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.

Probiotic Potential And Safety Characterization Of Enterococcus Hirae G24 Isolated From Indigenous Raw Goat Milk

In this paper, an investigation on lactic acid bacterial isolates from ethnic goat raw milk samples were examined for their probiotic potential and safety parameters. For this purpose, isolated bacterial cultures were screened based on certain parameters viz., sugar fermentation, tolerance to temperature, salt, low pH, bile salts, and phenol resistance. After that, these bacterial cultures were more estimated in vitro for auto-aggregation, cell surface hydrophobicity, response to simulated stomach duodenum channel, antibiotic resistance, and antimicrobial activity. Besides, probiotic traits show the absence of gelatinase and hemolytic activity supports its safety. The isolate G24 showed good viability at different pH, bile concentration, phenol resistance and response to simulated stomach duodenum passage but it did not show gelatinase and hemolytic activities. Isolate G24 was susceptible to amikacin, carbenicillin, kanamycin, ciprofloxacin, co-trimazine, nitrofurantoin, streptomycin, and tetracycline. Isolate G24 also exhibited antimicrobial action against five common pathogenic bacteria, such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogens, and Salmonella typhimurium. It displayed the maximum auto-aggregation, cell surface hydrophobicity to different hydrocarbons. Following molecular characterization the isolate G24 was identified as Enterococcus hirae with 16S rRNA gene sequencing and phylogeny. E. hirae G24 bears the excellent properties of probiotics.

Date Palm and Goat Milk Improve Haematological Parameters and Availability of Functional Iron in Iron Deficient Rats

@#Introduction: Iron deficiency anaemia (IDA) is endemic especially in the under-developed and developing countries and is a major public health concern. Improving nutrition is one of the ways to alleviate this condition. Consumption of locally available and affordable food such as date palm and goat milk which are rich in iron is one of the ways to overcome IDA. This study is aimed at evaluating the effect of date palm and goat milk supplementation on haematological parameters and iron bioavailability in IDA rats. Methods: 24 male Wistar rats were randomly divided into normal control and IDA group. The normal control was fed with normal diet and water ad libitum while the IDA group were fed on iron-deficient diet for two weeks to induce iron deficiency. The IDA rats were further divided into subgroups; each being supplemented with date palm, goat milk, a combination of date palm and goat milk, and ferrous fumarate as positive control. Blood were collected after 28 days for haematological parameters and iron profile determination. Iron bioavailability was assessed using the haemoglobin regeneration efficiency (HRE) index. Data was analysed by Student T Test and ANOVA using SPSS 23.0 software with p value < 0.05 considered as statistically significant. Results: Supplementation of date palm and goat milk for 28 days significantly improved Hb, RBC, PCV, MCV, MCH, serum iron and transferrin saturation (p<0.05) in all treatment groups compared to normal control. The iron bioavailability of date palm and goat milk supplemented rats was similar to that of the positive control. Conclusion: Supplementation of date palm and goat milk in IDA rats improves haematological parameters and iron bioavailability.

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.

Antimicrobial Activity of Silver Nanoparticles Synthesized Using Goat Milk against Pathogens of Selected Vegetables

This study was carried outtodetermine the antimicrobial activity of silver nanoparticles synthesized using goat milk against pathogens of selected vegetables. Synthesis of Silver nanoparticles was done usingGoat milk, and characterized using Ultra Violet-Visible absorption spectroscopy, Fourier-transform infrared spectroscopy (FTIR),X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Maximum absorbance of Goat milk synthesized AgNPs was observed at 417 nm, with FTIR peaks at3455 cm−1, 1628 cm−1,1402 cm−1, 1081 cm−1and 517 cm−1, indicating that proteins in Goat milk (GM) were the capping and stabilization molecules involved the synthesis of AgNPs. Transmission electron microscopy analysis showed that the biosynthesized particles were spherical in shape having a size of 10-100 nm, X-ray diffraction (XRD)pattern agreed with the crystalline nature and face-centered cubic phase of AgNPs. Evaluation of the antimicrobial activity of AgNPs synthesized using GM against the indicatorstrains (Staphylococcus aureusCIP9973, Pectobacterium carotovorumPec1, Enterobacter cloacaeAS10, Klebsiella aerogenesOFM28, Proteus mirabilisUPMSD3 and Escherichia coli 2013C-3342) isolated from selected vegetables, was carried out using the Agar diffusion assay at different concentrations of 25, 75 and 100 μl/ml. The present study demonstrated that the AgNPs synthesized using Goat milk have potent biological activities, which can find applications in diverse areas.

Isolation, Incidence and Molecular Characterization of Drug-resistant Escherichia coli of Goat Milk

Background: Goat milk is recognized for its high nutritive profile. The practise of antimicrobials in feeding of animals produces resistance in bacteria. Therefore, the present study was proposed to study the incidence of drug-resistant E. coli from raw goat milk samples and investigate the genes responsible for the resistance. Methods: A total of 250 raw milk samples were obtained from different farms of Taif province, Saudi Arabia. Collected samples were cultured on MacConkey agar. Morphological and biochemical tests were achieved for the identification of isolates. Antimicrobial resistance pattern of E. coli was estimated by the disk diffusion method. The resistance genes tet(A) and tet(B), ere(A), aadA1, blaSHV, aac(3)-IV, sul1, catA1 and cmlA, were examined by PCR. Results: Results of the present study showed that out of the 250 samples examined, 100 (40%) were found to be infected with E. coli. Antimicrobial resistance profile evaluated showed a higher resistance against ceftriaxone (90 %) and ticarcillin (86%), followed by amikacin and cefotaxime (87%), and augmentin and penicillin (85%). Lower percentage was observed for gentamicin (58%), ampicillin (66%), bacitracin (75%) and imipenem (32%). Furthermore, multi-drug resistance was observed in most of the isolates. Among E. coli isolates, 86% gave positive amplicons for the blaSHV gene followed by tet(A) and tet(B) genes (85%). Conclusion: The results suggested a probability of possible public health risk of multi-drug resistance of E. coli strains collecting from raw goat milk samples. Consequently, appropriate handling of goat milk processing is significant to prevent E. coli infection.

Characterization of Acinetobacter spp. from raw goat Milk / Caracterização de Acinetobacter spp. isolados de leite caprino cru

ABSTRACT: Goat's milk has been suggested as an alternative to cow's milk, being a better digestible and hypoallergenic option. However, the presence of contaminating bacteria may significantly affect the safety of the product. In this research, we reported the isolation and characterization of Acinetobacter spp. isolates from raw goat milk samples purchased in the state of Rio de Janeiro, Brazil. Twenty-one samples were analyzed and ten isolates of Acinetobacter spp. were obtained. Six were identified as A. guillouiae, three as A. ursingii, and one as A. bereziniae. These isolates were characterized and eight showed proteolytic activity, seven showed lipolytic activity, and five isolates were able to produce both enzymes. None of the isolates was biofilm producer. However, when the production of antibiotic resistance enzymes KPC and ESBL were investigated, all isolates presented ESBL-positive phenotype, while eight (80%) were KPC-positive. This research, therefore, demonstrated that raw goat's milk can also be a source of Acinetobacter spp., which can produce important thermostable deteriorating enzymes and may play a role of reservoirs of antibiotic resistance genes.

RESUMO: O leite de cabra tem sido sugerido como alternativa ao leite de vaca, sendo uma opção com melhor digestibilidade e menor alergenicidade. No entanto, a presença de bactérias contaminantes pode afetar significativamente a segurança do produto. Neste trabalho, relatamos o isolamento e caracterização de Acinetobacter spp. isolados de amostras de leite cru de cabra adquiridas no Estado do Rio de Janeiro, Brasil. Vinte e uma amostras foram analisadas e dez isolados de Acinetobacter spp. foram obtidos, sendo seis identificados como A. guillouiae, três como A. ursingii e um como A. bereziniae. Estes isolados foram caracterizados e oito apresentaram atividade proteolítica, sete mostraram atividade lipolítica e cinco foram capazes de produzir ambas as enzimas. Nenhum dos isolados foi produtor de biofilme. No entanto, todos os isolados apresentaram fenótipo ESBL-positivo, enquanto oito (80%) foram positivos para KPC. Este trabalho demonstra, portanto, que o leite de cabra cru também pode ser uma fonte de Acinetobacter spp., que podem produzir enzimas deteriorantes termoestáveis e desempenhar, também, um papel de reservatórios de genes de resistência a antibióticos.

Milk from different species on physicochemical and microstructural yoghurt properties / Influência do leite de diferentes espécies nas propriedades físico-químicas e micro estruturais do iogurte

ABSTRACT: The aim of the present research was to evaluate differences in chemical properties and physical structure of yoghurt produced with milk from different species (sheep, cow, and goat). For each trial, whole raw sheep (S), cow (C), and goat (G) milk were used to manufacture 4L of yoghurts (Y) from each species (SY, CY, and GY, respectively). The SY demonstrated the greatest (P<0.05) values of total solids, protein, and lipid contents, reflecting on greater (P<0.05) firmness, apparent viscosity and water-holding capacity, and lower (P<0.05) syneresis index than CY and GY. Consequently, SY exhibited a more compact microstructure and homogeneous matrix with fewer pores. Furthermore, CY and GY microstructure contained a greater number of pores, which exhibited greater size heterogeneity than SY. Therefore, based on the evaluated physicochemical and microstructural properties of yoghurt, SY demonstrated the most desirable parameter values for dairy industry representing an alternative substitution for cow's milk yogurt.

RESUMO: O objetivo da presente pesquisa foi avaliar as diferenças nas propriedades químicas e na estrutura física do iogurte produzido com leite de diferentes espécies (ovinos, bovinos e caprinos). Para cada experimento, leite de ovelha cru (S), vaca (C) e cabra (G), foram usados para fabricar 4L de iogurtes (Y) de cada espécie (SY, CY e GY, respectivamente). O SY demonstrou os maiores (P<0,05) valores de sólidos totais, proteína e conteúdo lipídico, refletindo em maior (P<0,05) firmeza, viscosidade aparente e capacidade de retenção de água e menor (P<0,05) índice de sinérese do que CY e GY. Consequentemente, o SY exibiu uma microestrutura mais compacta e uma matriz homogênea com menos poros. Além disso, a microestrutura CY e GY continha um maior número de poros, que exibiam maior heterogeneidade de tamanho do que o SY. Portanto, com base nas propriedades físico-químicas e micro estruturais avaliadas do iogurte, o SY demonstrou os valores de parâmetros mais desejáveis para a indústria de laticínios, representando uma alternativa de produto adequada aos iogurtes à base de leite de vaca.

Training small producers in Good Manufacturing Practices for the development of goat milk cheese

Abstract Training in Good Manufacturing Practices enhances quality during food processing. This paper evaluates GMP training aimed at improving the chemical, sensory and microbiological quality of goat milk cheese. We worked with 26 families that produce cheese as their main source of income. Semi-structured interviews and observation were conducted to select relevant topics. The manufacturing processes were compared and samples were analyzed before and after GMP training. We trained 80% of the producers. Before receiving training, they used to make cheese from raw milk in unhygienic conditions and with little equipment. The products obtained had bad sensory characteristics, cracks, eyes on the pasta, a high number of aerobic mesophilic bacteria and total coliforms. After training, the producers pasteurized the milk and standardized processing procedures, resulting in final products that contained higher protein and calcium content, suitable sensory characteristics, and a significant reduction in microorganisms, with total coliforms falling to ≤ 5.103 UFC/g. Therefore, this study shows that the manufacturing process and the chemical, sensory and microbiological parameters of goat milk cheese improved after GMP training.

Development of Yoghurt from Combination of Goat and Cow Milk

This study describes the technology of yoghurt preparation from goat and cow milk in combination ratio of 100:0, 70:30, 50:50, 30:70 and 0:100. The formulation of yoghurt includes the mixture of goat and cow milk, pectin LM-106AS and YM-115-L, prebiotic lactitol and Bifidobacterium and Lactobacillus ferments. Goat milk is a rich source of vitamin A, containing up to 42.3% more than that of cow's milk. Vitamins of B group were not significantly different. In comparison to cow's milk, goat milk had more vitamin C and E. Combination of goat and cow milk improved the sensory parameters of taste, color and flavor.  The yoghurt prepared from the mixture of goat and cow milk in proportion of 30:70 contains 2.8% protein, 4.0% fat and 14.2% carbohydrate; satisfies the sensory properties and meet the requirements of standard specification for yoghurts.

Qualidade microbiológica de queijos produzidos com leite de cabra / Microbiological quality of cheeses produced with goat's milk

O objetivo do presente estudo foi identificar a qualidade microbiológica de queijos com diferentes processos de produção elaborados com leite de cabra. Oito queijos, produzidos em um laticínio do Rio Grande do Sul, foram analisados de acordo com a legislação vigente para pesquisa de Salmonella spp. e Listeria spp. e quantificação de coliformes totais e termotolerantes, aeróbios mesófilos totais e Staphylococcus coagulase positiva (SCP). Determinou-se ausência de coliformes termotolerantes, salmonelas e Listeria spp. em todos os produtos analisados. Verificou-se a presença de SCP (2x102 a 4,2x103 UFC.g-1) em seis amostras, coliformes totais (2x103 NMP.g-1) em apenas uma amostra e micro-organismos mesófilos aeróbios (8,8x102 a 1x106 UFC.g-1) nas oito amostras. Seis amostras foram consideradas impróprias para consumo pela elevada contagem de SCP, sendo este o agente mais frequentemente associado à contaminação de queijos.

Estudo da disponibilidade de produtos lácteos caprinos

O leite de cabra é uma opção saudável e saborosa tanto para quem tem problemas relacionados com a ingestão de leite bovino quanto para quem gosta de variar sua alimentação com novos ingredientes. Neste sentido objetivou-se identificar os produtos lácteos caprinos oferecidos ao consumidor no comércio varejista de Porto Alegre e acompanhar a disponibilidade desses ao longo do ano. Identificaram-se, em quatorze pontos de venda, treze produtos: leite UHT (temperatura ultra-alta) nas apresentações integral, light e com extrato de soja, leite em pó, iogurte e oito tipos de queijo. Os leites UHT e em pó são os produtos mais disponíveis nos pontos de venda. Já os derivados, muitas vezes, estão disponíveis em apenas um estabelecimento e com frequência irregular. Nos queijos, no inverno ocorre uma nítida diminuição da variedade desses produtos. Conclui-se que apesar da grande variedade de produtos lácteos caprinos no Brasil, o consumidor de Porto Alegre tem acesso a uma restrita gama de produtos disponíveis. Da mesma forma, esses produtos não apresentam uma oferta constante em muitos dos estabelecimentos visitados. A constatação desses fatos pode ser útil àquelas pessoas envolvidas ou interessadas em otimizar a cadeia produtiva de lácteos caprinos.

Goat milk is a healthy, flavorful alternative both for those who have trouble ingesting cow milk and for those who enjoy changing their nutrition through the inclusion of new ingredients. This research aims mainly at (1) identifying goat milk products offered to the consumer in the retail market of Porto Alegre and (2) observing the availability of these products throughout a whole year. There were identified, in fourteen points of sale, thirteen products: UHT milk (whole, low-fat, and with soybeans extract), powdered milk, and yogurt, as well as eight types of cheese. The UHT milks and the powdered milk are the most available products in the points of sale. On the other hand, the milk derivatives are often available in only one point of sale and with irregular frequency. There is a clear decline in the variety of cheese available in winter. One can conclude that, despite the great diversity of goat milk products in Brazil, the Porto Alegre consumer has access only to a narrow range of available products. In addition, these products do not show a constant offer in many of the visited points of sale. Realizing these facts can be fruitful for those involved with, or interested in, optimizing goat milk production chain.

Características Físico Químicas y Composición de la Leche de Cabras Mestizas Canarias en Condiciones Tropicales / Physics and Chemistry Characteristics, and Composition of Goat Milk of Canarian Goats on Tropical Condition

Los factores que afectan las características y composición de la leche de cabra han sido bien estudiados en países de clima templado, pero no en países tropicales como Venezuela. El presente trabajo evaluó el efecto de grupo racial y de algunos factores no genéticos sobre las características fisicoquímicas y composición de la leche de cabras mestizas canarias, para lo cual, se analizaron 758 muestras de leche. Los datos se recolectaron en un periodo de nueve años. Las muestras fueron tomadas de un rebaño caprino multirracial confinado, ubicado en Maracay, en el estado Aragua, Venezuela (10º 16’ 25,30’’ N y 67º 36’ 35’’ O). Los resultados se analizaron mediante un modelo estadístico lineal aditivo, con el padre como efecto aleatorio y como efectos fijos, la edad al parto (EP), año (AP) y mes (MP) de parto, tipo de parto (TP), grupo racial (GR); y las covariables días en producción (efectos lineal y cuadrático). Las medias de las características fueron: crioscopía (ºC): -0,56; acidez (mLNaOH 0,1N/100 mL leche): 19,12; cloruros: (%): 0,22; WMT (mm): 10,75; pH: 6,55; composición de la leche (%): grasa: 4,32; proteína: 4,00; caseína: 2,63; humedad: 86,69; sólidos totales: 13,30; sólidos no grasos: 9,04; cenizas: 0,77 y lactosa: 4,27. Los resultados del estudio, muestran que todos los efectos fijos estudiados, afectaron en forma variable las características y la composición de la leche. El año de parto de la cabra, fue el factor que más influyó sobre la variación de las características de la leche; mientras que el GR ½ Canarias ½ Alpino Francés, estuvo por encima de los demás genotipos en cuanto al contenido porcentual de los diferentes sólidos de la leche.

Factors affecting the characteristics and composition of goat milk have been well studied in template countries, but not in tropical countries, such as Venezuela. The purpose of the present investigation was to evaluate the effect of breed group and some non-genetic factors on both characteristics and composition of milk from Canary crossbred goats in tropical conditions. To carry out the study, a total of 758 milk samples were analyzed. Data were collected in a period of nine years and milk samples were taken from a multiracial confined goat herd, located in Maracay, the State of Aragua, Venezuela (10° 16’ 25.30’’ N and 67º 36’ 35’’ W). Data were analyzed by a linear additive statistical model, with sire as random effect; age at calving (EC), year of calving (YC), month of calving (MC), prolificity (P), and breed group (BG), as fixed effects, and the covariates production days, as linear and quadratic effects. The means of the characteristics and composition (%) of goat milk were: cryoscopy (°C): -0.56; acidity (0.1 mL NaOH N/100 mL of milk): 19.12; chlorides (%): 0.22; WMT (mm): 10.75; pH: 6.55. Milk composition (%): fat: 4.32; protein: 4.00; casein: 2.63; humidity: 86.69; total solids: 13.30; non-fat solids: 9.04; ash: 0.77; and lactose: 4.27. The results of this study showed that all the fixed effects studied affected in a variable form, the characteristics and components of milk, being YC the most influential factor on the variation of the characteristic of milk. The BG “½ Canarian ½ Alpine” highlighted above all other genotypes, regarding the percentage content of the different solids of milk.

Estudo da disponibilidade de produtos lácteos caprinos / Study on the availability of goat milk products

O leite de cabra é uma opção saudável e saborosa tanto para quem tem problemas relacionados com a ingestão de leite bovino quanto para quem gosta de variar sua alimentação com novos ingredientes. Neste sentido objetivou-se identificar os produtos lácteos caprinos oferecidos ao consumidor no comércio varejista de Porto Alegre e acompanhar a disponibilidade desses ao longo do ano. Identificaram-se, em quatorze pontos de venda, treze produtos: leite UHT (temperatura ultra-alta) nas apresentações integral, light e com extrato de soja, leite em pó, iogurte e oito tipos de queijo. Os leites UHT e em pó são os produtos mais disponíveis nos pontos de venda. Já os derivados, muitas vezes, estão disponíveis em apenas um estabelecimento e com frequência irregular. Nos queijos, no inverno ocorre uma nítida diminuição da variedade desses produtos. Conclui-se que apesar da grande variedade de produtos lácteos caprinos no Brasil, o consumidor de Porto Alegre tem acesso a uma restrita gama de produtos disponíveis. Da mesma forma, esses produtos não apresentam uma oferta constante em muitos dos estabelecimentos visitados. A constatação desses fatos pode ser útil àquelas pessoas envolvidas ou interessadas em otimizar a cadeia produtiva de lácteos caprinos.

Goat milk is a healthy, flavorful alternative both for those who have trouble ingesting cow milk and for those who enjoy changing their nutrition through the inclusion of new ingredients. This research aims mainly at (1) identifying goat milk products offered to the consumer in the retail market of Porto Alegre and (2) observing the availability of these products throughout a whole year. There were identified, in fourteen points of sale, thirteen products: UHT milk (whole, low-fat, and with soybeans extract), powdered milk, and yogurt, as well as eight types of cheese. The UHT milks and the powdered milk are the most available products in the points of sale. On the other hand, the milk derivatives are often available in only one point of sale and with irregular frequency. There is a clear decline in the variety of cheese available in winter. One can conclude that, despite the great diversity of goat milk products in Brazil, the Porto Alegre consumer has access only to a narrow range of available products. In addition, these products do not show a constant offer in many of the visited points of sale. Realizing these facts can be fruitful for those involved with, or interested in, optimizing goat milk production chain.

Bactérias láticas produtoras de folato e riboflavina: Isolamento e avaliação do seu potencial de aplicação na produção de produtos lácteos caprinos com alto teor de vitaminas / Folate and riboflavin producing lactic acid bacteria: isolation and evaluation of their potential application for production of goat dairy products with higher vitamin content

O valor nutricional e as características físico-químicas fazem com que os produtos lácteos caprinos sejam muito apreciados e tenham um alto valor agregado. Muitas bactérias láticas (BAL) possuem a capacidade de produzir compostos com propriedades benéficas à saúde, inclusive vitaminas do grupo B, como a riboflavina (B2) e o folato (B9), que participam de importantes funções metabólicas. O presente estudo objetivou isolar e identificar BAL capazes de produzir folato e riboflavina, utilizando leite de cabra cru e de queijos de cabra como fonte, para em seguida, avaliar a produção destas vitaminas em leite de cabra UHT, para estimar uma possível aplicação na produção de derivados lácteos de cabra com teores mais altos destas vitaminas. Um total de 179 isolados de BAL, sendo 87 provenientes de leite e 92 de queijos, foram obtidas e analisados quanto à produção de folato e de riboflavina extracelular (EC) e intracelular (IC), empregando-se ensaios microbiológicos apropriados. A produção de folato em meio de cultura a 37ºC foi observada em 151 isolados (84,4%) e de riboflavina em 15 isolados (8,4%), sendo que 14 produziram as duas vitaminas concomitantemente. A média da produção folato total (EC + IC) foi 138,8 µg/L, sendo que em 77 isolados (51%) a produção estava acima da média. Houve diferença significativa entre as médias de produção de folato total pelos isolados de leite e de queijo. A média da produção de riboflavina total (EC + IC) foi 363,7 µg/L, sendo que em 9 isolados (60%) a produção foi acima da média. Com base no RAPD-PCR e sequenciamento da porção 16S do rDNA, foram obtidos 19 perfis genéticos diferentes e identificadas 7 espécies, com predominância de Streptococcus thermophilus (7 isolados), Weissella paramensenteroides (6 isolados) e Lactococcus lactis subsp. lactis (4 isolados). Oito isolados produtores de folato acima da média foram selecionados e submetidos à avaliação da produção de folato em leite de cabra UHT a 37°C, sendo 7 positivas, com média da concentração de folato total de 120,55 µg/L, variando de 12,97 a 261,91 µg/L. Os melhores produtores de folato em leite de cabra UHT foram Lc. lactis subsp. lactis FP368 e St. thermophilus FP34v, FP170v e FP268v. A concentração de folato produzido por estes isolados foi acima da média, evidenciando seu interessante potencial de aplicação na produção de novos derivados lácteos caprinos com teores aumentados desta vitamina. Por outro lado, não foi possível detectar a produção de riboflavina em leite de cabra por nenhum dos isolados testados

Due to the high nutritional value and physicochemical characteristics, goat milk and cheeses are highly appreciated. Many strains of lactic acid bacteria (LAB) are able to produce vitamins from the B complex, such as riboflavin (B2) and folate (B9). These vitamins have important metabolic roles. The present study aimed to isolate riboflavin- and folate-producing LAB strains from goat milk and cheeses, and evaluate the potential application of those strains in the production of goat dairy products with higher content of these vitamins. A total of 179 LAB isolates were obtained from milk (87) and cheese (92) samples. The isolates were evaluated for production of extra (EC) and intracellular (IC) riboflavin and folate, applying appropriate microbiological methods. Among these isolates, 151 (84.4%) were able to produce folate, while 15 (8.4%) displayed the ability to produce riboflavin, and 14 produced both vitamins. The average production of total folate (EC + IC) was 138.8 µg/L, and the amount of folates produced by 77 isolates (51%) were above this average. The differences observed for the average production of total folate from milk and cheese isolates were statistically significant. For total riboflavin (EC+ IC), the average rate was 363.7 µg/L. Nine isolates (60%) presented production rates above the average. No significant difference was observed between the average production of total riboflafin from milk or cheese isolates (319.3 µg/L and 379.8 µg/L, respectively). Based on RAPD-PCR and 16S rDNA sequencing, 19 different genetic profiles were obtained and 7 species were identified, with predominance of Streptococcus thermophilus (7 isolates), Weissella paramensenteroides (6 isolates), and Lactococcus lactis subsp. lactis (4 isolates). Eight isolates that produced folate above the average were selected and tested for vitamins production in UHT goat milk at 37°C. Seven isolates produced an average of 120.55 µg/L of folate in the milk and concentration varied from 12.97 to 261,91 µg/L. The best folate producers were Lactococcus lactis subsp. lactis FP368, Streptococcus thermophilus FP34v, Streptococcus thermophilus FP170v and Streptococcus thermophilus FP268v. The amount of folate produced by these isolates surpassed the average, and was above the amounts described in other studies, evidencing their potential application in the production of goat dairy products with higher content of folate. None of the tested isolates was able to produce riboflavin in UHT goat milk

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: characterization of the bacteriocin

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality.

Bacteriocinogenic Lactococcus lactis subsp: lactis DF04Mi isolated from goat milk: Evaluation of the probiotic potential

Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.

Occurrence of enterotoxin-encoding genes in Staphylococcus aureus causing mastitis in lactating goats / Ocorrência de genes codificadores de enterotoxinas em Staphylococcus aureus associados a mastite em cabras em lactação

Staphylococcal enterotoxins are the leading cause of human food poisoning worldwide. Staphylococcus spp. are the main mastitis-causing agents in goats and frequently found in high counts in goat milk. This study aimed to investigate the occurrence of enterotoxin-encoding genes in Staphylococcus aureus associated with mastitis in lactating goats in Paraiba State, Brazil. Milk samples (n=2024) were collected from 393 farms. Staphylococcus aureus was isolated in 55 milk samples. Classical (sea, seb, sec, sed, see) and novel (seg, seh, sei) enterotoxin-encoding genes were investigated by means of polymerase chain reaction (PCR). From thirty-six tested isolates, enterotoxin-encoding genes were detected in 7 (19.5 percent) S. aureus. The gene encoding enterotoxin C (seC) was identified in six isolates, while seiwas observed in only one isolate. The genes sea, seb, sed, see, seg and seh were not observed amongst the S. aureus investigated in this study. In summary, S. aureus causing mastitis in goats can harbor enterotoxin-encoding genes and seC was the most frequent gene observed amongst the investigated isolates. This finding is important for surveillance purposes, since enterotoxin C should be investigated in human staphylococcal food poisoning outbreaks caused by consumption of goat milk and dairy products.

As enterotoxinas estafilocócicas são as principais causas de intoxicação alimentar em humanos em todo o mundo. O principal agente causador da mastite caprina são os Staphylococcus spp., frequentemente encontrado em altas contagens no leite caprino. Este estudo objetivou investigar a ocorrência de genes codificadores de enterotoxinas em Staphylococus aureus associados com mastite em cabras em lactação no estado da Paraíba, Brasil. As amostras de leite (n=2024) foram coletadas em 393 propriedades. Foram isolados 55 S. aureus em amostras de leite. Os genes codificadores de enterotoxinas clássicas (sea, seb, sec, sed, see) e as novas (seg, seh, sei) foram investigadas por meio de reação em cadeia de polimerase (PCR). Foram testados trinta e seis isolados, foram detectados 7 (19,5 por cento) genes codificadores de enterotoxinas de S. aureus. O gene codificador da enterotoxina C (sec) foi identificado em seis isolados, enquanto sei foi observado em apenas um isolado. Os genes sea, seb, sed, see, seg e seh não foram observados entre os S. aureus investigados neste estudo. Em síntese, a mastite caprina causada por S. aureus pode abrigar genes codificadores de enterotoxinas e sec foi o gene mais frequentemente observado entre os isolados investigados. Essa descoberta é importante para fins de vigilância e a enterotoxina C deve ser investigada em surtos de intoxicações alimentares estafilocócicas em humanos causadas pelo consumo de leite caprino e seus derivados.

Lactobacilli isolated from Algerian goat's milk as adjunct culture in dairy products

In this study, nineteen Lactobacillus isolated from Algerian goat's milk, 13 belonging to L. plantarum, three to L. pentosus, two to L. rhamnosus and one to L. fermentum, were examined in vitro in order to be used as adjunct culture in dairy products. The strains were tested for their proteolytic activity, sensory and safety properties. Strains LbMS16 and LbMS21 L. plantarum and LbMF25 L. rhamnosus presented the highest proteolytic activity. All the tested lactobacilli were able to grow on MRS agar containing 0.5 and 1% (W/V) of oxgall, whereas none produced biogenic amine (BA) from the four tested amino acids and were resistant to pH 2.0 and 3.0, but some strains were able to grow at pH 3.5. None of examined strains were β-haemolytic when grown in hors blood agar. Result of antibiotic resistance showed that all the strains were susceptible to penicillin, erythromycin and resistant to vancomycin. Diacetyl production was observed for two strains of L. plantarum and one of L. rhamnosus. Most of strains were able to produce pleasant flavours in fermented milk and gave a good acceptance. According to these results, the strains LbMS16, LbMS21and LbMF25 could be good candidates to be used as adjunct culture, playing a probiotic role in dairy products manufacture in Algeria.

Parâmetros de qualidade do leite de cabra armazenado sob frio / Effects of cold storage on the quality parameters of goat milk

O leite de cabra é produzido em pequena escala, o que torna necessária sua estocagem, permitida pela legislação brasileira. O presente trabalho teve por objetivo avaliar a ação do resfriamento e congelamento sobre as características físico-químicas e microbiológicas do leite de cabra. Não foi observada variabilidade nos valores médios de acidez, estabilidade ao álcool, densidade, gordura, proteína, sólidos totais e lactose após armazenamento sob frio. Não foi observada instabilidade ao calor em nenhuma das amostras analisadas. Verificou-se tendência à diminuição na contagem de células somáticas (CSS) no leite congelado em relação ao fresco e ao refrigerado. A quantificação (NMP) de coliformes totais e termotolerantes variou de < 3 (ausência de crescimento) à > 1.100 UFC/mL, independentemente do armazenamento. Entretanto, determinou-se contagem de coliformes totais e termotolerantes significativamente maior (p < 0,0001) nas amostras mantidas sob refrigeração. Na prova de lactofermentação, observaram-se coágulos digeridos, floculosos e sulcados sem estabelecer correlação entre estes e a contagem bacteriana. A CCS e a contagem microbiana são critérios adotados no pagamento pela qualidade no leite caprino, e a temperatura de armazenamento pode influir sobre elas.(AU)

The small-scale goat milk production requires its storage, and such operation is allowed by Brazilian laws. This study aimed at evaluating the cooling and freezing effects on physical-chemical and microbiological characteristics of goat milk. However, no variability was verified in average acidity, alcohol stability, density, fat protein, total solids and lactose values after cold storage. Heat instability was not observed in any of the analyzed samples. There was a decreasing tendency in the somatic cell count (SCC) of frozen milk in comparison to fresh and refrigerated milk. The quantification (NMP) of total and thermo-tolerant coliforms varies from < 3 (no growth) to > 1,100 UFC/mL, regardless of the storage method. However, a slightly higher count (p < 0.0001) was observed for total and thermo-tolerant coliforms in the samples kept under refrigeration. In the lacto-fermentation test, digested, flocculated and grooved clots were observed without establishing a correlation between them and the bacterial count. SCC and microbial count are the criteria adopted when paying for the quality of goat milk, and the storage temperature may affect these criteria.(AU)