Leorges Fonseca | UFMG - The Federal University of Minas Gerais (original) (raw)

Papers by Leorges Fonseca

Figure S1. On the utilization of deep and ensemble learning to detect milk adulteration. (PDF 56 kb)

Fourier Transform Infrared Spectroscopy (FTIR) for MUN analysis in normal and adulterated Milk [E... more Fourier Transform Infrared Spectroscopy (FTIR) for MUN analysis in normal and adulterated Milk [Espectroscopia no Infravermelho em Transformada Fourier para a análise de ureia em leite normal e adulterado]

Handbook of Milk of Non-Bovine Mammals

Geriatrics, gerontology and aging, 2010

ABSTRACT Abstract Text: The aim of this study was to evaluate the seasonal correlation of somatic... more ABSTRACT Abstract Text: The aim of this study was to evaluate the seasonal correlation of somatic cell count (SCC) and composition of raw milk. A total of 287,000 samples of raw milk were analyzed during twelve consecutive months by the UFMG Milk Quality Laboratory (UFMG/Veterinary School; LabUFMG) for composition and SCC. The data were analyzed using descriptive statistics, according to the months of production and SCC ranges: Range 1: SCC ≤ 200,000 cells/mL; 2: SCC from 201,000 to 400,000 cells/ml; 3: SCC from 401,000 to 750,000 cells/ml, and 4: SCC> 750,000 cells/mL. The least significant difference between treatments was evaluated using Tukey’s test, with significance level of 5% in a randomized complete block design. SCC indexes (SCC Log/mL) were higher from January to April and from October to December, with peaks of SCC in February and March (rainy season). The lowest results for SCC (p<0.05) were observed from May to September (dry season), with lower average results during the month of May. The highest fat, protein and total solids contents, and the lowest SCC were found during the dry season (p < 0.05), while the lowest concentrations were observed during the rainy season (spring and summer). The increase in SCC was correlated with reduction in lactose, solids nonfat and protein concentrations (p < 0.05), except for SCC range higher than 750,000 cells/mL. In this range, protein content was higher if compared to the levels found in SCC range of 401,000 to 750,000 cells/mL (p < 0.05), but similar to the levels found in milk with SCC range from 201,000 to 400,000 (p > 0.05). This fact may be related to a reduction in milk secretion, and passage of serum proteins into the milk due to a more pronounced inflammatory process. Fat contents were higher (p<0.05) for elevated SCC, which may be linked to lower milk secretion because of mastitis. Keywords: milk quality, composition, somatic cells

Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2010

Avaliou-se o efeito protetor das frações proteicas do soro do leite sobre as vilosidades intestin... more Avaliou-se o efeito protetor das frações proteicas do soro do leite sobre as vilosidades intestinais de camundongos Balb/C, fêmeas, infectadas por Escherichia coli O157:H7. Foram utilizados 48 animais, distribuídos aleatoriamente em oito grupos de seis fêmeas cada um. Os animais dos grupos 1 e 2 (controles) receberam dieta AIN93G padrão; os dos grupos 3 e 4, AIN93G + alfalactalbumina; os dos grupos 5 e 6, AIN93G + betalactoglobulina e os dos grupos 7 e 8, AIN93G + concentrado proteico total e água ad libitum por sete dias. No dia zero, os animais dos grupos 2, 4, 6 e 8 foram inoculados, por meio de cânula de gavagem, com 0,5mL de E. coli O157:H7, na concentração de 7 x 10(10)UFC/mL. Os animais foram acompanhados clinicamente e sacrificados, no oitavo dia experimental. Verificou-se, por meio de exames histológicos e da morfometria, que as frações betalactoglobulina e alfalactalbumina exerceram efeito protetor sobre as vilosidades intestinais do jejuno distal e do íleo (P<0,05), re...

Scientia Agricola, 2017

Veterinary drug residues in bulk tank milk are important to all sectors of the dairy chain becaus... more Veterinary drug residues in bulk tank milk are important to all sectors of the dairy chain because they are one of the major factors which determine the safety of the final product. This study attempted to identify milk quality parameters that are associated with the occurrence of veterinary drug residues using multivariate principal component analysis (PCA). A total of 132 raw milk samples were collected from 45 dairy farms in the state of Minas Gerais-Brazil and analyzed for 42 analytes, including pyrethroids, macrocyclic lactones and antibacterials, using liquid chromatography coupled with mass spectrometry in tandem mode and gas chromatography with electron capture detection. Out of the 132 milk samples, 40 samples tested positive for at least one analyte (above the detection limit). The milk parameters associated with the antimicrobial residues by confirmatory tests were lactose and nonfat concentrations, as revealed by PCA. This analysis showed that fat and total solid concentrations, as well as the somatic cell and total bacteria counts were associated with macrocyclic lactone residues in bulk tank milk. A PCA assessing pyrethroid residues in bulk tank milk revealed that the lactose and nonfat solid concentrations and titratable acidity were inversely associated with these residues. Thus, the data analysis indicated that the veterinary drug residues were associated with certain milk quality parameters that can be used to target farms at higher risk of veterinary drug residue contamination for testing programs in combination with incentives, education and training programs to improve mammary health, milk hygiene and safety.

Pesquisa Veterinária Brasileira

ABSTRACT: A survey of veterinary drug residues in bulk milk tank from Minas Gerais State, Brazil,... more ABSTRACT: A survey of veterinary drug residues in bulk milk tank from Minas Gerais State, Brazil, was carried out through a broad scope analysis. Here, 132 raw milk samples were collected at 45 dairy farms in Minas Gerais from August 2009 to February 2010, and analyzed for 42 analytes, comprising pyrethroids, macrocyclic lactones and antibacterials, using liquid chromatography coupled with mass spectrometry in tandem mode and gas chromatography with electron capture detection. Within all milk samples, at least one veterinary drug residue was identified in 40 milk samples (30.30%) by confirmatory tests, whereas 16 samples (12.12%) showed the presence of at least two residues. With regard to the Brazilian maximum residue levels, 11 milk samples (8.33%) were non-compliant according to Brazilian Legislation. The veterinary drugs detected in the non-compliant milk samples include penicillin V (one sample), abamectin (one sample) and cypermethrin (nine samples). Furthermore, the antibacte...

Pesquisa Veterinária Brasileira, 2016

Revista do Instituto Adolfo Lutz, 1941

Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2014

Caseinomacropeptide (CMP) index is a method used to detect adulteration of milk by addition of ch... more Caseinomacropeptide (CMP) index is a method used to detect adulteration of milk by addition of cheese whey, since CMP is a glycopeptide characteristic produced during cheesemaking, and soluble in the whey phase. The objective of this work was to evaluate the caseinomacropeptide index of UHT milk stored under different temperatures. Six batches of recently processed UHT milk were collected and stored under three temperatures (21°C, 6°C, and -12°C) and analyzed by HPLC in the day of the milk collection (day 0) and at 30, 60, 90, and 120 days of storage. The experiment was run as a randomized block design with a 3x5 factorial arrangement, and the Student-Newman-Keuls (SNK) method was used as the posthoc test (p = 0.05). There was a progressive increase of the CMP index during the storage period of 120 days, and this indicates the possibility of false positive results if the CMP index is used as an adulteration test for long term stored UHT milk. The validity of the CMP index as an adulteration indicator is only possible soon after packaging, and sample freezing is the only alternative when immediate analysis is not possible. The method was found to be precise, with robust CV of 1.9% even with high CMP levels. Keywords: UHT whole milk, caseinomacropeptide, HPLC RESUMO O objetivo deste trabalho foi avaliar a influência da temperatura e do tempo de armazenamento de amostras de leite UAT, em relação ao índice de caseinomacropeptídeo, por cromatografia líquida de alta eficiência, e a precisão do método de detecção. Seis lotes foram coletados e armazenados em três temperaturas (21°C, 6°C e -12°C ± 1°C) e analisadas durante o armazenamento nos dias 0, 30, 60, 90 e 120 dias. Utilizou-se o delineamento em blocos casualizados com os tratamentos em arranjo fatorial 3x5 e os resultados foram comparados por meio do teste Student-Newman-Keuls (SNK) a 5% de significância. Houve aumento progressivo do índice de CMP por CLAE durante os 120 dias; portanto, um produto conforme pode se tornar não conforme sem que ocorra adulteração. A detecção de fraude por adição de soro lácteo em leite UAT pode ser detectada somente após o envase. Caso não seja possível a análise imediata, recomenda-se que as amostras sejam congeladas. O método é muito preciso (CV=1,9%) e indiferente aos níveis de CMP encontrados nas amostras. Palavras-chave: leite UAT, caseinomacropeptideo, CLAE

A água é fundamental para a sobrevivência do homem e para o equilíbrio de toda a natureza. Sua im... more A água é fundamental para a sobrevivência do homem e para o equilíbrio de toda a natureza. Sua importância faz com que hoje ela seja uma preocupação mundial diante das ameaças da poluição, do uso insustentável, das mudanças climáticas e no uso do solo, além dos riscos de escassez. Desta forma, garantir o abastecimento quantitativo e qualitativo nas áreas urbana e rural é um desafio cada vez maior para perpetuar a vida e os processos produtivos.

Arquivo Brasileiro de Medicina Veterinária e Zootecnia

[Comparison between standard method and electronic analyses for measurement of the bovine milk so... more [Comparison between standard method and electronic analyses for measurement of the bovine milk somatic cell count]