In poultry processing plants, disinfectants are often added to prechilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite) on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE) in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil) in pre-chilling tanks.

ResumoA textura, ou maciez, pode ser avaliada pela mensuração da força necessária para ocorrer o cisalhamento das fibras musculares. Objetivou-se, nesse trabalho, a análise da textura de músculos submetidos à fixação e conservação em álcool, ao longo de um ano, mediante uso de um aparelho analisador de textura. Foram utilizados 48 peitos de frangos jovens, pesados, fixados e conservados em álcool etílico 96° GL. As análises foram realizadas após 15, 30, 90, 180 e 360 dias de conservação, além do grupo controle de músculos frescos. Os valores da força de cisalhamento dos diferentes grupos aumentaram progressivamente de 3,38 (grupo controle) até 15,31 Kgf (180 dias), caindo para 9,53 Kgf após 360 dias. Concluiu-se que quando músculos são submetidos à fixação e conservação em álcool 96° GL, ocorre diminuição da maciez, tornando-os quase cinco vezes mais rígidos ao corte após seis meses, e três vezes mais rígidos após um ano. Sugere-se que a dissecção de peças anatômicas musculares ocorra até 90 dias após fixação e conservação em álcool 96° GL ou ao redor de um ano nesse agente conservante, pois há menor rigidez tissular nesses períodos. Embora se tenha estudado o efeito do álcool na textura de tecido muscular de aves, acredita-se que, devido à grande homogeneidade tissular neste caso, tais dados possam ser extrapolados ou servir de base para estudos similares em outras espécies. Palavras-chave:Enrijecimento. Fixador. Dissecção. AbstractTexture, or tenderness, may be evaluated by measuring the force necessary to cause rupture of muscle fibers. The aim of this paper was to analyze the texture of muscles fixed and kept in alcohol, throughout a year, by using a texture analyzer. Forty eight poultry breasts were weighted, fixed and kept in a 96° GL ethylic alcohol solution. Analyses were performed at 15, 30, 90, 180 and 360 days of conservation, besides the one of the control group of fresh breasts. Values of shear forces of different groups increased progressively from 3.38 (control group) to 15.31 Kgf (180 days), decreasing to 9.53Kgf after 360 days. It was concluded that when muscles are fixed and kept in ethylic alcohol 96° GL the tenderness is decreased, becoming almost five times harder during the first six months and three times harder after a year. It is suggested that muscle anatomic pieces dissection occurs up to 90 days after fixation and conservation in 96° GL alcohol or around 1 year on this conservation product because there is smaller muscle stiffness in these times. Although the alcohol effect in texture of poultry muscle tissue has being studied in this paper, it is believed that, due this great tissue homogeneity, these data might be taken or being basis to similar studies in other species.Keywords: Stiffness. Fixation. Dissection. IntroduçãoA maciez ou textura de um músculo pode ser avaliada mediante um analisador conhecido como texturômetro 1 . Esse aparelho mensura a força necessária para que uma lâmina rompa as fibras musculares de um fragmento tissular (força de cisalhamento -FC) e o resultado é e...

A maciez ou textura do peito de frango pode ser avaliada pela mensuração da força necessária para ocorrer o cisalhamento das fibras musculares. O objetivo deste trabalho foi quantificar o enrijecimento muscular em peitos de frango submetidos à fixação e conservação em formaldeído a 10%, ao longo de um ano. As análises foram feitas em peitos frescos (grupo controle) e em amostras com 7, 15, 30, 90, 180 e 360 dias de conservação. A força de cisalhamento variou de 3,38 kgf (grupo controle) a 17,37 kgf (grupo de 30 dias). No grupo de 15 dias de conservação, houve uma pequena queda nessa força (14,74 kgf), quando comparado aos grupos de 90 (16,94 kgf), 180 (16,71 kgf) ou 360 dias (15,42 kgf). Conclui-se que, quando peitos de frango são submetidos à fixação e conservação em solução aquosa de formaldeído 10%, ocorre diminuição da maciez, tornando-os quase cinco vezes mais rígidos ao cisalhamento a partir de sete dias de conservação nessa solução. Palavras-chave: Força de cisalhamento, Formaldeído, Textura AbstractQuantification of chicken breast muscle stiffening caused by formaldehyde. Tenderness or texture of chicken breast may be evaluated through measuring the force needed to lead to the rupture of muscle fibers. The aim of this paper was to quantify the muscle stiffening in chicken breasts which underwent fixing and storage in 10% formaldehyde solution, throughout a year. The analyses were carried out in fresh chicken breasts (control group) and in samples at 7, 15, 30, 90, 180, and 360 days of conservation. The shear force varied from 3.38 kgf (control group) to 17.37 kgf (30-day group). In the 15-day conservation group there was a little force decrease (14.74 kgf), when compared to the 90 (16.94 kgf), 180 (16.71 kgf), or 360 (15.42 kgf) day groups. One concludes that, when chicken breasts underwent fixing and storage in 10% formaldehyde aqueous solution, tenderness is decreased, and they become almost five times harder after seven days of storage in this solution.

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Antimicrobial sensitivity and pathogenicity level of 90 strains of Escherichia coli isolated from livers and intestines from commercial layer hens presenting diarrhea were analyzed. To evaluate the antimicrobial susceptibility, all samples were subjected to antimicrobial susceptibility testing using 11 commercial drugs. The results have showed none of the strains was susceptible to all antibiotics tested. All samples showed resistance to two or more drugs. According to the mortality rate of the birds, the in-vivo pathogenicity test classifies the strains into four classes: high, intermediate, low and nonpathogenic. The test has showed 23 (25.5%) of the samples were highly pathogenic, 21 (23.3%) of intermediate pathogenicity, 23 (25.5%) low pathogenic, and 23 (25.5%) non-pathogenic. When the results of the classes of pathogenicity from isolates have been associated with antimicrobial susceptibility, nonpathogenic strains were less sensitive to the antibiotic ampicillin and increased sensitive to streptomycin antimicrobial compared to the others classes of pathogenic. Nonpathogenic strains showed resistance to many antimicrobials, an alert for poultry, since these bacteria might acquire the virulence genes and infect birds, others animals and even human beings.