Experimental Protocol to Toxoplasma gondii Detection in Fresh Goat Milk.

Toxoplasma gondii is a zoonotic parasite with global distribution capable of infecting homeothermic animals. Transmission of protozoan to humans includes ingestion of water and raw food contaminated with sporulated oocysts, ingestion of raw or undercooked meat with tissue cysts, and tachyzoites' transplacental transmission. Fresh goat milk intake has already been linked to human toxoplasmosis outbreaks, but little is known about the infectious potential of this biological sample. Accordingly, the aim of the present study is to assess the survival and infectivity of T. gondii tachyzoites in fresh goat milk samples through an experimental protocol to detect this parasite via bioassay carried out with a murine model, DNA amplification, and serology. Swiss Webster mice were inoculated with fresh goat milk samples contaminated with different T. gondii RH strain tachyzoite concentrations per milliliter and stored for different refrigeration times. Animals showing clinical signs compatible to toxoplasmosis were euthanized. Milk samples contaminated with high parasitic loads and kept for a shorter refrigeration time were the most lethal ones. No significant differences were observed between mean death rates recorded for different goat milk contamination concentrations (p = 0.1888), and for the refrigeration time, contaminated milk samples were kept under (p = 0.9440). T. gondii DNA was amplified in all contaminated milk samples, but only one of the surviving mice was serologically positive. Results of the present study have shown T. gondii survival and infectivity in fresh goat milk samples, and it highlights its significant risk for public health. Therefore, molecular methods must be the tests of choice when milk samples are used to assess infection caused by protozoan in goats' dairy products.

Development and validation of a versatile analytical method for absolute quantification of seven oligosaccharides in human, bovine, and goat milk.

Oligosaccharides are significant in mammalian milk, where they serve as prebiotics that promote the growth of beneficial gut bacteria in infants. Comprehensive research of milk oligosaccharides requires precise and validated analytical methods for compositional studies. To address this need, the focus of our study was to develop and validate an analytical method using UPLC-MS/MS to quantify seven specific oligosaccharides found in mammalian milk. The developed and optimized method has adequate linearity, accuracy, and precision parameters. The detection (LOD) and quantification (LOQ) limits for the seven compounds ranged from 0.0018 to 0.0030 µg/mL and 0.0054-0.0063 µg/mL, respectively. The sample preparation method yielded recovery rates above 90.5 %. Furthermore, no significant matrix effect was observed. The validated method was successfully applied to human, goat, and bovine milk samples, demonstrating its proficiency in identifying variances in the concentration of oligosaccharides across different mammals. This versatile method will allow future research about factors affecting oligosaccharide composition.

Milk Composition of Creole Goats Raised at Different Altitudes in an Extensive Production System in Northeast Mexico.

Goat milk composition is affected by feeding, and in semiarid rangeland, information on Creole goat milk physicochemical composition is lacking. For the fulfillment of this objective, three agroecological regions (AR) considering altitude (lowland 87, highland 779, and mountain 1309 m above sea level) with different botanical compositions were chosen. Every AR analyzed accounted for 30 goat herds, with a total of 90 herds. The results demonstrated that altitude had an influence mainly on density and protein. Milk density increases as altitude increases; conversely, milk protein increases as altitude decreases. On the other hand, in the mountain and lowland ARs, the salts and solids not fat (SNF) percentages were higher compared to that of the highland AR (p < 0.05). The freezing point (FP) was higher at highland altitudes compared to that of mountain and lowland ARs (p < 0.01). In the milk fatty acids (FA) profile, only the C14:1 value was affected by altitude, whereas goat milk at lowland and mountain altitudes had higher values compared to that at highland altitudes (p < 0.05). Additionally, late lactation stage fat, FP, and pH values were higher compared to early lactation values. The opposite effect was observed for salts and SNF. In the FA profile, late lactation values were higher for C10:0 and C8:0 compared to early lactation values. The opposite trend was observed for C18:2n6t. The thrombogenic index was significantly higher at lowland altitudes compared to highland altitudes, and similar to the mountain AR. These goat milk characteristics could be explained as a consequence of animal nutrition, as well as the goat's meat-type phenotype.

Quality and sensory milk traits of goats grazing Caatinga or confined receiving either corn or spineless cactus-based diets in the Brazilian semiarid environment.

This study aimed to evaluate the yield, physical-chemical properties, fatty acid (FA) profile, and sensory traits of goat milk under different nutritional strategies in a Brazilian semiarid environment. Eighteen lactating crossbred dairy goats were distributed in a completely randomized design with three nutritional strategies: Caatinga strategy (1.5% of body weight with a concentrate supplementation), Corn-based confined strategy, and Spineless Cactus confined strategy. Daily milk yield was recorded, and milk samples were collected from all animals. Goats fed the spineless cactus-based diet presented a higher milk yield than goats feed the other strategies. Moreover, milk from goats fed with a spineless Cactus confined strategy presented higher saturated FA (SFA), and a lower proportion of cis- monounsaturated FA, trans-monounsaturated FA, and c9,t11-18:2 than milk from goats feed the other strategies. Milk from goats in the pasture system presented the highest proportions of 18:2n-6, 18:3n-3, and thus of polyunsaturated FA, when compared with milk from confined goats. We assume that milk from goats grazing in Caatinga pastures presents more benefits to human health due to the positive effects of this diet on the milk's fat content and FA profile, and this feeding strategy also results in a better sensory evaluation that may increase the acceptability of goat milk by consumers. All nutritional strategies evaluated herein and adopted in the semiarid region of Brazil are recommended for maintaining the yield, physical-chemical properties, and acceptability of milk goats.

Seasonal quality of milk from Creole grazing goats, stabled Saanen and French-Alpine goats / Calidad estacional de leche de cabras Criollas en pastoreo vs cabras estabuladas Saanen y Alpina-Francesa / Qualidade sazonal do leite de cabras Crioulas em pastagem vs cabras estábuladas Saanen e Franco-alpina

Abstract Background: Goat milk production has been increasing in northern Mexico; however, there is little information available about its quality. Objective: To compare goat milk quality during three seasons among creole goats in a traditional grazing system and stabled Saanen and French-Alpine goats. Methods: An experiment was performed in a completely randomized nested design with seasonality factor (fixed effects) with three levels (rain, transition, and drought) and breed factor (fixed effect with three levels (Creole, Saanen and French-Alpine)) nested within the season-of-the-year factor. Fifteen goats were randomly selected: five Creole in the extensive grazing system, five stabled Saanen, and five stabled French-Alpine. The factors assessed in milk were fat content, non-fat solids, protein, lactose, salts, density, freezing point, conductivity, and pH (using a Lactoscan® device). Results: With respect to season for all the breeds: fat, non-fat solids, protein, lactose, and salt contents were higher (p≤0.05) for goats sampled in the rainy season, followed by drought and transition seasons, respectively. The variables related to milk quality by breed and season showed that milk fat content of creole goats was greater (p≤0.05) in the drought season; salt and non-fat content (p≤0.05) in the three seasons of the year; density and protein increased (p≤0.05) in the transition and rainy seasons, while lactose was greater (p≤0.05) in drought and rainy seasons; protein was greater (p≤0.05) in transition and rainy seasons; and the freezing point was lower (p≤0.05) in the transition season. Regarding conductivity, French-Alpine milk was greater (p≤0.05) in the drought season. Conclusion: Season of the year significantly affects milk quality, with increased quality during the rainy season in creole grazing goats.

Resumen Antecedentes: La producción de leche de cabra se ha venido incrementando en el norte de México,; sin embargo, existe poca información sobre su calidad. Objetivo: Comparar la calidad de la leche de cabra durante tres épocas del año para cabras criollas en pastoreo y cabras puras de dos razas diferentes bajo estabulación. Métodos: El experimento se realizó mediante un diseño anidado completamente aleatorizado, con el factor época del año (efecto fijo) con tres niveles (lluvia, transición y sequia) y el factor raza (efecto fijo) con tres niveles (Criolla, Saanen y Alpino-Francesa) anidado dentro del factor época del año. En el sistema de pastoreo extensivo se eligieron al azar cinco cabras de raza Criolla, en el sistema estabulado se eligieron al azar cinco cabras de la raza Saanen y cinco de la raza Alpino-Francesa. La variables medidas fueron: contenido de grasa, sólidos no grasos, proteína, lactosa, sales, densidad, punto de congelación, conductividad y pH (utilizando el dispositivo Lactoscan®). Resultados: Respecto a la temporada del año para las tres razas se encontró que los contenidos en leche de grasa, sólidos no grasos, proteína, lactosa y sales fueron mayores (p≤0,05) en la época de lluvias, seguido por la leche muestreada en sequía y transición. Las variables por raza y temporada del año arrojaron que la grasa fue mayor (p≤0,05) en cabras criollas en sequía, solidos no grasos fue mayor (p≤0,05) en las tres temporadas del año en cabras criollas, la densidad aumentó (p≤0,05) en cabras criollas en transición y lluvia. La proteína fue mayor (p≤0,05) en cabras criollas en transición y lluvia, mientras que la lactosa fue mayor (p≤0,05) en cabras criollas en sequía y lluvia. El menor punto de congelación (p≤0,05) se presentó en cabras criollas en transición, la conductividad fue mayor (p≤0,05) en cabras Alpina-Francesa en sequía y la concentración de sales fue mayor (p ≤0,05) en cabras criollas durante las tres temporadas. Conclusión: Existe un marcado efecto de la temporada sobre la calidad de la leche, siendo la epoca de lluvias cuando se presenta mejor calidad en cabras criollas en pastoreo.

Resumo Antecedentes: No norte do México a produção de leite de cabra aumentou; no entanto, a qualidade do leite é desconhecida. Objetivo: Comparar a qualidade do leite de cabra durante três estações do ano com cabras crioulas em sistema de pastoreio tradicional e cabras Saanen e franco-alpinas em estábulos. Métodos: O experimento foi realizado através de um delineamento completamente casualizado com o fator de sazonalidade (efeitos fixos) com três níveis (chuva, transição e seca) e fator de raça (efeito fixo com três níveis (crioulo, Saanen e franco-alpino) aninhados dentro do fator estação do ano quinze cabras foram selecionadas aleatoriamente, cinco no sistema de pastejo extensivo, cinco Saanen e cinco Franco-Alpino no sistema estábulo. Os fatores avaliados no leite foram teor de gordura, sólidos desengordurados, proteína, lactose, sais, densidade, ponto de congelamento, condutividade e pH pelo aparelho Lactoscan®. Resultados: Em relação às estações do ano, nas três raças, mostrou que os teores de gordura, sólidos desengordurados, proteínas, lactose e sal foram maiores (p≤0,05) nas cabras cujo leite foi amostrado na ocasião um de chuvas seguido por aquele amostrado nas estações de seca e transição, respectivamente. As variáveis relacionadas à qualidade do leite de cabra por raça e ano, mostraram que nas cabras crioulas o teor de gordura foi maior (p≤0,05) na estação seca; teor de sal e gordura (p≤0,05) nas três estações do ano; a densidade aumentou significativamente e o teor de proteína foi maior (p≤0,05) nas estações de transição e chuvas, enquanto o valor de lactose foi maior (p≤0,05) nas estações seca e chuvosa; o teor de proteína foi maior (p≤0,05) nas estações de transição e chuvas; e o ponto de congelamento foi menor (p≤0,05) na estação de transição. Em relação à condutividade, o leite de cabra franco-alpino apresentou valor significativamente superior (p≤0,05) na seca. Conclusão: A qualidade do leite tem um efeito significativo por estação, sendo que a estação chuvosa aumentou a qualidade do leite em cabras crioulas em pastejo.

Genomic Analysis of a Community-Acquired Methicillin-Resistant Staphylococcus aureus Sequence Type 1 Associated with Caprine Mastitis.

This study aimed to investigate the genomic and epidemiological features of a methicillin-resistant Staphylococcus aureus sequence type 1 (MRSA ST1) strain associated with caprine subclinical mastitis. An S. aureus strain was isolated from goat's milk with subclinical mastitis in Paraiba, Northeastern Brazil, by means of aseptic procedures and tested for antimicrobial susceptibility using the disk-diffusion method. Whole genome sequencing was performed using the Illumina MiSeq platform. After genome assembly and annotation, in silico analyses, including multilocus sequence typing (MLST), antimicrobial resistance and stress-response genes, virulence factors, and plasmids detection were performed. A comparative SNP-based phylogenetic analysis was performed using publicly available MRSA genomes. The strain showed phenotypic resistance to cefoxitin, penicillin, and tetracycline and was identified as sequence type 1 (ST1) and spa type 128 (t128). It harbored the SCCmec type IVa (2B), as well as the lukF-PV and lukS-PV genes. The strain was phylogenetically related to six community-acquired MRSA isolates (CA-MRSA) strains associated with human clinical disease in North America, Europe, and Australia. This is the first report of a CA-MRSA strain associated with milk in the Americas. The structural and epidemiologic features reported in the MRSA ST1 carrying a mecA-SCCmec type IVa suggest highly complex mechanisms of horizontal gene transfer in MRSA. The SNP-based phylogenetic analysis suggests a zooanthroponotic transmission, i.e., a strain of human origin.

Distinguishing the milk microbiota of healthy goats and goats diagnosed with subclinical mastitis, clinical mastitis, and gangrenous mastitis.

Mastitis, mainly caused by bacterial intramammary infections, is the main problem in the breeding of dairy animals. The inflammations of the mammary gland is separated by types of mastitis, being subclinical, clinical, and the most severe, gangrenous mastitis. Here, we used 16S rRNA amplicon sequencing to characterize the bacterial microbiota of goat milk in the different types of goat mastitis caused by bacteria. We used 72 goat milk samples from a region of the state of Minas Gerais in Brazil, of which 12 were from clinically healthy animals, 42 from animals diagnosed with subclinical mastitis, 16 from animals with clinical mastitis, and 2 from animals with gangrenous mastitis. The group related to gangrenous mastitis was the most divergent in terms of alpha and beta diversity. The most abundant genus among samples of the groups was Staphylococcus spp., and we found a high abundance of Mycoplasma sp. in the milk of animals diagnosed with clinical mastitis. The most statistically relevant microorganisms among the groups were Prevotella sp., Ruminococcaceae, Prevotella ruminicola sp., and Providencia sp. We highlight a new association of bacterial agents in gangrenous mastitis among Escherichia sp./Shigella sp. and Enterococcus sp. and provide the second report of the genus Alkalibacterium sp., in milk samples. Only the taxa Staphylococcus sp., Bacteroides sp., Enterococcus, and Brevidabacterium sp., were present in all groups. The superpathway of L-tryptophan biosynthesis metabolites and the sucrose degradation III (sucrose invertase) pathway were the most prominent ones among the groups. In this study, we demonstrate how a rich microbiota of goat milk from healthy animals can be altered during the aggravation of different types of mastitis, in addition to demonstrating new bacterial genera in milk not previously detected in other studies as well as new associations between agents.

Comparative Analysis of the Protein Composition of Goat Milk from French Alpine, Nubian, and Creole Breeds and Holstein Friesian Cow Milk: Implications for Early Infant Nutrition.

Of the diversity of proteins and high digestibility, goat milk will be a food of significant value for infant nutrition. The genetic polymorphisms of milk proteins play an essential role in the different degrees of allergic reactions. This work aimed to identify the proteins and peptides in the composition of goat milk and compare them to those in cow's milk. The work was performed with goats French Alpine, Nubian, and Creole breeds and Holstein Friesian milking cows at the Universidad Autónoma de Querétaro, Amazcala. We investigated the relative abundance of goat and cow milk protein fractions by SDS-PAGE resolution and the densitometric analysis of gels. The protein alfa-casein was (17.67 ± 0.46) for Creole, (19.18 ± 0.88) French Alpine, (17.35 ± 0.49) Nubian, and (35.92 ± 1.96) Holstein cows. The relative abundance obtained from alfa-casein was statistically different between goats and cows, and this protein was vital because it is a protein related to allergies. On the other hand, the amino acid in position 67 of the beta-casein from three goat breeds is a Proline, so it is assumed that the beta-casein variant of goat milk is an A2-type. The latter has excellent relevance for infant nutrition and differs from cow milk.

Use of physical processes to maximize goat milk cream hydrolysis: Impact on structure and enzymatic hydrolysis.

This study evaluated the use of ultrasound (US), high-shear dispersion (HSD), stirring (ST), and low or high pressure homogenization (LPH or HPH) technologies to modify the goat milk cream (GMC) structure, focusing on improving the enzymatic hydrolysis of its lipids. The GMC structure was evaluated, as well as its creaming and emulsion stability index (ESI). The processed GMC was hydrolyzed by lipase at 50 °C for 300 min, and the fatty acids concentration (FAC) was evaluated over the reaction. ST, HPH, and HSD showed âˆ¼ 90% lower emulsion destabilization, 10 times higher ESI, and smaller fat globule size than unprocessed GMC. The pretreatments increased the hydrolysis rate up to 2.4 times and the final FAC up to 8.7 times. ST (4 min), HPH (40 MPa) and HSD (5 min/ 25,000 rpm) showed the best results, which were correlated with the changes in the GMC structure. The results suggest that the physical treatments impacted the substrate structure, favoring enzyme activity and accelerating the hydrolysis degree. Therefore, the application of physical processes can be an interesting strategy to enhance the hydrolysis of GMC, aiming to produce compounds of industrial interest.

Evaluation of the Fluorescence Polarization Assay for the Diagnosis of Brucellosis in Goat Milk.

The milk ring test is a detection assay for antibodies against Brucella in bovine milk. It has good sensitivity but tends to give false positive results. In this study, we standardized the application of the fluorescence polarization assay (FPA) for the detection of antibodies against B.melitensis in goat milk. We obtained negative serum and milk samples from healthy goat flocks in the northern zone of Nuevo León. Positive milk and negative, weak, and strong controls were obtained by mixing volumes of positive control serum with negative control milk. Milk samples were treated with citric acid, after which an FPA was performed. Results were then compared with the Rose Bengal test and the FPA in serum. Milk treatment allowed the quantification of antibodies in samples. Significant differences were found between the 2%, 4%, and 6% groups, compared with the control group (F3, 67 = 17.45, p < 0.0001) but not between the 2% and 4% groups (p = 0.0718). The cut-off value was 74.1 mP, with a sensitivity (Se) of 95% and a specificity (Sp) of 100%. Se and Sp values in field milk samples were 84% and 74.55%, respectively. Despite the FPA test on milk samples showed lower Se and Sp than the FPA test on serum samples, its cutoff may be adjusted. It may be recommended as a screening test in goat milk and become useful for the control and eradication of the disease.

Autochthonous adjunct culture of Limosilactobacillus mucosae CNPC007 improved the techno-functional, physicochemical, and sensory properties of goat milk Greek-style yogurt.

We evaluated the performance of Limosilactobacillus mucosae CNPC007 as an autochthonous adjunct culture in the production of goat milk Greek-style yogurt. The techno-functional, physicochemical, and sensory characteristics of the control yogurt (containing only starter culture, CY) and the probiotic yogurt (with the probiotic strain added, PY) were assessed during 28 d of refrigerated storage. Furthermore, we determined the survival of the strain throughout the gastrointestinal tract under simulated conditions. The PY yogurt had a lower extent of proteolysis index and a higher depth of proteolysis index. These results indicate that the proteolytic enzymes of L. mucosae may have a possible action in PY. The PY formulation exhibited viscosity almost 1.5 times as high as CY over the refrigeration period, probably due to higher production of exopolysaccharides by the probiotic strain, which directly interferes with the microstructure, texture, and viscosity of the product. The PY formulation received higher scores for color, flavor, and global acceptance at 1 d of storage and higher texture scores at 28 d. The counts of L. mucosae remained high (>7 log cfu/g and >8.5 log cfu/g) throughout mouth-ileum digestion and storage, respectively, in PY. The autochthonous adjunct culture of L. mucosae CNPC007 can be used for production of a novel potentially probiotic goat yogurt without negatively affecting the general characteristics of the product quality, adding value associated with maintaining its functional potential.

Replacement of corn with pre-dried cassava root silage in the diet for dairy goats

The objective of this study was to evaluate the effect of replacement of corn with pre-dried cassava root silage (CRS) on intake, ingestive behavior, production and composition of goat milk. Five lactating Saanen goats were used, with 42.5 ± 4.2 kg body weight and production of 2 kg milk day-1, distributed in a 5 x 5 Latin square with five treatments: 0, 28.6, 58.0, 81.6 and 100% replacement of corn with CRS in the diet dry matter. Goats were monitored for five periods of 15 days each. The intake of dry matter, crude protein and neutral detergent fiber decreased linearly (p <0.05) with the replacement of corn with CRS. Feeding (348.5 ± 62.1 min.) and rumination (468.8 ± 83.8 min.) times were not influenced (p >0.05) by the replacement of corn with CRS, but the ingestion and rumination efficiencies had a linear increase (p > 0.05). Milk production (2.17 ± 0.45 kg day-1), fat (3.49 ± 0.42%), protein (3.11 ± 0.13%) and lactose (4.47 ± 0,11%) of goat milk were not influenced (p >0.05) by the replacement of corn with CRS. Therefore, it is recommended the total replacement of corn with pre-dried cassava root silage in the diet for dairy goats with an average production of 2 kg day-1.(AU)

Probiotic Characterization of Enterococcus spp. Isolated from Raw Goat Milk

Abstract: The aim of this research was to determine the probiotic potential and safety of lactic acid bacteria (LAB) isolated from raw goat milk. Gram positive and catalase negative bacteria were isolated from raw goat milk (n = 61) and identified as LAB. LAB isolates were screened for antimicrobial, probiotic and technological characteristics. LAB isolates showed antimicrobial activity against foodborne pathogens (Staphylococcus aureus, Escherichia coli and Salmonella Typhimurium) and high survival rate at pH 2 (93.54-100.38% after 4h), in the presence of 0.3% bile salts (100.85-108.96% after 4h) and simulated gastric fluid (74.16-80.13% after 3h). Three LAB isolates (1, 3 and 13) with high antimicrobial activity against all foodborne pathogens and probiotics characteristics were subjected to 16S rRNA sequencing and identified as Enterococcus faecium strains. Enterococcus spp. exhibited milk coagulation potential, amylolytic activity, susceptibility to antibiotics and no evidence of hemolysis. Enterococcus spp. isolated from goat milk showed probiotic and technological characteristics and can be used as a starter culture after further safety evaluation.

Multiresistant zoonotic pathogens isolated from goat milk in Northeastern Brazil.

Dairy goats play a significant role in socio-economic, cultural, and nutritional development in many countries. This study aimed to identify multiresistant zoonotic pathogens causing mastitis in goats, in addition to characterizing them for the presence of resistance genes and phenotypic resistance. A total of 714 milk samples from 357 lactating goats in 12 farms in the Northeast region of Brazil were analyzed. The isolates were submitted to Matrix Associated Laser Desorption-Ionization - Time of Flight to identify bacterial species, Polymerase Chain Reaction (PCR) to search for resistance genes, and an antibiogram to evaluate the phenotypic profile of antimicrobial resistance. A total of 214 pathogens were identified and bacterial prevalence was 83.29 % (178/214) Staphylococcus spp.; 6.50 % (14/214) Micrococcus luteus; 3.73 % (8/214) Corynebacterium spp.; 2.80 % (6/214) Bacillus spp.; 1.38 % (3/214) Escherichia coli; 0.92 % (2/214) Enterobacter cloacae; 0.46 % (1/214) Aerococcus viridans; 0.46 % (1/214) Morganella morganii; and 0.46 % (1/214) Turicella otitidis. As for gene frequency, 64.60 % (115/178) of the isolates carried the blaZ gene; 37.07 % (66/178) norA; 22.47 % (40/178) tet(L); 16.85 % (30/178) tet(M); 14.04 % (25/178) norB; 8.42 % (15/178) vanA; 7.30 % (13/178) msrA; 6.41 % (5/178) tet-38; 4.49 % (8/178) norC; 2.25 % (4/178) mecA; and 0.56 % (1/178) vanB. Emerging multiresistant zoonotic pathogens are present in the goat milk production chain, especially the coagulase-negative Staphylococcus species that pose a risk to human and animal health.

Aflatoxin M1 in Brazilian goat milk and health risk assessment.

Contamination of goat milk with aflatoxin M1 (AFM1) is a public health concern. This study investigated filamentous fungi in goat feed and quantified AFM1 in milk samples (n = 108) from goat fed forage and concentrate. Based on the detected AFM1 concentration, risk assessment analyses were performed concerning the Estimated Daily Intake (EDI) for one-year-old children and adults. Filamentous fungi were found in goat feed samples in a range of 3.1 ± 1.9 to 4.2 ± 0.2 log CFU/g. Five genera were identified, to cite Aspergillus, Penicillium, Fusarium, Rhizopus and Acremonium. Aspergillus species comprised A. flavus, A. niger, and A. ochraceus. All goat milk samples were contaminated with AFM1 (5.60-48.20 ng/L; mean 21.90 ± 10.28 ng/L) in amounts below the limits imposed by regulatory agencies. However, EDI values for AFM1 through goat milk estimated for one-year-old children were above the Tolerable Daily Intake. The calculated Hazard Index for one-year-old children indicated potential risk of liver cancer due to goat milk consumption. The Margin of Exposure values to AFM1 in one-year-old children and adults consuming goat milk as the unique milk source indicated increased health risk. Therefore, contamination of goat milk with AFM1 should be considered a high priority for Brazil's risk management actions.

Antarctic fungus proteases generate bioactive peptides from caseinate.

The extracellular serine protease produced by Acremonium sp. L1-4B isolated from the Antarctic continent, was purified and used for the proteolysis of bovine and caprine sodium caseinate. Protein hydrolysates were evaluated in vitro to determine their antioxidant and antihypertensive potential, and later characterized by mass spectrometry. Bovine and caprine hydrolysates produced over 24 h showed a higher content of copper chelation (25.8 and 31.2% respectively), also at this time the ABTS+• scavenging was 65.2% (bovine sample) and 67.5% (caprine sample), and bovine caseinate hydrolysate (8 h) exhibited higher iron chelation capacity (43.1%). Statistically (p < 0.05), caprine caseinate hydrolysates showed relatively higher antioxidant potential in this study. All hydrolysates showed antihypertensive potential; however peptides released from caprine caseinate after 8 h of hydrolysis were able to inhibit 75% of angiotensin-converting enzyme (ACE) activity. Nano-ESI-Q-TOF-MS/MS analysis prospected a total of 23 different peptide sequences in the bovine hydrolysate fraction, originated from the αS1- and ß-casein chain, whilst in caprine hydrolysate, 31 sequences were detected, all from ß-casein. The low molecular weight bovine and caprine hydrolysates obtained in this research have the potential to act in the prevention of disorders caused by oxidative reactions and in the regulation of blood pressure. These findings support the development of new functional food and nutraceutical formulations.

Goat's Milk Intake Prevents Obesity, Hepatic Steatosis and Insulin Resistance in Mice Fed A High-Fat Diet by Reducing Inflammatory Markers and Increasing Energy Expenditure and Mitochondrial Content in Skeletal Muscle.

Goat's milk is a rich source of bioactive compounds (peptides, conjugated linoleic acid, short chain fatty acids, monounsaturated and polyunsaturated fatty acids, polyphenols such as phytoestrogens and minerals among others) that exert important health benefits. However, goat's milk composition depends on the type of food provided to the animal and thus, the abundance of bioactive compounds in milk depends on the dietary sources of the goat feed. The metabolic impact of goat milk rich in bioactive compounds during metabolic challenges such as a high-fat (HF) diet has not been explored. Thus, we evaluated the effect of milk from goats fed a conventional diet, a conventional diet supplemented with 30% Acacia farnesiana (AF) pods or grazing on metabolic alterations in mice fed a HF diet. Interestingly, the incorporation of goat's milk in the diet decreased body weight and body fat mass, improved glucose tolerance, prevented adipose tissue hypertrophy and hepatic steatosis in mice fed a HF diet. These effects were associated with an increase in energy expenditure, augmented oxidative fibers in skeletal muscle, and reduced inflammatory markers. Consequently, goat's milk can be considered a non-pharmacologic strategy to improve the metabolic alterations induced by a HF diet. Using the body surface area normalization method gave a conversion equivalent daily human intake dose of 1.4 to 2.8 glasses (250 mL per glass/day) of fresh goat milk for an adult of 60 kg, which can be used as reference for future clinical studies.

Eficiência da pasteurização lenta do leite de cabra em diferentes binômios tempo/temperatura / Efficiency of slow pasteurization of goat milk in the different time/temperature binomials

O presente estudo analisou um binômio de tempo-temperatura alternativo para ser utilizado na pasteurização lenta sobre a inativação da fosfatase alcalina no leite caprino. Sua eficiência foi demonstrada pela contagem padrão em placas, e foi feita a comparação no processamento de leite refrigerado e congelado. Foram utilizados 18 tratamentos em leite caprino cru (nove em leite refrigerado e nove em leite congelado). Estes foram acondicionados em frascos de 300 mL, pasteurizados a 60, 63 e 65°C durante 10-20-30 minutos, e testadas às enzimas fosfatase alcalina e peroxidase. A contagem padrão em placas (CPP) e coliformes a 35 e 45°C foi feita nas amostras cruas e em cada tratamento, em duplicata. Após a pasteurização, todos os tratamentos apresentaram: não crescimento de microrganismos mesófilos, coliformes com <0,3 NMP/mL, prova de fosfatase negativa e peroxidase positiva. A pasteurização foi eficiente para melhorar a qualidade microbiológica do leite tanto refrigerado quanto congelado. Todos os binômios avaliados apresentaram resultados satisfatórios para alcançar os parâmetros preconizados em legislação, sugerindo-se o menor binômio (60°C por 10 min). Não houve diferença entre as formas de armazenamento das amostras: refrigerada ou congelada.

The objective of this study was to investigate an alternative time-temperature binomial to be used in the slow pasteurization on the alkaline phosphatase inactivation in the goat milk. Its efficiency was demonstrated with the standard counting in plates, and also refrigerated and the frozen milks processing were compared. Eighteen treatments were used in the raw goat milk (nine refrigerated milk and nine frozen milk). They were packed in 300 mL-flasks, pasteurized at 60-63-65°C for 10, 20, 30 minutes, and then tested for alkaline phosphatase and peroxidase enzymes. The standard counts in plates (CPP) and coliforms at 35°C and 45°C were performed in the raw samples and in the every treatment, in duplicate. After the pasteurization process, all of the treatments showed: no growth of mesophilic microorganisms, coliforms with <0.3 MPN / mL, negative phosphatase and positive peroxidase tests. The pasteurization was efficient to improve the microbiological quality of the milk either refrigerated or frozen. All of the evaluated binomials presented satisfactory results to reach the recommended parameters preconized in the legislation, suggesting the smaller binomial (60°C for 10 min). There was no difference between the samples storage form, either refrigerated or frozen.

Study of the structural properties of goat's milk chocolates with different concentrations of cocoa mass.

The objective of this study was to assess the microstructural characteristics of goat's milk chocolates formulated with different concentrations of cocoa mass by rheological measurements and microscopy. For rheological characterization, rotational and oscillatory tests were performed, while crystal morphology was observed by means of atomic force microscopy (AFM) and 3D optical profilometer. It was verified that the chocolates presented pseudoplastic and thixotropic behavior. The Herschel-Bulkley model adequately described the flow behavior of the formulations. In the oscillatory tests, it was found that the tangent δ (loss) decreased from 0.33 to 0.17 as a function of the increase in cocoa mass concentration. The creep recovery tests were consistent with the other rheological tests. The analysis of AFM and profilometer indicated that there are different microscopic pores on the surface of the chocolates, and that with the increase in the concentration of cocoa mass, it has a structure with greater interactions.

Nisin Production by Enterococcus hirae DF105Mi Isolated from Brazilian Goat Milk.

The purpose of this study was to select the promising biopreservation bacteriocin producer strain from goat milk and characterize the expressed bacteriocin, related to its physiological and biochemical properties and specificity of operon encoding production and expression of antimicrobial peptide. Brazilian goat milk was used as the source for the selection of bacteriocin-producing lactic acid bacteria. One strain (DF105Mi) stood out for its strong activity against several Listeria monocytogenes strains. Selected strain was identified based on the biochemical and physiological characteristics and 16s rRNA analysis. The bacteriocin production and inhibitory spectrum of strain DF105Mi were studied, together with the evaluation of the effect of temperature, pH, and chemicals on bacteriocin stability and production, activity, and adsorption to target cells as well as to the cell surface of bacteriocin producers. Physiological and bio-molecular analyses based on targeting of different genes, parts of nisin operon were performed in order to investigate the hypothesis that the studied strain can produce and express nisin. Based on biochemical, physiological, and 16s rRNA analysis, the strain DF105Mi was classified as Enterococcus hirae. The selected strain produces a bacteriocin which is stable in a wide range of pH (2.0-12.0), temperature (up to 120 °C), presence of selected chemicals and presents adsorption affinity to different test organisms, process influenced by environmental conditions. Higher bacteriocin production by Ent. hirae DF105Mi was recorded during stationary growth phase, but only when the strain was cultured at 37 °C. The strain's genetic analysis indicated presence of the genes coding for the production of the bacteriocin nisin. This result was confirmed by cross-checking the sensitivity of the produced strain to commercial nisin A. The strong anti-Listeria activity, bacteriocin adsorption, and stability of produced bacteriocin indicate that Ent. hirae DF105Mi presents a differentiated potential application for biopreservation of fermented dairy products.