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 [Espectroscopia no Infravermelho em Transformada Fourier para a análise de ureia em leite normal e adulterado]
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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... 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
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... 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...
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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... 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...
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ABSTRACT O presente trabalho teve como objetivos quantificar o teor de soro e o índice de caseinomacropeptídeo (CMP) de bebidas lácteas fermentadas preparadas em laboratório, adicionadas de diferentes concentrações de soro (0, 10, 20 e... more
ABSTRACT O presente trabalho teve como objetivos quantificar o teor de soro e o índice de caseinomacropeptídeo (CMP) de bebidas lácteas fermentadas preparadas em laboratório, adicionadas de diferentes concentrações de soro (0, 10, 20 e 40%), fermentadas e armazenadas em refrigeração (8-10oC) por tempos distintos (zero, sete, 14 e 21 dias), por cromatografia líquida de alta eficiência-filtração em gel (CLAE-FG), bem como verificar a interferência da cultura utilizada no preparo das bebidas lácteas fermentadas e do tempo de armazenamento na detecção de soro lácteo e CMP. Quando os teores de soro lácteo e os índices de CMP obtidos por CLAE-FG de bebidas lácteas fermentadas foram analisados ao longo do tempo de armazenamento, verificou-se que não houve diferença (p&gt;0,05) para o leite (0% de soro) e as bebidas lácteas com 10 e 20% de soro nos tempos de zero, sete, 14 e 21 dias de armazenamento. No entanto, para a bebida láctea fermentada adicionada de 40% de soro, foi observada diferença para o tempo de armazenamento de 21 dias (p&lt;0,05), em que o teor de soro e o índice de CMP obtidos foram maiores que os demais, que se mostraram equivalentes entre si (p&gt;0,05) para os tempos de zero, sete e 14 dias.
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Abstract Text: Production of antimicrobial substances by Staphylococcus aureus isolated from food has been reported. Since it is a highly prevalent etiologic agent for mastitis in dairy herds, inhibition of starter culture due to S.... more
Abstract Text: Production of antimicrobial substances by Staphylococcus aureus isolated from food has been reported. Since it is a highly prevalent etiologic agent for mastitis in dairy herds, inhibition of starter culture due to S. aureus inhibitory activity is possible during the processing of fermented dairy products, such as cheeses. The objective of the current work was to evaluate the antimicrobial substances produced by samples of S. aureus isolated from cow’s milk during mastitis occurrence and their effect against strains of Lactococcus spp. Individual milk samples, obtained from 54 herds, were analyzed for S. aureus presence and isolated strains were tested for inhibitory activity using the deferred-antagonism assay, with Corynebacterium fimi (NCTC 7547) as indicator. Proteic nature of the antimicrobial substances was investigated using protease type XIV from Streptomyces griseus (Sigma P-5147). Inhibitory spectrum was tested against nine Lactococcus spp. strains, previous...
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... more
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...
Abstract Text: The microbial contamination of milk is influenced by several factors and it is one of the major hindering problems for milk quality improvement in Brazil. The objective of the present work was to evaluate total bacteria... more
Abstract Text: The microbial contamination of milk is influenced by several factors and it is one of the major hindering problems for milk quality improvement in Brazil. The objective of the present work was to evaluate total bacteria counting of milk collected in different storage systems. A total of 1,080 samples of milk from three regions of Minas Gerais State (Triângulo Mineiro, Sul, and Leste) were analyzed for total bacteria counting, during a 12-month period. The samples were randomly selected from three storage systems, individual bulk tank milk, collective bulk tank milk, and cans. The last two storage systems are exceptionally allowed in Brazil under specific conditions. Each storage system was represented by 360 samples, which were preserved with azidiol, and sent to the laboratory for analysis in up to 72 hours, using insulated boxes with reusable ice. All samples were evaluated by flow cytometry in the official federal net of laboratories for milk quality analysis in Br...
Abstract Text: High solids, fat and protein contents of sheep’s milk render it an attractive option for production of exclusive cheeses. However, this activity is still being structured in Brazil. The objective of the present work was to... more
Abstract Text: High solids, fat and protein contents of sheep’s milk render it an attractive option for production of exclusive cheeses. However, this activity is still being structured in Brazil. The objective of the present work was to evaluate the composition and yield of cheeses produced with milk obtained from sheeps fed diets containing soybean seed or linseed. Twenty-eight Lacaune, Santa Inês and crossbreeds sheep were allocated to two equal groups according to the diet. The milk obtained from each experimental group was used for cheese manufacture, and samples of this milk and whey were collected for laboratorial analyses and to complement cheese yield determination. The cheeses were aged for 30 days under low temperature storage (10-12°C), and analyzed for determinations of fat, protein, moisture and total solids contents. The data was evaluated using SNK test at 5% of significance. No influence of the diets on milk and whey composition was found (p>0.05). Similarly, no ...
Abstract Text: Ultra high temperature (UHT) milk-whey-based-drinks are obtained by processing a mix of milk and cheese whey. In Brazil, this may additionally be added of food ingredients, vegetable fat, and other milk derivatives. The... more
Abstract Text: Ultra high temperature (UHT) milk-whey-based-drinks are obtained by processing a mix of milk and cheese whey. In Brazil, this may additionally be added of food ingredients, vegetable fat, and other milk derivatives. The intake of this product is popular among children in Brazil, and it is commonly used to replace milk consumption. Consequently, nutritional concerns emerge because of the low protein content due to whey addition. The objective of this work was to evaluate the protein content and microbial contamination, and to estimate the caseinomacropeptide index (CMP) of this beverage. Fifty-six samples of UHT chocolate milk-whey-based drinks from seven dairy plants, and eight production lots each were collected in the city of Belo Horizonte, MG (Brazil) and analyzed for protein content (Kjeldahl), CMP index by high performance liquid chromatography (HPLC) and count of aerobic mesophilic bacteria (total plate count). Descriptive statistics was used. All samples were ...
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Moisture determination in cheese is a critical test for regulatory compliance, functionality, and economic reasons. Common methods for moisture determination in cheese rely upon the thermal volatilization of water from cheese and... more
Moisture determination in cheese is a critical test for regulatory compliance, functionality, and economic reasons. Common methods for moisture determination in cheese rely upon the thermal volatilization of water from cheese and calculation of moisture content based on the resulting loss of mass. Residual sugars, such as lactose and galactose, are commonly present in cheeses at levels ranging from trace amounts to 5%. These sugars are capable of reacting with other compounds in cheese, especially under the thermal conditions required for moisture determination, to yield volatile reaction products. The hypothesis of this work is that residual sugars in cheese will be converted into volatile compounds over the course of moisture determination at a level sufficient to result in overestimated cheese moisture. A full-factorial statistical design was used to evaluate the effects of cheese type, sugar type, sugar level, method type, and all interactions. Cheddar and low-moisture, part-skim (LMPS) Mozzarella cheeses were prepared with 1, 3, and 5% added lactose or galactose, and subjected to either vacuum oven or microwave-based moisture determination methods. Browning index and colorimetry were measured to characterize the color and extent of browning. Volatile analyses were performed to provide chemical evidence of the reactions proposed. The presence of residual sugars altered moisture calculations as a function of cheese type, sugar type, sugar level, method type, and numerous interactions. At higher concentrations of residual sugar, the percentage moisture determinations were increased by values of up to 1.8. Measures of browning reactions, including browning index, colorimetry, and volatile profiles demonstrate that the proposed browning reactions played a causative role. This work establishes the need to consider cheese type, sugar type, sugar levels, and method type as a means of more accurately determining moisture levels.
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... Métodos físicos e químicos. Diário Oficial da União, n.83, p.15, seção 1, 2003. [ Links ]. CHIAPPINI, CCJ; FRANCO, RM; OLIVEIRA, LAT Avaliação do soro de queijo quanto aos coliformes totais e coliformes fecais. Rev. Inst. Lat. Cândido... more
... Métodos físicos e químicos. Diário Oficial da União, n.83, p.15, seção 1, 2003. [ Links ]. CHIAPPINI, CCJ; FRANCO, RM; OLIVEIRA, LAT Avaliação do soro de queijo quanto aos coliformes totais e coliformes fecais. Rev. Inst. Lat. Cândido Tostes, v. 50, p.253-257, 1995a. [ Links ]. ...
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Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the... more
Casein (CN) micelles are colloidal aggregates of protein dispersed in milk, the importance of which in the dairy industry is related to functionality and yield in dairy products. The objective of this work was to investigate the correlation of milk CN micelles diameter from Holstein and Zebu crossbreds with milk composition (protein, fat, lactose, total and nonfat solids and milk urea nitrogen), somatic cell count (SCC), age, lactation stage and production. Average casein micelles diameters of milk samples obtained from 200 cows were measured using photon correlation spectroscopy and multiple regression analysis was used to find relationship between variables. CN micelle diameter, SCC and nonfat solids were different between animals with different Holstein crossbreed ratios, which suggests influence of genetic factors, mammary gland health and milk composition. Overall, results indicate the potential use of CN micelle diameter as a tool to select animals to produce milk more suitabl...
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The influence of somatic cells counts (SCC) in milk on bioactive amines in Mozzarella cheese was investigated. High SCC milk had lower lactose and higher pH compared to low and medium SCC. Low spermine levels were found in milk... more
The influence of somatic cells counts (SCC) in milk on bioactive amines in Mozzarella cheese was investigated. High SCC milk had lower lactose and higher pH compared to low and medium SCC. Low spermine levels were found in milk irrespective of SCC. The cheeses had similar characteristics, but the extension and depth of proteolysis increased with SCC. Cheese from all SCC categories contained spermine; whereas tyramine and tryptamine were only detected in cheese from high SCC milk. During 60-days refrigerated storage, significant positive effects were observed between SCC and proteolysis, storage time and pH and storage time and proteolysis. There was a significant positive effect of storage time on spermine and serotonin levels. Only cheese from high SCC milk showed significantly higher serotonin levels. Tyramine and tryptamine were found in cheese from high SCC milk.
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A specific range of methyl ketones contribute to the distinctive flavor of traditional blue cheeses. These ketones are metabolites of lipid metabolism by Penicillium mold added to cheese for this purpose. Two processes, namely, the... more
A specific range of methyl ketones contribute to the distinctive flavor of traditional blue cheeses. These ketones are metabolites of lipid metabolism by Penicillium mold added to cheese for this purpose. Two processes, namely, the homogenization of milk fat and the addition of exogenous lipase enzymes, are traditionally applied measures to control the formation of methyl ketones in blue cheese. There exists little scientific validation of the actual effects of these treatments on methyl ketone development. The present study evaluated the effects of milk fat homogenization and lipase treatments on methyl ketone and free fatty acid development using sensory methods and the comparison of selected volatile quantities using gas chromatography. Initial work was conducted using a blue cheese system model; subsequent work was conducted with manufactured blue cheese. In general, there were modest effects of homogenization and lipase treatments on free fatty acid (FFA) and methyl ketone concentrations in blue cheese. Blue cheese treatments involving Penicillium roqueforti lipase with homogenized milk yielded higher FFA and methyl ketone levels, for example, a ∼20-fold increase for hexanoic acid and a 3-fold increase in 2-pentanone.
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Despite being the largest state producer of milk in the country, Minas Gerais and comprehensive little work has updated on the interference of climatic factors on the animal. The objective with the present study, to assess the climatic... more
Despite being the largest state producer of milk in the country, Minas Gerais and comprehensive little work has updated on the interference of climatic factors on the animal. The objective with the present study, to assess the climatic effects on the chemical composition of milk and blood composition of Holstein cows from the region of Montes Claros. We used 10 female Holstein in milk, and observed parameters of the chemical composition of milk and blood, and records the respiratory rate, body temperature, milk production and index of thermal comfort, such as temperature and humidity index (THI) and index of the globe temperature and humidity (BGHI). It is concluded that there was interference of climatic factors in levels of compounds in milk, as well as some components of blood.