O objetivo do presente trabalho foi avaliar a perda da hermeticidade do sistema de embalagens plásticas flexíveis utilizadas para o envase de carne bovina cozida e desidratada (Beef Jerky) que é realizado por meio da aplicação de vácuo, atmosfera modificada e a inserção de absorvedores de oxigênio. Durante 1 (um) mês foram realizadas avaliações dos defeitos que ocasionam a perda da hermeticidade na produção do Beef Jerky em três plantas fabris localizadas no Brasil. Os defeitos encontrados foram mapeados, identificados e avaliados por meio de análises microscópicas da estrutura do filme flexível, análises de oxigênio do espaço livre da embalagem e ensaios de verificação dos canais de solda. Os resultados apresentados nesta pesquisa demonstraram que as origens da perda da hermeticidade estão relacionadas a fatores físicos, biológicos e humanos. Após a realização de melhorias como a alteração da linha de produção e treinamento dos operadores, o aumento da espessura da solda e a redução da quantidade de vácuo aplicada, houve a redução de 33,66%, 51,32% e 43,59% de defeitos de hermeticidade respectivamente. Foi observado também que a taxa de permeabilidade ao O2 da embalagem (TPO2) pode ser reduzida e consequentemente a barreira mecânica pode ser aumentada possibilitando a redução de defeitos mecânicos nas embalagens. A substituição dos sachês absorvedores, que podem ser danificados pelo contato com o produto, por sistemas de embalagens ativas que contém o princípio ativo incorporado ao filme também foi proposta, porém não foi recomendada uma vez que o oxigênio residual não atingiu menos que 1% de oxigênio após 72 horas. O resultado preliminar demonstrou que este sistema é menos eficiente do que o atual e que novos estudos e aprimoramentos da tecnologia devem ser realizados para que a aplicação das embalagens no sistema de envase de Beef Jerky seja eficiente. / The objective of the present study was to evaluate the leakage of the flexible plastic packaging system used for the packaging of Beef Jerky, which is carried out through the application of vacuum, modified atmosphere and the insertion of oxygen absorbers. During 1 month were made evaluations of the defects that causes the leakage in the production of Beef Jerky at three plants located in Brazil. The defects were mapped, identified and evaluated through microscopic analysis of the flexible film structure, oxygen analyzes of the packaging headspace and the seal channels verification tests. The results presented in this research demonstrated that the origins of leakage are related to physical, biological and human factors. After improvements such as the alteration of the production line and training of the operators, the increase of the seal thickness and the reduction of the applied vacuum amount, there was noted a reduction of 33,66%, 51,32% e 43,59% of sealing defects, respectively. It has also been observed that the package O2 transmission rate (OTR) can be reduced and consequently the mechanical barrier can be increased enabling reduction of mechanical defects in the packages. The replacement of the absorbent sachets, which may be damaged by contact with the product, for the active packaging systems containing the active principle incorporated in the film was also proposed, but it was not recommended since the residual oxygen did not reach less than 1% of after 72 hours. The preliminary result has shown that this system is less efficient than the current one and that further studies and improvements of the technology must be made so that the application of the packages in the system of Beef Jerky packaging will be efficient.

This study evaluated the thermal drying process commonly used by small and very small beef jerky operations in Texas. It was intended to determine the impact of relative humidity on the production of beef jerky and to provide documentation to beef jerky producers to support their Hazard Analysis and Critical Control Point programs. This project was divided into two phases: Phase I provided a low level of relative humidity (15-25%), whereas Phase II provided a high level (100%) for 25% of the cooking cycle. Both phases consisted of three trials, each representing one of the treatments (n=18) applied to the samples. The first treatment served as the control group and included samples that were non-inoculated, while the other two treatments included inoculations of samples with a bovine fecal slurry and rifampicin-resistant Salmonella Typhimurium. Each of the three treatments for both phases was analyzed for reduction of microbial levels in addition to temperature and product composition. Once the two phases had been completed and all data were analyzed, it was concluded that there was not a statistical difference between the level of reduction for Aerobic Plate Counts, coliforms, Escherichia coli and Salmonella provided by Phase I with low humidity and Phase II with high humidity. Both levels of humidity provided similar levels of reduction within each trial, suggesting that the level of humidity does not have a great impact on the level of microbial reduction achieved. However, this study did not provide the adequate level of initial inoculation levels to support the required 6.5 log reduction stated in 9 CFR 318.7. Inoculation levels were lower than 6.5 logs for all three treatments in both phases, resulting in lower levels of overall reduction. Therefore, based upon the information provided by this study, it cannot be concluded that a low level of humidity will achieve a 6.5 log reduction as mandated in 9 CFR 318.17.

Beef jerky is a dried meat snack which is rich in protein but of low calorific value. This ready-to- eat meat snack is in high demand among hikers, bikers and travelers due to its compact nature and nutritional value. The current processing methods such as smoke house and home dehydrators take 6-10 h. Increasing market for this shelf-stable meat product increases the need for alternate efficient processing method. Also, this meat snack market depends on its textural characteristics which denote the consumer acceptability. In this research, three different methods of drying beef jerky were examined. Influences of pH and salt on different characteristics of beef jerky were investigated using combined microwave-convection drying. Also, the effects of relative humidity and airflow rates in forced air thin layer drying on jerky processing were studied. Samples of beef jerky dried using a combined microwave-convection drier and thin layer drying unit were compared with samples dried in a smoke house. The results obtained showed that pH and salt content had a significant influence on drying, physical and textural characteristics of jerky. It was found that samples with low pH (5.15) and high salt content (3.28% (w/w)) dried faster than samples with high pH and low salt content due to their high drying rates. These samples had shown high shrinkage and weight loss compared to samples with pH 5.65 and 1.28% (w/w) salt content. Analysis of the textural characteristics such as tensile force, puncture force and texture profile showed that the samples with high pH and low salt content were comparably softer than the rest of the samples. Results of the effect of relative humidity and airflow rate in forced air thin layer drying on jerky processing showed that relative humidity and airflow rate influenced the drying, physical, chemical and textural characteristics of beef jerky. Combination of low relative humidity and high airflow rate showed desirable drying characteristics. However, samples dried at this combination showed high shrinkage and weight loss. The hardness of the beef jerky increased with increase in airflow rate and reduction in relative humidity. A comparison of the drying methods revealed that different drying methods produced different desirable properties. Combined microwave-convection drying was found to be efficient and very rapid (8.25 min). The low shrinkage and weight losses along with high drying rate obtained using this method would pave a way to fast and efficient processing. The color and textural characteristics were different from those of samples dried in a smoke house. Surprisingly, combined microwave-convection drying method produced softer beef jerky than thin layer and smokehouse methods. However, the commercially available jerky is tougher than the one dried using combined microwave-convection drying. The samples dried in a thin layer drier had comparable color and textural characteristics with samples dried in a smoke-house. Also, forced-air thin layer drying method reduced drying time of beef jerky from 7 to 3 h. The forced air thin layer drier has the potential to produce beef jerky with similar color and textural characteristics to commercially available smoke house dried samples.

Beef jerky is a dried meat snack which is rich in protein but of low calorific value. This ready-to- eat meat snack is in high demand among hikers, bikers and travelers due to its compact nature and nutritional value. The current processing methods such as smoke house and home dehydrators take 6-10 h. Increasing market for this shelf-stable meat product increases the need for alternate efficient processing method. Also, this meat snack market depends on its textural characteristics which denote the consumer acceptability. In this research, three different methods of drying beef jerky were examined. Influences of pH and salt on different characteristics of beef jerky were investigated using combined microwave-convection drying. Also, the effects of relative humidity and airflow rates in forced air thin layer drying on jerky processing were studied. Samples of beef jerky dried using a combined microwave-convection drier and thin layer drying unit were compared with samples dried in a smoke house. The results obtained showed that pH and salt content had a significant influence on drying, physical and textural characteristics of jerky. It was found that samples with low pH (5.15) and high salt content (3.28% (w/w)) dried faster than samples with high pH and low salt content due to their high drying rates. These samples had shown high shrinkage and weight loss compared to samples with pH 5.65 and 1.28% (w/w) salt content. Analysis of the textural characteristics such as tensile force, puncture force and texture profile showed that the samples with high pH and low salt content were comparably softer than the rest of the samples. Results of the effect of relative humidity and airflow rate in forced air thin layer drying on jerky processing showed that relative humidity and airflow rate influenced the drying, physical, chemical and textural characteristics of beef jerky. Combination of low relative humidity and high airflow rate showed desirable drying characteristics. However, samples dried at this combination showed high shrinkage and weight loss. The hardness of the beef jerky increased with increase in airflow rate and reduction in relative humidity. A comparison of the drying methods revealed that different drying methods produced different desirable properties. Combined microwave-convection drying was found to be efficient and very rapid (8.25 min). The low shrinkage and weight losses along with high drying rate obtained using this method would pave a way to fast and efficient processing. The color and textural characteristics were different from those of samples dried in a smoke house. Surprisingly, combined microwave-convection drying method produced softer beef jerky than thin layer and smokehouse methods. However, the commercially available jerky is tougher than the one dried using combined microwave-convection drying. The samples dried in a thin layer drier had comparable color and textural characteristics with samples dried in a smoke-house. Also, forced-air thin layer drying method reduced drying time of beef jerky from 7 to 3 h. The forced air thin layer drier has the potential to produce beef jerky with similar color and textural characteristics to commercially available smoke house dried samples.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2016-10-06T17:42:59Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao revisao FINAL.pdf: 661499 bytes, checksum: d43fc86e349e9c7d614609bf8c904ca4 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-10-11T20:38:40Z (GMT) No. of bitstreams: 2 dissertacao revisao FINAL.pdf: 661499 bytes, checksum: d43fc86e349e9c7d614609bf8c904ca4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-10-11T20:38:40Z (GMT). No. of bitstreams: 2 dissertacao revisao FINAL.pdf: 661499 bytes, checksum: d43fc86e349e9c7d614609bf8c904ca4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-12-22 / Sem bolsa / A busca crescente dos consumidores por praticidade destaca-se dentre as principais tendências de consumo de alimentos no mundo. Neste contexto, enquadra-se o Beef Jerky, um produto cárneo produzido através de processo térmico, que não necessita de refrigeração no ponto de venda. Entretanto, por ser um alimento pronto para o consumo, deve-se garantir sua segurança e uma das bactérias patogênicas que, uma vez presente neste alimento, pode causar danos à saúde dos consumidores, é Listeria monocytogenes. O objetivo deste estudo foi avaliar a ocorrência de L. monocytogenes em uma linha de produção de Beef Jerky localizada no município de Bagé, Rio Grande do sul- Brasil. Foram realizadas sete coletas, nas quais se avaliaram 12 pontos ao longo da linha de processamento, dentre eles a matéria-prima, superfícies com e sem contato com o produto, bem como o produto final. As amostras foram analisadas no equipamento Mini Vidas® bioMérieux e, aquelas que apresentaram resultado positivo para L. monocytogenes, foram submetidas a PCR, utilizando-se o gene prs para confirmação de gênero, e os genes inlA, inlC e inJ para confirmação da espécie L. monocytogenes. A ocorrência global de L. monocytogenes foi de 7,14%, sendo 21,42% em superfícies sem contato com produto, 1,78% em superfícies de contato com produto, e 28,57% na matéria-prima, entretanto, não se identificou o patógeno no produto final. Observa-se que a matériaprima é uma importante fonte de contaminação e introdução de L. monocytogenes na indústria produtora de Beef Jerky e que a contaminação por esse microorganismo em superfícies de contato e sem contato com o alimento, reforça a importância dos programas de higienização como forma de evitar contaminação cruzada para o produto final. Entretanto, como o produto final (Beef Jerky) não apresentou contaminação por L. monocytogenes, as etapas do processo de produção que envolvem barreiras à multiplicação de patógenos e morte microbiana, podem ter sido efetivas no controle do patógeno. / The growing demand of consumers for convenience, stands out among the main trends in food consumption in the world. In this context is the beef jerky a meat product produced by thermal process that does not require refrigeration at the point of sale, ensuring practicality of use. However, being a food ready for consumption, should ensure its security and one pathogenic bacteria that, once present, can harm the health of consumers is Listeria monocytogenes. The objective of this research was to identify the occurrence of L. monocytogenes in a Beef Jerky production line located in the municipality of Bage, Rio Grande do Sul- Brazil. We evaluated 12 points along the processing line, including the raw materials, surfaces with and without contact with the product as well as the final product, in seven collections. Samples were analyzed in Mini Vidas® bioMérieux equipment and those that tested positive for L. monocytogenes, were subjected to PCR using the prs gene for gender confirmation and the inlA genes, inlC and inlJ to confirm the species L. monocytogenes. The overall occurrence of L. monocytogenes was 7.14% and 21.42% on surfaces without contact with product, 1.78% on product contact surfaces, and 28.57% in the raw material, however, it did not identify the pathogen in the final product. It is observed that the raw material is a major source of contamination and introduction of L. monocytogenes in producer Beef Jerky industry and the contamination by that micro-organism contact surfaces without contact with food, reinforces the importance of cleaning programs in order to avoid cross-contamination of the final product. However, since the final product (Beef Jerky) showed no contamination by L. monocytogenes, the steps of the production process involving barriers to multiplication of pathogens and microbial death, may have been effective in pathogen control.