Effect of ripening time on bacteriological and physicochemical goat milk cheese characteristics.

Cheese ripening involves lactose metabolism, lipolysis and proteolysis, which are affected by many factors. The aim of this study was to assess changes due to ripening (90 days) of goat milk cheese through bacteriological and physicochemical analysis in order to verify if, at the end of ripening period, this cheese could be considered "lactose-free". Three batches of the goat milk cheese were manufactured and ripened at 10 °C and 80% relative humidity for 90 days. Titratable acidity increased by about 59 °D due to carbohydrate degradation and organic acid production. However, pH (5.31-5.25) remained constant. Lactococcus was the dominant cheese microbiota, acting in the fermentation of lactose (1.17-0.06 mg/g) and lactic acid production (5.49-s10.01 mg/g). Thus, ripening time was decisive for bacteriological and physicochemical goat milk cheese characteristics.

Detection of efflux pump CmeABC in enrofloxacin resistant Campylobacter spp. strains isolated from broiler chickens (Gallus gallus domesticus) in the state of Rio de Janeiro, Brazil / Detecção da bomba de efluxo CmeABC em cepas de Campylobacter spp. resistentes à enrofloxacina isoladas de frangos de corte (Gallus gallus domesticus) no Estado do Rio de Janeiro, Brasil

Fowls are the main reservoirs of the highly important food-originating pathogen called Campylobacter spp. and broilers' meat and byproducts are the main vehicles of this microorganism. Increasing of Campylobacter spp. resistant strains to fluorquinolones, an antimicrobial class often employed in poultry farming and in human medicine has become a great concern to poultry breeders. In fact, several studies evaluated increasing bacterial resistance against these antimicrobial agents. The role of CmeABC efflux system has been underscored among the resistance mechanisms in Campylobacter spp. to fluorquinolones. This study investigated the occurrence of CmeABC efflux pump in 81 and 78 enrofloxacin resistant strains of Campylobacter jejuni and C. coli respectively, isolated from broilers collected from six abattoirs situated at São José do Vale do Rio Preto/RJ poultry center and from two commercial abattoirs situated at Metropolitan Region of Rio de Janeiro, from 2013 to 2016. The resistance to enrofloxacin was assessed by agar dilution to determine minimum inhibitory concentration (MIC). The CmeABC efflux system was investigated through the detection of genes genes cmeA, cmeB and cmeC by PCR. The activity of CmeABC efflux pump was investigated in 20 strains by using the efflux pump inhibitor Phenylalanine-Arginine ß-Naphthylamide (PAßN). The three genes cmeA, cmeB and cmeC were detected in 94.3% of the strains (C. jejuni = 80 and C. coli = 70), whereas the system was absent or incomplete in 5.7% of strains (C. jejuni = 1 and C. coli = 8). MIC varied between 0.5µg/ml and 64µg/ml, and 88.7% of strains were enrofloxacin resistant and 11.3% featuring intermediate resistance. The inhibition of the efflux pump by PAßN reduced the MIC to enrofloxacin up to eight times in fifteen strains (75%). These results indicate that this system is frequent and active in Campylobacter spp. Resistant strains in the presence of enrofloxacin.(AU)

As aves são os principais reservatórios de Campylobacter spp., importante patógeno de origem alimentar e a carne de frango e produtos derivados são os principais veículos desse microrganismo. O aumento de cepas de Campylobacter spp. resistentes às fluorquinolonas, uma classe antimicrobiana frequentemente empregada na avicultura e na medicina humana, tornou-se uma grande preocupação para os produtores de aves e vários estudos avaliaram o aumento da resistência bacteriana a esses antimicrobianos. O papel do sistema de efluxo CmeABC tem sido enfatizado entre os mecanismos de resistência em Campylobacter spp. à fluorquinolonas. O presente estudo investigou a ocorrência da bomba de efluxo CmeABC em 81 cepas de Campylobacter jejuni e 78 cepas de Campylobacter coli resistentes à enrofloxacina, isoladas de frangos de corte coletados em seis abatedouros situados no polo avícola de São José do Rio Preto/RJ e de dois abatedouros comerciais situados na Região Metropolitana do Rio de Janeiro, de 2013 a 2016. A resistência à enrofloxacina foi avaliada pelo método de diluição em ágar para determinar a concentração inibitória mínima (CIM). O sistema de efluxo CmeABC foi investigado através da detecção dos genes cmeA, cmeB e cmeC por PCR. A atividade da bomba de efluxo CmeABC foi investigada em 20 cepas utilizando o inibidor da bomba de efluxo Phenylalanine-Arginine ß-Naftilamida (PAßN). Os três genes cmeA, cmeB e cmeC foram detectados em 94,3% das cepas (C. jejuni = 80 e C. coli = 70), enquanto o sistema estava ausente ou incompleto em 5,7% das cepas (C. jejuni = 1 e C coli = 8). A CIM variou entre 0,5µg/ml e 64µg/ml e 88,7% das cepas foram resistentes à enrofloxacina, enquanto 11,3% apresentaram resistência intermediária. A inibição da bomba de efluxo pelo PAßN reduziu a CIM da enrofloxacina até oito vezes em quinze cepas (75%). Estes resultados indicam que este sistema é frequente e ativo em cepas resistentes de Campylobacter spp. na presença de enrofloxacina.(AU)

Short communication: Antimicrobial activity of pequi (Caryocar brasiliense) waste extract on goat Minas Frescal cheese presenting sodium reduction.

Sodium chloride reduction in foods is a significant focus of the dairy industry; however, it can interfere with dairy product quality. Thus, researchers have carried out studies on alternatives to maintain dairy product safety when presenting reduced NaCl content, such as natural antimicrobial addition. Caryocar brasiliense (pequi) is a fruit with high phenolic compound concentrations in the pulp and peel and known antioxidant and antimicrobial properties. This study aimed to define the optimum stage for pequi waste extract addition during cheese manufacturing in order to maintain and prolong the shelf life of reduced-sodium goat Minas Frescal cheese. Four different goat Minas Frescal cheese treatments were carried out: control cheese (without extract; CC), pequi extract addition to milk (CM), pequi extract addition to mass (CS), and cheese immersion in pequi extract (CIE). The treatments were subjected to microbiological (Staphylococcus spp., Escherichia coli, Enterobacteriaceae, coliforms and fecal coliforms, Lactococcus spp., and lactic acid bacteria counts), textural (hardness and consistency), and instrumental color (luminosity, yellow intensity, red intensity, chroma, hue angle, and total color change) analyses. No Enterobacteriaceae, Staphylococcus spp., E. coli, or coliforms and fecal coliforms were detected during storage for any of the assessed samples, including CC. Regarding texture, all samples presented a trend for decreasing rigidity during storage. In addition, lower luminosity values were also observed in cheeses produced with added pequi extract (CM, CS, and CIE) when compared with CC. All cheeses produced with added pequi were stable regarding all evaluated parameters; however, pequi extract addition to milk (CM) was shown to be more efficient, leading to higher textural parameters and better microbiological quality during storage. Thus, the CM treatment is the most recommended for pequi waste extract addition during Minas Frescal cheese manufacture.

Consumer perception, health information, and instrumental parameters of cupuassu (Theobroma grandiflorum) goat milk yogurts.

Although the demand for goat milk products has been growing, they have lower consumer acceptability than products derived from cow milk. However, the addition of cupuassu pulp can be used to improve the formulation of these products. For this reason, the aim of this study was to investigate the influence of new goat milk yogurt manufactured with cupuassu pulp on physicochemical properties, consumers' perceptions, and overall consumer acceptance. In addition, the effect of antioxidant health information on consumer acceptance and purchase intention of cupuassu goat milk yogurts was evaluated. The results demonstrated a positive expectation regarding linking and familiarity to goat milk products and products with cupuassu pulp. The pH, total phenolic content, lightness, redness, yellowness, and apparent viscosity were potentially affected by the addition of cupuassu, with the highest concentration of cupuassu (10%) exhibiting the greatest changes in parameters. Based on principal component analysis, partial least squares regression, and just-about-right and penalty analysis, the addition of cupuassu pulp improved some sensory attributes of goat milk yogurt, such as cupuassu aroma, cupuassu flavor, yellow color, consistency, and viscosity, which positively influenced product acceptance. In addition, antioxidant health information increased the acceptance and purchase intention of cupuassu goat milk yogurts. Taking into account the parameters investigated in this study, the best scoring formulation was goat milk yogurt with 10% cupuassu pulp. Our results suggest that cupuassu pulp can be considered a potential ingredient to improve the sensory and texture properties of goat milk yogurt. Furthermore, the antioxidant health information could be a sensory strategy to increase the acceptance of cupuassu goat milk yogurts.

Effect of different fat replacers on the physicochemical and instrumental analysis of low-fat cupuassu goat milk yogurts.

The aim of this Research Communication was to investigate the changes in physicochemical, colour, apparent viscosity and texture properties in low-fat goat milk yogurts prepared with cupuassu pulp by the addition of inulin (SI), maltodextrin (SM), whey protein (SW) and skim milk powder (SP). Three batches of each cupuassu goat milk yogurt were prepared and analysed on the 1st day of storage by pH, proximate composition, colour, apparent viscosity, and texture. In comparison to yogurts from whole (W) or skimmed milk (S), all of the fat replacers improved the physicochemical properties (P < 0·05). The addition of the carbohydrates (inulin and maltodextrin) and proteins (whey protein and skim milk powder) also influenced the colour of the low-fat cupuassu goat milk yogurt (P < 0·05). All fat replacer treatments (SI, SM, SW and SP) presented a higher (P < 0·05) apparent viscosity than W and S yogurts. However, only the addition of skim milk powder increased the texture parameters (firmness and consistency) (P < 0·05). These results suggest that skim milk powder can be used to improve the texture properties of low-fat cupuassu goat milk. Furthermore, inulin, maltodextrin, and whey protein can potentially be applied in the goat dairy industry to increase the viscosity of yogurts.

Cupuassu (Theobroma grandiflorum) pulp, probiotic, and prebiotic: Influence on color, apparent viscosity, and texture of goat milk yogurts.

Cupuassu is an acidic fruit that has a characteristic aroma, flavor, and texture; its fiber-rich pulp can provide a different consistency than other fruit pulps. Goat milk is an excellent source of amino acids, fatty acids, and minerals, and is widely used for processing fermented milks, such as yogurt. However, compared with cow milk yogurts, it is difficult to make goat milk yogurts with a good consistency. Therefore, it is necessary to use certain technological strategies. This study was carried out to investigate the possibility of adding cupuassu pulp, probiotic (Lactobacillus acidophilus LA-5), and prebiotic (inulin) to improve the texture of goat milk yogurt. A total of 6 treatments were performed: natural (N), probiotic (Pro), prebiotic (Pre), synbiotic (S), cupuassu (C), and probiotic with cupuassu (PC). The viability of probiotic in yogurts (Pro, S, and PC) was evaluated. In addition, instrumental analyses (pH, color, apparent viscosity, and texture) were performed to evaluate the influence of these different ingredients on goat milk yogurts. The probiotic bacteria remained viable (≥7 log cfu·mL(-1)) throughout the 28d of refrigerated storage, which exceeded the minimum count required to confer probiotic physiological benefits. The pH levels of the yogurts inoculated with L. acidophilus (Pro, S, and PC) were lower than others yogurts (N, Pre, and C). However, all yogurt samples underwent gradual decreases in pH until 7 to 14d of storage. The lightness (L*) was affected initially by addition of all ingredients (cupuassu pulp, probiotic, and prebiotic). The addition of cupuassu pulp (C and PC) increased the L* during the period of storage. Apparent viscosity and firmness decreased in the PC yogurt. The consistency was highest in the yogurts with added prebiotic (Pre and S) than the other yogurts (N, Pro, C, and PC) at the end of the storage period (d 28). The cohesiveness remained constant in all yogurts (N, Pro, Pre, S, C, and PC). Based on the results obtained from the current study, it was concluded that cupuassu pulp addition improves the texture of goat milk yogurts. Therefore, this pulp could be an important technological strategy for the dairy goat industry.

Detecção de resistência às fluoroquinolonas em Campylobacter isolados de frangos de criação orgânica / Detection of fluoroquinolone resistance in Campylobacter strains from organic poultry

Estudos têm revelado que a resistência às quinolonas em cepas de Campylobacter está relacionada à presença da mutação Treonina-86 para Isoleucina. Com o objetivo de investigar a presença dessa mutação em cepas de Campylobacter sensíveis e resistentes à ciprofloxacina e enrofloxacina, o conteúdo cecal de 80 frangos de corte de criação orgânica, abatidos sob Serviço de Inspeção Estadual (S.I.E.) do Estado do Rio de Janeiro, foram coletados e investigados para a presença de Campylobacter. A determinação da resistência à ciprofloxacina e enrofloxacina foi feita pela técnica de difusão em disco e de diluição em ágar para determinação da Concentração Inibitória Mínima (CIM). A detecção da mutação na Região Determinante de Resistencia às Quinolonas (RDRQ) no gene gyrA foi realizada através de sequenciamento. Campylobacter foi isolado a partir de 100% das amostras avaliadas, sendo 68,75% correspondente à C. jejuni e 31,25% à C. coli. No teste de difusão em disco, 100% das cepas foram resistentes à ciprofloxacina e 56,25% das cepas foram resistentes à enrofloxacina. No teste de diluição em ágar, todas as cepas foram resistentes à ciprofloxacina apresentando CIM variando de ≥ 16-64μg/mL, e resistência ou resistência intermediaria à enrofloxacina foi detectada em 42,50% (CIM ≥ 4-32μg/mL) e 38,75% (CIM = 2μg/mL) das cepas, respectivamente. A mutação Tre-86-Ile, foi observada em 100% das cepas analisadas. Além dessa mutação, foram observadas outras mutações não silenciosas (Val-73-Glu, Ser-114-Leu, Val-88-Asp, Ala-75-Asp, Ser-119-Gli, Arg-79-Lis) e mutações silenciosas (His-81-His, Ser-119-Ser, Ala-120-Ala, Fen-99-Fen, Ala-122-Ala, Gli-74-Gli, Ile-77-Ile, Ala-91-Ala, Leu-92-Leu, Val-93-Val, Ile-106-Ile, Tre-107-Tre, Gli-113-Gli, Ile-115-Ile, Gli-110-Gli). A observação de que cepas sensíveis à enrofloxacina pelos testes fenotípicos apresentavam a substituição Tre-86 para Ile sugere que outros mecanismos podem contribuir para a resistência à enrofloxacina em Campylobacter...

Studies have shown that resistance to quinolones in Campylobacter strains is related with Threonine-86-Isoleucine mutation. In order to investigate the presence of this mutation in sensitive and resistant Campylobacter strains to ciprofloxacin and enrofloxacin, the cecal contents of 80 broilers from organic raising chickens, slaughtered under State Inspection Service (S.I.S) of the State of Rio de Janeiro, were collected and tested for the presence of Campylobacter. The determination of ciprofloxacin and enrofloxacin susceptibility was done by disk diffusion and agar dilution methods for determining the Minimum Inhibitory Concentration (MIC). The detection of mutation in Quinolone Resistance Determinant Region (QRDR) in gyrA gene was done by sequencing. Campylobacter was isolated from 100% of the samples, being 68.75% C. jejuni and 31.25% C. coli. By the disk diffusion method, resistance to ciprofloxacin was observed in all isolates and 56.25% of the strains were resistant to enrofloxacin. By agar dilution method, all strains were resistant to ciprofloxacin (MIC ≥ 16μg/mL to ≥ 64μg/mL) and full and intermediate resistance to enrofloxacin was detected in 42.50% (MIC ≥ 4-32μg/mL) and 38.75% (MIC =2μg/mL) of the strains, respectively. Mutation Thr-86-Ile was observed in 100% of the isolates investigated. In addition to this mutation, others no silent mutations (Val-73-Glu, Ser-114-Leu, Val-88-Asp, Ala-75-Asp, Gly-119-Ser, Arg-79-Lys) and silent mutations (His-81-His, Ser-119-Ser, Ala-120-Ala, Phe-99-Phe, Ala-122-Ala, Gly-74-Gly, Ile-77-Ile, Ala-91-Ala, Leu-92-Leu, Val-93-Val, Ile-106-Ile, Thr-107-Thr, Gly-113-Gly, Ile-115-Ile, Gly-110-Gly) were detected. All the enrofloxacin-sensitive strains by the phenotypic methods had the Thr-86 to Ile substitution, which suggests other mechanisms contributing to enrofloxacin resistance in Campylobacter...