Elisa Helena Giglio Ponsano

Chemical composition of Rhodocyclus gelatinosus biomass produced in poultry slaughterhouse wastewater

Universidade Estadual Paulista Medicina Veterinaria Departamento de Apoio; Producao e Saude Animal

Isolation of Rhodocyclus gelatinosus from poultry slaughterhouse wastewater

Four cultures of photosynthetic bacteria isolated from poultry slaughterhouse wastewater were identified as Rhodocyclus gelatinosus based on the following properties: reddish color of cultures in synthetic medium, presence of motility, slightly curved Gram-negative rods morphology, gelatin liquefying activity, utilization of citrate as carbon source and production of bacteriochlorophyl a and carotenoids of the spirilloxanthin alternative series. R. gelatinosus may represent a source of nutrients and pigments with application in poultry feed.

Utilisation of bacterial (Rubrivivax gelatinosus) biomass for egg yolk pigmentation.

The effects of Rubrivivax gelatinosus biomass inclusion in diets of Dekalb White laying hens were assessed. The traits studied were yolk colour, consumer preference and hepatic and renal function. Broken-line regression was used to assess the biomass requirements for yolk colour attributes. Hens were fed one of six experimental diets formulated with the bacterial biomass at 0 (control), 1.5, 3.0, 4.5, 6.0 and 7.5 g/kg into a corn–soybean meal basal feed for 30 days. All tested concentrations of the biomass caused darkening and increased redness of yolks but did not affect yellowness. The yolk colour most preferred by an untrained panel was achieved by inclusion of a dietary biomass of 4.5 g/kg, the same as the requirement for maximum redness. Biochemical and histological analysis indicated an absence of deleterious effects of the product on liver and kidney functions during the study period. These results indicate that R. gelatinosus biomass can be used to increase red yolk pigmentation.

Comparison between freeze and spray drying to obtain powder Rubrivivax gelatinosus biomass

The use of colorants in products of animal origin is justified by the improvement in the color of foods since this attribute is considered a quality criterion. These additives can be produced using industrial effluents as substrates and appropriate organisms, such as Rubrivivax gelatinosus. Oxycarotenoids represent a class of carotenes responsible for the pigmentation of animals and vegetables. R. gelatinosus grows in fish industry effluent with the resulting production of a bacterial biomass containing oxycarotenoids. The purpose of this study was to compare the use of two drying processes - spray and freeze drying - to obtain powder biomass in terms of the process parameters (yield, productivity, and product recovery) and the product characteristics (color, proximate composition, and oxycarotenoids). No difference was detected in the yield between these techniques, while productivity was higher using spray drying. Higher product recovery and moisture were achieved with freeze drying, while ash was higher with spray drying. The freeze dried biomass was redder, darker and less saturated than the spray dried biomass. No difference in oxycarotenoids was detected between the biomasses. Although it results in lower recovery rate, spray drying was faster and more productive, and it provided the same yield as freeze drying, which makes it the method of choice for obtaining R. gelatinosus biomass.

Desempenho produtivo e qualidade da carne de frangos alimentados com ração contendo óleo de linhaça

The objective of this work was to assess the effect of linseed oil as a substitute to soybean oil on yield performance and meat traits of broilers of both sexes. Three hundred and twenty birds were raised in a 4x2 factorial arrangement, consisting of four receiving periods combinations of soybean oil and linseed oil and two sexes, with four replications. Yield performance was evaluated by weighting feed and broilers aging 1, 21, 42 and 49 days, when they were slaughtered. After slaughtering, carcass yield and composition in main cuts, viscera and abdominal fat were quantified. Total lipids, moisture and cholesterol contents in meat were determined. Linseed diets improved the nutritional quality of the lipid fraction of broilers meat but were harmful to broilers performance.

Efeito do consumo de óleo de linhaça e de vitamina E no desempenho e nas características de carcaças de frangos de corte

Foi avaliado o efeito da utilizacao de oleo de linhaca na racao, em substituicao ao oleo de soja em diferentes proporcoes, e de vitamina E, ate o nivel de 400mg/kg de racao, sobre o desempenho e a composicao de carcaca de frangos de corte. O desempenho produtivo foi avaliado com base em pesagens das aves e da racao aos 21 e 49 dias de idade. No 49o dia, as aves foram abatidas, e os rendimentos de carcaca e dos principais cortes comerciais e a porcentagem de visceras e de gordura abdominal foram avaliados. A composicao da fracao oleosa da racao, de forma geral, nao interferiu nos parâmetros de desempenho avaliados (P>0,05). Os machos consumiram mais racao e ganharam mais peso que as femeas (P<0,01). As femeas apresentaram, em geral, pior conversao alimentar, associada a maior deposicao de gordura abdominal. Os machos apresentaram maior porcentagem de coxa com sobrecoxa em relacao ao peso da carcaca eviscerada, e as femeas apresentaram maior porcentagem de peito. A porcentagem de asas e visceras nao diferiu entre os sexos.

Espessura da lâmina de cisalhamento na avaliação instrumental da textura da carne

Standardization of texture is one of the main problems related to beef quality. Because of that, objective evaluation of tenderness performed by mechanic methodologies has been studied for years. In order to count on instrumental texture evaluation as a valuable tool in meat tenderness studies, it is necessary to minimize the causes of variation that might be involved in the trial. Nowadays, Warner-Bratzler shear force is widely used for meat tenderness determination. The standard protocol of this methodology establishes the utilization of shear blade 1.016mm tick. The aim of this study was to compare beef texture data provided by Warner-Bratzler standard shear blade, 1.016mm thick, with those provided by a thicker one, 3.05mm thick. After slaughtering, Longissimus dorsi muscle samples with similar contents of moisture, lipids and proteins were subjected to two different cooling temperatures,reaching different rates of temperature drop and hence different muscle contraction extents, which were confirmed by the determination of sarcomere length. Results indicated the superior sensibility of the Warner-Bratzler standard shear blade to detect variations in meat texture due to cooling velocity.

MÉTODO SIMPLES PARA ESTIMAR ENCURTAMENTO PELO FRIO EM CARNE BOVINA

E bem conhecido o fato de que o encurtamento pelo frio pode influenciar negativamente a textura da carne. Por isso, a determinacao do grau de contracao do tecido muscular e um recurso analitico de grande importância quando se estuda a otimizacao dos procedimentos industriais. Neste trabalho, foram avaliadas comparativamente duas metodologias de microscopia. Para isso, os musculos Biceps femoris, Longissimus dorsi e Semimembranosus obtidos de nove carcacas bovinas com tres diferentes graus de acabamento foram analisados de forma pareada por ambos os metodos. O musculo Longissimus dorsi apresentou menor comprimento de sarcomero e o m. Semimembranosus o maior (p 0,05), revelando a possibilidade de emprego do metodo mais simples.

Características e potencial tecnológico da carne da capivara

ABSTRACT The good rank capybara meat has reached withinthe exotic meat market justifies studies on its physical-chemicalcomposition and also on the improvement of the productionprocess. With that aim, Longissimus dorsi and Semimembranosus muscles of male animals ageing 12 to 18months were evaluated about composition and technologicalproperties. It was found a low fat content in capybara meat –0.4% and 0.3% for L. dorsi and Semimembranosus muscles,respectively. A inverse correlation (P<0.001) was found betweensarcomere length and shear force. L. dorsi showed a shortersarcomere lenght and a higher shear force (P<0.001) than Semimembranosus muscle (1.88 μ m and 2.43 m; 11.2 kgand 9.1kg, respectively), what denotes that capybara ham meatis tenderer than loin meat. Moreover, trimmings and viscerawere used in the elaboration of meat products as hamburger,pate and mortadella. Sensory analysis of those products showedgood acceptance. Key words: capybara, meat, technology, meat products.

Encurtamento pelo frio de fibras musculares oxidativas de bovinos pela técnica de NADH-TR

Bovine carcasses quickly cooled may develop a muscle contraction known as cold shortening. This process, harmful to meat texture, occurs mainly in the oxidative muscle fibers. This work was aimed at studing an analytical tool to distinguish these fibers and to evaluate, more precisely, the muscle contraction through the measurement of sarcomeres length. Longissimus dorsi muscles of 12 heifers were used as samples. Samples from one of the half carcasses were fast cooled and the samples from the others half carcasses were slowly cooled. An analytical technique based on Nicotinamide Adenine Dinucleotide - Tetrazolium Redutase (NADH-TR) methodology was performed to measure, by microscopy, the red fibers sarcomeres lenghts. Temperature and pH drops in the samples, shear force and rib eye area were also evaluated. Results pointed out that the temperature is the main responsible for the sarcomere length in the fast cooling and that, when slow cooling is performed, the influence of this parameter is less important. These results indicate that the NADH-TR technique is able to estimate cold shortening occurrence in bovine skeletal muscles.