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

Submitted by Michele Mologni (mologni@unoeste.br) on 2017-06-23T18:41:21Z No. of bitstreams: 1 Paulo Claudeir Gomes da Silva.pdf: 571629 bytes, checksum: f7391bc494fd29db3b9d4ae8dbbe14dc (MD5) / Made available in DSpace on 2017-06-23T18:41:21Z (GMT). No. of bitstreams: 1 Paulo Claudeir Gomes da Silva.pdf: 571629 bytes, checksum: f7391bc494fd29db3b9d4ae8dbbe14dc (MD5) Previous issue date: 2015-12-17 / Production systems involving the cultivation of grasses and legumes can significantly change the fertility of the soil as well as soil preparation. Therefore, we carried out an experiment to evaluate the accumulation of organic matter, nitrogen, ammonium, nitrate and potassium in production systems with succession grass/grass and grass/legume. The study was conducted in the field, in Unoeste Experimental farm with several crops: sorghum/ corn single, sorghum/corn intercropped, soybean/corn single and soy/corn intercropped under no tillage and the conventional tillage. The experimental design was a strip block with four replications. Samples were collected in the begin of the experiment in August 2012. The depth collection was 0-20 and 20-40 cm deep. The other samples were collected in February and August of the 2014 and August of the 2015. In this time the depth collection was 0-5, 5-10, 10-20, 20-40 and 40-60 cm. The yields for sorghum, soybeans and corn were evaluated. The total N content and NO3- in the soil increased significantly in the no tillage, with the succession soybean/ corn intercropped with gras. The NH4+ was the highest amount in soybeans /corn in the no tillage system. For nutrient K+ contents were similar in for all the tratments, but the higher concentrations was in soil management under no tillage system. The leaching it occurred to total N, NH4+, K + and NO3-, when the in depth incriased. The highest yield occurred in the single corn grown in the no tillage after soybeans. The soybean crop was better in the succession of single corn under conventional tillage and corn/grass. Under notillage system, sorghum crop the had similar results, but no tillage was higher dry matter yield hectare. / Sistemas de produção envolvendo o plantio de gramíneas e leguminosas podem alterar a fertilidade do solo significativamente, assim como o preparo de solo. Sendo assim, realizou-se um experimento para avaliar o acúmulo de matéria orgânica, nitrogênio total, amônio, nitrato e potássio em sistemas de produção com sucessões gramínea/gramínea e gramínea/leguminosa, sob plantio direto e convencional. O estudo foi realizado a campo, na fazenda experimental da UNOESTE, com inicio em agosto de 2012 e término em agosto de 2015, com as seguintes sucessões de culturas: sorgo/milho solteiro, sorgo/milho com braquiária e soja/milho solteiro e soja/milho com braquiária em sistema de plantio direto (SPD) e sistema de plantio convencional SPC. O delineamento experimental foi faixas com quatro repetições. As amostragens foram realizadas no inicio do experimento agosto de 2012, para caracterização da área, nas camadas de 0-20 e 20-40 cm de profundidade, as demais amostras foram fevereiro, agosto de 2014 e agosto de 2015, a 0-5, 5-10,10-20, 20-40 e 40-60 cm de profundidade. Foram avaliadas as produtividades para sorgo, soja e milho. O teor de N-total e NO3- no solo teve um aumento expressivo no SPD referente ao SPC, com a sucessão da soja/milho-Urochloa, já o NH4+ a maior quantidade foi na sucessão soja/milho no SPD. Para o nutriente K+ os teores encontrados foram semelhantes nas sucessões de culturas adotadas, mas com maiores teores no manejo de solo SPD. A lixiviação ocorreu em profundidade para N-total, NH4+, NO3- e K+. A maior produtividade ocorreu no milho cultivado solteiro no SPD após soja. A cultura da soja foi melhor na sucessão de milho solteiro no SPC e milho/Urochloa no SPD e para cultura do sorgo os sistemas adotados obtiveram resultados semelhantes, sendo SPD com maior produtividade de matéria seca hectare.

Embora a indústria da carne utilize a marinação em larga escala, o comportamento da penetração da salmoura em bifes massageados de carne bovina é pouco conhecido. O músculo Biceps femoris tem sido considerado pouco macio e suculento e apresentado grande variação de maciez intermuscular. Desta forma, o objetivo deste estudo foi avaliar o efeito da marinação com adição de proteína hidrolisada de soja sobre a estrutura muscular de porções distintas do Biceps femoris e suas implicações sobre a qualidade de carne. No Capítulo 2, 3 e 4, seis músculos bovinos foram submetidos aos tratamentos: CONTROLE (bifes não massageados), CS (bifes massageados com salmoura) e SPHS (bifes massageados com salmoura adicionada de proteína hidrolisada de soja). No capítulo 2, os músculos foram divididos em duas porções: Origem (PO) e Inserção (PI), e os tempos de massageamento foram 30 e 60 min. No capítulo 3 e 4, os músculos foram divididos em três porções: Origem (PO), Inserção 1 (PI1) e Inserção 2 (PI2), e os bifes destas porções foram armazenados por 1 e 12 dias após equalização da salmoura, exceto os bifes CONTROLE que foram armazenados somente por 1 dia. As análises realizadas foram: mensuração da penetração da salmoura, determinação do melhor tempo de massageamento, pH, rendimento (REND), colágeno total (CT), composição centesimal, perdas por gotejamento (PPG), perdas por cocção (PPC), força de cisalhamento (FC), microscopia eletrônica de varredura (MEV), análises microbiológicas e sensoriais. O delineamento experimental utilizado foi em blocos inteiramente casualizados, onde cada músculo representou um bloco. A análise de mensuração da penetração da salmoura demonstrou que os bifes SPHS, massageados por maior tempo (60 min), obtiveram maior absorção e retenção de salmoura ao longo da profundidade dos bifes. A PI2 apresentou menor quantidade de CT em comparação às demais, para o CONTROLE. Já os bifes CS e SPHS da PO e PI1 obtiveram menores quantidades de CT em comparação aos bifes destes mesmos tratamentos da PI2. Os bifes massageados não sofreram efeito de tempo de armazenamento e foram mais macios, suculentos e melhor pontuados para impressão global em comparação ao CONTROLE. O pH dos bifes se elevou com os tratamentos CS e SPHS e pareceu influenciar sobre o REND das porções de forma que, a PO obteve menor pH e maior REND, enquanto a PI resultou em maior pH e menor REND. Menores PPG, PPC e FC foram observados para os bifes CS e SPHS e o período de 12 dias de armazenamento permitiu que as PPC e FC diminuíssem. Respostas similares entre a maciez sensorial e objetiva foram observadas nas porções do músculo de forma que, as PIs foram mais macias do que a PO. A analise MEV demonstrou inchaço das fibras e diminuição dos espaços interfibrilares nos bifes massageados CS e SPHS. / Although meat industry uses marination in large-scale, the brine penetration behavior in tumbled steaks from bovines is little known. The Biceps femoris muscle has been considered little tender and juicy, and presented large range of intramuscular tenderness. Therefore, the objective of this work was to evaluate the effect of marination added of hydrolyzed soy protein on the muscular structure of different portions from the Biceps femoris and its implication on beef quality. In Chapter 2, 3 and 4, steaks from six bovine muscles were submitted to the treatments: CONTROL (no tumbling or addition of brine), WTB (with tumbling and addition of brine), and WTB/HSP (with tumbling and addition of brine plus hydrolyzed soy protein). In Chapter 2, the muscles were divided in two portions: Origin (OP) and Insertion (IP), and the tumbling times were 30 and 60 min. In Chapter 3 and 4, the muscles were divided in three portions: Origin (OP), Insertion 1 (IP1) and Insertion 2 (IP2), and their steaks were stored for 1 and 12 days after equalization of brine, except to the CONTROL steaks that were only stored for 1 day. The analyses performed were: monitoring of brine penetration, pH, yield (YIE), total collagen (TC), proximate composition, drip loss (DL), cooking loss (CL), shear force (SF), scanning electron microscopy (SEM), microbiologic and sensory. The experimental design was completely randomized blocks, where each muscle represented one block. The analysis of monitoring of the brine penetration showed that the WTB/HSP steaks, tumbled for largest time (60 min), had higher absorption and retention of brine along the depth of the steaks. The IP2 presented lower TC amount in relation to other portions, in CONTROL steaks. However, the WTB and WTB/HSP steaks from OP and IP1 had lower TC amount when compared to IP2, in these same treatments. The tumbled steaks were not affected by storing time and were tender, juicier and better scored for overall satisfaction with regard to CONTROL steaks. The pH of the steaks was elevated with the WTB and WTB/HSP treatments and appeared to influence the YIE of the portions, where OP had lower pH and higher YIE, while IP resulted in higher pH and lower YIE. Lower DL, CL and SF were observed for WTB and WTB/HSP steaks and the storing time of 12 days allowed that the CL and SF declined. Similar responses between sensory tenderness and SF were observed in the muscle portions, which IPs were tender than OP. The SEM analysis showed swelling of fibers and decrease of spaces between fibrils in tumbled WTB and WTB/HSP steaks

No description available.

Over the past decades the world has become increasingly interconnected, and global commodity trade has increased substantially in scope and complexity. Simultaneously, we are rapidly moving towards a future with an increased risk of severe disruption caused by the effects of climate change globally. As trade flows can connect distant regions thousands of miles apart, they can also transmit risks of climate change via impacts on supply chains. This study examines these risk flows through a case study, focusing on exposure to climate change risks to the Swedish consumption of Brazilian soy. Taking in to account both the exposure of climate change to agricultural production in Brazil, and the potential climate vulnerability of the transport network that is used in the agricultural supply, this study brings together data and methods from eight different sources to assess climate risks to production and transport in a novel integrated climate risk assessment. The ability to link consumption data, production data and transport network information together at a municipality resolution constitutes a major innovation and step forward in climate-related supply chain risk assessment. The study find that future risks posed to Swedish sourcing of Brazilian soy are relatively low. Considering dynamic effects of the future market does however suggest that securing future supplies of soy can still be a challenging task for Sweden.

<p>Detection of pathogens, toxins, hazardous chemicals, and allergens in the food industry with reliable, sensitive, efficient, and rapid results has increased the demand to develop innovative diagnostic tools. Surface-enhanced Raman spectroscopy (SERS) sensors have demonstrated to detect a wide variety of analytes using nanomaterials like metal nanoparticles. Concerns of synthetic materials that can affect the environment with disposal of sensors have opened the possibility of fabricating SERS sensors with biodegradable materials. Fabrication of electrospun nanofibers from natural polymeric materials such as soy protein isolate can be used as a SERS platform. In the first part of this research, the characteristics of SPI solutions blended with NaOH and polyethylene oxide (PEO) such as PEO Mw, zeta potential and viscosity as well operating parameters such as voltage (15, 20, and 27 kV) were studied to evaluate the best solutions for a nanofibrous SERS platform. Characteristics of electrospun nanofibers, such as surface wettability, fiber diameters, and morphology using SEM, helped determine the most feasible fibers for decoration with noble metal nanoparticles. Fibers fabricated with 12 wt% SPI + 5 wt% PEO (0.1 MDa) + 1 wt% NaOH solution showed the smallest fiber diameter and highest water contact angle measurements. Glutaraldehyde (GLA) was added as a crosslinker to partly increase nanofibers hydrophobicity. These nanofibers were decorated with Au-nanostars and Au@Ag-NPs suspended in 90% butanol and in water. Partly hydrophobic nanofibers decorated with Au-nanostars and Au@Ag-NPs in butanol showed the most feasible results for a SERS platform due to smallest fiber diameter and higher water contact angle. In the second part of this research, decorated SPI nanofibers were evaluated to study its feasibility as a SERS platform for detecting bisphenol A (BPA), a toxic chemical present in food packaging materials. However, SERS spectra were difficult to obtain due to CCD overflow (excessive number of photons) at all laser powers on SPI nanofiber mats. Optimizing other Raman spectroscopy parameters such as the exposure time and the number of averages could enhance the SERS measurements. The fabricated SPI nanofibers in this research showed that hydrophilic and partly hydrophobic nanofibers mats could be used for decoration with metal nanoparticles by suspending the nanoparticles in a hydrophobic solvent. Hydrophilic nanofiber mats with nanoparticles in a hydrophobic solvent open a new strategy for developing another type of SERS platform.</p>

The effect of sub-lethal chlorine stress on various strains/serotypes of Salmonella on biofilm formation and thermal resistance was studied. The effect of oxidative stress (induced by 150 ppm of chlorine in TSB) on Salmonella biofilm formation on polystyrene and stainless steel surfaces at three temperatures (4°C, 30°C, and room temperature) in nutrient rich (full strength TSB) and nutrient limited conditions (1/10th TSB) was evaluated. On polystyrene surface, chlorine stressed S. Heidelberg (strain ID 72), S. Newport (strain ID 107) and S. Typhimurium (ATCC 14028) formed stronger (P < 0.05) biofilms at 30°C. On stainless steel, the chlorine stressed S. Heidelberg (ATCC 8326) and S. Enteritidis (ATCC 4931) at room temperature formed stronger (P < 0.05) biofilms as compared to the non-stressed control cells. The thermal resistance of short-term (1h) and long-term (27d) chlorine stressed Salmonella Heidelberg and S. Typhimurium were compared with the non-stressed controls at three different temperatures (55°C, 58°C and 61°C) and two growth phases (logarithmic and stationary). The short-term stressed log phase cells (both serotypes) were found to be more sensitive (P< 0.05) to thermal inactivation in TSB. Upon long-term sub-lethal chlorine exposure, Salmonella developed a rugose morphotype on tryptic soy agar at 37°C. The rugose morphotype provided significant thermal protection (P< 0.05) against heat stress as compared to smooth morphotype. In chicken broth, at 55°C, short-term chlorine stressed stationary phase S. Typhimurium displayed a higher D55 value compared to non-stressed cells. The findings from this research reveal that some Salmonella strains have the potential to form stronger biofilms and exhibit higher thermal tolerance upon exposure to sub-lethal chlorine concentration.

No description available.

This research project was conducted to evaluate the effects of adhesive type, wood species, and cure temperature on the strength and durability properties of a finger joint. The adhesives were a resorcinolormaldehyde(RF),polyurethane/aqueous emulsion polymer (PU/AEP), and a resorcinolormaldehyde/soy-isolate honeymoon system. The species of wood were keruing (Dipterocarpus spp.), southern pine (Pinus spp.), and Douglasir (Pseudotsuga menziesii). The cure temperatures of the adhesives were ambient (26-35° C, 78-95° F) and elevated (43-49° C, 110-120° F). Joints were subjected to three test procedures; a tension test, a bending test, and a bending test following an accelerated aging procedure. The response variables measured for each of the bending tests included modulus of rupture, modulus of elasticity, and percent wood failure. The response variables measured for the tension tests were tensile strength and percent wood failure. The RF adhesive performed the best in flexural and tensile strength of the three adhesives studied. However in most cases, the PU/AEP adhesive could be considered a comparable system. Given adequate adhesive performance, strength and stiffness of the joints studied were dependent on density of the wood species, with keruing having the greatest density.

No description available.