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Escherichia (E.) coli O157:H7 survival in dry cured (uncooked) meat products leading to human illness outbreaks is an international problem. Their manufacture does not involve a heat kill step to ensure the destruction of the organism, and the adverse conditions created during processing may not be sufficient to prevent E. coli O157:H7 survival. Deodorized yellow mustard powder has antimicrobial properties from glucosinolate (sinalbin) hydrolysis catalyzed by the endogenous enzyme myrosinase, generating antimicrobial isothiocyanate (PHBIT). Previous work has shown that its addition during dry sausage manufacture was capable of eliminating the pathogen. In this study, its use for the same purpose was investigated during dry cured Westphalian ham production. Hams were inoculated with a 7.5 log cfu•g-1 cocktail of E. coli O157:H7, surface applied with 4% or 6% (w/w) deodorized yellow mustard powder, and monitored for E. coli O157:H7 survival during 80d ham maturation. One trial included the inoculation of Staphylococcus (S.) carnosus, a meat starter culture with myrosinase-like activity, onto the hams (after salt equilibration) to accelerate formation of antimicrobial isothiocyanate from mustard glucosinolate and help control the pathogen. In both trials, E. coli O157:H7 was reduced 3 log cfu•g-1 by 21d on hams treated with mustard powder, whereas only a 1 log cfu•g-1 reduction was found in the inoculated control which was not treated with mustard. By 45d, hams treated with mustard powder showed a reduction of >5 log cfu•g-1 E. coli O157:H7, whereas it took 80d to for numbers in control hams to be similarly reduced. Since a 5 log kill of E. coli O157:H7 was achieved in control hams by the end of 80d, dry cured Westphalian ham manufacture would be considered capable of controlling the risk of E. coli O157:H7 survival by North American regulatory agencies. However, deodorized yellow mustard powder at 4%, and to a greater extent at 6%, eliminated the pathogen at a significantly faster rate than the control during ham processing. Addition of the S. carnosus starter culture in trial 2 may have contributed to the maintenance of this effect through isothiocyanate formation. It also helped restore numbers of staphylococci, which were found to be sensitive to deodorized mustard powder.

Escherichia (E.) coli O157:H7 survival in dry cured (uncooked) meat products leading to human illness outbreaks is an international problem. Their manufacture does not involve a heat kill step to ensure the destruction of the organism, and the adverse conditions created during processing may not be sufficient to prevent E. coli O157:H7 survival. Deodorized yellow mustard powder has antimicrobial properties from glucosinolate (sinalbin) hydrolysis catalyzed by the endogenous enzyme myrosinase, generating antimicrobial isothiocyanate (PHBIT). Previous work has shown that its addition during dry sausage manufacture was capable of eliminating the pathogen. In this study, its use for the same purpose was investigated during dry cured Westphalian ham production. Hams were inoculated with a 7.5 log cfu•g-1 cocktail of E. coli O157:H7, surface applied with 4% or 6% (w/w) deodorized yellow mustard powder, and monitored for E. coli O157:H7 survival during 80d ham maturation. One trial included the inoculation of Staphylococcus (S.) carnosus, a meat starter culture with myrosinase-like activity, onto the hams (after salt equilibration) to accelerate formation of antimicrobial isothiocyanate from mustard glucosinolate and help control the pathogen. In both trials, E. coli O157:H7 was reduced 3 log cfu•g-1 by 21d on hams treated with mustard powder, whereas only a 1 log cfu•g-1 reduction was found in the inoculated control which was not treated with mustard. By 45d, hams treated with mustard powder showed a reduction of >5 log cfu•g-1 E. coli O157:H7, whereas it took 80d to for numbers in control hams to be similarly reduced. Since a 5 log kill of E. coli O157:H7 was achieved in control hams by the end of 80d, dry cured Westphalian ham manufacture would be considered capable of controlling the risk of E. coli O157:H7 survival by North American regulatory agencies. However, deodorized yellow mustard powder at 4%, and to a greater extent at 6%, eliminated the pathogen at a significantly faster rate than the control during ham processing. Addition of the S. carnosus starter culture in trial 2 may have contributed to the maintenance of this effect through isothiocyanate formation. It also helped restore numbers of staphylococci, which were found to be sensitive to deodorized mustard powder.

Ohmic heating is an electrical resistance heating resulting from the passage of electrical current through an electrically conductive material offering some resistance. Most food products possess sufficient electrical conductivity to be able to take advantage of ohmic heating. This research was undertaken to evaluate the quality changes associated with fine ham emulsions prepared under ohmic heating conditions as compared to those produced by conventional heating. / In the first part of the study, kinetics of quality changes (color, texture, water holding capacity, cooking loss and water activity) associated with fine ham emulsion subjected to conventional heating conditions were evaluated. The second part of the study was to standardize ohmic heating conditions for achieving target time-temperature combinations. It was desired to achieve cooking conditions (temperature come-up and hold times) both similar to and faster than conventional heating so that meaningful quality comparisons could be made between the two. / The final part of the study was to compare the quality changes of fine ham emulsion subjected to ohmic heating under different rates, and to compare them with conventional heating. (Abstract shortened by UMI.)

This diploma thesis deals with questions of the present meat products market, meat products quality and the relevant legislation with focus on steamed ham. According to the present legislation ham is divided into three categories based on the content of pure muscle protein. The categories are as follows: top-grade quality ham, choice ham and standard ham. Use of starch, food colouring ingredients, fibrous additives, vegetable protein and different animal protein is not allowed with top-grade quality ham and choice ham. Within the practical part of the diploma work twenty samples of ham from all categories were examined. The tests showed that starch was not added to any top-grade quality ham or choice ham. Starch was found only in two samples of standard ham, in which starch addition is allowed by legislation.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The industrial processing of fish fillets generates large amount of waste that can cause serious environmental problems due to improper disposal. However, after filleting, muscles of good quality are found in the carcass, which can be used for human consumption. An alternative is the production of mechanically separated meat (MSM) or mincend fish for use in the processing ham-like products. In this context, in order to facilitate the use of co-products from fish industry, and increase the nutritional value of processed products, a ham-like product was prepared with different levels of mincend catfish (Rhamdia quelen). However, as the MSM of fish is highly perishable, it was first studied the antioxidant activit of different concentrations of phytic acid on fish mincend and fillets. Concentrations of 0,025% and 0,05% of phytic acid were tested, comparing them to the effect of 0,05% sodium erythorbate. Results demonstrate better antioxidant potential of phytic acid in a concentration of 0,05%. Having defined this concentration, hams were prepared with levels of 25, 50 and 75% minced catfish treated with 0,05% phytic acid in order to evaluate the effect of adding different amounts of mincend fish treated with natural antioxidant attributes on chemical composition, color and instrumental texture as well as sensory characteristics in ham-like products, was elaborated based hams with levels 25, 50 and 75% mincend catfish treated with 0,05% phytic acid. Adding minced fish in different concentrations to hams preparation influenced on the centesimal composition of each formulation. Moisture content was significantly affected. The 25% minced fish formulation was the only one which did not differ from the control. Moisture decreased as minced fish content increased. Regarding ash, the formulation containing 50% minced fish was the only one which showed significant difference while the control did not differ from the ones containing minced fish. Protein levels did not differ significantly among formulations. With exception of the formulation with 50% mincend of red color intensity decreased with increasing content of mincend. The lightness was not significantly different at the end of the period in all formulations and yellow color after sixty days, the formulations with the addition of mincend had higher intensity as the content. Texture analysis showed significant difference among formulations only for the variable thoughness, showing that by increasing the amount of minced fish content, the product becomes less tough. Sensory analysis did not show significant difference for variables of color and appearance. As to color, the increase of minced fish content decreased preference. The most accepted flavor was the control formulation. All formulations showed significant difference in texture. For a purchase attitude, the best values were attributed to the control formulation. Prices decreased according to the increase of minced fish content. The final product oxidation and pH were assessed for sixty days and showed that the use of phytic acid in ham-like cooked products is more efficient than sodium erythorbate. Based on these results, it is concluded that producing ham by replacing part of pork meat with minced fish containing phytic acid is viable because it presents characteristics for human consumption. / O processamento industrial de filés de pescados gera grande quantidade de resíduos que pode causar sérios problemas ambientais pelo descarte inadequado. Entretanto, na carcaça, após a filetagem, encontram-se músculos de boa qualidade que podem ser utilizados para a alimentação humana. Uma alternativa é a fabricação de carne mecanicamente separada (CMS) ou polpa de pescado para uso no processamento de produtos, como por exemplo, os embutidos. Neste contexto, a fim de viabilizar o aproveitamento de co-produtos da indústria de pescados, e aumentar o valor nutricional de produtos processado, elaborou-se embutido cárneo com diferente teores de polpa de jundiá (Rhamdia quelen). Contudo, visto que a CMS de pescado é altamente deteriorável, estudou-se primeiro a ação antioxidante de diferentes concentrações de ácido fítico sobre filés e polpa do pescado. Foram testadas concentrações de 0,025% e 0,05% de ácido fítico, comparando-as ao efeito do eritorbato de sódio 0,05%. Os resultados demonstram melhor potencial antioxidante do ácido fítico na concentração de 0,05%. Definida essa concentração, com o objetivo de avaliar o efeito da adição de diferentes teores de polpa de pescado tratada com antioxidante natural sobre atributos de composição química, cor e textura instrumental e características sensoriais em embutidos, elaborou-se apresuntados com teores 25, 50, e 75% de polpa de jundiá tratada com ácido fítico 0,05%. A adição de polpa de pescado em diferentes proporções as formulações dos apresuntados exerceu influência sobre a composição centesimal de cada uma. A umidade foi afetada significativamente, apenas a formulação com 25% de polpa não diferiu da controle. Quanto maior o teor de polpa, menor a umidade. Quanto as cinzas, entre as formulações com adição de polpa, apenas a com 50% apresentou diferença significativa e a controle não diferiu das que contém polpa. O teor de proteína não apresentou diferença significativa entre as formulações. Com exceção da formulação com 50% de polpa a intensidade de cor vermelha diminuiu a conforme o aumento do teor de polpa. A luminosidade não apresentou diferença significativa ao final do período em todas as formulações e na cor amarela, após sessenta dias, as formulações com adição de polpa apresentaram maior intensidade conforme o teor. A análise de textura apresentou diferença significativa entre as formulações apenas para a variável dureza, demonstrando que o aumento do teor de polpa torna o produto menos duro. A análise sensorial não demonstrou diferença significativa para as variáveis de aparência e cor. Quanto ao odor, a preferência diminuiu com o aumento de polpa. O sabor mais aceito foi o da formulação controle. Na textura todas as formulações apresentaram diferença significativa. Para atitude de compra, os melhores valores foram atribuídos a formulação controle, com decréscimo conforme o aumento do teor de polpa. A oxidação e o pH do produto acabado foram avaliados ao longo do período de sessenta dias e demonstraram que a utilização do ácido fítico em embutidos cárneos curados cozidos tipo apresuntado é mais eficaz que o eritorbato de sódio. A partir destes resultados pode-se concluir que a fabricação de apresuntado com substituição de parte da carne suína por polpa de pescado adicionada de ácido fítico é viável por apresentar características aceitáveis ao consumo.

Doctor of Philosophy / Department of Entomology / Thomas W. Phillips / The phase-out of methyl bromide production, the most effective fumigant for the control of the ham mite, Tyrophagus putrescentiae (Schrank) (Acari: Acaridae), on dry-cured ham has necessitated the search for other management methods. The foundation of a successful management program is an effective monitoring program that provides information on pest presence and abundance over time and space to help in making management decisions. By using the standard trap made from disposable Petri dishes and a dog food-based bait, mite activity was monitored weekly in five dry-cured ham aging rooms from three commercial processing facilities from June 2012 to September 2013. Results indicated that mite numbers in traps in facilities typically had a pattern of sharp decline after fumigation, followed by a steady increase until the next fumigation. Average trap captures varied due to trap location, indicating that traps could be used to identify locations where mite infestation of hams may be more likely to occur. Experiments were also conducted in 6 m x 3 m climate-controlled rooms to determine the effects of some physical factors on trap capture. Factors such as trap design, trap location, trap distance, duration of trapping, and light conditions had significant effects on mite capture. Mites also responded differently to light emitting diodes of different wavelengths, either as a component of the standard trap or as a stand-alone stimulus to orientation. To determine the relationship between trap capture and mite density, experiments were carried out in the climate-controlled rooms. Mite density was varied but trap number remained constant for all mite densities. There was strong positive correlation between trap capture and mite density. In simulated ham aging rooms, the distribution of mites on hams was determined and different sampling techniques such as vacuum sampling, trapping, rack sampling, ham sampling and absolute mite counts from whole hams were compared and correlated. Results showed weak or moderate correlations between sampling techniques in pairwise comparisons. Two sampling plans were developed to determine the number of samples required to estimate mite density on ham with respect to fixed precision levels or to an action threshold for making pest management decisions. Findings reported here can help in the optimization of trapping and sampling of ham mite populations to help in the development of efficient, cost-effective tools for pest management decisions incorporated with alternatives to methyl bromide.

A cor vermelha brilhante característica do presunto Parma é resultante, principalmente, do pigmento Zinco-protoporfirina IX (ZnPP). A ZnPP é formada a partir da mioglobina por uma reação de transmetalação, catalisada pela enzima ferroquelatase (FECH), em que o íon de Fe(II) coordenado ao grupo heme é substituído pelo íon Zn(II). O presunto Parma apresenta uma maior estabilidade oxidativa em relação aos demais produtos cárneos curados além de não conter nitrito e nitrato, portanto, são considerados mais saudáveis. A utilização da FECH no processamento de carnes curadas pode permitir a produção de produtos cárneos curados mais saudáveis e em menor tempo. No presente trabalho a proteína ferroquelatase de Bacillus subtilis (BsFECH) foi expressa em células de E. coli BL21(DE3), purificada por cromatografia de afinidade ao níquel e exclusão por tamanho e caracterizada por dicroísmo circular, emissão de fluorescência do triptofano e cromatografia de exclusão por tamanho analítico. Em termos de estabilidade foi encontrado que altas concentrações de sal aumentam a estabilidade da proteína frente aos agentes denaturantes ureia e temperatura. A BsFECH produzida é capaz de ligar-se ao substrato modelo de porfirina (TPPS), conforme verificado por espectroscopia de UV-Vis, com uma Ka = 3,8x105 M-1 e é capaz de se associar à metamioglobina, conforme verificado por reação de cross-linking com dissuccinimidil suberato e avaliado por SDS-PAGE. A BsFECH aumenta significativamente a taxa de inserção de íons de zinco na TPPS e mostra uma cinética de saturação com uma constante de ligação aparente de Zn(II) ao complexo [BsFECH-TPPS] de 1,3x104 M e uma constante de primeira ordem de 6,6x10-1 h-1 para a dissociação do complexo ternário. A reação de troca ferro/zinco na mioglobina catalisada pela BsFECH é facilitada pela proteólise limitada da mioglobina com pepsina que abre um caminho para a reação de troca metálica com base na interação proteína-proteína entre o fragmento globina da mioglobina e a BsFECH. / The bright red color, characteristic of the Parma ham, results mainly of the pigment Zinc-Protoporphyrin IX (ZnPP). The ZnPP is formed from myoglobin by the reaction, catalyzed by ferrochelatase enzyme (FECH), in which Fe(II) ions coordinated to the heme group is replaced by Zn(II) ions. Parma ham shows greater oxidative stability when compared to others cured meat products besides do not contain nitrite and nitrate and, therefore, is considered healthier. The use of FECH in the processing of cured meats may allow the production of healthier cured meat products in a shorter period of time. In this work, the ferrochelatase protein from Bacillus subtilis was expressed in E. coli BL21(DE3) cells, purified by nickel affinity chromatography and size exclusion, and characterized by circular dichroism, fluorescence emission of tryptophan and analytical size exclusion chromatography. In terms of stability, it was found that the high salt content enhances the protein stability against the denaturation agents urea and temperature. The BsFECH produced is able to bind to the porphyrin model substrate (TPPS), as verified by UV-Vis spectroscopy, with Ka = 3.8x105 M-1 and is capable to associate to metamyoglobin as verified by cross-linking reaction with dissuccinimidil suberato, as observed by SDS-PAGE. The BsFECH increases, significantly, the zinc ions insertion rate in TPPS and shows a saturation kinetics behavior with an apparent biding constant of Zn(II) to the [BsFECH-TPPS] complex of 1.3x104 M and a first order rate constant for the dissociation of ternary complex of 6.6x10-1 h-1. The Fe/Zn exchange reaction in the myoglobin as catalyzed by BsFECH is facilitated by myoglobin-limited proteolysis with pepsin that opens a reaction channel for the metallic exchange based on protein-protein interaction between the globin moiety of myoglobin and BsFECH.

Orientador: Pedro Eduardo de Felicio, Expedito Tadeu Facco Silveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T13:59:07Z (GMT). No. of bitstreams: 1 BergaminFilho_Walter_M.pdf: 465962 bytes, checksum: 7133c03c01d649f1e25c78b4b0f9e052 (MD5) Previous issue date: 2005 / Resumo: A metodologia de elaboração de presunto cru proposta neste trabalho foi planejada com base na combinação de desossa, adição de transglutaminase, massageamento e moldagem das peças previamente à secagem e maturação. Analisaram-se os efeitos de dois teores de NaCl adicionado (3,5% e 5% do peso da carne) nas propriedades físico-químicas do produto final, como Aw, teor de cloretos (NaCl%) e de umidade, e perda de peso. Como nos processos tradicionais, fez-se a salga seca utilizando nitrato de sódio, nitrito de sódio e sal grosso comercial tipo I. As médias de temperatura (T) e umidade relativa (UR) desta etapa ficaram em torno de 2,5 ± 1,31ºC e 83 ± 2,75%, respectivamente. Já na etapa de secagem, houve redução da UR média para 71,62 ± 1,75% e aumento da T média para 4,5 ± 0,85ºC. Na maturação, as temperaturas foram acrescidas de 1ºC a cada nove (ou sete) dias, até atingir 16ºC, enquanto a UR foi mantida em ±70%. Ao final do processo, os presuntos crus apresentaram as seguintes características físico-químicas: Aw no centro da peça de 0,900 e 0,905, para os tratamentos 3,5% e 5% de sal, respectivamente; para os teores de umidade, não houve diferença significativa, porém, o tratamento 5% apresentou um valor de 53,04 ± 2,37%, superior ao do tratamento 3,5%, que foi de 48,65 ± 2,76%. Este último parâmetro é conseqüência da perda de peso dos presuntos durante todo o processo, que foi significativamente maior no tratamento 3,5%, atingindo 39,74 ± 4,02%, contra os 37,22 ± 2,96% do tratamento 5%. O curto período de maturação e as temperaturas amenas durante esta fase, retardaram a ação enzimática responsável pela hidrólise de aminoácidos, provocando a queda do pH final, que atingiu valores de 5,60 e 5,56 para os tratamentos 3,5 e 5% de sal, respectivamente. Quanto às características microbiológicas, ambos os tratamentos estavam de acordo com a legislação vigente no país. Os presuntos crus obtidos no término do processo apresentaram formato e espessura apropriados para o fatiamento, excelente aparência, aroma característico e principalmente, um sabor muito próximo ao dos presuntos crus tradicionais encontrados no mercado brasileiro / Abstract: The methodology proposed to produce the dry-cured ham in this work was based on a technology combining bonning, transglutaminase application, tumbling and molding. It was evaluated the effects of two levels of NaCl added for fresh meat (3.5 and 5%) on the physicochemical characteristics of the final products such as water activity (Aw), chloride content (NaCl%) and weight loss. Similar to the traditional processing of dry cured hams, salting was carried out using dry cure, combining NaCl, sodium nitrate and sodium nitrite. The average temperature (T) and relative humidity (RH) in this phase were 2,5 ± 1,31ºC and 83 ± 2,75%, respectively. In the drying period, the average RH was reduced to 71,62 ± 1,75% and average T was increased up to 4,5 ± 0,85ºC. During the ageing, the T was increased gradually 1ºC each nine (or seven) days up to 16ºC, while the RH was fixed to ± 70%. At the end of the processing time, the dry cured hams presented: Aw values 0.900 and 0.905, measured in the inner part of the product for the treatments 3.5% and 5%, respectively. Treatment 5% presented higher values (53.04 ± 2.37%) of moisture than the 3.5% (48.65 ± 2.76%). This last parameter was a consequence of the weight loss during the processing time, that where higher in the treatment 3.5% (39.74 ± 4.02%) than the 5% (37.22 ± 2.96%). The mild temperatures during the short ageing time have possibly decreased the amino acids hydrolysis, and this the probable cause of the final pH, which were 5.60 and 5.56 for the treatments 3.5 and 5%, respectively. In the microbiological counts, both treatments satisfy the Brazilian current legislation requirement. The dry cured hams at the end of the processing presented shape and thickness appropriate to slicing, excellent appearance, characteristic aroma, and mainly, similar flavor to the traditional dry cured hams found in the Brazilian market / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos

Ett konstant problem med e-post är mängden skräppost som skickas dagligen och bidrar till en osäkerhet bland hemanvändare samt medför stora kostnader för företag. Att kunna skydda sig och filtrera bort skräppost är av stor vikt. Vad är egentligen skräppost?Programvaror mot skräppost använder flera metoder för att lösa problemet.Arbetet behandlar en av dessa metoder och hur effektivt den används i olika programvaror. Den metod som arbetet fokuserar på är bayesisk filtrering och programvarornas förmåga att utnyttja den. I studien kommer en analys huruvida Spamassassin och GFI MailEssentials utnyttjar bayesisk filtrering utföras. Tester kommer att genomföras med samma förutsättningar på de två programvarorna, det vill säga alla filter och skydd kommer att vara inaktiverade förrutom bayesisk filtrering. Testerna kommer att ge resultat som sedan analyseras där effektiviteten av filtret visar sig.