RESUMEN
Bovine mastitis is a multifactorial disease, caused mainly by bacteria, whose most traditional method of treatment is the use of antibiotics. However, incorrect administration of these drugs may lead to the emergence of resistant strains. The objective of this study was to identify the most common pathogens causing subclinical mastitis in the northwest State of Paraná, Brazil and establish their antimicrobial susceptibility profiles. A total of 507 foremilk samples were collected in 13 municipalities. Bacteria were identified and their profile of antimicrobial susceptibility were tested. The distribution of positive samples was not homogeneous among the cities. Streptococci were the most frequently genus observed (61%), followed by staphylococci (28%) and other genera (11%). Among streptococci and staphylococci, Streptococcus uberis and Staphylococcus aureus were the most frequently identified species, respectively. Overall, 40% of the isolates showed resistance to at least one of the antibiotics used in this study. A high proportion of cefoperazone resistant Staphylococcus spp. and bacitracin resistant Streptococcus were observed. The isolated microorganisms showed little resistance to enrofloxaxin. The results obtained show the importance of isolating the microorganism causing mastitis and testing its resistance to antibiotics before performing the treatment of the disease.
Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Staphylococcus aureus Resistente a Meticilina , Femenino , Animales , Bovinos , Leche , Brasil/epidemiología , Mastitis Bovina/epidemiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , StaphylococcusRESUMEN
The purpose of the research paper was firstly to identify bacteriocin-producing lactic acid bacteria characterizing strains with anti-listeria activity and, secondly, to characterize bacteriocin evaluating its in vitro efficiency as a natural preservative and, thirdly, to evaluate the anti-listeria effect of the bacteriocinogenic strain of Lactiplantibacillus plantarum in cheeses and produce an edible film with anti-listerial effect. Of 355 lactic acid bacteria strains tested, two were able to produce bacteriocin against Listeria monocytogenes and were identified as Lactiplantibacillus plantarum and Lactiplantibacillus pentosus. A bactericidal effect of strain QS494 (Lactiplantibacillus plantarum) was observed in the first 8 h, with a reduction of 1.7 log, using cell-free supernatant with Listeria monocytogenes, where viable cells were counted on listeria selective agar. Both strains showed good technological characteristics and were without production of virulence factors. Changes in the pH of the cell-free supernatant obtained from Lactiplantibacillus plantarum did not affect its antimicrobial activity, which remained stable after heat treatments for up to 15 min at 121°C. Inhibitory activity was also observed after 12 weeks of storage at -20°C. In the evaluation of the anti-listeria effect in cheeses, a 3 log reduction in the Listeria monocytogenes count was observed in 120 h in cheeses produced with bacteriocinogenic lactic acid bacteria, while in cheeses produced with non-bacteriocinogenic culture, we observed a 2 log increase in the count. Edible films produced with the addition of precipitate from the cell free supernatant showed an antimicrobial effect against Listeria monocytogenes. Thus, the two strains studied have technological and biosafety potential.
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Bacteriocinas , Queso , Lactobacillales , Listeria monocytogenes , Listeria , Animales , Queso/análisis , Microbiología de Alimentos , Bacteriocinas/farmacología , Antibacterianos/farmacologíaRESUMEN
This research communication delineates the quality of pasteurized cow milk sold in Brazil from 2015 to 2020. A cross-sectional study was performed gathering 1749 samples, which were evaluated for microbiological and physicochemical parameters, including Salmonella spp., total and thermotolerant coliforms, freezing point, alkaline phosphatase and lactoperoxidase. The proportion of compliant and non-compliant samples was compared through the years and jurisdiction of the inspection services. Interactions between the design and response variables were assessed by log-linear analysis. Overall, a considerable non-conformity rate (12%) was found for at least one microbiological or physicochemical parameter. Post-pasteurization contamination by coliforms was the major challenge for dairy industries. Notably, the non-compliance rate for freezing point increased during the SARS-CoV-2 pandemic. In addition, the ability to comply was linked to the type of inspection service. Thus, it is suggested that the SARS-CoV-2 pandemic is affecting the dairy industries in Brazil, and we strengthen the need for more studies monitoring the quality of milk over the years, which could assist industries and regulatory agencies to ensure the compliance of pasteurized milk.
RESUMEN
This paper uses the internet-based biosurveillance to describe the Brazilian e-commerce of non-inspected dairy products and maps its traditional sale in a medium-sized city (Londrina). We searched the sales of illegal dairy products on Facebook Marketplace and conducted a census of street markets and a random sample of formal markets. Although prohibited in Brazil, consumers can easily find informal dairy products on internet and retail sale. In addition, 7% of the food products hold a false label to mimic food inspection. The e-commerce was linked with regions with higher access to technology and Human Development Index (HDI). We believe that our approach shows a step forward in the public health interventions and could be replicated stimulating debates about policies required to improve the public health surveillance.
Asunto(s)
Medios de Comunicación Sociales , Humanos , Vigilancia en Salud Pública , Comercio , Ciudades , BrasilRESUMEN
This research communication depicts the quality and authenticity of grated Parmesan cheese sold in Brazil, with novel emphasis on ripening time. The sampling included all brands manufactured and packed at Brazilian dairy plants under federal inspection and sold in Londrina between June and September 2017. A total of 24 samples were analyzed (3 batches of 8 brands) for microbiological and compositional characteristics, including urea-PAGE electrophoresis for the quantitative determination of the milk proteins. About 80% of the samples were insufficiently ripened and 32% with low-fat content. Faced with these economically motivated food frauds, the authenticity of grated Parmesan in Brazil may be under threat. It is high recommended that future surveys and regulatory agencies go further than microbiological assessment, including and emphasizing the ripening time as the main parameter of grated Parmesan cheese.
RESUMEN
In this research communication the genetic diversity of Pseudomonas fluorescens (n = 67) and Pseudomonas putida (n = 44) isolated from refrigerated raw milk from bulk tank trucks were verified. The relationship between the genetic profile of the isolates and their lipoproteolytic potential was evaluated using skim milk agar and tributyrin agar (21°C/72 h). The lipoproteolytic potential (low or high), evaluated by the diameter of the halos (cm), was correlated with the number of milk producing properties that contributed to each sample (one sample = one bulk tank truck; 8-80 producers/sample) and the distance between the dairy properties and the processing plant (21-370 km). P. fluorescens was confirmed in all samples, while P. putida in 60% samples. For both species, two clusters (I and II) were observed, and the first one showed lower genotypic diversity and the presence of isolates with 100% similarity. P. fluorescens isolates presenting at least 70% similarity were 83.9% in Cluster I (n = 31) and 44.4% in Cluster II. In both clusters (I and II) observed in the P. fluorescens dendrogram, the occurrence of high proteolytic and lipolytic potential were equivalent. The higher the number of farms per milk sample, the greater the lipoproteolytic intensity of P. fluorescens isolates. In relation to P. putida isolates, 74% presented at least 50% similarity in Cluster I (n = 27) and only 35% in Cluster II (n = 17). The occurrence of high proteolysis linked to P. putida was proportional between both Clusters, but the occurrence of high lipolysis was greater in Cluster II. No significant association was detected between P. putida isolates and the variables studied. The results indicate the circulation of P. putida and P. fluorescens with 100% similarity in different milk producing regions. The level of genetic diversity was related only to the lipolytic capacity of P. putida.
RESUMEN
Considering the high prevalence of subclinical mastitis and its impacts on milk production, thematic studies are need to provide strategic data for its control. This study aimed at investigating the most frequent microorganisms associated with subclinical mastitis in dairy cows in Brazil through compiling the occurrence of the etiological agents and their sensitivity to antibiotics. The systematic review includes articles published between 2009 and 2019. Fiftyseven articles evaluating 22,287 milk samples were selected. The number of publications and the sample size were not homogeneous among Brazilian regions. Most of the studies and sampling were conducted in Rio Grande do Sul, whereas no studies were found in some states in the north and midwest regions. The most frequent pathogen was Staphylococcus spp. It was isolated in all studies and had an average prevalence of 49% in the analyzed samples. Resistance to penicillin was the most frequent microbial resistance found in Brazil, with an average of 66% among the isolates evaluated. Moreover, bacterial resistance to cephalexin, cefoperazone, erythromycin, gentamicin, neomycin, penicillin, tetracycline, and trimethoprim increased over the research period. Given the territorial extension, the etiological diversity, and the lack of studies with a representative sample, the compilation of scientific data must be interpreted with caution. Regions where a greater number of studies were conducted and with numerous samples, such as the South, provided a comprehensive scenario that is closer to reality. Nevertheless, although decision making on the farm cannot be replaced by scientific studies, it can be supported by such efforts.
Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Animales , Bovinos , Femenino , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Brasil/epidemiología , Mastitis Bovina/epidemiología , PenicilinasRESUMEN
Lactose is the main carbohydrate in milk, and its absorption occurs via enzymatic hydrolysis, generating glucose and galactose. Lactose intolerance is the reduction of intestinal hydrolysis capacity due to hypolactasia, which results in the need to consume dairy foods with low levels of this carbohydrate. ß-galactosidase enzymes are used in dairy industries to hydrolyze lactose, thereby allowing intolerant consumers access to dairy products without the negative health implications. Alternative and official analytical methods are used to quantify the carbohydrate content resulting from enzymatic hydrolysis. The objective of this study was to evaluate the enzymatic hydrolysis of two distinct industrial enzymes produced by the microorganisms Bacillus licheniformis and Kluyveromyces lactis using three analytical methods: enzymatic method, cryoscopy, and high performance liquid chromatography (HPLC) using artificial intelligence to improve the control of the industrial processes. After adding the enzymes to skim milk, time kinetics was performed by collecting samples at time 0, every 10 min for 1 h, and every 30 min until the end of 5 h of hydrolysis. In 97% of the cases, a decrease in lactose concentration was observed by HPLC, followed by the deepening of the cryoscopic point. Glucose measurements by absorbance and HPLC quantification were correlated (r = 0.79; p < 0.01) but not concordant (p < 0.01). It was concluded that by means of artificial intelligence, it was possible to indirectly estimate lactose concentration using an algorithm that associates cryoscopy and glucose concentration.(AU)
O principal carboidrato do leite é a lactose e a sua absorção ocorre devido à hidrólise enzimática, gerando glicose e galactose. A intolerância à lactose é a redução da capacidade de hidrólise intestinal devido à hipolactasia, gerando a necessidade do consumo de alimentos lácteos com baixo teor deste carboidrato. As enzimas ß-galactosidase são utilizadas nas indústrias de laticínios para hidrolisar a lactose, proporcionando ao consumidor intolerante a possibilidade de ingerir os produtos lácteos sem prejuízos à saúde. Para quantificar o conteúdo de carboidratos resultante da hidrólise enzimática, são utilizados métodos analíticos alternativos e oficiais. O objetivo deste estudo foi avaliar a hidrólise enzimática de duas enzimas industriais distintas produzidas pelos microrganismos Bacillus licheniformis e Kluyveromyces lactis, por meio de três métodos analíticos: método enzimático, crioscopia e HPLC. A inteligência artificial foi utilizada para melhorar o controle dos processos industriais. Após a adição das enzimas ao leite desnatado, foi realizada a cinética de tempo coletando as amostras no tempo 0, a cada 10 minutos, até completar 1 hora de reação, e a cada 30 minutos até serem atingidas 5 horas de reação de hidrólise. Em 97% dos casos, a diminuição da concentração de lactose por HPLC acompanhou o aprofundamento do ponto crioscópico. As medições de glicose por absorbância e HPLC foram correlacionadas (r = 0,79; p < 0,01), mas não concordantes (p < 0,01). Concluiu-se que, por meio da inteligência artificial, é possível estimar indiretamente a concentração de lactose a partir de um algoritmo que associa a crioscopia e a concentração de glicose.(AU)
Asunto(s)
Inteligencia Artificial , Hidrólisis , Lactosa , Kluyveromyces , Bacillus licheniformisRESUMEN
In an age of flexible conditions about mandatory milk pasteurisation, this opinion-based research reflection supports the view that the knowledge and the awareness of milk-borne infections are key requirements to decrease the risks associated with raw milk. Providing an analysis of the current potential risks related to consumption of raw milk and raw milk products, we discuss the main reasons to continue to be vigilant about milk-borne pathogens and the current scenario in relation to the formal and clandestine sale of raw milk. Finally, we select some highly effective strategies to reduce the risks associated with raw milk in food services. Regardless of whether a country regulation allows or prohibits the trade of raw milk and its products, this is not the time to be negligent.
Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Leche/microbiología , Pasteurización , Animales , Brucella , Comportamiento del Consumidor , Productos Lácteos/microbiología , Industria Lechera , Enterotoxinas , Microbiología de Alimentos , Inocuidad de los Alimentos , Servicios de Alimentación , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Factores de RiesgoRESUMEN
BACKGROUND: Provolone can be fresh or ripened, with its taste varying from sweet to spicy. The high psychrotrophic density of raw milk is associated with thermoresistant enzymes that can change cheese characteristics such as texture, promote sensory defects and decrease industrial yield. Two batches of provolone-type smoked cheese were produced from chilled raw milk with 3 log cfu mL-1 (Treatment 1) and 7 log cfu mL-1 (Treatment 2) of psychrotrophs. The psychrotrophic (21 °C for 25 h) and physical-chemical profile of the raw milk were determined. Cheeses were evaluated by fat level, primary and secondary proteolysis index, yield, protein profile (Urea-polyacrylamide gel electrophoresis), and texture (hardness, cohesiveness, elasticity, and chewiness) at 14, 30, and 60 days of storage time. Sensorially, the cheeses were evaluated (100 tasters/period) using the triangular test. RESULTS: The treatments did not influence proteolysis index, although maturation influenced the proteolytic depth index after 60 days. The psychrotrophic population influenced αs 1- and ß-casein fractions, while maturation time influenced αs 1- and γ-casein fractions. Treatment 2 induced a 3% reduction in cheese yield. Hardness and chewiness showed a linear and positive relationship with the milk's psychrotrophic load. There was a significant difference in the fat content of the cheeses, with Treatment 2 having a lower level. The triangular test showed no difference between the cheeses. CONCLUSION: Although the larger psychrotrophic population in raw milk was associated with superior values of hardness and chewiness, as well as an increase in protein fractions indicating that proteolysis was observed, the tasters did not identify sensorial differences between the cheeses. © 2020 Society of Chemical Industry.
Asunto(s)
Queso/análisis , Manipulación de Alimentos/métodos , Leche/química , Animales , Bovinos , Dureza , Humanos , Proteolisis , GustoRESUMEN
BACKGROUND: Innovative approaches to combine whey with other ingredients and the use of new techniques in product development should be explored to meet consumers' needs and expectations. However, the question arises here of whether whey protein could be used as a suitable food matrix for supplementation with ß-glucan, an attractive glucose polymer and a physiologically functional component. The present study addresses the challenge associated with the design and characterization of whey protein spread as a substrate for ß-glucan delivery. The results are discussed on the basis of physical-chemical and microbiological characteristics, which are subsequently linked to its sensorial profile. RESULTS: A whey protein spread can be developed without the addition of NaCl, with physicochemical characteristics (pH, viscosity), microbiological counts, and sensory acceptance (color, aroma, overall impression) similar to the product with NaCl. This spread can be refrigerated for 28 days. The whey protein spread presented high whey protein content (18.67-19.17 g 100 g-1 ) and could be a good source of carbohydrates (8.30-8.68 g 100 g-1 ), with low levels of fat (0.2 g 100 g-1 ) and lactose (1.56-1.61 g 100 g-1 ). The sensorial results showed that women would prefer a product with lower salt content. CONCLUSION: This is the first study to evaluate the development of a whey protein spread enriched with ß-glucan, providing results that are of interest for the dairy sector. The combination of whey and ß-glucan can be explored industrially as a whey protein spread, with satisfactory results for physicochemical, microbiological, and sensory acceptance. © 2019 Society of Chemical Industry.
Asunto(s)
Proteína de Suero de Leche/química , beta-Glucanos/análisis , Adolescente , Adulto , Femenino , Manipulación de Alimentos , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Gusto , Viscosidad , Suero Lácteo/química , Suero Lácteo/metabolismo , Proteína de Suero de Leche/metabolismo , Adulto Joven , beta-Glucanos/metabolismoRESUMEN
This study aimed to determine the frequency of Pseudomonas fluorescens, P. putida, and P. aeruginosa in refrigerated raw milk; their proteolytic potential; and your association with the aprX gene. Of the 173 isolates confirmed as belonging to Pseudomonas spp., 37% were P. fluorescens, 25.4% P. putida, and none belongs to P. aeruginosa. The aprX gene was distributed proportionally between P. putida (68%) and P. fluorescens (75%), but it was not associated with low or high proteolytic potential in both species. P. putida (16) and P. fluorescens (14) isolates with no aprX gene identified also had proteolytic potential. Considering the synthesis of proteases other than AprX by the isolates under study, we concluded that P. fluorescens and P. putida represented 62.4% of the Pseudomonas genus, with high probability of having the aprX gene and proteolytic potential. However, there was no association between the deteriorating potential with the presence of the aprX gene.(AU)
O objetivo do estudo foi verificar a frequência, em leite cru refrigerado de Pseudomonas fluorescens, P. putida e P. aeruginosa, o potencial proteolítico dos isolados e sua associação com a presença do gene aprX. Dos 173 isolados confirmados como pertencente ao gênero Pseudomonas spp, 37% foram P. fluorescens, 25,4% P. putida e nenhum pertencia à espécie P. aeruginosa. A prevalência do gene aprX se distribuiu proporcionalmente entre P.putida (68%) e P.fluorescens (75%) porém não foi associada ao baixo ou alto potencial proteolítico nas duas espécies avaliadas. P. putida (16) e P. fluorescens (14) que não tiveram o gene aprX identificado também expressaram potencial proteolítico, considerando-se a síntese de outras proteases além da AprX pelos isolados estudados. Concluiu-se que Pseudomonas fluorescens e P. putida representaram 62,4 % do gênero Pseudomonas ssp., com alta probabilidade da presença do gene aprX e potencial proteolítico, porém sem associação da expressão do potencial deteriorante com a presença do gene aprX.(AU)
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Animales , Femenino , Péptido Hidrolasas/análisis , Pseudomonas/aislamiento & purificación , Leche/microbiología , Ascorbato Peroxidasas/genéticaRESUMEN
The experiments reported in this Research Communication aimed to determine if a domestic strip test to detect ethanol residues in breast milk (Milkscreen®) is comparable to a previously established official method for detecting ethanol residues in milk. The two methods are examined in terms of overall sensitivity, robustness against storage and acidity and selectivity against formaldehyde residues. Here, Milkscreen® provided advantages, with faster results (2 min), good sensitivity (≥0.017%), no false results due formaldehyde residues and equal robustness against storage, but with lower sensitivity in acid milk samples. In summary, strip tests for the rapid detection of ethanol residues in breast milk can be used for screening purposes by dairy manufacturers, combining it with the official method to make a final diagnosis.
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Residuos de Medicamentos/química , Etanol/metabolismo , Leche/química , Tiras Reactivas , Animales , Etanol/química , Reproducibilidad de los ResultadosRESUMEN
The aim of this work was to use X-ray diffraction to identify substances used for adulteration of raw milk and to determine if crystallographic analysis can detect extraneous substances in milk. Two unknown substances were sent anonymously by employers linked to the dairy chain, who claimed that they were added directly in milk prior to water addition by truck drivers. The samples were analyzed by X-ray diffraction and submitted to physicochemical analysis. The first substance was identified by X-ray diffraction as sodium citrate, complying with its physicochemical attributes, such as the powerful ability to decrease the freezing point. The second substance was identified by X-ray diffraction as sucrose and this result was also in agreement with its ability to increase the density, decrease the freezing point and finally, to be positive for sucrose in the resorcinol qualitative test. To evaluate if X-ray diffraction can detect extraneous substances already mixed in milk, fresh raw milk samples tampered with urea, sodium hydroxide, sodium citrate and sucrose were freeze dried and analyzed by X-ray diffraction, with no detection of any extraneous substances at any percentage. This is the first report of attempted diagnosis of extraneous substances in milk by X-ray diffraction. However, this technique can be useful only when applied to identify substances used for adulteration prior to its dilution in milk, since the amorphous nature of milk seems to be a limitation for the accurate detection of extraneous substances.
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Cristalografía por Rayos X/veterinaria , Contaminación de Alimentos/análisis , Leche/química , Animales , Bovinos , Fenómenos Químicos , Citrato de Sodio/análisis , Sacarosa/análisis , Agua/análisisRESUMEN
This research paper aimed to evaluate the role of inulin as a fat replacer on the quality of Frescal sheep milk cheese. Sheep milk and its derivatives are a promising niche in the dairy industry, mainly due to increasing interest of consumers in diversified products. Three Frescal sheep milk cheese formulations, namely whole milk cheese (WMC), semi-skimmed cheese (SSC) and semi-skimmed cheese with 5 g/100 g inulin (SSCI) were prepared. Their composition was evaluated and the feasibility of using inulin as a fat substitute was investigated. SSC and SSCI were considered 'reduced fat' or 'reduced calorie' products. The addition of inulin to SSCI cheeses yielded textural parameters (firmness, adhesiveness, cohesiveness, and gumminess) with intermediate characteristics between SSC and WMC. All the formulations presented scores higher than 7.6 in sensory analysis. In conclusion, the use of inulin in semi-skimmed sheep cheese allowed the production of cheese with texturizing properties similar to whole milk sheep cheese, enabling the development of a foodstuff with lower caloric content and beneficial characteristics valued by consumers.
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Queso/análisis , Grasas de la Dieta/análisis , Inulina/análisis , Leche/química , Ovinos , Animales , Brasil , Dieta con Restricción de Grasas , Ingestión de Energía , Manipulación de Alimentos/métodos , Calidad de los Alimentos , SensaciónRESUMEN
Enhancing industrial sustainability by converting whey into alternative high value-added products is a scientific trend in food science and technology. However, without other ingredients, rennet, or sour, whey has an unappetizing flavor. This sensory challenge can be overcome by blending it with citrus flavor from orange juice. This study assessed a micro-filtered beverage from whey and orange juice without enzymatic treatment. Four formulations (27:10, 8.6:10, 2.4:10 and 1:10 v/v whey:juice ratio) were processed through a 1.4 m microfiltration system with four different transmembrane pressures (1, 2, 3, and 4.15 bar) and then stored at 5 °C for 28 days. The micro-filtered beverage was analyzed for physicochemical, sensorial and microbial changes. It was possible overcome the technological challenges of orange juice microfiltration without enzymatic treatment with high transmembrane pressures. The whey:orange juice ratio was also decisive for permeation. A clear beverage with lower viscosity, turbidity, and protein levels was obtained, without altering mineral concentrations thus showing that the product has good capacity for hydration. The beverage presented good microbiological quality and remained stable for 28 days at 5 °C. Sensory evaluation data indicate that the beverage can be directed to young people and women, regardless of their physical activity. The combination of whey and orange juice can be explored industrially as a micro-filtered beverage, with satisfactory results of physicochemical, microbiological and sensory acceptance.
Asunto(s)
Citrus sinensis , Microcribado , Suero Lácteo , Jugos de Frutas y Vegetales , Industria de AlimentosRESUMEN
Enhancing industrial sustainability by converting whey into alternative high value-added products is a scientific trend in food science and technology. However, without other ingredients, rennet, or sour, whey has an unappetizing flavor. This sensory challenge can be overcome by blending it with citrus flavor from orange juice. This study assessed a micro-filtered beverage from whey and orange juice without enzymatic treatment. Four formulations (27:10, 8.6:10, 2.4:10 and 1:10 v/v whey:juice ratio) were processed through a 1.4 m microfiltration system with four different transmembrane pressures (1, 2, 3, and 4.15 bar) and then stored at 5 °C for 28 days. The micro-filtered beverage was analyzed for physicochemical, sensorial and microbial changes. It was possible overcome the technological challenges of orange juice microfiltration without enzymatic treatment with high transmembrane pressures. The whey:orange juice ratio was also decisive for permeation. A clear beverage with lower viscosity, turbidity, and protein levels was obtained, without altering mineral concentrations thus showing that the product has good capacity for hydration. The beverage presented good microbiological quality and remained stable for 28 days at 5 °C. Sensory evaluation data indicate that the beverage can be directed to young people and women, regardless of their physical activity. The combination of whey and orange juice can be explored industrially as a micro-filtered beverage, with satisfactory results of physicochemical, microbiological and sensory acceptance.(AU)
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Suero Lácteo , Citrus sinensis , Jugos de Frutas y Vegetales , Microcribado , Industria de AlimentosRESUMEN
BACKGROUND: Milk ethanol stability is not only associated with microbiological acidification, but is a phenomenon with many variables that influence the balance of soluble salts, mainly calcium ion activity. On this basis, we wanted to find out more about milk ethanol stability by studying its relationship with milk protein fractions and others major components. The influence of milk composition on ethanol stability was assessed through a predictive model comprising 180 individual raw milk samples. An additional model was used to assess the ethanol stability status as a response to the proteins fractions quantified by electrophoresis. RESULTS: Of the total samples, 68% were classified as stable and 32% as unstable to alcohol. Milk ethanol instability increased at low values of lactose content and high values of ash percentage. α-Lactalbumin (α-La) was also associated with ethanol stability, and the higher the α-La percentage the lower were the chances of ethanol instability. CONCLUSION: The lower values of α-La in unstable milk samples might be related to lower content of lactose, as α-La promotes lactose synthesis, a key component for the osmotic balance of milk and thus its ethanol stability. This is the first field report linking ethanol stability indirectly with α-La. © 2017 Society of Chemical Industry.
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Etanol/química , Lactalbúmina/química , Lactosa/química , Leche/química , Animales , Bovinos , ElectroforesisRESUMEN
BACKGROUND: High-performance liquid chromatography (HPLC) is widely employed to determine the caseinomacropeptide (CMP) index and to detect milk tampering with rennet whey. Prior to HPLC analysis, CMP is subject to a trichloracetic acid isolation, causing further soluble proteins in the sample to precipitate. On this basis, we aimed to determine whether rennet whey acidification could adversely affect the HPLC sensitivity with respect to detecting this peptide. RESULTS: As hypothesized, the CMP index from milk with added acidified rennet whey was, on average, half that quantified from milk with added rennet whey. Moreover, the quantum satis of acidified whey added to milk sufficient to demonstrate a HPLC CMP > 30 mg L-1 was 94% greater than that required for this threshold to be reached with rennet whey. CONCLUSION: Milk tampering with acidified rennet whey may limit the analytical sensitivity of the reversed-phase HPLC employed for the screening of CMP and, ultimately, disguise the fraudulent addition of whey to milk. © 2017 Society of Chemical Industry.
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Caseínas/análisis , Cromatografía Líquida de Alta Presión/métodos , Quimosina/análisis , Contaminación de Alimentos/análisis , Leche/química , Fragmentos de Péptidos/análisis , Suero Lácteo/química , Animales , Concentración de Iones de HidrógenoRESUMEN
Este estudo avaliou o status do cálcio sérico em 39 vacas com deslocamento de abomaso (DA), provenientes de 30 propriedades leiteiras selecionadas, na região de Campos Gerais no Paraná. O diagnóstico do deslocamento de abomaso foi realizado por percussão auscultatória, além dos sinais clínicos e informações da anamnese. Previamente ao procedimento cirúrgico, amostras de sangue foram coletadas para a mensuração dos níveis sanguíneos de cálcio, albumina, proteína e glicose. Como grupo controle, amostras de sangue foram coletadas de vacas hígidas que se encontravam em semelhante período de lactação. Das 39 vacas com deslocamento de abomaso, 35 apresentaram hipocalcemia e no grupo controle, apenas um animal. Concentrações sanguíneas de glicose e proteína foram inferiores nos animais com DA, quando comparados com animais do grupo controle.(AU)
This study evaluated the status of serum calcium in 39 Holstein cows with displacement of the abomasum (DA), from 30 dairy farms selected in the region of Campos Gerais, Paraná state, Brazil.. The diagnosis of abomasal displacement was performed by auscultation and percussion, besides the clinical signs and history information. Before surgery, blood samples were collected to measure blood levels of calcium, albumin, protein and glucose. As a control group, blood samples were collected from healthy cows that were in similar period of lactation. Of the 39 cows with abomasal displacement, 35 had hypocalcemia and in the control group only one cow. Blood glucose and protein concentrations were lower in the animals with DA when compared with the control group.(AU)