Effects of a 10% xylitol solution (X) on adhesion of Escherichia coli O157:H7 and Salmonella serotype Typhimurium to meat surfaces were examined utilizing three approaches. In Experiment 1, rifampicin-resistant strains of E. coli O157:H7 and S. Typhimurium were dispersed in xylitol or a peptone solution (containing approximately 8.9 mean log per ml of each pathogen) and used to inoculate beef outside round meat surfaces. Samples were then rinsed with water or not rinsed in a 2X2 factorial arrangement. No interaction existed between inoculum type and post-inoculation treatments (P > 0.84). Incubation of pathogens in peptone or xylitol had minimal impact on pathogen adhesion (P > 0.76). Rinsing reduced counts by approximately 0.5 log CFU/cm2 (P < 0.01). Experiment 2 meat samples received a pretreatment of a water rinse, xylitol, or no rinse, followed by inoculation with pathogens dispersed in peptone solution (containing approximately 8.6 log mean log per ml of each pathogen). Samples received a post-inoculation treatment of a water rinse, xylitol rinse or no rinse in a 3X3 factorial arrangement. No interactions between pre- and post-inoculation factors were observed for surface pathogen load (P > 0.50). Post-inoculation rinsing reduced counts by approximately 0.5 log CFU/cm2 (P < 0.01) with no difference between water and xylitol (P > 0.64). Experiment 3 carcass surfaces were inoculated with pathogens at an initial level of 5.5 log CFU/cm2 and received a hot (35°C) water wash, 2.5% L-lactic acid spray, 10% xylitol spray, lactic acid + xylitol or hot water + xylitol. Pathogen counts were taken at 0 and 24 h post treatment. Lactic acid treatments reduced Salmonella by 3.3 log CFU/cm2 at 0 h (P < 0.01) and by 2.6 log CFU/cm2 after 24 h (P < 0.02). Hot water treatments reduced Salmonella by 1.5 log CFU/cm2 at 0 h (P < 0.07). Xylitol did not minimize pathogens (P > 0.62) nor did it increase effectiveness of other treatments. These data indicate that xylitol is ineffective at preventing E. coli O157:H7 and S. Typhimurium adhesion to meat surfaces.

Two similarly managed trials were conducted to investigate serial ultrasound measures of body composition (longissimus muscle area (ULMA), 12th - rib fat thickness (UFAT), and percentage of intramuscular fat (UIMF)) early in the lives of feeder calves as they compared to carcass traits. Group 1 cattle were Charolais-sired by Brahman-British crossbred dams whereas Group 2 cattle were purebred Beefmaster. Both groups were fed at the same commercial feedlot (Graham Land and Cattle Co.) in Gonzales, Texas. In both data sets classifications were developed for ribeye area of Lower (less than 70.95 cm2, Middle (between 70.95 cm2 and 90.3 cm2) and Upper (over 90.3 cm2) based on a range that fit within the ribeye specifications of such branded beef programs as Certified Angus Beef and Nolan Ryan?s Tender Aged Beef. Differences among ribeye area and quality grade (Choice vs. Select) categories were evaluated for ultrasound and carcass traits. As reported previously, correlations between ultrasound measures and carcass traits became larger at times closer to harvest. In both sets of cattle, there were no differences in fat thickness or intramuscular fat at the ultrasound scan sessions or in these carcass traits due to ribeye area category. The same trend for quality grade classification was not seen across both groups of cattle however. In Group 1, there were no differences in early measures of body composition between carcass quality grade classes except for ultrasound fat thickness at weaning. However, in Group 2 cattle there were differences in ultrasound fat at times 1 and 2, IMF at time 1, and ribeye area at time 2 between cattle that graded choice verses those that graded select. Correlations between ultrasound measures of REA (r of .26 to .50) and ultrasound REA and carcass REA (r of .16 to .81) appeared to be lower in Group 1 vs. Group 2 (r of .55, and .64 to 81 respectively). Results from this project imply that changes in ribeye area will not automatically result in changes of marbling and vice versa. Furthermore, these results also show that ultrasound is useful to help predict beef carcass traits, but that early measures of body composition used alone do not explain a large portion of the variation in the carcass measures and specific methods should be developed by different biological cattle types.

Orientador: Roberto de Oliveira Roça / Resumo: Um total de 180 bovinos Bos indicus (Nelore), terminados em confinamento, foi dividido em grupos com 6, 12 ou 24 horas de jejum pré-abate para verificar se a redução deste tempo resulta em melhor condição higiênica e sanitária durante o processo de abate. Amostras de fezes pré e pós-jejum, de pele e de carcaça foram colhidas e analisadas para ocorrências e contagens de bactérias aeróbias mesófilas, Escherichia coli genérica, coliformes totais, assim como, E. coli produtora de toxinas Shiga (STEC) e enteropatogênica (EPEC). As amostras de fezes também foram analisadas quanto ao pH e os teores percentuais de matéria seca (MS%) e de fibras em detergente neutro (FDN%) e ácido (FDA%). Os dados foram analisados com modelos logísticos, análises de variância e regressões, ao nível de 5% de significância. A extensão do tempo de jejum pré-abate reduziu a MS%, mas elevou o pH, FDN% e FDA% das fezes. O gradual aumento do jejum pré-abate resultou em maior excreção fecal de STEC (stx1 e stx2), entretanto, com decréscimo de aeróbios mesófilos, mas sem interferência na E. coli genérica. A extensão do tempo de jejum pré-abate também resultou na maior contaminação da pele por STEC (stx1) e EPEC, assim como, das carcaças por aeróbios mesófilos, E. coli genérica e coliformes totais. Dessa forma, conclui-se que a condição higiênica e sanitária durante o processo de abate de bovinos pode ser melhorada com a redução do tempo de jejum pré-abate. Para as indústrias da carne isto pode representar a re... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Submitted by GUILHERME SICCA LOPES SAMPAIO null (guilhermeslsampaio@yahoo.com.br) on 2017-01-30T16:59:48Z No. of bitstreams: 1 Tese de Doutorado - Guilherme S. L. Sampaio (versão final).pdf: 1435860 bytes, checksum: d3afaf1a274ca2aaa24f6ebb66f4ae63 (MD5) / Rejected by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: Incluir o número do processo de financiamento nos agradecimentos da dissertação/tese. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2017-02-01T12:47:13Z (GMT) / Submitted by GUILHERME SICCA LOPES SAMPAIO null (guilhermeslsampaio@yahoo.com.br) on 2017-02-01T12:59:33Z No. of bitstreams: 1 Tese de Doutorado - Guilherme S. L. Sampaio (versão final).pdf: 1436609 bytes, checksum: a731559ab98fc75f6ee45c3b1a2e8208 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-02-01T13:09:02Z (GMT) No. of bitstreams: 1 sampaio_gsl_dr_bot.pdf: 1436609 bytes, checksum: a731559ab98fc75f6ee45c3b1a2e8208 (MD5) / Made available in DSpace on 2017-02-01T13:09:02Z (GMT). No. of bitstreams: 1 sampaio_gsl_dr_bot.pdf: 1436609 bytes, checksum: a731559ab98fc75f6ee45c3b1a2e8208 (MD5) Previous issue date: 2017-01-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Um total de 180 bovinos Bos indicus (Nelore), terminados em confinamento, foi dividido em grupos com 6, 12 ou 24 horas de jejum pré-abate para verificar se a redução deste tempo resulta em melhor condição higiênica e sanitária durante o processo de abate. Amostras de fezes pré e pós-jejum, de pele e de carcaça foram colhidas e analisadas para ocorrências e contagens de bactérias aeróbias mesófilas, Escherichia coli genérica, coliformes totais, assim como, E. coli produtora de toxinas Shiga (STEC) e enteropatogênica (EPEC). As amostras de fezes também foram analisadas quanto ao pH e os teores percentuais de matéria seca (MS%) e de fibras em detergente neutro (FDN%) e ácido (FDA%). Os dados foram analisados com modelos logísticos, análises de variância e regressões, ao nível de 5% de significância. A extensão do tempo de jejum pré-abate reduziu a MS%, mas elevou o pH, FDN% e FDA% das fezes. O gradual aumento do jejum pré-abate resultou em maior excreção fecal de STEC (stx1 e stx2), entretanto, com decréscimo de aeróbios mesófilos, mas sem interferência na E. coli genérica. A extensão do tempo de jejum pré-abate também resultou na maior contaminação da pele por STEC (stx1) e EPEC, assim como, das carcaças por aeróbios mesófilos, E. coli genérica e coliformes totais. Dessa forma, conclui-se que a condição higiênica e sanitária durante o processo de abate de bovinos pode ser melhorada com a redução do tempo de jejum pré-abate. Para as indústrias da carne isto pode representar a redução de custos operacionais e com a infraestrutura dos currais de abate, menos condenações e falhas no controle de produção, maior rendimento produtivo e incremento na validade comercial. A redução de STEC, além de ser um fomento à saúde publica, constitui-se em um estimulo à economia brasileira pela redução de barreiras comerciais e menor devolução de mercadorias. / A total of 180 Bos indicus (Nellore) cattle finished in feedlot were divided into groups of 6, 12 or 24 hours of pre-harvest fasting to verify if time reduction results in better hygiene and sanitary conditions during the slaughter process. Pre-fasting and post-fasting samples of feces, and post-fasting samples of hide, and carcass were collected and analyzed for the occurrence and counting of mesophilic aerobic bacteria, generic Escherichia coli, total coliforms, as well as Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC). The feces samples were also analyzed for pH and content percentage of dry matter (DM%), neuter detergent fiber (NDF%) and acid detergent fiber (ADF%). Data were analyzed with logistic models, analyses of variance and regressions at 5% significance. The extension of pre-harvest fasting time reduced DM% but increased pH, NDF% and ADF% of feces. The gradual increase of pre-harvest fasting time resulted in greater fecal excretion of STEC (stx1 and stx2) with reduction of mesophilic aerobic bacteria, but without interference in generic E. coli. The extension of this time also resulted in greater contamination of hide by STEC (stx1) and EPEC as well as of carcass by mesophilic aerobic bacteria, generic E. coli and total coliforms. Thus, it was concluded that the hygiene and sanitary condition during the slaughter process of bovines can be improved with the reduction of pre-harvest fasting time. For the meat industry, can represent a reduction of costs with operations and facilities of lairage pens, less with condemnations and failures in the production control besides a greater productive yield and increment in the commercial validity. STEC reduction, besides being a development in public health, becomes a stimulus to the Brazilian economy by decreasing commercial barriers and return of goods. / FAPESP: 2015/02208-3 / FAPESP: 2014/01109-9

Orientador: Pedro Eduardo de Felicio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-10T03:26:36Z (GMT). No. of bitstreams: 1 PflanzerJunior_SergioBertelli_M.pdf: 3041050 bytes, checksum: 4c250d50371a5d13f85624668b3d27f0 (MD5) Previous issue date: 2008 / Resumo: A classificação pode ser utilizada para agrupar carcaças com características semelhantes de sexo, maturidade, peso, gordura de cobertura e conformação, visando uniformizar a qualidade e o rendimento da carne. No Brasil, há falta de informações científicas a respeito desses parâmetros. Objetivou-se nesta pesquisa avaliar o efeito da maturidade dentária e do acabamento de carcaças em atributos físicos, químicos e sensoriais do contrafilé de costela (m. L. thoracis). Meias carcaças (n=60) de machos castrados da raça Nelore foram selecionadas no abate de 822 bovinos, em uma das etapas do Circuito Boi Verde. Foram em seguida agrupadas em 6 categorias, de acordo com a maturidade dentária (2, 4 e 6 dentes incisivos permanentes), e acabamento (2 ¿ escassa e 3 - mediana). O período de resfriamento foi de 24 h, e na desossa foram obtidas as porções de contrafilé, compreendidas entre a 5ª e a 9ª costela, que foram embaladas a vácuo, maturadas por 14 dias e congeladas a -18°C. Cinco bifes de 2,5 cm de espessura foram avaliados quanto à cor instrumental, no sistema CIE L*, a* e b*, e em análise visual para os atributos cor e mármore. Determinou-se o comprimento de sarcômero, a força de cisalhamento por Warner-Bratzler, as perdas de peso por cozimento e os atributos sensoriais de cada uma das sessenta amostras. Houve efeito (P<0,01) da maturidade sobre o peso das carcaças, que aumentou com o número de dentes incisivos permanentes. Carcaças com maiores grau de acabamento ou nível de maturidade apresentaram maiores teores de lipídios e menores teores de umidade (P<0,01) na carne. O comprimento de sarcômero não foi afetado (P>0,05) pela maturidade ou acabamento. A maturidade dentária não influenciou (P>0,05) a maciez do contrafilé medida por instrumento ou análise sensorial, mas a carne de carcaças com mais acabamento foi mais macia (P<0,01) e perdeu menos peso (P<0,01) na cocção. Não houve efeito (P>0,05) da maturidade no teor de mármore, nem na cor por análises visuais e instrumentais, enquanto as carcaças com mais acabamento tiveram maior teor de mármore (P<0,05) na avaliação visual, e maior valor de L (P<0,05) na análise instrumental da cor da carne. Concluiu-se que não se justificam bonificações pela qualidade do contrafilé de costela em função de maturidade, mas sim em função do acabamento / Abstract: Classification schemes are useful for grouping carcasses with similar characteristics of sex, maturity, fatness and conformation, aiming to keep homogeneity of quality and yields within classes. In Brazil, there is a lack of scientific information on these classification parameters. The objective of this research was to evaluate the effects of teeth maturity and carcass fatness on the physical, chemical and sensory attributes of the boneless rib cut (m. L. thoracis). Carcass sides (n=60) from Nelore steers were selected at the kill floor among 822 heads of cattle in one of the ¿Circuito Boi Verde¿ (green steers circuit) carcass contests. They were grouped in 6 categories according to teeth maturity (2, 4 and 6 permanent incisors), and fatness (fat cover 2- slight; 3-medium). The chilling time was 24 hrs, and then a boneless rib section between the 5th and 9th rib from each side was obtained, vacuum packaged, aged for 14 days and frozen. Five 2,5 cm steaks were evaluated for instrumental color in the CIE L*, a*, e b* scheme, and in visual analysis for color and marbling. Sarcomere length, Warner-Bratzler shear force, cooking losses and sensory attributes with a trained panel were determined. There was effect (P<0,01) of maturity on carcass weight, which increased with the number of permanent incisors. Carcasses with higher degree of fatness or maturity level presented increased percentage of lipids and lower (P<0,01) moisture in the meat. The sarcomere length was not affected (P>0,05) by maturity or fatness. Teeth maturity did not affect (P>0,05) the WB shear force or the sensory tenderness of the rib steaks, while the meat from higher level of fatness was more tender (P<0,01) and showed lower cooking losses (P<0,01). No effects (P>0,05) of maturity in marbling degree, and in instrumental or visual color were detected, while samples from higher fatness level carcasses had higher level of marbling (P<0,05), and higher (P<0,05)L value. It was concluded that bonuses aiming at the quality of boneless rib cut would not be justifiable for young maturity, but it would so for carcass fatness / Mestrado / Mestre em Tecnologia de Alimentos

<p>U radu je ispitan i razvijen novi pristup tretmanu kože goveda prirodnom smolom &scaron;elak, koja je dozvoljena za kori&scaron;ćenje u hrani, u cilju redukcije unakrsne mikrobiolo&scaron;ke kontaminacije sa kože na goveđe meso. Mehanizam ovog tretmana je baziran na imobilizaciji mikroorganizama na dlaci tretirane kože i prevenciji njihovog fizičkog prenosa sa dlake na meso trupova tokom procesa obrade zaklanih goveda.<br />U in vitro uslovima, tretman uzoraka vizuelno čiste i suve kože 23% rastvorom &scaron;elaka u etanolu je redukovao prenos sa kože na sunđere kojima je koža uzorkovana brisevima: ukupne mikroflore (TVC) za 6,6 log (&gt;1000 puta vi&scaron;e u odnosu na 2,9 log redukcije kod tretmana samo etanolom), generičke Escherichia coli za najmanje 2,9 i Enterobacteriaceae za najmanje 4,8 log. Ove redukcije sve tri grupe mikroorganizama su bile značajno vi&scaron;e u odnosu na redukcije postignute tretmanom kože kombinacijom ispiranja sanitajzerom i vakumiranja. Značajno vi&scaron;e redukcije prenosa TVC sa kože na sunđerske briseve su postignute kori&scaron;ćenjem vi&scaron;ih koncentracija &scaron;elaka (23% i 30%) u odnosu na niže (4,8-16,7%) i u slučajevima kada je temperatura rastvora &scaron;elaka bila 20, 30 ili 40oC u odnosu na 50oC i 60oC. Takođe, tretman kože &scaron;elakom je značajno (3,7 puta) redukovao prevalencu E. coli O157 na prirodno kontaminiranoj, neinokulisanoj koži, kao i broj E. coli O157 na ve&scaron;tački inokulisanim kožama (redukcija od 2,1 log), u odnosu na odgovarajuće netretirane kontrole.<br />U uslovima laboratorijskog modela direktnog kontakta kože i mesa, tretman kože (različitih kategorija čistoće) 23% rastvorom &scaron;elaka je značajno smanjio prenos mikroorganizama sa tretirane kože na sterilno goveđe meso: do 3,6 log cfu/cm2 redukcije ukupnog broja bakterija (TVC), do 2,5 log cfu/cm2 Enterobacteriaceae (EC) i do 1,7 log cfu/cm2 generičke E. coli (GEC). Redukcija prenosa TVC je bila značajno vi&scaron;a, a redukcije EC i GEC slične, u odnosu na redukcije nakon tretiranja kože kombinacijom ispiranja-vakumiranja sanitajzerom.<br />U uslovima male komercijalne klanice sa nezadovoljavajućom procesnom praksom (klanje prljavih goveda i neadekvatna higijena procesa klanja i obrade), tretman koža zaklanih goveda 23% rastvorom &scaron;elaka je rezultirao značajnom mikrobnom redukcijom na mesu trupova goveda nakon skidanja kože: 1,7 log cfu/cm2 TVC, 1,4 log cfu/cm2 EC i 1,3 log cfu/cm2 GEC. Redukcija TVC na mesu trupova je bila značajno vi&scaron;a, a redukcije EC i GEC slične, u odnosu na redukcije nakon tretiranja kože ispiranjem-vakumiranjem sanitajzerom.<br />Ova istraživanja su po prvi put pružila naučne dokaze da se tretman kože goveda u cilju imobilizacije mikroflore na dlaci može uspe&scaron;no koristiti u cilju smanjenja kontaminacije mesa trupova tokom procesa skidanja kože, unapređenja finalnog mikrobiolo&scaron;kog statusa mesa i bezbednosti goveđeg mesa uop&scaron;te. Da bi se ostvario puni potencijal ovog novog tretmana u praksi, neophodna su dalja istraživanja u cilju njegove tehničke optimizacije u uslovima industrije mesa.</p> / <p> In this research, a new approach to cattle hide treatments, based on using a natural, food-grade resin, Shellac, to reduce microbial cross-contamination from the hides onto carcass meat, was developed and evaluated. The basis of this treatment is immobilisation of microorganisms on cattle hide&rsquo;s hair and subsequent reduction of their transmissibility from the hair onto carcass meat during dressing of slaughtered cattle.<br /> Under in vitro conditions, treatment of samples of visually clean and dry hides with 23% Shellac-in-ethanol solution reduced sponge-swabbing recoveries of general microflora (TVC) by a factor of 6.6 logs (&gt;1000-fold greater than the 2.9 log reduction observed by ethanol alone), and of generic E. coli (GEC) and Enterobacteriaceae (EC) by factors of at least 2.9 and 4.8 logs, respectively. The reductions of these three groups of microorganisms were superior to those achieved by a sanitizer rinse-vacuum hide treatment. Significantly greater reductions of TVC recoveries from hides were achieved when using higher Shellac concentrations (23.0% and 30.0% rather than 4.8-16.7%) and when Shellac solution temperatures were 20-40&deg;C rather than 50-60&deg;C. Furthermore, the Shellac-based treatment also markedly reduced the E. coli O157 prevalence (3.7-fold reduction) on natural, uninoculated hides, as well as the counts of E. coli O157 on artificially inoculated hides (2.1 log reduction) when compared to corresponding untreated controls.<br /> Under the conditions of a hide-to-meat direct contact laboratory-based model, treatment of hides (of varying visual cleanliness) with the 23% Shellac solution produced significant reductions of microbial transfer from treated hide onto sterile beef: up to 3.6 log10 CFU/cm2 of TVC, up to 2.5 log10 CFU/cm2 of EC and up to 1.7 log10 CFU/cm2 of GEC. TVC reductions of microbial transfer from treated hide onto beef achieved by the Shellac hide treatment were superior to those achieved by the comparative sanitizer rinse-vacuum hide treatment, but reductions of EC and GEC did not differ between the two hide treatments.<br /> In a small commercial abattoir with unsatisfactory process practices (slaughtering dirty cattle, inadequate process hygiene), treatment of hides with Shellac produced significant microbial reductions on skinned beef carcasses: 1.7 log10 CFU/cm2, 1.4 log10 CFU/cm2 and 1.3 log10 CFU/cm2 of TVC, EC and GEC, respectively. TVC reductions on skinned beef carcasses achieved by the Shellac hide treatment were superior to those achieved by the comparative sanitizer rinse-vacuum hide treatment, but reductions of EC and GEC did not differ significantly between the two hide treatments.<br /> These investigations produced the first scientific evidence that treatment of cattle hides with aim of immobilising microflora on the hair can be very successfully used to reduce carcass meat contamination during the skinning operation, thus improving the microbiological status of the final beef carcasses as well as the beef safety in general. To achieve the full potential of this new treatment in practice, further research aimed at its further technical optimization under real-life meat industry conditions is necessary.</p>