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1.
Meat Sci ; 206: 109324, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37683507

RESUMO

This research aimed to evaluate the influence of high-intensity ultrasound (HIU) levels (control: 0; high: 747.79; ultra-high: 1344.17 Wcm-2) on pH, instrumental color (redness, R630/580, hue angle and chroma) and oxidative stability (lipid and protein oxidation) of Psoas major (PM) muscle from Nellore cattle raised in two feeding systems: grain and pasture. Using a structural equation modeling (SEM) approach, the relations (P > 0.05) between exogenous (HIU levels) and endogenous (pH, color, lipid and protein oxidation) variables were observed. In beef from grain-fed animals the pH was directly and negatively related to lipid oxidation (γ = -0.321), hue angle (γ = -0.847) and chroma (γ = -0.442) and protein oxidation (γ = -0.752). In PM from pasture-fed HIU exhibited a negative relation with lipid (γ = -0.144) and protein (γ = -0.743) oxidation, suggesting a possible positive influence on the oxidative stability of meat and a positive relation with redness (γ = 0.197) and R630/580 (γ = 0.379). The HIU positively influenced the color and oxidative stability of beef from Bos indicus cattle, and a synergistic effect of HIU and feeding system on beef from pasture-fed animals.

2.
J Dairy Sci ; 103(11): 10022-10035, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32896416

RESUMO

The aim of this study was to evaluate the effect of ricotta whey (RW), cheese whey (CW), and butter whey (BUW) as replacers of whole milk (WM) at different ratios (0:100, 25:75, 50:50, 75:25, and 100:0) in the physicochemical and sensory qualities of ice cream. All formulations, including a commercial sample used as reference, were analyzed for nutritional composition, energy value, pH, titratable acidity (TA), melting behavior, desorption index, instrumental color properties, instrumental hardness, and consumer sensory testing. Overall, the addition of RW, CW, and BUW increased the moisture content, TA, melting rate, and redness (a*) and yellowness (b*) values but decreased the pH, lightness (L*) value, energy value, levels of ash, protein, lipid, and carbohydrate. As exception, CW did not influence the TA, and BUW resulted in lower lipid reduction and in lower hardness changes, and it did not affect the content of ash, protein, and a* and b* values of ice creams. Any ice cream formulation had dietary fibers and a desorption index. Ricotta whey and CW at all ratios and BUW at 25% did not affect overall liking compared with the commercial sample, whereas purchase intention was only decreased by the addition of BUW from 50 to 100%. Ricotta whey at 75 and 100% decreased melting velocity and creaminess, and BUW at 50, 75, and 100% increased hardness, TA, and cream flavor but decreased creaminess, which contributed negatively to overall liking. Therefore, the evaluated dairy by-products, especially RW and CW, have great potential for replacing milk in ice creams.


Assuntos
Queijo/análise , Sorvetes/normas , Substitutos do Leite/química , Soro do Leite/química , Carboidratos/análise , Fenômenos Químicos , Comportamento do Consumidor , Laticínios/análise , Concentração de Íons de Hidrogênio , Lipídeos/análise , Proteínas/análise , Paladar
3.
J Appl Microbiol ; 127(5): 1564-1575, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31330563

RESUMO

AIMS: First, two inactivation models were compared for different phenotypic profiles of Escherichia coli O26 using ultraviolet-C light (UV-C) and thermal treatment (T), by means of Central Composite Rotatable Design of Experiment (CCRD). Second, we aimed to evaluate the subsequent survival and persistence of cells in simulated gastric fluid (SGF). METHODS AND RESULTS: Two strains of E. coli O26, a wild-type strain and a clinical ATCC strain were used in both steps. A CCRD was used in a 22 arrangement in random order. The goodness-of-fit of the models was determined. The lack of fit, and the normality of residual data were checked with the Shapiro-Wilk test, and the model accuracy factor, bias factor and the model mean square error (MSE) were measured. Subsequently, the resistance capacity of the strains was evaluated after exposure to simulated gastric acid. The CCRD results obtained indicate that the mild heat (<70°C) has a recovery effect. In addition, for the clinical strain, the UV-C and heat (above 70°C) has an additive inactivation effect. Moreover, temperature (65°C) induced SGF resistance by the wild-type and clinical strain. For the clinical strain, cells exposed to UV-C were more sensitive to SGF. In contrast to clinical strain, exposing cells of the wild-type strain to UV-C increased the survival capacity in the SGF. CONCLUSION: Response surface analyses showed that the wild-type O26 strain has higher persistence under unfavourable conditions than the clinical strain, and the stresses caused by applied microbial control technologies can increase the survival capacity in the SGF. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study shed light on different phenotypic responses in the same bacterium serogroup. Moreover, the impact of the study was that strain selection criteria must be adequate to develop effective models of inactivation.


Assuntos
Escherichia coli/efeitos da radiação , Ácido Gástrico/química , Contagem de Colônia Microbiana , Escherichia coli/química , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/microbiologia , Temperatura Alta , Humanos , Temperatura , Raios Ultravioleta
4.
Lett Appl Microbiol ; 66(4): 352-359, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29397031

RESUMO

Salmonella pathogenicity relies on virulence factors many of which are clustered within the Salmonella pathogenicity islands. Salmonella also harbours mobile genetic elements such as virulence plasmids, prophage-like elements and antimicrobial resistance genes which can contribute to increase its pathogenicity. Here, we have genetically characterized a selected S. Typhimurium strain (CCRJ_26) from our previous study with Multiple Drugs Resistant profile and high-frequency PFGE clonal profile which apparently persists in the pork production centre of Rio de Janeiro State, Brazil. By whole-genome sequencing, we described the strain's genome virulent content and characterized the repertoire of bacterial plasmids, antibiotic resistance genes and prophage-like elements. Here, we have shown evidence that strain CCRJ_26 genome possible represent a virulence-associated phenotype which may be potentially virulent in human infection. SIGNIFICANCE AND IMPACT OF THE STUDY: Whole-genome sequencing technologies are still costly and remain underexplored for applied microbiology in Brazil. Hence, this genomic description of S. Typhimurium strain CCRJ_26 will provide help in future molecular epidemiological studies. The analysis described here reveals a quick and useful pipeline for bacterial virulence characterization using whole-genome sequencing approach.


Assuntos
Genoma Bacteriano/genética , Salmonelose Animal/microbiologia , Salmonella typhimurium/genética , Suínos/microbiologia , Animais , Antibacterianos , Brasil , Farmacorresistência Bacteriana/genética , Ilhas Genômicas/genética , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Prófagos/genética , Carne Vermelha/microbiologia , Salmonella typhimurium/classificação , Salmonella typhimurium/isolamento & purificação , Virulência/genética
5.
J Appl Microbiol ; 124(6): 1347-1365, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29345036

RESUMO

The aim of this review is to present the methodologies currently applied to identify microbiota and pathogens transmitted to humans through seafood consumption, focusing on molecular techniques and pointing out their importance, advantages, disadvantages and applicability. Knowledge of available techniques allows researchers to identify which technique best fits their expectations. With such discernment, it will be possible to infer which disadvantages will be present and, therefore, not interfering with the final result. Two methodologies can be employed for this purpose, dependent and independent cultures. However, the dependent culture has certain limitations that can be solved through the independent cultivation techniques, such as PCR, PFGE and NGS, especially through the sequencing of the 16S rRNA region, providing a complete view of microbial diversity. These have revolutionized microbiological knowledge, mainly because they allow for the identification of uncultivable micro-organisms, which represent a substantial portion of total micro-organisms, making it possible to elucidate not yet described taxa which may display pathogenic potential, besides quantifying microbial communities, microbiota genetics, translated proteins and produced metabolites. In addition, transcriptomic and metabolomic techniques also allow for the evaluation of possible impacts that microbial communities may create in their environment, as well as the determination of potential pathogenicity to humans.


Assuntos
Bactérias/isolamento & purificação , Microbiota , Reação em Cadeia da Polimerase/métodos , Alimentos Marinhos/microbiologia , Análise de Sequência de DNA/métodos , Bactérias/classificação , Bactérias/genética , Doenças Transmitidas por Alimentos/microbiologia , Humanos
6.
Arq. bras. med. vet. zootec. (Online) ; 69(3): 551-558, jun. 2017. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-846881

RESUMO

The aim of this study was to evaluate the effect of diets containing whole cottonseed (WC) on blood biochemical parameters of bulls. Thirty bulls with 30±6 months and 382.7±28.4kg were kept in feedlot (85 days) and fed the following WC levels: 0, 2.22, 4.44, 6.66, 8.88 and 11.11%. In comparing biochemical indicators from the beginning to the end of the experiment, the control group (CG) and those fed diets containing 2.22, 8.88 and 11.11% of WC had an increase (P<0.05) in serum Ca concentrations (8.34±0.65−9.56±0.92mEqL-1). In relation to Fe (202.79±69.04−300.04±79.88µg/dL), the CG and those treated with 6.66% WC showed an increase (P<0.05) in serum concentrations. As to the Mg (1.92±0.18−2.40±0.27mEqL-1), groups treated with diet containing 2.22, 4.44 and 6.66% of WC had higher (p<0.05) concentrations at the end of the study. Regarding blood lipids, groups with diets containing 2.22; 4.44; 6.66 and 8.88% of WC increased (p<0.05), respectively, in concentrations of HDL, TG, VLDL and COL. The group that received 11.11% of WC increased (P<0.05) in the concentrations of COL and HDL. It can be concluded that diets containing WC, caused no alterations in the concentrations of blood parameters analyzed in this study, with the exception of Mg.(AU)


Objetivou-se avaliar o efeito de dietas contendo caroço de algodão (CA) sobre os parâmetros sanguíneos de bovinos. Trinta touros com 30±6 meses e 382,7±28,4kg foram confinados (85 dias) e receberam dietas com as seguintes proporções de CA: 0; 2,22; 4,44; 6,66; 8,88, e 11,11%. Ao se compararem as concentrações dos indicadores bioquímicos do início com as do final do experimento, foi observado que o grupo controle e aqueles com dietas contendo 2,22; 8,88 e 11,11% de CA apresentaram aumento (P<0,05) na concentração sérica de Ca (8,34±0,65−9,56±0,92 mEqL-1). Já em relação ao Fe (202,79±69,04−300,04±79,88µg/dL), observou-se que apenas o grupo controle e aquele tratado com 6,66% apresentaram aumento (P<0,05) em sua concentração. Quanto ao Mg (1,92±0,18−2,40±0,27 mEqL-1), os grupos tratados com 2,22; 4,44 e 6,66% de CA apresentaram maiores concentrações (P<0,05) ao final do estudo. Com relação aos lipídeos sanguíneos, os grupos com dietas contendo 2,22; 4,44; 6,66 e 8,88% de CA tiveram aumento (P<0,05), respectivamente, nas concentrações de HDL, TG, VLDL e COL. O grupo que recebeu 11,11% de CA teve aumento (P<0,05) nas concentrações de COL e HDL. Conclui-se que as dietas contendo CA não causaram alterações (P>0,05) nas concentrações dos parâmetros sanguíneos analisados, com exceção do Mg.(AU)


Assuntos
Animais , Bovinos , Ração Animal , Análise Química do Sangue/veterinária , Dieta/veterinária , Gossypium
7.
Poult Sci ; 96(3): 747-753, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27630200

RESUMO

The aim of the present research was to evaluate the influence of organic and non-organic production systems on color stability and lipid oxidation of broiler meat Pectoralis major (PM) stored under refrigeration (4°C) for 9 days. PM samples from organic (ORG) and non-organic (NORG) production systems were compared based on physicochemical analyses (instrumental color, myoglobin concentration, metmyoglobin reducing activity (MRA), pH, and lipid oxidation) performed in 4 different trials (n = 4). In general, NORG broilers demonstrated higher (P < 0.05) b* and lipid oxidation values than ORG, whereas ORG samples exhibited increased (P < 0.05) MRA, ratio of reflectance at 630 per 580 nanometers (R 630/580), and a* values. The lower color stability observed in NORG samples can be partly due to lipid oxidation. Therefore, the production system can affect color and lipid stability of broiler breast meat during storage.


Assuntos
Criação de Animais Domésticos/métodos , Metabolismo dos Lipídeos , Carne/normas , Agricultura Orgânica , Músculos Peitorais/fisiologia , Animais , Galinhas , Cor , Carne/análise , Oxirredução
8.
Arq. bras. med. vet. zootec ; 68(4): 1069-1076, jul.-ago. 2016. tab
Artigo em Inglês | LILACS, VETINDEX | ID: lil-792466

RESUMO

Sensory and instrumental analyses evaluated the meat and fat characteristics of feedlot-finished steers fed a diet containing cottonseed. Global impression, texture, meat color, and fat color were assessed. Thirty Nellore bulls with an average age of 30 ± 6 months and initial body weight of 382.7 ± 28.4kg were kept in feedlot stalls and fed the following cottonseed levels: 0; 2.22 %; 4.44 %; 6.66 %; 8.88 %; 11.11 % of the dietary dry matter. The cottonseed used in this experiment had an average free gossypol content of 4.5g/kg of cottonseed. The overall impression of the samples, assessed by the triangle test for difference, did not differ for more than 62 % of the panelists (P>0.01). The shear strength of roasted meat varied from 6.00 to 6.54kg. According to texture profile analysis (TPA), the hardness, springiness, and chewiness of roast meat ranged from 24.15 to 28.01 N, 0.52 to 0.56, 8.42 to 11.01 N, respectively; of raw meat, 9.51 to 13.86 N, 0.26 to 0.29, and 1.38 to 1.81 N, respectively. The different treatments did not affect meat texture, meat color, or fat color (P>0.05). Meat color, luminosity, and red intensity ranged from 37.71 to 42.85, 20.68 to 25.25, and 6.74 to 8.61, respectively; fat color, luminosity, and yellow intensity ranged from 62.26 to 63.78, 11.13 to 11.62, and 10.53 to 10.86, respectively. Cottonseed intake of up to 1.13kg/animal/day, equivalent to a free gossypol intake of 5.05g/animal/day, in place of soybean meal and ground corn, did not significantly change the global sensory impression, texture, and color of the meat and fat.(AU)


Avaliou-se, por meio de análise sensorial e instrumental, o efeito da adição de caroço de algodão à dieta de bovinos confinados sobre as características da carne e da gordura. Foram avaliadas a impressão global, a textura, a cor da carne e a cor da gordura. Trinta touros da raça Nelore, com médias de idade e peso vivo inicial de 30 ± 6 meses e 382,7 ± 28,4kg, foram confinados e receberam dietas com os seguintes teores de caroço de algodão: 0; 2,22%; 4,44%; 6,66%; 8,88%; 11,11% na matéria seca da dieta. O caroço de algodão utilizado neste experimento apresentou conteúdo médio de 4,5g de gossipol livre/kg de caroço de algodão. A impressão global da carne, avaliada por meio de teste triangular de diferença, mostrou que mais de 62% dos provadores não perceberam diferença significativa (P>0,01) entre as amostras. A textura da carne assada avaliada por meio do teste de força de cisalhamento variou de 6,00 a 6,54kg. Na análise do perfil de textura (TPA) da carne assada, a dureza, a elasticidade e a mastigabilidade variaram, respectivamente, de 24,15 a 28,01N, de 0,52 a 0,56N e de 8,42 a 11,01N. Na TPA da carne crua, variaram, respectivamente, de 9,51 a 13,86N, de 0,26 a 0,29N e de 1,38 a 1,81N. Na avaliação da cor da carne, a luminosidade, a intensidade de vermelho e a intensidade de amarelo da cor da carne variaram, respectivamente, de 37,71 a 42,85, de 20,68 a 25,25 e de 6,74 a 8,61. E para a cor da gordura, variaram, respectivamente, de 62,26 a 63,78, de 11,13 a 11,62 e de 10,53 a 10,86. A textura, a cor da carne e a cor da gordura não apresentaram diferenças significativas (P>0,05) entre os diferentes tratamentos. O consumo de caroço de algodão em até 1,13kg/animal/dia, que resultou no consumo de 5,05g de gossipol livre/animal/dia, em substituição ao farelo de soja e ao grão de milho triturado, não causou alterações significativas nas características da carne quanto à impressão sensorial global, à textura, à cor da carne e à cor da gordura.(AU)


Assuntos
Animais , Masculino , Bovinos , Ração Animal/análise , Ração Animal/estatística & dados numéricos , Fenômenos Fisiológicos da Nutrição Animal , Gossipol , Carne Vermelha/análise , Cromatografia/veterinária , Indústria da Carne
9.
J Dairy Sci ; 99(6): 4160-4168, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26995125

RESUMO

The present study aimed to evaluate the physicochemical parameters of sheep milk yogurt smoothies (SMY) containing inulin at different levels (0, 2, 4, and 6%). Titratable acidity and pH, yogurt bacteria counts, fatty acids profile, and healthy lipid indices were evaluated during 28 d of refrigerated storage. As expected for yogurts, Streptococcus thermophilus counts decreased 1 to 3 log cycles and Lactobacillus delbrueckii ssp. bulgaricus counts decreased 1 to 2 cycles from d 1 to 28. The protective effect of inulin on bacteria survival and viability in the food matrix was not verified in the prebiotic SMY during storage, regardless of inulin level. Although lower post-acidification was observed in prebiotic SMY due to inulin addition, no changes were verified in short-chain fatty acids (SCFA) or polyunsaturated fatty acids (PUFA). In contrast, an increase in medium- and long-chain fatty acids (MCFA and LCFA) and monounsaturated fatty acids (MUFA) was observed during storage in all SMY. The most significant levels of fatty acids in SMY were oleic acid, followed by palmitic and myristic acids. A high positive correlation between conjugated linoleic acid (CLA) and oleic acid (r=0.978) was observed. The cis-9,trans-11 CLA isomer represented approximately 78% of total PUFA and 2% of total fatty acids, whereas α-linoleic acid comprised about 22% PUFA and 1% of total fatty acids in SMY. The fatty acid changes during storage were associated with the metabolic activity of the starter bacteria, especially for oleic acid and cis-9,trans-11 CLA isomer. Thus, the SMY represented a great source of these compounds. We observed that inulin levels did not affect fatty acids. A nonsignificant decrease in atherogenic index was observed during storage in all SMY, and a positive correlation (r=0.973) was found between atherogenic index and thrombogenic index of SMY. High correlations were observed between lauric and myristic acids and saturated fatty acids (r=0.907 and r=0.894, respectively), providing evidence of their atherogenic and thrombogenic potential. A negative correlation was observed between stearic acid and atherogenic index (r=-0.612) and between oleic acid and atherogenic index. Sheep milk yogurt could be characterized as a food with low atherogenic and thrombogenic risk because of its healthy lipid composition. Therefore, addition of inulin to SMY could be a good option to improve functionality of this food matrix for dairy companies wishing to enter the functional food market.


Assuntos
Inulina , Iogurte/microbiologia , Animais , Ácidos Graxos , Ácidos Linoleicos Conjugados , Leite/química , Óvulo , Ovinos , Streptococcus thermophilus/metabolismo
10.
Food Chem ; 196: 628-37, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26593536

RESUMO

The partial substitution of sodium chloride by potassium chloride (0%, 25%, and 50%) and addition of arginine (1% w/w) in probiotic Minas cheese was investigated. Microbiological (Lactococcus lactis and Lactobacillus acidophilus counts, and functionality of the prebiotics L. acidophilus), physicochemical (pH, proteolysis, organic acids, fatty acids, and volatile profiles), rheological (uniaxial compression) and sensory (hedonic test with 100 consumers) characterizations were carried out. The sodium reduction and addition of arginine did not constitute a hurdle to lactic and probiotic bacteria survival, with presented values of about 9 log CFU/g, ranging from 7.11 to 9.21 log CFU/g, respectively. In addition, lower pH values, higher proteolysis, and a decrease in toughness, elasticity and firmness were observed, as well as an increase in lactic, citric, and acetic acid contents. In contrast, no change was observed in the fatty acid profile. With respect to the sensory acceptance, the probiotic low-sodium Minas cheese presented scores above 6.00 (liked slightly) for the attributes flavor and overall acceptance. The addition of arginine can be a potential alternative for the development of probiotic dairy products with reduced sodium content.


Assuntos
Arginina/análise , Queijo/análise , Aditivos Alimentares/análise , Probióticos/análise , Queijo/microbiologia , Contagem de Colônia Microbiana , Aromatizantes/análise , Armazenamento de Alimentos , Humanos , Lactobacillus acidophilus/crescimento & desenvolvimento , Lactococcus lactis/crescimento & desenvolvimento , Sódio/análise , Paladar
11.
PLoS One ; 10(10): e0139910, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26444286

RESUMO

Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR), Viçosa (AV) e Lavras (AD)], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when p<0.05. The highest palmitic acid content, which is antimutagenic compost, was seen in AV grain (36.6g/100g fatty acids), which may have contributed to increasing the antimutagenic potential in fermented milk. Higher monounsaturated fatty acid (25.8 g/100g fatty acids) and lower saturated fatty acid (72.7 g/100g fatty acids) contents were observed in AV, when compared to other grains, due to higher Δ9-desaturase activity (0.31) that improves the nutritional quality of lipids. Higher oleic acid (25.0 g/100g fatty acids) and monounsaturated fatty acid (28.2g/100g fatty acids) and lower saturated fatty acid (67.2g/100g fatty acids) contents were found in stored kefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality.


Assuntos
Produtos Fermentados do Leite , Ácidos Graxos/análise , Fermentação , Armazenamento de Alimentos , Leite/química , Animais , Cromatografia Gasosa
12.
J Dairy Sci ; 98(3): 1443-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25557891

RESUMO

Dulce de leche samples available in the Brazilian market were submitted to sensory profiling by quantitative descriptive analysis and acceptance test, as well sensory evaluation using the just-about-right scale and purchase intent. External preference mapping and the ideal sensory characteristics of dulce de leche were determined. The results were also evaluated by principal component analysis, hierarchical cluster analysis, partial least squares regression, artificial neural networks, and logistic regression. Overall, significant product acceptance was related to intermediate scores of the sensory attributes in the descriptive test, and this trend was observed even after consumer segmentation. The results obtained by sensometric techniques showed that optimizing an ideal dulce de leche from the sensory standpoint is a multidimensional process, with necessary adjustments on the appearance, aroma, taste, and texture attributes of the product for better consumer acceptance and purchase. The optimum dulce de leche was characterized by high scores for the attributes sweet taste, caramel taste, brightness, color, and caramel aroma in accordance with the preference mapping findings. In industrial terms, this means changing the parameters used in the thermal treatment and quantitative changes in the ingredients used in formulations.


Assuntos
Comportamento de Escolha , Comportamento do Consumidor , Laticínios , Preferências Alimentares , Brasil , Doces , Carboidratos , Análise por Conglomerados , Cor , Humanos , Análise dos Mínimos Quadrados , Modelos Logísticos , Odorantes , Análise de Componente Principal , Olfato , Paladar
13.
Food Chem ; 169: 471-7, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25236253

RESUMO

The physicochemical profile of Dulce de Leche (DL) was determined by both routine analysis and others techniques (HPLC, GC-MS and ICP-OES). Seven Brazilian commercial brands were characterised for moisture content, protein, fat, ash, pH and titratable acidity, mineral content (sodium, potassium, calcium, and phosphorus), colour parameters and instrumental analysis (carbohydrates content and volatile compounds). Overall, extensive variability among all the parameters evaluated were observed, suggesting different operational procedures in the dairy factories along the DL processing. In this sense, an increase of intrinsic quality of DL is related closely the standardization of operational parameters using during the manufacture.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Leite/química , Animais , Brasil , Cálcio/química , Carboidratos/química , Cromatografia Líquida de Alta Pressão , Cor , Laticínios , Cromatografia Gasosa-Espectrometria de Massas , Glucose/química , Concentração de Íons de Hidrogênio , Lactose/química , América Latina , Fósforo/química , Potássio/química , Análise de Componente Principal , Sódio/química
14.
Poult Sci ; 93(9): 2304-13, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24974390

RESUMO

Radiation from UV-C has been demonstrated as a potential surface decontamination method in addition to several advantages over regular sanitation methods. However, UV-C radiation possibly affects the physicochemical properties of meat products. To determine the optimum exposure time for bacterial reduction, 39 chicken breasts, inoculated with a pool of Salmonella spp., were submitted to 3 levels of UV-C intensities (0.62, 1.13, and 1.95 mW/cm²) for up to 120 s. After the optimum exposure time of 90 s was determined, changes in the biogenic amines, total aerobic mesophilic bacteria, Enterobacteriaceae, lipid oxidation, pH, and instrumental color were evaluated in 84 chicken breasts that were irradiated (0.62, 1.13, and 1.95 mW/cm²) and stored at 4°C for 9 d. The groups treated with UV-C radiation exhibited an increase in tyramine, cadaverine, and putrescine contents (P < 0.05). The highest UV-C intensity (1.95 mW/cm²) promoted a decrease in the initial bacterial load, and extended the lag phase and the shelf life. The groups irradiated with 1.13 and 1.95 mW/cm² exhibited a more stable b* value than the other groups; similar trends for L*, a*, pH, and TBA reactive substance values were observed among all groups. The UV-C light was demonstrated to be an efficient alternative technology to improve the bacteriological quality of chicken meat without negatively affecting the physical and chemical parameters of chicken breast meat. Nonetheless, the increases on the biogenic amines content should be considered as an effect of the UV processing and not as an indicator of bacterial growth.


Assuntos
Bactérias/efeitos da radiação , Aminas Biogênicas/efeitos da radiação , Microbiologia de Alimentos/métodos , Conservação de Alimentos/métodos , Carne/efeitos da radiação , Carne/normas , Raios Ultravioleta , Animais , Bactérias/crescimento & desenvolvimento , Aminas Biogênicas/análise , Aminas Biogênicas/química , Galinhas , Temperatura Baixa , Contagem de Colônia Microbiana , Concentração de Íons de Hidrogênio/efeitos da radiação , Metabolismo dos Lipídeos/efeitos da radiação , Carne/análise , Carne/microbiologia , Oxirredução/efeitos da radiação , Músculos Peitorais/microbiologia , Músculos Peitorais/fisiologia , Músculos Peitorais/efeitos da radiação , Salmonella/crescimento & desenvolvimento , Salmonella/efeitos da radiação , Fatores de Tempo
15.
Poult Sci ; 93(6): 1571-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24879707

RESUMO

The combined effects of cooking, vacuum packing, freezing, and high-dose gamma irradiation in the microbiological conservation and in biogenic amine (BA) contents of ready-to-eat grilled breast chicken fillets are investigated in this work. After seasoning, cooking, and vacuum packing, one-third of the samples were stored at -25°C (T1). The remaining two-thirds were treated with 48 kGy, one-third being stored at -25°C (T2) and the other one-third kept at room temperature (T3). All samples were periodically analyzed to determine growth of heterotrophic aerobic mesophilic bacteria (HAMB) and levels of BA (tyramine, TYM; putrescine, PUT; cadaverine, CAD; spermidine, SPD; histamine, HYM; and spermine, SPM). Variance analysis was performed to determine significant changes in the measured data. Grilling caused HAMB counts in seasoned samples to drop from 5.3 log cfu/g to zero. In addition, no viable HAMB cells were detected in the samples throughout the 12-mo storage time. Regarding the BA analyses, the highest mean levels were measured for SPM and CAD with significantly higher levels (P < 0.05) being determined in nonirradiated samples (T1). Furthermore, significantly lower mean levels for the total content of BA were observed in the irradiated samples. Relative to T1 (7.5 ± 1.5 mg/kg), the figures were 47 ± 23% for T2 and 60 ± 25% for T3, mostly due to loss of CAD by radiolysis. Therefore, it can be concluded that the combination of grilling, vacuum packing, freezing, and high-dose gamma irradiation efficiently eliminated HAMB, while sustaining acceptable levels of BA in ready-to-eat chicken breast fillets throughout the 12 mo of storage at room temperature.


Assuntos
Aminas Biogênicas/análise , Manipulação de Alimentos/métodos , Carne/análise , Carne/microbiologia , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Contagem de Colônia Microbiana , Culinária , Embalagem de Alimentos/métodos , Armazenamento de Alimentos , Congelamento , Raios gama , Músculos Peitorais/microbiologia , Músculos Peitorais/fisiologia , Fatores de Tempo
16.
Food Res Int ; 64: 380-386, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30011664

RESUMO

The performance of different chemometric approaches to discriminate artisanal and industrial pork sausages using traditional physicochemical parameters was investigated. A total of 90 samples of sausages marketed in various supermarkets and open-markets in Rio de Janeiro, Brazil were analyzed for their content of moisture, protein, fat, nitrite, sodium and calcium. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used as exploratory methods, while linear and non-linear classification methods, such as k-nearest neighbors (k-NN), soft independent modeling of class analogy (SIMCA), partial least square discriminant analysis (PLSDA) and artificial neural networks (ANN) were used for assessing the data. Different behaviors for all parameters were analyzed between the classes. Principal component analysis and hierarchical cluster analysis did not show a complete discrimination of the samples. KNN and ANN results showed excellent performance for both categories with 100% correct prediction while SIMCA and PLSDA presented performance of 100% and 85.7% for inspected and artisanal sausages, respectively. According to the SIMCA, PLSDA and ANN, the contents of moisture and fat showed the highest discriminative power. Overall, the findings emphasize the use of multivariate techniques to evaluate the quality of processed foods, as pork sausages.

17.
Arq. bras. med. vet. zootec ; 64(2): 274-280, abr. 2012. mapas
Artigo em Português | LILACS | ID: lil-622477

RESUMO

Estimou-se a prevalência de tuberculose em bovinos, e em seus respectivos rebanhos, abatidos em 2009 no estado de Mato Grosso, utilizando como diagnóstico confirmatório o exame bacteriológico e o molecular a partir de fragmentos de tecidos lesionados. Nos sete abatedouros selecionados, detentores de serviço de inspeção federal (SIF), foram inspecionados 41.193 bovinos, sadios ao exame ante mortem, procedentes de 492 rebanhos originários de 85 (60%) municípios mato-grossenses. Um total de 198 carcaças apresentaram lesões suspeitas. Apenas três carcaças (3/198) apresentaram lesões confirmadas como tuberculosas pelos diagnósticos laboratoriais. A prevalência aparente de tuberculose bovina em animais e rebanhos abatidos no estado de Mato Grosso foi de 0,007% [IC 95% = -0,001%; 0,016%] e 0,61% [IC 95% = -0,08%; 1,30%], respectivamente. O estado do Mato Grosso possui, naturalmente, um status sanitário considerado de baixa prevalência.


The prevalence of bovine tuberculosis in cattle, and its herds, slaughtered in 2009 in the state of Mato Grosso, Brazil, was estimated using bacteriological analysis and molecular test, from fragments of injured tissues as well as direct DNA templates. 41,193 cattle, which appeared healthy in the ante mortem examination, from seven selected slaughterhouses, under Brazilian federal inspection services (SIF), were inspected. The animals were from 492 herds located in 85 (60%) different cities of Mato Grosso. A total of the 198 carcasses had suspicious lesions. Three carcasses (3/198) had lesions that were found to be tuberculous in laboratory diagnosis. The apparent prevalence of bovine tuberculosis in the total number of animals and in herds slaughtered in Mato Grosso was 0.007% [IC 95% = -0.001%; 0.016%] and 0.61% [IC 95% = -0.08%; 1.30%], respectively. The sanitation status demonstrated in Mato Grosso indicates the progress in this state toward the eradication of bovine tuberculosis.

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