Pathogens in low-moisture foods are an emerging food safety concern due to increased survival and thermotolerance in matrices with low water activity. However, limited data is publicly available for the thermotolerance of Listeria monocytogenes, Salmonella spp., and Enterococcus faecium NRRL B-2354 (a Salmonella surrogate). The aims of this study were to identify differences in thermal inactivation rates between these organisms in three different low-moisture foods. Three model low-moisture foods (peanut butter, powder infant formula, and wheat flour) were inoculated with either E. faecium, a Salmonella spp. cocktail, or a L. monocytogenes cocktail using a dry inoculation method for a total of 9 treatments. Samples were heat treated in a hot water bath at predetermined temperatures, and bacterial survival was detected via direct plating on tryptic soy agar with 0.6% yeast extract. In peanut butter and most of the powder infant formula treatments, Salmonella spp. had significantly higher D-values than L. monocytogenes using comparable temperatures (p < 0.05). However, D-values between Salmonella spp. and L. monocytogenes were comparable in wheat flour and one of the treatment temperatures in powder infant formula (p > 0.05). For all but one of the treatments at the same temperature, E. faecium had significantly higher D-values than L. monocytogenes and Salmonella spp. in each food matrix (p < 0.05). The observed matrix effect on thermotolerance for each of the bacteria was reported in descending order as powder infant formula > peanut butter > wheat flour in the majority of the comparable D-values. While Salmonella continues to be the pathogen of concern in low-moisture foods due to survival and outbreaks, these results indicate L. monocytogenes can exhibit similar thermotolerances in relevant model low-moisture foods matrices.

Limited data are currently available characterizing the thermal resistance of foodborne pathogens in semolina flour and intermediate pasta matrices representative of commercial conditions during mixing, extrusion, and drying. These data are essential to pasta producers seeking to be compliant with federal regulations since Salmonella spp. and Escherichia coli demonstrate survival in wheat flour and dried pasta products. This study investigated the heat resistance of Salmonella, pathogenic E. coli, and E. faecium NRRL B-2354 in raw semolina flour and partially dried pasta intermediates via thermal death time (TDT) studies. This study also assessed the appropriateness of E. faecium NRRL B-2354 as a surrogate in semolina flour and pasta matrices. Inoculated pasta matrices equilibrated to target water activities of 0.85, 0.88, and 0.91 (measured at 25°C) underwent isothermal inactivation treatments at 65°C, 70°C, and 75°C. Serial dilution and direct plating methods allowed for estimation of bacterial survival at each treatment. In representative pasta matrices, the D-values for each microorganism increased as water activity decreased from 0.91 to 0.85. Surprisingly, Salmonella and E. coli did not exhibit significantly different thermal resistance in pasta. The greatest heat resistance was seen in semolina flour (aw 0.45). E. faecium was significantly more thermal resistant than both pathogens in all treatments when the temperature was ≤ 70°C. The results show that E. faecium strain NRRL B-2354 is not an ideal proxy for Salmonella and E. coli in semolina and pasta matrices. Analysis of the TDT data also found that a long-goods pasta drying process can achieve ≥7-log reductions of Salmonella and E. coli when following Good Manufacturing Practices.

Mental retardation is a heterogeneous group of disorders with countless causes. It is characterised by cognitive and functional limitations in everyday skills, for example social skills, communication skills and motor skills and can be classified in behavioural, etiological and educational systems. Down's syndrome and Fetal Alcohol Syndrome are two of the many syndromes defined under mental retardation. The goal of this dissertation was to determine the effect of a water activity intervention programme on the motor proficiency levels of children with Down's syndrome and Fetal Alcohol Syndrome. These aims were addressed by structuring the dissertation in five chapters: Chapter one constituting the introduction and statement of the problem, Chapter 2 presenting a review of relevant literature, Chapters 3 and 4 consisting of two research articles, addressing the specific aims of the study, and Chapter 5 including the summary, conclusions and recommendations. All the children who participated in the study were intuitionalized in a school for the mentally and physically handicapped. The MABC-test was used as the main evaluation instrument, and components of the Charlop-Atwell test were used to evaluate the coordination skills of the children with Down's syndrome. The first aim of this study was to determine the effect of a specially designed water activity intervention programme on the motor proficiency levels of children with Down's syndrome. Six children classified as having Down's syndrome, formed part of the research group. Their chronological age ranged between 9 and 14 years while their mental age classification was that of a 4 to 5 year old. The data was analysed by means Summary of descriptive statistics, and effect sizes were determined. The second aim of the study was to determine the effect of a water activity intervention programme on the motor proficiency levels of children with Fetal Alcohol Syndrome. Six children participated in the programme. Their chronological age ranged between 7 and 17 years while their mental age classification was that of a 4 to 11 year old. Reporting the results were in the form of case studies, and effect sizes of differences were determined. With regard to the first aim of the study the results indicated that the motor proficiency levels of the experimental group with Down's syndrome improved, especially regarding the MABC-total, balance- and total body coordination skills. With reference to the second aim of the study, the results indicated that improvement in the motor proficiency levels of the children with Fetal Alcohol Syndrome had a lasting effect. The MABC total, ball skills and manual dexterity were the components that showed the best improvement. It can be concluded that a water activity intervention programme is a suitable method for rectifying motor deficiencies among children with Down's syndrome and Fetal Alcohol Syndrome. Recommendations for the improvement of the water activity programme were presented, as well as suggestions for further studies. / Thesis (M.A. (Human Movement Science))--North-West University, Potchefstroom Campus, 2004.

Mental retardation is a heterogeneous group of disorders with countless causes. It is characterised by cognitive and functional limitations in everyday skills, for example social skills, communication skills and motor skills and can be classified in behavioural, etiological and educational systems. Down's syndrome and Fetal Alcohol Syndrome are two of the many syndromes defined under mental retardation. The goal of this dissertation was to determine the effect of a water activity intervention programme on the motor proficiency levels of children with Down's syndrome and Fetal Alcohol Syndrome. These aims were addressed by structuring the dissertation in five chapters: Chapter one constituting the introduction and statement of the problem, Chapter 2 presenting a review of relevant literature, Chapters 3 and 4 consisting of two research articles, addressing the specific aims of the study, and Chapter 5 including the summary, conclusions and recommendations. All the children who participated in the study were intuitionalized in a school for the mentally and physically handicapped. The MABC-test was used as the main evaluation instrument, and components of the Charlop-Atwell test were used to evaluate the coordination skills of the children with Down's syndrome. The first aim of this study was to determine the effect of a specially designed water activity intervention programme on the motor proficiency levels of children with Down's syndrome. Six children classified as having Down's syndrome, formed part of the research group. Their chronological age ranged between 9 and 14 years while their mental age classification was that of a 4 to 5 year old. The data was analysed by means Summary of descriptive statistics, and effect sizes were determined. The second aim of the study was to determine the effect of a water activity intervention programme on the motor proficiency levels of children with Fetal Alcohol Syndrome. Six children participated in the programme. Their chronological age ranged between 7 and 17 years while their mental age classification was that of a 4 to 11 year old. Reporting the results were in the form of case studies, and effect sizes of differences were determined. With regard to the first aim of the study the results indicated that the motor proficiency levels of the experimental group with Down's syndrome improved, especially regarding the MABC-total, balance- and total body coordination skills. With reference to the second aim of the study, the results indicated that improvement in the motor proficiency levels of the children with Fetal Alcohol Syndrome had a lasting effect. The MABC total, ball skills and manual dexterity were the components that showed the best improvement. It can be concluded that a water activity intervention programme is a suitable method for rectifying motor deficiencies among children with Down's syndrome and Fetal Alcohol Syndrome. Recommendations for the improvement of the water activity programme were presented, as well as suggestions for further studies. / Thesis (M.A. (Human Movement Science))--North-West University, Potchefstroom Campus, 2004.

The theme of this thesis is technology of production of fermented meat products and is focused on Lovecky salami. In the literature review, the work deals with the history, legislation, materials and technologies for the production of this group of meat products. There are also described methods of sensory analyse. Practical part dealt with: a) measuring of selected physical and chemical quantities (pH, water activity) during rippening and long-term storaging of Lovecky salami; b) influence of packaging method (unpacked, modified atmosphere, vacuum) on sensory value during long-term storaging. These results provide information about the ripening of Lovecky salami and cunsumer preferences in terms of packaging method. Experiment was cunducted in company MasoWest s.r.o. which starts with production of Lovecky salami.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo deste estudo foi avaliar o potencial antioxidante do Ãcido anacÃrdico (AA), sobre a estabilidade da gema de ovo in natura e desidratada e da carne e mortadela de frango. No experimento 1, adicionou-se o AA Ãs gemas antes do processo de desidrataÃÃo e de acordo com os seguintes tratamentos: sem adiÃÃo de antioxidante, com adiÃÃo de 100 ppm de BHT e com adiÃÃo de 50, 100, 150 ou 200 ppm de AA. As gemas foram armazenadas em temperatura ambiente por 180 dias. No experimento 2, as mortadelas foram adicionadas de antioxidantes no momento da formulaÃÃo de acordo com os seguintes tratamentos: sem adiÃÃo de antioxidante; com adiÃÃo de 100 ppm de BHT e com adiÃÃo de 50, 100, 150 ou 200 ppm de AA. As mortadelas foram armazenadas sob refrigeraÃÃo por 90 dias. No experimento 3, o lÃquido da castanha de caju (LCC) foi adicionado à alimentaÃÃo das poedeiras como fonte de AA. As aves foram alimentadas de acordo com os seguintes tratamentos: raÃÃo sem adiÃÃo de antioxidante e raÃÃes com adiÃÃo de 0,25; 0,50; 0,75 ou 1,00% de LCC. Os ovos frescos foram armazenados sob refrigeraÃÃo por 60 dias. No experimento 4, o anacardato de cÃlcio (AC) foi adicionado à alimentaÃÃo de frangos de corte como fonte de AA. As aves foram alimentadas de acordo com os seguintes tratamentos: raÃÃo sem adiÃÃo de antioxidante e raÃÃes com adiÃÃo de 0,25; 0,50; 0,75 ou 1,00% de AC. Os peitos de frango foram armazenados sob congelamento por 90 dias. Durante os perÃodos de armazenamento realizaram-se as anÃlises de oxidaÃÃo lipÃdica (TBARS), atividade de Ãgua e cor (L*, a* e b*) das gemas desidratadas, das gemas frescas, da mortadela e da carne de frango. Os valores de TBARS das gemas desidratadas que continham 150 e 200 ppm de AA apresentaram comportamento quadrÃtico ao longo do armazenamento, atingindo valor mÃximo (aproximadamente 100 dias) e diminuindo em seguida. Para a dose de 150 e 200 ppm, os valores de TBARS foram menores que os obtidos para as gemas sem adiÃÃo de antioxidante com 0, 90, 135 e 180 dias. Para o componente b*, houve reduÃÃo com a estocagem. As gemas adicionadas de AA tiveram maiores valores de b* do que Ãquelas dos tratamentos controle e contendo BHT. Para as mortadelas, a adiÃÃo de 150 ou 200 ppm de AA, resultou em menores valores de TBARS quando comparados aos dos tratamentos controle e contendo BHT. Para o componente a*, houve reduÃÃo com a estocagem, sendo que as mortadelas formuladas com 200 ppm de AA apresentaram os valores mais baixos em comparaÃÃo aos demais tratamentos. Para os ovos frescos, os valores de TBARS das gemas apresentaram efeito quadrÃtico ao longo do armazenamento, atingindo valor mÃximo (aproximadamente 38 dias) e diminuindo em seguida. As gemas das aves alimentadas com 0,50 e 0,75% de LCC apresentaram os menores valores de TBARS. Para o componente b*, houve aumento com o tempo de estocagem. As gemas das aves alimentadas com raÃÃo contendo 0,25% de LCC apresentaram menores valores de b* em comparaÃÃo aos dos demais tratamentos. Para a carne de peito dos frangos, os valores de TBARS das aves alimentadas sem adiÃÃo de antioxidante, com 0,25 e 1,00% de AC aumentaram com a estocagem. Para os frangos alimentados com 0,50% de AC, observou-se efeito quadrÃtico do tempo e, os valores de TBARS da carne diminuÃram atingindo valor mÃnimo (aproximadamente 50 dias) e aumentando em seguida. Os nÃveis de 0,75 e 1,00% proporcionaram menores valores de TBARS que o tratamento sem antioxidante ao longo do armazenamento. Para o componente a* houve aumento com a estocagem. Os resultados deste estudo sugerem que o Ãcido anacÃrdico à um potencial antioxidante natural podendo ser incluÃdo diretamente em gemas destinadas à desidrataÃÃo ou em mortadelas de frango antes do cozimento, bem como na alimentaÃÃo das aves para ajudar no controle da oxidaÃÃo lipÃdica dos ovos in natura ou da carne de frango. / The objective of this study was to evaluate the antioxidant potential of anacardic acid (AA), on the storage stability of fresh and spray dried yolks, of chicken meat and bologna-type chicken mortadella. In experiment 1, AA was added just before yolk spray drying according to the following treatments: no added antioxidant, addition of 100 ppm BHT and addition of 50, 100, 150 or 200 ppm AA. After drying, yolks were stored at room temperature for 180 days. In experiment 2, chicken mortadellas were added of antioxidants at the moment formulation according to the following treatments: no added antioxidant, addition of 100 ppm BHT and addition of 50, 100, 150 or 200 ppm AA. The products were stored under refrigeration for 90 days. In experiment 3, cashew nut shell liquid (CNSL) was added to the laying hen diets as a source of AA. Birds were fed according to the following treatments: diet without antioxidant and diets containing 0.25, 0.50, 0.75, or 1.00% CNSL. Fresh eggs were stored under refrigeration for 60 days. In experiment 4, calcium anacardate (CA) was added to the broilers diets as a source of AA. Birds were fed according to the following treatments: diet without antioxidant and diets containing 0.25, 0.50, 0.75, or 1.00% CA. Broiler breast meats were frozen stored for 90 days. During the storage, fresh and spray dried yolks, broiler meat and chicken mortadella were analyzed for lipid oxidation (TBARS), water activity and color (L*, a* and b*). TBARS values of spray dried yolks added of 150 and 200 ppm of AA had a quadratic effect with storage time, reaching a maximum value (100 days) and then decreasing. According to the results, at 0, 90, 135 and 180 days, the 150 and 200 ppm AA concentrations were more effective in retarding lipid oxidation in spray dried yolks. The color component b* of the yolks decreased with storage. Yolks added of AA had higher color component b* values than those of the control and the BHT containing treatments. Chicken mortadellas containing 150 and 200 ppm of AA had lower TBARS values compared to those of the control and BHT treatments. The values of color component a* decreased with storage. Chicken mortadellas containing 200 ppm of AA had lower a* values than those from the other treatments. For fresh eggs, TBARS values had quadratic effect with storage time, reaching a maximum value (38 days) and then decreasing. Yolks from laying hens fed with diets containing 0.50 and 0.75% CNSL had lower TBARS values than those from the other treatments. Color component b* increased with storage time. Yolks from laying hens fed diets containing 0.25% CNSL had lower values of color component b* than those from the others treatments. For broiler breast meats, TBARS values for breast meats from broilers fed without antioxidant or with 0.25 and 1.00% CA increased with storage time. Storage time also had a quadratic effect on broiler breast meats from birds fed 0.50% CA, reaching a minimum value (50 days) and then increasing. The 0.75 and 1.00% levels of CA provided lower meat TBARS values than that without antioxidant throughout the storage time. Color component a* values increased with storage time. Thus, the results of this study demonstrate that anacardic acid is a potential natural antioxidant that could be included directly in the yolks to be spray dried or in chicken mortadella formulations before cooking, as well as, in poultry diets, as CNSL or CA to delay lipid oxidation of fresh egg yolks or broiler meat, respectively.

Orientadores: Antonio Jose de Almeida Meirelles, Pedro de Alcantara Pessoa Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-14T08:10:52Z (GMT). No. of bitstreams: 1 MonteiroFilho_EliasdeSouza.pdf: 12530059 bytes, checksum: 1e25eb71e0f6b6a45db80658070acd61 (MD5) Previous issue date: 2009 / Resumo: A proposta do presente trabalho foi estudar o equilíbrio de fases de sistemas binários e ternários formados por um polímero sintético de óxido de propileno (PO) ou de um co-polímero bloco de óxido de etileno (EO) e PO e/ou um carboidrato de glicose dissolvidos em água. No total 25 diagramas de equilíbrio líquido-líquido (ELL) foram determinados a temperaturas entre 288,15 e 308,15 K para sistemas ternários, 4 diagramas de ELL para sistemas binários e 9 conjuntos de dados de atividade de água para soluções aquosas binárias e ternárias de diversos dos reagentes estudados. Dos diagramas de ELL ternários, 18 são diagramas cujo oligossacarídeo é polidisperso. A polidispersão influencia significativamente no comportamento do sistema. A temperatura também foi adotada como variável em alguns casos. Os resultados obtidos contribuem para elucidar o comportamento em solução aquosa de co-polímeros bloco de EO e PO com diversas massas molares e relações entre os blocos, e de glicose, maltose ou diversos polímeros de glicose em uma faixa razoável de temperaturas. Estes polímeros são bastante pesquisados para uso em sistemas bi ou mesmo polifásicos para purificação de substâncias de origem biotecnológica. Diferentes tipos de diagramas foram observados, bem como comportamentos diversos da atividade de água. A modelagem termodinâmica foi realizada com base em diversas equações propostas e de uso corrente. Incorpora, ainda, o comportamento diferenciado devido à polidispersão e à temperatura. Os resultados indicam que um bom modelo termodinâmico é capaz não apenas de fornecer informações para controle de processos, mas também sobre as interações moleculares e, com isso, predizer o comportamento de sistemas mais complexos / Abstract: This work relates phase equilibrium of binary and ternary systems formed by aqueous mixtures of EO-PO block co-polymers of five different molar masses and EO/PO ratios, and maltodextrins of three different mean molar masses studied at 298.15 K. 25 Liquid-Liquid Equilibrium (LLE) phase diagrams for ternary systems at temperatures ranging from 288,15 to 308,15 K, plus 4 LLE diagrams for binary systems and 9 water activity data sets, were determined. Of the ternary systems, 18 contain a polydisperse carbohydrate, and this polidispersity influences markedly the system's behavior. Temperature was also investigated in some cases. The results obtained contribute to elucidate the behavior of water solutions containing EO-PO block co-polymers of various molar masses and blocks ratios and glucose, maltose or several glucose polymers in a reasonable temperature range. These polymers are investigated for applications in aqueous two-phase systems. Different kinds of diagrams were observed, as well as water activity reductions. Thermodynamic modeling was performed employing current models. Also, polydispersity and temperature effects were incorporated. The results indicate that a good thermodynamic model is capable of not only provide information for process control purposes, but also about molecular interaction and predict the behavior of more complex systems / Universidade Estadual de Campi / Engenharia de Alimentos / Doutor em Engenharia de Alimentos

Le développement de simulateurs de procédés alimentaires est limité par le manque d’outils permettant de prédire les propriétés physicochimiques (pH, aw, Eh) dans les aliments. Les aliments sont généralement des milieux très complexes contenant un nombre élevé de constituants (eau, solvants organiques, solides dissous, gaz dissous, espèces ioniques, macromolécules), et ces propriétés sont essentielles pour caractériser leur qualité technologique, sanitaire et organoleptique. Cependant, elles évoluent au cours d’un procédé de transformation ou de conservation. La prédiction de ces propriétés physicochimiques passe par la détermination de potentiels chimiques. Une approche de modélisation basée sur la thermodynamique est utilisée pour prédire l’évolution du pH et de l’aw de produits carné et produits laitiers dans certaines conditions rencontrées en industrie alimentaire. En s’appuyant sur le modèle ULPDHS développé par Achard en 1992 pour les milieux liquides, ce travail a nécessité la création de molécules fictives à ayant le même comportement que les aliments modélisés. La cohérence entre les données expérimentales et les données prédites est satisfaisante, le modèle thermodynamique permet de prédire correctement le pH et l’aw des différents milieux étudiés. Cependant l’intégration du modèle thermodynamique dans un simulateur de procédé nécessite la création d’un réseau de neurone mimétique du modèle thermodynamique. En conséquent a été développé un réseau de neurones dont les sorties sont identiques aux sortie du modèle thermodynamique. Ainsi il est possible d’intégrer les résultats du modèles thermodynamique dans un simulateur de procédé sans trop rallonger les temps de simulations. Les résultats obtenus dans ce travail peuvent être une aide importante à la formulation de nouveaux produits. Le modèle étant entièrement prédictif, il est possible de déterminer l’effet d’une modification de composition de l’aliment sur le pH et l’aw. / The development of food process simulators is actually limited by absence of tools that can predict de evolution of the physical-chemical properties (pH, aw, Eh) in food. Food are generallymulticomponent medias (including water, organic solvents, dissolved solids, dissolved gases, ionic species, macromolecules), and these properties are essential to characterize technological, sanitary and organoleptic qualities. However, these physical-chemical properties change during transformation or preservation process. The prediction of these properties requires the determination of chemical potentials. Thermodynamic approach is used to predict pH and water activity of meat and dairy products in different condition encountered in the food industry. Based on the model ULPDHS developed by Achard in 1992 for liquid medias, this work required the creation of fictive molecule who have the same behavior as modeled food. Consistency between the experimental data and the predicted data is very satisfactory, the thermodynamic model correctly predict the pH and aw of different products studied. The integration of the thermodynamic model in a process simulator requires the creation of a mimetic neural network. Therefore, was developed a neural network whose outputs are identical to the output of the thermodynamic model. So it is possible to integrate the results of thermodynamic models in a process simulator without too lengthen the time simulations. The results obtained in this work can be an important aid to the formulation of new products. The model is completely predictive and it is possible to determine the effect of a change in the composition of the feed on the pH and aw.

The aim of this study was to evaluate quality parameters of dry fermented sausages. Samples of two types of dry fermented sausages were sampled – sausage “Poličan“ and “Lovecký salám“, from three different producers. Basic physical-chemical analysis of quality parameters were performed in sausage mixture and immediately after end of ripening (21 days for Poličan and 16 days for Lovecký salám). Results of quality parameters analysis were compared with requirements of Czech legislation and differences between producers were observed. There were significant differences between producers, however all of them met requirements set by 326/2001 Czech notification as amended of Ministry of agricultural.

Für die Herstellung pharmazeutisch interessanter α-Hydroxyketone ist die dynamsich kinetische Racematspaltung (DKR) der korrespondierenden Racemate eine interessante und leistungsfähige Methode. Die dafür benötigten Lipasen zeichnen sich insbesondere durch ihre Aktivität und Stabilität in rein organischen Lösungsmitteln aus. Der Verzicht von Cofaktoren macht diese Enzymklasse für einen industriellen Einsatz besonders attraktiv. Für α-Hydroxyketone mit großen Seitenketten hat sich die Lipase TL aus Pseudomonas stutzeri als Biokatalysator als am geeignetsten gezeigt. In vorherigen Studien wurde die Lipase TL erfolgreich mit dem homogenen Shvo-Katalysator für eine effektive DKR von Benzoin und Benzoinderivaten kombiniert und eine strikte (S)-Selektivität der Lipase TL festgestellt. In einer weiteren Studie wurde eine komplett heterogene DKR etabliert. Hierbei wurde die Lipase TL adsorptiv auf dem Polypropylenträger Accurel MP1001 immobilisiert und der Shvo-Katalysator durch verschiedene Metallkatalysatoren ersetzt. Als Modellsubstrat wurde Benzoin verwendet. Das beste Ergebnis der DKR von Benzoin wurde mit den Katalysator Zr-TUD-1 (25) im Lösungsmittel Toluol erreicht. Hauptziel dieser Arbeit war die Übertragung der heterogenen DKR von Benzoin auf weitere pharmazeutisch relevante α-Hydroxyketone. Dafür wurde zunächst eine generelle Optimierung der Immobilisierung der Lipase TL durch Verwendung verschiedener trägerbasierter und trägerloser Methoden und die Charakterisierung der Wasseraktivitätsabhängigkeit der KR und der Racemisierung durchgeführt. Zur Verbesserung der Umweltfreundlichkeit der Reaktion wurden außerdem alternative Lösungsmittel als Reaktionsmedium untersucht. Das optimierte Reaktionssystem wurde auf ausgewählte symmetrische und asymmetrische α-Hydroxyketone übertragen und die Eignung der Lipase TL sowie der CALB als Biokatalysatoren überprüft. Nach der Wahl der passenden Lipase wurde die DKR der ausgewählten α-Hydroxyketone untersucht und optimiert.