre a ocorrência e prevenção

Mycotoxins are toxic metabolites produced by filamentous fungi and are widely dispersed in cereals. Aflatoxin M 1 (AFM 1 ) is the principal Aflatoxin B 1 (AFB 1 ) metabolite present in the milk. This mycotoxin is a potent human and animal carcinogen and remains stable during the industrial processes to which milk is subjected when manufacturing dairy products, consequently, it can be found in cheeses. In cheese, AFM 1 levels are higher than others dairy products due the affinity of AFM 1 for milk protein. This fact represents a serious public health problem because cheeses are consumed by all age groups from infants to the aged. In this review, were discussed the occurrence and prevention of AFM 1 contamination in cheeses, including the new limits established by ANVISA from 2011 and quantification methods commonly used. Based on the Theory of Obstacles of Leistner was constructed a schematic illustration of the main barriers to aflatoxin contamination animal feeds and, consequently, prevention of the risk of AFM 1 contamination in cheeses. Conventional and alternative methods for decontamination and prevention of aflatoxin contamination of foods were also addressed. Can be concluded that the occurrence of AFM 1 in cheeses is high and it constitutes a risk to consumer health, however, in this review was not observed samples higher than the limit established by Brazilian legislation for cheeses. On the other hand, a continuous monitoring and more studies are necessary to quantify AFM 1 in cheeses and other milk products marketed in Brazil.