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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Understanding physicochemical stability of proteins in solution and development of new analytical methods for freeze-dried protein formulations /

Bai, Shujun. January 2008 (has links)
Thesis (Ph.D. in Pharmaceutical Sciences) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 134-146). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
12

Estudos de renaturação de proteínas agregadas utilizando altas pressões hidrostáticas / Renaturation studies of aggregate proteins using high hydrostatic pressure

VALLEJO, NATALIA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:35:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:37Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:08/57338-5
13

Efeito do tratamento termico do leite e retentado na qualidade de queijo minas frescal light fabricado por ultrafiltração / Effect of milk and retentate heat treatment on quality of light mins frescal cheese manufactured by ultrafiltration

Kikuchi, Mariana 29 February 2008 (has links)
Orientador: Walkiria Hanada Viotto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-10T12:05:36Z (GMT). No. of bitstreams: 1 Kikuchi_Mariana_M.pdf: 738866 bytes, checksum: 1d9fee5c55f1a964b93d69d44841373b (MD5) Previous issue date: 2008 / Resumo: O conhecimento do efeito do tratamento térmico do leite e retentado sobre as características do queijo Minas Frescal com reduzido teor de gordura pode auxiliar no desenvolvimento de tecnologias que melhorem a qualidade sensorial e aumentem o rendimento desse tipo de queijo. Assim, o objetivo deste trabalho foi avaliar o efeito de diferentes níveis de tratamento térmico, realizados antes e depois do processo de ultrafiltração, na composição, rendimento, tempo de coagulação, capacidade de retenção de água, proteólise, microestrutura e aceitação sensorial de queijo Minas Frescal com reduzido teor de gordura. Os tratamentos térmicos foram: a) tratamento térmico do leite (72°C/15 s ou 80°C/4s) e b) tratamento térmico do retentado (68°C/2 minutos ou 63°C/2 minutos). Leite cru integral foi padronizado a 2,0% de gordura, pasteurizado em trocador de calor de placas a 72oC/ 15 s, ou a 80°C/4 s e ultrafiltrado até atingir fator de concentração 3,5. O retentado foi então divido em duas partes, respectivamente tratadas a 68°C/2 minutos e 63°C/2 minutos. Para fabricação do queijo, o retentado foi adicionado de sal, ácido lático e coalho e coagulado diretamente na embalagem. Leite, retentado e permeado foram pesados e suas composições determinadas. O rendimento de fabricação também foi calculado. Os queijos foram analisados com relação à sua composição, tempo de coagulação, capacidade de retenção de água, reologia, textura, proteólise, microestrutura e aceitação sensorial. Os tratamentos térmicos mais intensos do leite e do retentado resultaram em maior tempo de coagulação e maior capacidade de retenção de água. O tratamento térmico mais intenso aplicado ao retentado resultou em queijos com maior teor de caseína. Os queijos obtidos a partir dos retentados tratados a 68°C também apresentaram menores índices de proteólise. A análise de Perfil de Textura (TPA) e o teste de Creep demonstraram que os queijos obtidos do leite tratado a 80°C/4s são mais moles que os obtidos do leite tratado a 72°C/15 min. A microestrutura dos queijos também mostra uma matriz protéica mais densa e compacta para os queijos produzidos a partir de leite tratado a 80 °C/4 s. Sensorialmente os queijos não diferiram entre si em nenhum dos atributos avaliados / Abstract: The knowledge of milk and retentate heat treatment effect on quality of Minas Frescal light cheese (low fat content) may assist the development of technologies which will improve its sensorial quality and yield. Therefore, the objective of this work was to determine the effect of heat treatment of milk and retentate on the composition, yield, coagulation time, water retention capacity, proteolysis, microstructure and sensory acceptance of Minas Frescal cheese with low fat content. The heat treatments were: a) milk heat treatment (72°C/15s or 80°C/4s) and b) retentate heat treatment (68°C/2minutes or 63°C/2minutes). Raw milk was standardized to 2,0% fat, heat treated and ultrafiltered until reach concentration factor of 3,5. The retentate was divided in two parts, respectively treated at 68°C/2 minutes and 63°C/2minutes. To manufacture this cheese, the retentate was added of salt, lactic acid and rennet and coagulated directly in the packaging. Milk, retentate and permeate were weighed and their compositions determined. The manufacture yield was also calculated. The composition, water retain capacity, rheology, texture, proteolysis, microstructure and sensory acceptance of cheese were determined. Increasing the intensity of milk and retentate heat treatment resulted in a longer coagulation time and higher water retention capacity of the cheese. The more intense heat treatment applied to the retentate resulted in cheese with higher casein content. Cheese made from the retentate treated at 68°C/2 min presented the lowest rate of proteolysis. The Texture Profile Analysis and the Creep test showed that cheese from the milk treated at 80°C/4s were the softest. The protein matrix was more compact for the cheese made from the treated milk at 80°C/4s. From the sensorial point of view, there was non significant difference among the cheeses / Mestrado / Mestre em Tecnologia de Alimentos
14

Secagem de clara de ovo em leito de jorro fluidizado bidimensional / Drying of egg white in a 2D spouted fluidized bed.

Christ, Divair 14 February 2006 (has links)
Orientadores: Rosiane Lopes da Cunha, Florencia Cecilia Menegalli / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T17:14:21Z (GMT). No. of bitstreams: 1 Christ_Divair_D.pdf: 2473666 bytes, checksum: ca400b2519c40ad806addec20990ae8c (MD5) Previous issue date: 2006 / Resumo: O objetivo deste estudo foi avaliar o processo de secagem da clara de ovo utilizando um secador de leito de jorro fluidizado bidimensional com esferas de vidro como inertes. Um planejamento fatorial completo 24 foi realizado, com 3 pontos centrais e oito axiais, utilizando-se as seguintes variáveis independentes: temperatura (55-95 °C) e vazão total do ar de secagem (97,1-138,3 m³/h), razão entre vazão de ar de jorro e ânulo (0,6-1,4) e vazão de alimentação de pasta (2,0-10,0 g/min). Como respostas foram avaliadas a distribuição de umidade no leito durante a secagem, teor de umidade do produto, massa de matéria seca retida pelas esferas inertes, eficiência de recuperação do pó, cor do produto em pó e depois de dissolvido em água, propriedades térmicas, teor de proteína, solubilidade em meio aquoso e propriedades reológicas a baixas e altas deformações de géis térmicos de clara de ovo. O uso de planejamento fatorial completo e superfícies de resposta foram fundamentais para avaliar o efeito simultâneo das condições de secagem em leito de jorro fluidizado sobre o processo e o produto obtido. Esta metodologia diminuiu significativamente o número de experimentos e se mostrou eficiente para conhecer a relação de causa e efeito das condições de processo sobre as respostas. Todas as condições de processo estudadas influenciaram nas características do produto obtido, porém a temperatura e a vazão de ar foram as mais importantes na definição da qualidade da clara de ovo seca em leito de jorro fluidizado. Para avaliar a relação entre as várias respostas obtidas e as variáveis de processo, bem como determinar as condições ótimas de operação do secador foi aplicada a técnica estatística da desejabilidade. Concluiu-se que os níveis ótimos de operação do secador seriam: temperatura de 73,7 °C, vazão de ar de 110,8 m³/h, razão vazão de jorro/vazão de ânulo de 1,1 (58,04 m³/h e 52,76 m³/h de vazão de jorro e ânulo, respectivamente) e vazão de pasta de 9,2 g/min. Nestas condições, 60% do total desejado para todas as respostas seria atendido, sendo que a eficiência de recuperação de matéria seca pelo ciclone seria de 74,4% e o grau de desnaturação das proteínas seria baixo (conalbumina: 42,1% e ovalbumina: 25,5%), o que resultaria em elevado grau de solubilidade (em torno de 98%). Neste caso, a temperatura de início de desenvolvimento da estrutura do gel seria estimada em 62 ºC, porém a força da rede seria dada pela desnaturação da ovalbumina (temperatura de desnaturação próxima a 80 oC) e por isto, as características reológicas de géis térmicos de clara de ovo foram estudadas. Os géis térmicos (80 ºC/30 min) de clara de ovo seca em leito de jorro fluidizado mostraram alta deformabilidade e características elásticas similares aos géis obtidos a partir de clara de ovo liofilizada. Assim, a partir da análise dos resultados obtidos foi possível otimizar a secagem da clara de ovo em leito de jorro fluidizado alcançando-se boa eficiência de processo e preservando suas propriedades funcionais / Abstract: The objective of this study was to evaluate an egg white drying process using a two-dimensional spouted fluidized bed dryer with glass spheres as the inert particles. A complete 24 factorial design was used, with 3 central and 8 axial points, using the following independent variables: temperature (55-95ºC), total drying air flow rate (97.1-138.3 m3/h), ratio between spout and annulus air flow rates (0.6-1.4)and paste feed flow rate (2.0-10.0 g/min). As responses, the moisture distribution in the bed during drying, product moisture content, mass of dry matter adhered to inert particles, powder recovery efficiency, product colour as powder and after dissolving in water, thermal properties, protein content, solubility in aqueous medium and rheological properties at high and low deformation of heat-induced egg white gels. The use of a complete factorial design and response surfaces was fundamental to evaluate the simultaneous effect of the drying conditions in a spouted fluidized bed on the process and obtained product. This methodology significantly reduced the number of experiments and showed to be efficient to understand the cause and effect relationship of process conditions on responses. All the process conditions studied influenced the characteristics of the product obtained, but temperature and air flow rate were the most important variables in defining the quality of the egg white dried in a spouted fluidized bed. The statistical technique of desirability was used to evaluate the relationship between the various responses obtained and the process variables, and to determine the optimum dryer operating conditions. It was concluded that the optimum operational levels for the dryer were: temperature of 73.7ºC, air flow rate of 110.8 m3/h, ratio of spout/annulus flow rate of 1.1 (58.04 m3/h and 52.76 m3/h of spout and annulus flow rate, respectively) and paste flow rate of 9.2 g/min. Under these conditions, 60% of the desired total for all the responses would be attained, the recovery efficiency of the dry material by the cyclone would be 74.4% and the degree of protein denaturation would be low (conalbumin: 42.1% and ovalbumin: 25.5%), resulting in very good solubility (about 98%). In this case, the temperature at the start of the gel structure development would be estimated at 62ºC, although the gel strength would be given by the ovalbumin denaturation (denaturation temperature near 80ºC) and for this reason, the rheological characteristics of the thermal egg white gels were investigated. The thermal gels (80ºC/30 min) of egg white dried in a spouted fluidized bed, obtained in this study, showed high deformability and elastic characteristics, similar to the gels obtained from freeze-dried egg white (literature data). Thus, from the analysis of the obtained results it was possible to optimize the drying of egg white in a spouted fluidized bed, obtaining good process efficiency yet preserving the functional properties / Doutorado / Doutor em Engenharia de Alimentos
15

Estudos de renaturação de proteínas agregadas utilizando altas pressões hidrostáticas / Renaturation studies of aggregate proteins using high hydrostatic pressure

VALLEJO, NATALIA M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:35:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:37Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / No presente trabalho estudamos a renaturação sob alta pressão hidrostática de uma forma mutante da proteína verde fluorescente (enhanced GFP, eGFP), a qual somente emite fluorescência característica quando enovelada na sua forma nativa. A abordagem do presente estudo foi focada no controle da bioatividade da proteína recombinante, a fluorescência, como alternativa à determinação de solubilidade da proteína, fator que não é um indicador ideal de enovelamento proteico adequado. A ação da alta pressão na solubilização dos corpos de inclusão (CI) de eGFP produzidos em bactérias E. coli recombinantes e no enovelamento da proteína foi estudada. A compressão dos CI de eGFP em 2,4 kbar durante 30 minutos promoveu a dissociação dos agregados. No entanto, a incubação nesta condição não favoreceu o enovelamento da eGFP. O processo de renaturação foi avaliado em diversas condições de descompressão após a dissociação em 2,4 kbar. Durante a descompressão gradual, o aumento da fluorescência foi obtido em pressões que variaram entre a pressão atmosférica e 1,38kbar. Os níveis mais elevados de fluorescência de eGFP foram obtidos por incubação durante várias horas a níveis de pressão entre 0,35 e 0,69 kbar. Esta condição de pressão se mostrou favorável à renaturação de eGFP e é possível que também possa ser utilizada para favorecer o enovelamento de outras proteínas monoméricas. Ainda utilizando a eGFP como modelo, verificamos que os CI desta proteína produzidos por bactérias cultivadas em menor temperatura (37ºC) possuem maior quantidade de proteína recombinante apresentando a fluorescência característica em 509 nm, ou seja, na sua forma nativa, do que os CI expressos em temperaturas mais elevadas (42ºC e 47ºC). A análise realizada por espectroscopia de infravermelho (FT-IR) também demonstrou que os CI produzidos em temperaturas mais brandas possuem maior grau de estruturas secundárias semelhantes às da proteína na sua forma nativa. Além disso, os CI produzidos a 37ºC também são mais facilmente solubilizados pela ação da alta pressão do que aqueles produzidos em maior temperatura. Conforme esperado, a renaturação da eGFP a partir de CI produzidos a 37ºC foi 25 vezes mais eficiente do que a obtida utilizando CI produzidos a 47ºC. No presente estudo demonstramos também que a dissociação dos agregados exercida pela ação da alta pressão (2,4 kbar) pode ser amplificada quando em associação com a incubação em baixa temperatura (-9ºC) e que a combinação destas duas propriedades físicas eleva a solubilização dos agregados em CI, com a consequente elevação dos rendimentos de renaturação de eGFP. Mostramos ainda no presente estudo que a cinética de renaturação de eGFP em 0,69 kbar é proporcional à temperatura de incubação (entre 10ºC e 50ºC). O nível mais elevado de fluorescência foi obtido quando a renaturação de eEGP foi realizada a 20ºC. A taxa de maturação do cromóforo da eGFP é mais fortemente afetada pela temperatura do que a taxa de enovelamento da proteína. Em conclusão, a temperatura de produção dos CI, a temperatura de dissociação dos agregados e a temperatura de enovelamento podem afetar muito o rendimento e a cinética da renaturação de eGFP em alta pressão. Os resultados do presente estudo podem abrir novas perspectivas para melhorias no processo de enovelamento de proteínas a partir de CI utilizando alta pressão. Também neste trabalho descrevemos a renaturação das proteínas de Xac, PilB e os produtos dos genes XAC2810 e XAC3272 nunca antes obtidas na forma solúvel. Os rendimentos de solubilização destas três proteínas foram muito altos, entre 75% e 89%. A proteína PilB renaturada em alta pressão apresentou atividade ATPasica elevada, o que nunca antes foi demonstrado para a PilB de Xac. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:08/57338-5
16

Interações físicas e químicas entre isolado protéico de soja e glúten vital durante a extrusão termoplástica a alta e baixa umidade para a obtenção de análogo de carne = Physical and chemical interactions between isolated soy protein and vital gluten during thermoplastic extrusion at high and low moisture content to obtain meat analogue / Physical and chemical interactions between isolated soy protein and vital gluten during thermoplastic extrusion at high and low moisture content to obtain meat analogue

Schmiele, Marcio, 1979- 24 August 2018 (has links)
Orientador: Yoon Kil Chang / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T06:53:45Z (GMT). No. of bitstreams: 1 Schmiele_Marcio_D.pdf: 9722936 bytes, checksum: 95d9146270f349c5f3e7ad761ac0d266 (MD5) Previous issue date: 2014 / Resumo: Os análogos de carne obtidos por extrusão termoplástica de proteínas vegetais são caracterizados pelo seu elevado teor proteico e estrutura semelhante às fibras da carne, envolvendo diversos tipos de ligações e/ou interações químicas entre as proteínas. O objetivo deste trabalho foi avaliar as características tecnológicas e físico-químicas de análogos de carne, à base de isolado proteico de soja, obtidos por processo de extrusão termoplástica a alta umidade (AU) e baixa umidade (BU). Para cada condição de umidade foi utilizado um Delineamento Composto Central Rotacional de três variáveis independentes (glúten vital, umidade de condicionamento e temperatura de extrusão). As variáveis dependentes avaliadas foram a textura instrumental, cor instrumental, capacidade de absorção de água, índice de solubilidade em água, capacidade de absorção de óleo, índice de dispersibilidade de proteína, energia mecânica específica e o tipo de interações proteicas. Estas interações foram avaliadas através de sete tipos de solventes específicos: (i) tampão fosfato para as proteínas no estado nativo; (ii) dodecil sulfato de sódio para as interações hidrofóbicas e iônicas; (iii) Triton 100X para as interações hidrofóbicas; (iv) ureia para as interações hidrofóbicas e pontes de hidrogênio; (v) ß-mercaptoetanol para as ligações dissulfeto; e (vi) ß-mercaptoetanol e ureia e (vii) dodecil sulfato de sódio e ureia, para avaliar o efeito sinérgico entre os sistemas. O ponto otimizado (caracterizado principalmente por promover maiores valores de L* e de capacidade de absorção de água, menores valores de índice de solubilidade em água, de capacidade de absorção de óleo, de desnaturação proteica e valores intermediários de textura instrumental e de energia mecânica específica) foi processado juntamente com uma amostra controle para ambos os processos com o intuito de validar os modelos matemáticos e avaliar as possíveis alterações na morfologia dos análogos de carne, na massa molecular das proteínas, na composição de aminoácidos totais e na desnaturação proteica. As melhores condições de processamento foram obtidos para os análogos de carne contendo de 12 e 5 % de glúten vital, 58 e 18 % de umidade de condicionamento e 135 e 100 °C para a temperatura de extrusão, para o processo AU e BU, respectivamente. As principais interações proteína-proteína encontradas nos análogos de carne foram as ligações dissulfeto e ligações de hidrogênio para o processo AU e as ligações dissulfeto e interações iônicas para o processo BU. A adição de glúten vital promoveu uma aparência mais lisa e melhor orientação na estrutura das fibras. Verificou-se que ocorreu aumento nas proteínas de baixa massa molecular e diminuição nas proteínas de alta massa molecular. No perfil de aminoácidos totais houve maior variação negativa para os aminoácidos essenciais (triptofano e treonina), semi essenciais (cisteína) e não essenciais (serina), indicando que houve redução no valor nutricional. As estruturas secundárias (a-hélice, ß-folha, ß-volta e a estrutura desordenada) mostraram alteração na sua conformação devido à desnaturação proteica e formação de novos agregados / Abstract: Meat analogue obtained by termoplastic extrusion of vegetable proteins are characterized by its high protein levels and structure similar to meat fibers, which comprises many types of chemical bonds and/or interactions between proteins. The aim of this work was to evaluate the technological and physico-chemical characteristics of meat analogue based on isolated soy protein obtained by thermoplastic extrusion process at high moisture (HM) and low moisture (LM) content. For each moisture condition was used a Central Rotational Composite Design with three independent variables (vital gluten, moisture content and extrusion temperature). The dependent variables evaluated were instrumental texture, instrumental color, water absorption capacity, water solubility index, oil absorption capacity, protein dispersibility index, specific mechanical energy, and the type of protein interactions. These interactions were evaluated using seven specific solvents types: (i) phosphate buffer for proteins in native state; (ii) sodium dodecil sulphate for hydrophobic and ionic interactions; (iii) Triton 100X for hydrophobic interactions; (iv) urea for hydrophobic interactions and hydrogen bonds; (v) ß-mercaptoethanol for dissulfide bonds; and (vi) ß-mercaptoethanol and urea and (vii) sodium dodecil sulphate and urea, for the synergistic effect between the systems. The optimized point (characterized mainly by promoting higher values for L* and water absorption capacity, lower values for water solubility index, oil absoption capacity and protein denaturation and intermediate values for instrumental texture and specific mechanical energy) was processed, together with a control sample for each processes, in order to validate the mathematical models and to evaluate possibles changes in the meat analogues morphology, in the protein molecular weight, in the total amino acid composition, and in the protein denaturation. The best processing conditions were obtained for the meat analogue containing 12 and 5 % of vital gluten, 58 and 18 % of moisture content and 135 and 100 °C of extrusion temperature, for the HM and LM processes, respectively. The main protein-protein interactions found in meat analogues were the dissulfide bonds and hydrogen bonds for the LM process and the dissulfide bonds and ionic interactions for the HM process. The addition of vital gluten promoted a smoother appearance and better orientation in the fiber structure. It was found that occured an increase in the protein with low molecular weight and a reduction in the protein with high molecular weight. There were a greater negative variation for the essential (tryptophan and threonine), semi-essential (cysteine) and nonessential (serine) amino acids in the total amino acid profile, indicating a reduction of the nutritional value. The secondary structure (a-helix, ß-sheet, ß-turn and disordered structure) showed alteration in its conformation due to the protein denaturation and formation of new aggregates / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos
17

Nutritional characteristics of New Zealand export lamb and functional properties of selected beef forequarter muscles : a thesis presented in partial fulfilment of the requirements for the degree of Masters of technology in Bioprocess Engineering at Massey University, Palmerston North, New Zealand

Jansen, Eion January 2001 (has links)
Richmond Ltd. has recently undergone a change in strategy, away from the traditional commodity based meat industry, towards the modern food business. To do this, opportunities to add value to their current product range must be identified. This involves the conversion of traditionally low value commodity based products into products that demand a premium. An example of this is converting muscles that are currently used for grinding meat into a further processed convenience food (i.e. ready meals). Another method is to add further value to premium products by making them more appealing to consumers (i.e. nutritional information on labels). This work details investigations into the functional properties of selected beef forequarter muscles (low value commodity products) and the nutritional properties of selected export lamb products (premium products). The functional properties of a number of beef forequarter muscles were measured to identify which had the best potential for further processing applications with respect to ready meals. The functional properties of tenderness, cook loss and shrinkage were measured for the Latissimus Dorsi, Pectorialis Profundus (Point End Brisket), Infraspinatus (Cross Cut Blade), Triceps Brachi Longhead (Main muscle in Bolar Shoulder Clod), Supraspinatus (Chuck Tender), Serratus Ventralis and Triceps Brachi Medialhead (Muscle in Bolar Shoulder Clod. From the tests conducted the Infraspinatus and the Triceps Brachi Longhead have been identified as having the best functional properties with respect to further processing for ready meal applications. As well as conducting tests to identify the forequarter muscles with the best potential for further processing applications, investigations were carried out to identify cooking regimes that would optimise the functional properties. This work confirmed that there are three major chemical reactions, which determine the resultant functional properties of cooked meat. They are the denaturation and aggregation of the myofibrillar proteins and the denaturation and solubilisation of connective tissue (collagen). At around 50°C myosin (45% to 50% of the myofibrillar proteins) denatures, which results in a substantial increase in cook loss and reduction in water holding capacity. At around 60°C collagen (main connective tissue protein) denatures, which results in a substantial increase in tenderness and increase in cook loss. This is because as the collagen denatures it loses it mechanical strength (increase in tenderness) and can no longer support its own structure, and causes it to contract. This contraction causes fluid within the meat and cook loss caused by the denaturation of myosin to be expelled from the meat by compressive forces (squeezed out). At around 70°C actomyosin (22% of the myofibrillar proteins) denatures. This results in a substantial increase in the cook loss and firming of the meat. The increase in cook loss or decrease in water holding capacity that occurs with myofibrillar protein denaturation is due to the fact that when these proteins denature and aggregate their ability to bind water is greatly reduced. From the results of the cooking regime trials it is recommended that for functional property considerations that during the cooking of further processed meat products (i.e. ready meal applications) a meat temperature of 62°C should be aimed for, for the slowest heating region during cooking (usually the centre). This is because it has been identified that a cooking temperature of 65°C should not be exceeded otherwise detrimental effects can occur to the functional properties of the cooked meat. For health concerns a 7D bacterial death reduction has to be achieved. This means that for a cooking temperature of 62°C the meat has to be held at this temperature for at least 5 minutes. Therefore the total cooking time would be the time needed to heat all the meat to 62°C plus 5 minutes to ensure a safe product. The heating or cooking system employed should also ensure that a minimal amount of the meat is heated above 65°C. This can be easily achieved by minimising the external cooking temperature, but long cooking times will result. An industrial cooking process will be a compromise between the cost associated with longer residence time and product functionality. As mentioned earlier another way to add value is to supply nutritional information for selected cuts. Consequentially one of the objectives of this project was to provide some nutritional information for selected meat cuts. Though the primary objective of this part of the project was to develop a method for producing the needed information, so that Richmond N.Z. Ltd. can develop further information on an as needs basis. The nutritional characteristics of a number of export lamb cuts from the saddle region has also been investigated and a method devised to allow further characterisation of other cuts. The method involves breaking down a standard cut into its constituent components (e.g. Frenched rack consists of loin eye, fat cap, intercostals and fatty tissue). The constituent components are tested for their nutritional properties. The frenched rack nutritional properties are calculated from the nutritional properties of the constituents components and the yield data (percentage of each constituent component within a frenched rack) for frenched racks. This method allowed the identification of the main sources of variation for nutritional characteristics. These differences were found to be caused by the lean to fat ratio, not nutritional differences in lean tissue from the same region of lamb (i.e. loin eye and tenderloin very similar nutritionally). The difference in lean to fat ration also accounts for the variation between grades (i.e. PX grade lamb cuts have a higher fat content than YX grade lamb cuts due to PX grade cuts having a higher percentage fat tissue in their cuts). The cuts characterised were the shortloin section (whole section or chop), rack section (whole section or chop), 75mm racks frenched 25mm, boneless loin and tenderloin for both PX and YX grade lamb. The method will be applicable to other regions of lamb (i.e. hindquarter and forequarter) for which nutritional information already exists, but for which yielding data will have to be collected. The method would also be applicable to other species such as beef and venison, but both nutritional data for constituent components and yielding data would have to be collected.
18

Nutritional characteristics of New Zealand export lamb and functional properties of selected beef forequarter muscles : a thesis presented in partial fulfilment of the requirements for the degree of Masters of technology in Bioprocess Engineering at Massey University, Palmerston North, New Zealand

Jansen, Eion January 2001 (has links)
Richmond Ltd. has recently undergone a change in strategy, away from the traditional commodity based meat industry, towards the modern food business. To do this, opportunities to add value to their current product range must be identified. This involves the conversion of traditionally low value commodity based products into products that demand a premium. An example of this is converting muscles that are currently used for grinding meat into a further processed convenience food (i.e. ready meals). Another method is to add further value to premium products by making them more appealing to consumers (i.e. nutritional information on labels). This work details investigations into the functional properties of selected beef forequarter muscles (low value commodity products) and the nutritional properties of selected export lamb products (premium products). The functional properties of a number of beef forequarter muscles were measured to identify which had the best potential for further processing applications with respect to ready meals. The functional properties of tenderness, cook loss and shrinkage were measured for the Latissimus Dorsi, Pectorialis Profundus (Point End Brisket), Infraspinatus (Cross Cut Blade), Triceps Brachi Longhead (Main muscle in Bolar Shoulder Clod), Supraspinatus (Chuck Tender), Serratus Ventralis and Triceps Brachi Medialhead (Muscle in Bolar Shoulder Clod. From the tests conducted the Infraspinatus and the Triceps Brachi Longhead have been identified as having the best functional properties with respect to further processing for ready meal applications. As well as conducting tests to identify the forequarter muscles with the best potential for further processing applications, investigations were carried out to identify cooking regimes that would optimise the functional properties. This work confirmed that there are three major chemical reactions, which determine the resultant functional properties of cooked meat. They are the denaturation and aggregation of the myofibrillar proteins and the denaturation and solubilisation of connective tissue (collagen). At around 50°C myosin (45% to 50% of the myofibrillar proteins) denatures, which results in a substantial increase in cook loss and reduction in water holding capacity. At around 60°C collagen (main connective tissue protein) denatures, which results in a substantial increase in tenderness and increase in cook loss. This is because as the collagen denatures it loses it mechanical strength (increase in tenderness) and can no longer support its own structure, and causes it to contract. This contraction causes fluid within the meat and cook loss caused by the denaturation of myosin to be expelled from the meat by compressive forces (squeezed out). At around 70°C actomyosin (22% of the myofibrillar proteins) denatures. This results in a substantial increase in the cook loss and firming of the meat. The increase in cook loss or decrease in water holding capacity that occurs with myofibrillar protein denaturation is due to the fact that when these proteins denature and aggregate their ability to bind water is greatly reduced. From the results of the cooking regime trials it is recommended that for functional property considerations that during the cooking of further processed meat products (i.e. ready meal applications) a meat temperature of 62°C should be aimed for, for the slowest heating region during cooking (usually the centre). This is because it has been identified that a cooking temperature of 65°C should not be exceeded otherwise detrimental effects can occur to the functional properties of the cooked meat. For health concerns a 7D bacterial death reduction has to be achieved. This means that for a cooking temperature of 62°C the meat has to be held at this temperature for at least 5 minutes. Therefore the total cooking time would be the time needed to heat all the meat to 62°C plus 5 minutes to ensure a safe product. The heating or cooking system employed should also ensure that a minimal amount of the meat is heated above 65°C. This can be easily achieved by minimising the external cooking temperature, but long cooking times will result. An industrial cooking process will be a compromise between the cost associated with longer residence time and product functionality. As mentioned earlier another way to add value is to supply nutritional information for selected cuts. Consequentially one of the objectives of this project was to provide some nutritional information for selected meat cuts. Though the primary objective of this part of the project was to develop a method for producing the needed information, so that Richmond N.Z. Ltd. can develop further information on an as needs basis. The nutritional characteristics of a number of export lamb cuts from the saddle region has also been investigated and a method devised to allow further characterisation of other cuts. The method involves breaking down a standard cut into its constituent components (e.g. Frenched rack consists of loin eye, fat cap, intercostals and fatty tissue). The constituent components are tested for their nutritional properties. The frenched rack nutritional properties are calculated from the nutritional properties of the constituents components and the yield data (percentage of each constituent component within a frenched rack) for frenched racks. This method allowed the identification of the main sources of variation for nutritional characteristics. These differences were found to be caused by the lean to fat ratio, not nutritional differences in lean tissue from the same region of lamb (i.e. loin eye and tenderloin very similar nutritionally). The difference in lean to fat ration also accounts for the variation between grades (i.e. PX grade lamb cuts have a higher fat content than YX grade lamb cuts due to PX grade cuts having a higher percentage fat tissue in their cuts). The cuts characterised were the shortloin section (whole section or chop), rack section (whole section or chop), 75mm racks frenched 25mm, boneless loin and tenderloin for both PX and YX grade lamb. The method will be applicable to other regions of lamb (i.e. hindquarter and forequarter) for which nutritional information already exists, but for which yielding data will have to be collected. The method would also be applicable to other species such as beef and venison, but both nutritional data for constituent components and yielding data would have to be collected.
19

Nutritional characteristics of New Zealand export lamb and functional properties of selected beef forequarter muscles : a thesis presented in partial fulfilment of the requirements for the degree of Masters of technology in Bioprocess Engineering at Massey University, Palmerston North, New Zealand

Jansen, Eion January 2001 (has links)
Richmond Ltd. has recently undergone a change in strategy, away from the traditional commodity based meat industry, towards the modern food business. To do this, opportunities to add value to their current product range must be identified. This involves the conversion of traditionally low value commodity based products into products that demand a premium. An example of this is converting muscles that are currently used for grinding meat into a further processed convenience food (i.e. ready meals). Another method is to add further value to premium products by making them more appealing to consumers (i.e. nutritional information on labels). This work details investigations into the functional properties of selected beef forequarter muscles (low value commodity products) and the nutritional properties of selected export lamb products (premium products). The functional properties of a number of beef forequarter muscles were measured to identify which had the best potential for further processing applications with respect to ready meals. The functional properties of tenderness, cook loss and shrinkage were measured for the Latissimus Dorsi, Pectorialis Profundus (Point End Brisket), Infraspinatus (Cross Cut Blade), Triceps Brachi Longhead (Main muscle in Bolar Shoulder Clod), Supraspinatus (Chuck Tender), Serratus Ventralis and Triceps Brachi Medialhead (Muscle in Bolar Shoulder Clod. From the tests conducted the Infraspinatus and the Triceps Brachi Longhead have been identified as having the best functional properties with respect to further processing for ready meal applications. As well as conducting tests to identify the forequarter muscles with the best potential for further processing applications, investigations were carried out to identify cooking regimes that would optimise the functional properties. This work confirmed that there are three major chemical reactions, which determine the resultant functional properties of cooked meat. They are the denaturation and aggregation of the myofibrillar proteins and the denaturation and solubilisation of connective tissue (collagen). At around 50°C myosin (45% to 50% of the myofibrillar proteins) denatures, which results in a substantial increase in cook loss and reduction in water holding capacity. At around 60°C collagen (main connective tissue protein) denatures, which results in a substantial increase in tenderness and increase in cook loss. This is because as the collagen denatures it loses it mechanical strength (increase in tenderness) and can no longer support its own structure, and causes it to contract. This contraction causes fluid within the meat and cook loss caused by the denaturation of myosin to be expelled from the meat by compressive forces (squeezed out). At around 70°C actomyosin (22% of the myofibrillar proteins) denatures. This results in a substantial increase in the cook loss and firming of the meat. The increase in cook loss or decrease in water holding capacity that occurs with myofibrillar protein denaturation is due to the fact that when these proteins denature and aggregate their ability to bind water is greatly reduced. From the results of the cooking regime trials it is recommended that for functional property considerations that during the cooking of further processed meat products (i.e. ready meal applications) a meat temperature of 62°C should be aimed for, for the slowest heating region during cooking (usually the centre). This is because it has been identified that a cooking temperature of 65°C should not be exceeded otherwise detrimental effects can occur to the functional properties of the cooked meat. For health concerns a 7D bacterial death reduction has to be achieved. This means that for a cooking temperature of 62°C the meat has to be held at this temperature for at least 5 minutes. Therefore the total cooking time would be the time needed to heat all the meat to 62°C plus 5 minutes to ensure a safe product. The heating or cooking system employed should also ensure that a minimal amount of the meat is heated above 65°C. This can be easily achieved by minimising the external cooking temperature, but long cooking times will result. An industrial cooking process will be a compromise between the cost associated with longer residence time and product functionality. As mentioned earlier another way to add value is to supply nutritional information for selected cuts. Consequentially one of the objectives of this project was to provide some nutritional information for selected meat cuts. Though the primary objective of this part of the project was to develop a method for producing the needed information, so that Richmond N.Z. Ltd. can develop further information on an as needs basis. The nutritional characteristics of a number of export lamb cuts from the saddle region has also been investigated and a method devised to allow further characterisation of other cuts. The method involves breaking down a standard cut into its constituent components (e.g. Frenched rack consists of loin eye, fat cap, intercostals and fatty tissue). The constituent components are tested for their nutritional properties. The frenched rack nutritional properties are calculated from the nutritional properties of the constituents components and the yield data (percentage of each constituent component within a frenched rack) for frenched racks. This method allowed the identification of the main sources of variation for nutritional characteristics. These differences were found to be caused by the lean to fat ratio, not nutritional differences in lean tissue from the same region of lamb (i.e. loin eye and tenderloin very similar nutritionally). The difference in lean to fat ration also accounts for the variation between grades (i.e. PX grade lamb cuts have a higher fat content than YX grade lamb cuts due to PX grade cuts having a higher percentage fat tissue in their cuts). The cuts characterised were the shortloin section (whole section or chop), rack section (whole section or chop), 75mm racks frenched 25mm, boneless loin and tenderloin for both PX and YX grade lamb. The method will be applicable to other regions of lamb (i.e. hindquarter and forequarter) for which nutritional information already exists, but for which yielding data will have to be collected. The method would also be applicable to other species such as beef and venison, but both nutritional data for constituent components and yielding data would have to be collected.
20

Nutritional characteristics of New Zealand export lamb and functional properties of selected beef forequarter muscles : a thesis presented in partial fulfilment of the requirements for the degree of Masters of technology in Bioprocess Engineering at Massey University, Palmerston North, New Zealand

Jansen, Eion January 2001 (has links)
Richmond Ltd. has recently undergone a change in strategy, away from the traditional commodity based meat industry, towards the modern food business. To do this, opportunities to add value to their current product range must be identified. This involves the conversion of traditionally low value commodity based products into products that demand a premium. An example of this is converting muscles that are currently used for grinding meat into a further processed convenience food (i.e. ready meals). Another method is to add further value to premium products by making them more appealing to consumers (i.e. nutritional information on labels). This work details investigations into the functional properties of selected beef forequarter muscles (low value commodity products) and the nutritional properties of selected export lamb products (premium products). The functional properties of a number of beef forequarter muscles were measured to identify which had the best potential for further processing applications with respect to ready meals. The functional properties of tenderness, cook loss and shrinkage were measured for the Latissimus Dorsi, Pectorialis Profundus (Point End Brisket), Infraspinatus (Cross Cut Blade), Triceps Brachi Longhead (Main muscle in Bolar Shoulder Clod), Supraspinatus (Chuck Tender), Serratus Ventralis and Triceps Brachi Medialhead (Muscle in Bolar Shoulder Clod. From the tests conducted the Infraspinatus and the Triceps Brachi Longhead have been identified as having the best functional properties with respect to further processing for ready meal applications. As well as conducting tests to identify the forequarter muscles with the best potential for further processing applications, investigations were carried out to identify cooking regimes that would optimise the functional properties. This work confirmed that there are three major chemical reactions, which determine the resultant functional properties of cooked meat. They are the denaturation and aggregation of the myofibrillar proteins and the denaturation and solubilisation of connective tissue (collagen). At around 50°C myosin (45% to 50% of the myofibrillar proteins) denatures, which results in a substantial increase in cook loss and reduction in water holding capacity. At around 60°C collagen (main connective tissue protein) denatures, which results in a substantial increase in tenderness and increase in cook loss. This is because as the collagen denatures it loses it mechanical strength (increase in tenderness) and can no longer support its own structure, and causes it to contract. This contraction causes fluid within the meat and cook loss caused by the denaturation of myosin to be expelled from the meat by compressive forces (squeezed out). At around 70°C actomyosin (22% of the myofibrillar proteins) denatures. This results in a substantial increase in the cook loss and firming of the meat. The increase in cook loss or decrease in water holding capacity that occurs with myofibrillar protein denaturation is due to the fact that when these proteins denature and aggregate their ability to bind water is greatly reduced. From the results of the cooking regime trials it is recommended that for functional property considerations that during the cooking of further processed meat products (i.e. ready meal applications) a meat temperature of 62°C should be aimed for, for the slowest heating region during cooking (usually the centre). This is because it has been identified that a cooking temperature of 65°C should not be exceeded otherwise detrimental effects can occur to the functional properties of the cooked meat. For health concerns a 7D bacterial death reduction has to be achieved. This means that for a cooking temperature of 62°C the meat has to be held at this temperature for at least 5 minutes. Therefore the total cooking time would be the time needed to heat all the meat to 62°C plus 5 minutes to ensure a safe product. The heating or cooking system employed should also ensure that a minimal amount of the meat is heated above 65°C. This can be easily achieved by minimising the external cooking temperature, but long cooking times will result. An industrial cooking process will be a compromise between the cost associated with longer residence time and product functionality. As mentioned earlier another way to add value is to supply nutritional information for selected cuts. Consequentially one of the objectives of this project was to provide some nutritional information for selected meat cuts. Though the primary objective of this part of the project was to develop a method for producing the needed information, so that Richmond N.Z. Ltd. can develop further information on an as needs basis. The nutritional characteristics of a number of export lamb cuts from the saddle region has also been investigated and a method devised to allow further characterisation of other cuts. The method involves breaking down a standard cut into its constituent components (e.g. Frenched rack consists of loin eye, fat cap, intercostals and fatty tissue). The constituent components are tested for their nutritional properties. The frenched rack nutritional properties are calculated from the nutritional properties of the constituents components and the yield data (percentage of each constituent component within a frenched rack) for frenched racks. This method allowed the identification of the main sources of variation for nutritional characteristics. These differences were found to be caused by the lean to fat ratio, not nutritional differences in lean tissue from the same region of lamb (i.e. loin eye and tenderloin very similar nutritionally). The difference in lean to fat ration also accounts for the variation between grades (i.e. PX grade lamb cuts have a higher fat content than YX grade lamb cuts due to PX grade cuts having a higher percentage fat tissue in their cuts). The cuts characterised were the shortloin section (whole section or chop), rack section (whole section or chop), 75mm racks frenched 25mm, boneless loin and tenderloin for both PX and YX grade lamb. The method will be applicable to other regions of lamb (i.e. hindquarter and forequarter) for which nutritional information already exists, but for which yielding data will have to be collected. The method would also be applicable to other species such as beef and venison, but both nutritional data for constituent components and yielding data would have to be collected.

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