• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 2
  • 1
  • Tagged with
  • 12
  • 8
  • 7
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Studies on egg yolk

Chang, Charlotte Mary Nowak, January 1969 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
2

Properties of several types of salted yolk and functionality in mayonnaise

Harrison, Lisa J. January 1984 (has links)
Call number: LD2668 .T4 1984 H37 / Master of Science
3

Viscosity and Acid Stability in Low-fat Mayonnaise with Varying Proportions of Xanthan Gum and Guar Gum

Bergecliff, Terese January 2016 (has links)
Mayonnaise is a mixture of egg yolk, vinegar, water, spices and 70-80% oil forming a semi-solid oil-in-water emulsion. When preparing a low-fat mayonnaise with an increased water content, thickening agents are required for increased viscosity and emulsion stability. The hydrocolloids xanthan gum and guar gum are sometimes used for this purpose and they act synergistically creating a viscosity increase. However, guar gum has poor acid stability, and because mayonnaise is an acidic product guar gum will eventually start to degrade causing a viscosity decrease and subsequent emulsion separation. Despite this fact, guar gum and xanthan gum are extensively used in mayonnaises today. The aim of this degree project was to explore how the synergy between guar gum and xanthan gum influences the viscosity of a low fat mayonnaise and whether high acidity will have an impact on the viscosity over a 4-week period. This was to examine if and if so, how a mayonnaise recipe can be modified to maintain a cost efficient product with the desired rheological properties in times of hydrocolloid price fluctuations. The study was conducted by preparing 15 mayonnaises with 50% fat, either at pH 3,5; 4 or 5 and a total of 0,6 % hydrocolloids with varying proportions of guar gum and xanthan gum. The mayonnaise samples were studied by measurements of viscosity, color changes and a visual comparison of their mayonnaise-like flow-properties compared to Hellmann’s Real Mayonnaise used as reference. The viscosity of the mayonnaises increased with increasing ratio of guar gum. On the other side, there were greater viscosity losses in mayonnaises with increasing ratio of guar gum 4 weeks after preparation compared to 4 days, with no apparent signs of correlation between higher acidity and hydrocolloid degradation. Mayonnaises with 20% xanthan gum and 80% guar gum had the texture most similar to the reference. In these low-fat mayonnaises, the use of more xanthan gum led to an undesired “slimy” texture and a lower viscosity – an important aspect if adjusting a low-fat mayonnaise recipe by increasing the ratio of xanthan gum. Because a commercial mayonnaise sometimes is consumed several months after manufacturing, that time frame is most likely required in order to fully measure how much the high acidity in mayonnaise will affect its viscosity. This project has shown a pattern where viscosity in the assessed mayonnaises starts to decrease a few weeks after preparation. However to find out exactly to what extent and how this would affect the overall product, and ultimately: if guar gum/xanthan gum combinations are suitable for long-term mayonnaise applications, further studies are required. / Viskositet och syrastabilitet i majonnäs med låg fetthalt och olika proportioner av xantan och guarkärnmjöl Majonnäs är en blandning av äggula, vinäger, vatten, kryddor och 70-80% olja som bildar en semi-solid olja-i-vatten-emulsion. För att tillverka en lågfettsmajonnäs med högre vatteninnehåll behöver förtjockningsmedel tillsättas för viskositet och emulsionsstabilitet. Hydrokolloiderna xantangummi och guarkärnmjöl används ibland i detta syfte och de utövar en synergi som ger ökad viskositet. Dock har guarkärnmjöl dålig syrastabilitet och eftersom majonnäs är en sur produkt kommer guarkärnmjölet efter ett tag att brytas ned vilket leder till en viskositetsminskning och emulsionsseparation. Trots detta används guarkärnmjöl och xantangummi i stor utsträckning i majonnäser idag. Syftet med examensarbetet var att undersöka hur synergin mellan guarkärnmjöl och xantangummi påverkar viskositeten i en lågfettsmajonnäs och huruvida en hög syrahalt kommer att påverka viskositeten under en 4-veckorsperiod. Detta för att se om och i så fall hur ett majonnäsrecept kan modifieras för att erhålla en kostnadseffektiv produkt om priset på hydrokolloider växlar. För arbetet bereddes 15 majonnäser med 50% fetthalt, antingen med pH 3,5; 4 eller 5 och totalt 0,6% hydrokolloider med olika proportioner av guarkärnmjöl och xantangummi. Majonnäserna undersöktes genom mätning av viskositet, färgförändringar och en visuell jämförelse av deras majonnäsliknande flytegenskaper i förhållande till Hellmann’s Real Mayonnaise som användes som referens. Viskositeten i majonnäserna ökade med ökande halt guarkärnmjöl. Å andra sidan minskade viskositeten i högre grad med ökande halt guarkärnmjöl 4 veckor efter tillverkning jämfört med 4 dagar, men inga tydliga samband mellan högre syrahalt och nedbrytning av hydrokolloider syntes. Majonnäser med en blandning av 20% xantangummi och 80% guarkärnmjöl hade den konsistens som var mest lik referensen. I dessa försök med lågfettsmajonnäser ledde användandet av högre halt xantangummi till en oönskad ”slimig” textur och en lägre viskositet – en viktig aspekt om ett recept på lågfettsmajonnäs ska modifieras genom att öka halten xantangummi. Eftersom en kommersiell majonnäs ibland konsumeras flera månader efter tillverkning så är det troligtvis den tidsramen som krävs för att helt kunna mäta hur mycket den höga syrahalten i majonnäs kommer att påverka dess viskositet. Detta projekt har påvisat ett mönster där viskositeten i de analyserade majonnäserna börjar minska några veckor efter tillverkningen. Men för att få reda på exakt i vilken utsträckning och hur detta skulle påverka produkten i sin helhet, och i slutändan: om kombinationen med guarkärnmjöl och xantangummi är lämplig för majonnäser med lång hållbarhet krävs ytterligare studier.
4

Obtenção de manoproteína e β-glucana de levedura descartada em cervejaria com potencial para aplicação em alimentos

Araújo, Vilma Barbosa da Silva 11 February 2014 (has links)
Made available in DSpace on 2015-04-17T14:49:37Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1723546 bytes, checksum: d6ebd3071471297d43af6b6d405af8d9 (MD5) Previous issue date: 2014-02-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Yeasts of the genus Saccharomyces spp. are used as biotechnological tool in brewery and after five fermentative production processes; they are discarded by the beer industry. The cell wall of yeasts is mainly composed of β - glucan, which is a glucose homopolymer capable of changing the immune response in the host, and by manoproteins (MP), which have recognized emulsifying properties. The aim of the present study was to obtain these two cell wall fractions of discarded yeast employing an additional step to obtain MP in a process applicable to the extraction of β - glucan. The fractions obtained were characterized and MP was evaluated for potential for application as an emulsifier in mayonnaise formulations. From the cell wall of yeasts on dry basis, the MP and β glucan yield was 4.16% and 10 %, respectively. The residual moisture of β - glucan was 4.9 ± 0.1 % and MP was 3.9 ± 0.9 % and no changes in this parameter were observed during 28 days of storage in bi-oriented polypropylene packs (BOPP) at 10°C, 25°C or 40° C. The SDS-PAGE profile of MP showed proteins with molecular weight of 58 kDa and 64 kDa, and the highest content of constituent amino acids was observed for valine (8.9%), aspartic acid (8.2%) and leucine (6.9%). Each 100 g of mayonnaise prepared with MP at concentrations of 0.6%, 0.8 % and 1.0 % contained, on average, 25 ± 0.27 g moisture, 1.6 ± 0.10 g ash, 2.4 ± 0.04 g protein, 56 g ± 0.41 lipid and 14 ± 0.12 g carbohydrates, and no changes in attributes aroma, color, flavor and texture were observed in the study period (28 days). The results showed applicability of the method proposed for obtaining β -glucan and MP and suggest that MP has potential for application as bioemulsifier in foods, particularly in mayonnaise formulations. / Leveduras do gênero Saccharomyces spp. são empregadas como ferramenta biotecnológica, na produção de cerveja e após em média cinco processos fermentativos de produção, são descartadas pela indústria cervejeira. A parede celular de leveduras é formada principalmente pelas β-glucana, que são homopolímeros de glicose capazes de alterar a resposta imune no hospedeiro, e pelas manoproteínas (MP) que possuem reconhecidas propriedades emulsificantes. No presente estudo foi proposto obter estas duas frações da parede celular de levedura descartada em cervejeira empregando uma etapa adicional para obtenção da MP em um processo aplicável a extração da β-glucana. As frações obtidas foram caracterizadas e a MP avaliada quanto ao potencial para aplicação como emulsificante em formulações de maionese. A partir da parede celular de levedura em base seca, o rendimento da MP e da β-glucana foi de 4,16% e 10%, respectivamente. A umidade residual da β-glucana foi de 4,9 ± 0,1% e da MP foi de 3,9 ± 0,9% e não foram observadas alterações neste parâmetro durante 28 dias de armazenamento em embalagens de polipropileno bi-orientado (BOPP) a 10 °C, 25 °C ou 40 °C. O perfil de SDS-PAGE da MP evidenciou proteínas de peso molecular de 58 kDa e 64 kD e o maior teor de aminoácidos constituintes foi observado para a valina (8,9%), ácido aspártico (8,2%) e leucina (6,9%). Cada 100 g de maionese preparada com MP nas concentrações de 0,6%; 0,8% e 1,0% continham, em média, 25 ± 0,27g de umidade, 1,6 ± 0,10 g de cinzas, 2,4 ± 0,04 g de proteína, 56 ± 0,41 g de lipídeos e 14 ± 0,12 g de carboidratos, e não foram observadas alterações nos atributos aroma, cor, sabor, textura no período analisado (28 dias). Os resultados obtidos evidenciam aplicabilidade do método proposto para obtenção de MP e β-glucana e sugerem que a MP possui potencial para aplicação como bioemulsificante em alimentos, em especial em formulações de maionese.
5

Modificação química de amido de mandioca e aplicação em emulsão / Chemical modification of cassava starch and application in emulsion

Del Bem, Marília Sbragia [UNESP] 22 February 2016 (has links)
Submitted by MARÍLIA SBRAGIA DEL BEM null (msbragia@gmail.com) on 2016-04-11T17:40:10Z No. of bitstreams: 1 Dissertação Marília Sbragia Del Bem.pdf: 4218662 bytes, checksum: 6a79164a0b53df57f2a07e3084e7fa8e (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-12T18:04:49Z (GMT) No. of bitstreams: 1 delbem_ms_me_bot.pdf: 4218662 bytes, checksum: 6a79164a0b53df57f2a07e3084e7fa8e (MD5) / Made available in DSpace on 2016-04-12T18:04:49Z (GMT). No. of bitstreams: 1 delbem_ms_me_bot.pdf: 4218662 bytes, checksum: 6a79164a0b53df57f2a07e3084e7fa8e (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No presente trabalho, objetivou-se avaliar os efeitos de parâmetros variáveis na fosfatação do amido nativo de mandioca sobre as propriedades físicas dos amidos modificados e avaliar o uso do amido fosfatado na produção de emulsão tipo maionese. O amido de mandioca nativo e o amido de milho comercial foram analisados quanto à composição físico-química, amilose aparente, difração por raios-X e cristalinidade relativa, morfologia geral, tamanho e distribuição dos grânulos, poder de inchamento e solubilidade, propriedades de pasta e térmicas. O amido de mandioca nativo foi fosfatado pela mistura de fosfato de sódio monobásico anidro (NaH2PO4) e fosfato de sódio dibásico anidro (Na2HPO4) totalizando sete tratamentos com diferentes quantidades em mol de fosfato. Todas as análises realizadas nos amidos de mandioca nativo e no amido de milho comercial foram também realizadas nos amidos fosfatados de mandioca, com exceção da composição físico-química. Além dessas análises, os amidos fosfatados foram analisados quanto ao teor de fósforo e grau de substituição (DS). Foram realizados testes de aplicação do amido de milho comercial (P), amido nativo de mandioca (T1) e dos amidos de mandioca fosfatados (T2 e T3) em maioneses com 30 % (m/m) de óleo. As maioneses foram submetidas às análises de pH, acidez titulável, textura, estabilidade da emulsão, microscopia óptica e análise sensorial. Nos amidos de mandioca nativo e milho comercial foram observadas diferenças significativas tanto na composição físico-química, quanto na caracterização morfológica, estrutural e física. Nos amidos modificados houve aumento nos teores de fósforo e no DS com o aumento das concentrações de fosfato, sendo que nas maiores concentrações testadas os valores finais ultrapassaram o permitido pela legislação. O aumento das concentrações ocasionou aumento aproximado de 4 vezes no diâmetro médio e menor uniformidade dos grânulos, intensificando-se a partir da quinta concentração, ou seja, 5,20 milimol de fosfato g-1 de amido. No primeiro tratamento, ou quantidade em mol de fosfato igual a 0, o teor de amilose aparente era de 23,21 %, mas na maior concentração de fosfato esse valor teve uma diminuição aproximada de 12 vezes. A fosfatação provocou o rompimento das ligações de hidrogênio das duplas hélices de amilopectina, responsáveis pela formação dos cristais, reduzindo a cristalinidade relativa. O poder de inchamento e a solubilidade do amido aumentaram com o aumento das concentrações, assim como a viscosidade inicial a 25 °C. Houve redução nos picos, na quebra, na viscosidade final e na tendência à retrogradação. A adição de fosfato também reduziu as temperaturas de gelatinização e a variação da entalpia (ΔHgel), enquanto a porcentagem de retrogradação aumentou até a concentração estimada de 3,96 milimol de fosfato g-1 de amido, diminuindo com as próximas concentrações. As maioneses testadas com o amido de milho comercial (P), amido de mandioca nativo (T1) e amidos de mandioca fosfatados com teores de fósforo aceitáveis pela legislação para uso em alimentos (T2 e T3) apresentaram resultados de pH, acidez titulável e estabilidade da emulsão dentro do esperado. O amido de mandioca modificado T2 mostrou-se mais estável frente às forças mecânicas em relação aos demais amidos. O aumento das concentrações de fosfato reduziu a firmeza das maioneses, no entanto, todas foram bem aceitas na avaliação sensorial em todos os atributos, inclusive em relação à textura e à intenção de compra. O amido de mandioca fosfatado, obtido no presente trabalho, pode ser utilizado como substituinte do amido de milho comercial na produção de maionese, sendo o tratamento T2 (0,88 milimol de fosfato g-1 de amido) o mais recomendado. / This study aimed to evaluate the effects of the variable parameters of chemical modification of on the phosphating of cassava starch and the influence of this modification on the physical properties of the starch, as well as studying the application of the phosphate cassava starch in mayonnaise. The cassava starch and commercial corn starch were analyzed for physical-chemical composition, apparent amylose, diffraction X-rays, relative crystallinity, general morphology, size and distribution of the granules, swelling power and solubility, paste and thermal properties. Native cassava starch was phosphated by the mixture of anhydrous sodium monobasic phosphate (NaH2PO4) and anhydrous dibasic sodium phosphate (Na2HPO4), with a total of seven treatments with different amounts of mol phosphate. All analyzes performed on starches of cassava and commercial corn starches were also carried out in phosphate starch cassava, except for the physical and chemical composition. In addition to these analyzes, the phosphate starches were analyzed for phosphorus content and degree of substitution (DS). Tests of application were conducted with commercial corn starch (P), native cassava starch (T1) and phosphate cassava starches (T2 and T3) on mayonnaise with 30 % (w/w) of oil. The mayonnaises were analyzed for pH, titratable acidity, texture, emulsion stability, optical microscopy and sensory analysis. Significant differences in the physical and chemical composition as well as the morphological, structural and physical characteristics were observed between the starches of cassava and maize. The analysis of modified cassava starches showed that there was increase in phosphorus content and degree of substitution with increasing phosphate doses used, whereas in conditions of higher concentrations tested the final values of phosphorus in starches were greater than allowed by legislation. Increased concentrations led to an increase in about four times the average diameter of the starch granules and promoted a lower uniformity of the granules, intensifying from the fifth concentration or phosphate or 5.20 millimoles g-1 of starch. In the first treatment, or quantity in moles of phosphate 0, the apparent amylose content was 23.21 %, but in higher phosphate concentration, this value had an approximate decrease of twelve times. The phosphating caused the rupture of hydrogen bonds of amylopectin double helices, responsible for the formation of crystals, reducing the relative crystallinity. The swelling power of the starch and solubility increased with the increasing concentrations, and the initial viscosity at 25 °C (cold viscosity). There was a reduction in the peaks, breakdown, final viscosity and retrogradation tendency. The addition of phosphate also reduced gelatinisation temperatures and the variation of enthalpy (ΔHgel), while the percentage of retrogradation increased up to an estimated concentration of 3.96 millimoles phosphate g-1 of starch, decreasing with higher concentrations. The mayonnaise tested with commercial corn starch (P), starch native tapioca (T1) and phosphate cassava starch with phosphorus levels acceptable by law for food use (T2 and T3) showed pH results, titratable acidity and stability the emulsion as expected. The cassava modified starch T2 was more stable compared to the mechanical forces than the other starches. The increase in phosphate concentrations reduced the firmness of mayonnaise, however, all were well accepted in the sensory evaluation in all attributes, including with respect to texture and purchase intent. The tapioca starch phosphate obtained in the present study may be used as the substituent of commercial corn starch in the production of mayonnaise and the treatment T2 (0.88 millimoles phosphate g-1 of starch) as recommended.
6

Étude des facteurs physicochimiques modulant les propriétés structurales et rhéologiques de la purée de lentilles rouges et usage en tant que substitut de l'huile dans des sauces mayonnaises

Feroussier, Auriane 29 August 2024 (has links)
Les systèmes hétérogènes issus de sources végétales tendent à être valorisés pour une utilisation comme ingrédients « naturels », communément appelés *clean label*, dans les produits alimentaires ; dans ce contexte, il est nécessaire de comprendre leur structure en lien avec leur fonctionnalité. Les purées de légumineuses ont un potentiel innovant : en plus de leur haute valeur nutritionnelle, elles diffèrent des ingrédients à base de légumineuses par les traitements de cuisson et broyage appliqués lors de leur préparation. Comme démontré dans des fruits et légumes, les purées sont des matrices complexes, composées d'une pulpe dispersée dans un sérum, et chacune des phases impacte les propriétés rhéologiques de la purée. Cependant, à ce jour très peu de travaux ont porté sur les purées de légumineuses dans une optique d'utilisation comme ingrédient alimentaire. Dans cette thèse, un modèle de purée à base de lentilles rouges a été développé pour comprendre les facteurs structuraux déterminant leurs propriétés rhéologiques, et ensuite étudier l'impact de l'incorporation de ces purées dans une application de type sauce mayonnaise en remplacement de l'huile. Les deux premiers volets de la thèse ont consisté à étudier la purée sur la base des particules cellulaires composant la pulpe d'une part, et de la phase sérum d'autre part. En premier lieu, la purée a été fractionnée pour séparer la pulpe sur la base de la taille des particules, et obtenir ainsi quatre fractions représentant respectivement : 1) des fragments cellulaires, 2) des cellules isolées, 3) des amas cellulaires et 4) une fraction mixte. Les travaux ont démontré l'implication des propriétés morphologiques des particules et de la localisation de l'amidon sur les propriétés rhéologiques des fractions. Les cellules isolées et les amas cellulaires, de taille importante et aux parois cellulaires faiblement brisées, étaient constitués d'amidon intracellulaire, contribuant à l'élasticité élevée du réseau. Les fragments, agrégés dans une matrice extracellulaire riche en amidon, permettaient plutôt de maintenir la stabilité face à la sédimentation lors de la dilution. Le rôle des particules sur les propriétés rhéologiques de la purée a donc été mis en lumière dans un premier temps, et le deuxième volet du projet s'est concentré sur l'impact de la mobilité de l'eau des purées et de la composition du sérum sur l'évolution de leurs propriétés rhéologiques et texturales. Pour ce faire, des purées à différentes teneurs en solides (15 à 25% p/p) et valeurs de pH (4.0 et 6.5) ont été réalisées, et entreposées jusqu'à 4 jours pour étudier l'effet de l'entreposage également. Une organisation structurale extracellulaire, impliquant la formation d'un réseau de protéines et d'amidon sous l'effet combiné du pH et du temps d'entreposage, a été proposé. À pH acide et lors d'un entreposage prolongé, la formation d'agrégats protéiques en combinaison avec la rétrogradation de l'amidon accentueraient le resserrement du réseau, générant une perte d'eau par synérèse et l'augmentation de fermeté des purées. Ces résultats ont donc démontré que la pulpe et le sérum de la purée contribuaient de manière complémentaire à ses propriétés rhéologiques, la pulpe étant composée de différentes particules cellulaires générant un système viscoélastique renforcé par le réseau extracellulaire, lui-même modulé par la composition du sérum. Les deux volets suivants consistaient à développer une application alimentaire concrète, soit une sauce mayonnaise allégée, dans laquelle les purées étaient utilisées comme substitut de l'huile à des fins de stabilisation techno-fonctionnelle. D'abord, les purées de lentilles rouges aux mêmes teneurs en solides qu'étudiées précédemment (15 à 25% p/p) ont été incorporées dans les sauces mayonnaises pour réduire la teneur en huile de 80% p/p (témoin) à 60, 40 et 20% p/p. Les purées ont démontré un effet stabilisateur sur les mayonnaises, en donnant lieu à des propriétés rhéologiques variables selon la teneur en huile. L'étude a révélé la transition entre un renforcement du réseau de gouttelettes d'huile entassées par la purée à 60% p/p d'huile, jusqu'à la formation d'un réseau élastique issu des particules de purées à 20% p/p d'huile, en passant par une étape intermédiaire transitionnelle provoquant une perte d'élasticité à 40% p/p. L'augmentation de la quantité de purée dans la mayonnaise (réduction d'huile) ainsi que l'augmentation de la teneur en solides totaux de la purée ont contribué à renforcer le réseau, probablement par effet stérique lié aux particules générant une augmentation des interactions extracellulaires. Dans la dernière partie de la thèse, les propriétés sensorielles des sauces mayonnaises, aux teneurs en huile préalablement étudiées, ont été analysées selon une méthode sensorielle de type « *Sorted Napping/Ultra Flash Profiling* » en utilisant trois types de purées de légumineuses (lentilles rouges, lentilles noires et pois jaune) comme substituts de l'huile. A travers l'expertise culinaire de chefs cuisiniers, les différences sensorielles des mayonnaises ont révélé un effet de la teneur en huile, en distinguant principalement les mayonnaises sur la base de leur texture et de leur acidité. L'utilisation de différents types de légumineuses a démontré que chacune conférait des propriétés sensorielles spécifiques selon la teneur en huile, élargissant ainsi le potentiel d'utilisation des purées dans des sauces. Ainsi, ce projet de thèse constitue une preuve de concept systématique de l'utilisation de nouveaux ingrédients complexes, nutritionnels et peu transformés, tels que des purées de légumineuses, pour pallier les défis fonctionnels rencontrés lors de l'enrichissement nutritionnel de produits alimentaires. La compréhension des mécanismes impliqués permet ainsi d'expliquer ensuite la fonctionnalité de ces ingrédients afin de les valoriser pleinement dans différents produits. / Heterogeneous systems derived from plant-based raw materials are valued for their use as clean label ingredients in food products. In this context, understanding their structure in relation to their functionality is crucial. Pulse purees hold innovative potential as they originate from a high-nutritional-value source, differing from legume-based ingredients due to the processing methods (cooking and grinding) used for their preparation. As demonstrated based on fruits and vegetables, purees are complex matrices composed of a pulp phase dispersed in serum, and each phase influences the rheological properties of the puree. However, very few studies have explored the potential of using pulse purees as food ingredients. In this thesis, a puree model based on red lentils was developed to understand the structural factors that determine its rheological properties. It was followed by the study of the puree addition impact into a mayonnaise sauce as a fat replacer. The first two parts of the thesis focused on studying the puree based on cellular particles composing the pulp on one hand, and serum phase on the other hand. First, the puree was fractionated to separate the pulp based on the particle size, resulting in fractions of: 1) cell fragments, 2) single cells, 3) cell clusters, and 4) a mixed fraction. The work demonstrated the involvement of particle morphological properties and starch localization on the rheological properties of the fractions. Single cells and cell clusters of large size and made of weakly disrupted cell walls contained intracellular starch and contributed to the high elasticity of the network. Cell fragments, aggregated in a starch-rich extracellular matrix, helped to maintain the network stability by limiting sedimentation upon dilution. The role of particles on the rheological properties of the puree was thus highlighted, and the second part of the project focused on the impact of water mobility in the puree and the serum composition on the evolution of their rheological and textural properties. To achieve this, purees with different total solid contents (15 to 25%) and pH values (4.0 and 6.5) were prepared and stored for up to 4 days to study the effect of storage time as well. An extracellular structural organization involving the formation of a specific network of starch and protein under the combined effects of pH and storage time was proposed. At acidic pH and extended storage, the formation of protein aggregates combined with starch retrogradation would tighten the network, leading to water loss through syneresis and increased firmness of the purees. These results demonstrated that the particles and the serum phase contributed in a complementary way to the purees rheological properties, the pulp being composed of various cellular particles generating a significant viscoelastic system reinforced by the extracellular network, modulated itself by the serum composition. The last two parts of the project aimed to develop a food application, a light mayonnaise sauce, in which purees were used as an oil substitute for techno-functional stabilization. Red lentil purees with the same solid contents as previously studied (15 to 25%) were incorporated into mayonnaise sauces to reduce the oil content from 80% (control) to 60, 40, and 20%. The purees demonstrated a stabilizing effect on mayonnaises, resulting in variable rheological properties depending on the oil content. A structural transition was suggested, from the reinforcement of the close-packed oil droplets network by puree components at 60% oil to the formation of an elastic network based on puree particles at 20% oil, while an intermediate transitional stage caused an elasticity drop at 40%. The increase of puree content in mayonnaises (oil reduction) and of puree solid contents both contributed to strengthen the network by steric hindrance from the puree particles, increasing extracellular interactions. In the final part of the thesis, the sensory properties of mayonnaise sauces made with the previously studied oil contents were analyzed using a « *Sorted Napping/Ultra Flash Profiling* » sensory method using three types of pulse purees (red lentils, black lentils, and yellow peas) as oil substitutes. Through the culinary expertise of chefs, sensory differences in mayonnaises revealed a main effect of the oil content, distinguishing the sauces based mainly on their texture and acidity. Each type of puree conferred specific sensory properties based on the mayonnaise oil content, thereby expanding their potential as fat replacers. Thus, this thesis project constitutes a systematic proof of concept for the use of novel, complex, nutritive and minimally processed ingredients such as pulse purees, to address the functional challenges encountered during the nutritional enrichment of food products. Understanding the mechanisms clarifies the role of these ingredients' functionality, enabling their upcoming valorization in various products.
7

Avaliação da ação de antimicrobianos naturais no controle de Salmonella Enteritidis em salada de legumes com maionese / Evaluation of the activity of natural antimicrobials on the control of Salmonella Enteritidis in mayonnaise-based legume salad

Silva, Janine Passos Lima da 20 August 2007 (has links)
Salmonella Enteritidis (SE) é um enteropatógeno de grande preocupação para indústria de alimentos, principalmente de produtos que não podem ser submetidos a tratamento térmico, como as saladas à base de maionese, freqüentemente envolvidas em surtos de salmonelose. O uso de antimicrobianos naturais nesses produtos pode ser um método alternativo para o controle de SE. Assim, o objetivo deste trabalho foi avaliar o efeito antimicrobiano de óleo essencial de orégano, EDTA e nisina individualmente e a combinação de nisina com EDTA e nisina com óleo essencial de orégano no controle da multiplicação SE em salada de legumes com maionese. A atividade inibitória foi inicialmente avaliada in vitro e posteriormente em salada preparada com legumes, experimentalmente contaminados com SE, misturados à maionese, na concentração de 103 UFC/g, e armazenados em refrigeração (8°C) e em temperatura ambiente (30°C). Os resultados da avaliação in vitro indicaram que o OEO usado individualmente tem melhor efeito antimicrobiano contra SE do que quando empregado em combinação com nisina. Nem a nisina nem o EDTA, quando testados isoladamente ou combinados apresentaram efeito sobre SE. Na salada de legumes com maionese preparada artesanalmente, a presença de 0,2% de OEO resultou em redução na contagem de SE, constituindo-se em uma barreira adicional para a multiplicação do patógeno nesse produto. A análise sensorial da salada de legumes com maionese contendo 0,2% de OEO indicou que houve 95% de aceitação do aroma, 93% de aceitação do sabor e 74% de intenção de compra. A análise sensorial da maionese contendo 0,5% ou 1% de OEO indicou a inviabilidade de se aumentar a concentração do OEO na maionese como alternativa para melhorar o efeito antimicrobiano. / Salmonella Enteritidis (SE) is an enteropathogen relevant for the food industry, especially in foods that do not require heat treatment before consumption such as salads prepared with mayonnaise, frequently associated to outbreaks of salmonellosis. Natural antimicrobials can be used as an alternative procedure to control SE in these foods. The aim of the present study was to evaluate the effect of origanum essential oil (OEO), nisin and EDTA, used individually and in combination, on the growth of SE in mayonnaise and in mayonnaise-based legume salad. The inhibitory activity was evaluated in vitro, in home made mayonnaise and in mayonnaise-based legume salad experimentally contaminated with SE at 103 CFU/g, stored under refrigeration (8°C) and at room temperature (30°C). The results of the in vitro tests indicated that a better antimicrobial effect of OEO on SE was achieved when OEO was used individually than when used combined with nisin or EDTA. Nor nisin nor EDTA, used individually, presented any effect against SE. The presence of OEO in mayonnaise did not add any additional effect to the antimicrobial activity of the intrinsec parameters in this food. In mayonnaise-based legume salad, 0.2% of OEO caused a reduction in the counts of SE, and was an additional hurdle for the growth of the pathogen in this product. The sensorial testing of mayonnaise-based legume salad containing 0.2% OEO indicated an acceptance of 95% for the aroma and 93% for the taste and 74% of purchasing intention. The sensorial testing of mayonnaise containing 0.5% or 1% OEO indicated that the increase in the content of OEO to increase the antimicrobial activity is not feasible.
8

Avaliação da ação de antimicrobianos naturais no controle de Salmonella Enteritidis em salada de legumes com maionese / Evaluation of the activity of natural antimicrobials on the control of Salmonella Enteritidis in mayonnaise-based legume salad

Janine Passos Lima da Silva 20 August 2007 (has links)
Salmonella Enteritidis (SE) é um enteropatógeno de grande preocupação para indústria de alimentos, principalmente de produtos que não podem ser submetidos a tratamento térmico, como as saladas à base de maionese, freqüentemente envolvidas em surtos de salmonelose. O uso de antimicrobianos naturais nesses produtos pode ser um método alternativo para o controle de SE. Assim, o objetivo deste trabalho foi avaliar o efeito antimicrobiano de óleo essencial de orégano, EDTA e nisina individualmente e a combinação de nisina com EDTA e nisina com óleo essencial de orégano no controle da multiplicação SE em salada de legumes com maionese. A atividade inibitória foi inicialmente avaliada in vitro e posteriormente em salada preparada com legumes, experimentalmente contaminados com SE, misturados à maionese, na concentração de 103 UFC/g, e armazenados em refrigeração (8°C) e em temperatura ambiente (30°C). Os resultados da avaliação in vitro indicaram que o OEO usado individualmente tem melhor efeito antimicrobiano contra SE do que quando empregado em combinação com nisina. Nem a nisina nem o EDTA, quando testados isoladamente ou combinados apresentaram efeito sobre SE. Na salada de legumes com maionese preparada artesanalmente, a presença de 0,2% de OEO resultou em redução na contagem de SE, constituindo-se em uma barreira adicional para a multiplicação do patógeno nesse produto. A análise sensorial da salada de legumes com maionese contendo 0,2% de OEO indicou que houve 95% de aceitação do aroma, 93% de aceitação do sabor e 74% de intenção de compra. A análise sensorial da maionese contendo 0,5% ou 1% de OEO indicou a inviabilidade de se aumentar a concentração do OEO na maionese como alternativa para melhorar o efeito antimicrobiano. / Salmonella Enteritidis (SE) is an enteropathogen relevant for the food industry, especially in foods that do not require heat treatment before consumption such as salads prepared with mayonnaise, frequently associated to outbreaks of salmonellosis. Natural antimicrobials can be used as an alternative procedure to control SE in these foods. The aim of the present study was to evaluate the effect of origanum essential oil (OEO), nisin and EDTA, used individually and in combination, on the growth of SE in mayonnaise and in mayonnaise-based legume salad. The inhibitory activity was evaluated in vitro, in home made mayonnaise and in mayonnaise-based legume salad experimentally contaminated with SE at 103 CFU/g, stored under refrigeration (8°C) and at room temperature (30°C). The results of the in vitro tests indicated that a better antimicrobial effect of OEO on SE was achieved when OEO was used individually than when used combined with nisin or EDTA. Nor nisin nor EDTA, used individually, presented any effect against SE. The presence of OEO in mayonnaise did not add any additional effect to the antimicrobial activity of the intrinsec parameters in this food. In mayonnaise-based legume salad, 0.2% of OEO caused a reduction in the counts of SE, and was an additional hurdle for the growth of the pathogen in this product. The sensorial testing of mayonnaise-based legume salad containing 0.2% OEO indicated an acceptance of 95% for the aroma and 93% for the taste and 74% of purchasing intention. The sensorial testing of mayonnaise containing 0.5% or 1% OEO indicated that the increase in the content of OEO to increase the antimicrobial activity is not feasible.
9

CARACTERIZAÇÃO DE FARINHAS DE FEIJÃO CRIOULO (Phaseolus vulgaris L.) E SUA UTILIZAÇÃO NA ELABORAÇÃO DE MAIONESE / CHARACTERIZATION OF THE LANDRACE COMMON BEAN FLOUR (Phaseolus vulgaris L.) AND THEIR USE IN THE PREPARATION OF MAYONNAISE

Alves, Jamila dos Santos 14 March 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to characterize the two landrace common bean flour (in shell and shelled) and then apply one of them in partial replacement of mayonnaise in egg yolk. After obtaining the flour, it was performed performance analysis, chemical composition, pH, color, total phenolic compounds, flavonoid and antioxidant activity in vitro (DPPH and FRAP) and technological functional properties of absorbency for water and oil and emulsifying properties. The results show that the chemical composition of the landrace common bean flour (LCBF) is an important source of protein and fiber. Phenolic compounds were higher than in the LCBF in shell, and to cultivar Manteigão showed the highest reducing power by FRAP method, higher content of phenolic compounds and antioxidant capacity of the Carioca. The LCBF in shell from two cultivars showed better water absorption capacity and capacity oil absorption, indicating that can be used in food systems such as soups, bakeries, meat products which require high absorption of water and fat. As the results preliminary, the LCBF in shell Carioca was chosen flour for the preparation of mayonnaise. Mayonnaise were developed four formulations: T1 (Default) 100% egg yolk (EY); T2 75% EY and 25% LCBF; T3 50% EY and 50% LCBF; T4 25% EY and 75% LCBF. Analyses of chemical composition were held, calories, cholesterol, microbiological analysis, microscopy, rheology study, pH, Aw, color, stability and sensory analysis. The partial replacement of the EY by LCBF improved nutritional characteristics of mayonnaise, increased protein content and decreased the content of lipids and cholesterol. All samples showed non-Newtonian shear thinning behavior, yet, all samples showed the hysteresis phenomenon. The values of n were increased and K showed a decrease over storage. There was a decrease in apparent viscosity values for all the mayonnaise samples. The pH and Aw values decreased during storage, as well as the values of L * indicates a darkening of the product over the 30 days of storage. For the stability of the emulsion, treatment with a higher proportion of LCBF was less stable during storage. In sensory evaluation, the tasters did not notice difference between treatments for the color, odor, and overall appearance. In purchase intent test, T1, T2 and T3 showed the highest response rates for the score "Probably buy." The replacement of 50% of egg yolk by 50% landrace common bean flour (T3) showed up a good alternative for the production of mayonnaise, as obtained good acceptability, showed an increase in protein content, total dietary fiber and decrease the included lipids and cholesterol content of the product. / O objetivo deste estudo foi caracterizar a farinha de duas cultivares de feijão crioulo (com casca e sem casca) e posteriormente aplicar uma delas em substituição parcial da gema de ovo em maionese. Após a obtenção das farinhas, foram realizadas as análises de rendimento, composição centesimal, pH, cor, conteúdo de compostos fenólicos totais, flavonoides e atividade antioxidante in vitro (DPPH e FRAP) e as propriedades funcionais tecnológicas de capacidade de absorção de água e óleo e propriedades emulsificantes. Os resultados obtidos na composição química demonstram que as farinhas de feijão crioulo (FFC) são importantes fontes de proteínas e fibra alimentar. Os compostos fenólicos foram superiores nas FFC com casca, sendo que a cultivar Manteigão apresentou maior poder redutor pelo método FRAP, maior teor de compostos fenólicos e capacidade antioxidante que a cultivar Carioca. As FFC com casca das duas cultivares apresentaram melhores capacidade de absorção de água e capacidade de absorção de óleo, o que indica que podem ser utilizados em sistemas alimentares como sopas, panificação e produtos cárneos que requerem alta absorção de água e gordura. A FFC com casca da cultivar Carioca foi a farinha escolhida para a elaboração da maionese devido aos resultados de cor e propriedades funcionais tecnológicas. Foram desenvolvidas quatro formulações de maionese: T1 (Padrão) 100% gema de ovo (GO); T2 75% GO e 25% FFC; T3 50% GO e 50% FFC; T4 25% GO e 75% FFC. Foram realizadas análises de composição centesimal, valor calórico, colesterol, análises microbiológicas, microscopia, reologia, viscosidade, pH, atividade de água (Aw), cor, estabilidade e análise sensorial. A substituição parcial da GO por FFC aumentou o teor proteico e diminuiu o teor de lipídios e colesterol das maioneses. Observou-se uma diminuição dos valores de viscosidade aparente para todas as amostras de maionese. Os valores de pH e Aw diminuíram durante o armazenamento, assim como os valores de L* indicando um escurecimento do produto ao longo dos 30 dias de armazenamento. Para a estabilidade da emulsão, o tratamento com maior proporção de FFC se mostrou menos estável durante o armazenamento. Na análise sensorial, os provadores não notaram diferença entre os tratamentos para os atributos de cor, odor e aparência global. No teste de intenção de compra, o T1, T2 e T3 apresentaram os maiores percentuais de resposta para a afirmativa "Provavelmente compraria . A substituição de 50% de gema de ovo por 50% de farinha de feijão crioulo (T3) mostrou-se uma ótima alternativa para a produção de maionese, visto que obteve boa aceitação sensorial, apresentou um aumento no teor proteico, inclusão de fibra alimentar total e diminuição do teor de lipídios e colesterol do produto.
10

Verificação das boas práticas de fabricação (BFP) e análise da qualidade microbiológica de saladas adicionada de maionese comercializadas na cidade de São José do Rio Preto - SP

Seixas, Fernanda Rosan Fortunato [UNESP] 18 February 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-18Bitstream added on 2014-06-13T20:10:50Z : No. of bitstreams: 1 seixas_frf_me_sjrp.pdf: 308372 bytes, checksum: 79dc807bb402317ba0cb325f7c61e4fa (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No Brasil, estima-se que, de cada cinco refeições, uma não é efetuada em casa, sendo a salada de maionese um dos alimentos comumente consumidos. Este produto alimentício é basicamente constituído por vegetais cozidos posteriormente adicionados de maionese. Portanto, além da microbiota presente nos vegetais, a falta de higiene dos manipuladores durante o seu preparo, bem como as condições de armazenamento do produto, faz com que os microrganismos possam vir a ocasionar deteriorações no alimento ou intoxicações alimentares nos consumidores. Neste trabalho as Boas Práticas de Fabricação (BPF) foram verificadas em 10 estabelecimentos produtores de saladas de maionese aplicando um check - list que se constituiu de 123 itens de verificação baseado na legislação vigente no país (Resolução da Diretoria Colegiada - RDC nº. 216 de 2004) e análise da qualidade microbiológica perante 57 amostras destas saladas comercializadas na cidade de São José do Rio Preto - SP. As análises microbiológicas foram realizadas em 2 etapas: a primeira em 30 amostras no período de junho, agosto e outubro de 2006, e a segunda etapa no período de fevereiro, abril e junho de 2007, após a aplicação do check - list e orientações para o correto manuseio desse alimento. Foram realizadas as seguintes análises: contagem de bolores e leveduras, Staphylococcus aureus, Número Mais Provável (NMP) de coliformes totais, termotolerantes, pesquisa de Escherichia coli e de Salmonella spp., bem como procedeu-se a identificação das leveduras isoladas e o teste de resistência frente a diferentes concentrações do conservante sorbato de potássio. De acordo com o check - list aplicado para verificação das BPF, 70,0% dos estabelecimentos apresentaram não conformidades superiores a 25,0%, sendo classificados como insatisfatórios para produção de alimentos... / The aim of this work was to verify the Good Manufacturing Practices (GMP) and the microbiologic quality of the salads added of mayonnaise marketed in São José do Rio Preto - SP, through the following analyses: check - list application, based on the legislation in force in the country, which classified the levels of suitability presented by the producers, counting of mould and yeast, Staphylococcus aureus, determining the Most Probable Number of total and heat resistant coliforms, Escherichia coli and Salmonella spp research, and proceeded to identification isolated yeast and resistance test to different concentrations of potassium sorbate conserver. According to the check - list applied to GMP verification, 70,0% of the establishments showed no conformities above 25,0%, being classified as unsatisfactory for food production. The obtained result for mould and yeast counting varied from 1,9 x 103 to 6,0 x 106.. The biggest number of mayonnaise salad contamination was caused by Staphylococcus aureus with variations of < 100 a 1,8 x 107 UFC/g. For The Most Probable Number determination of total and heat resistant coliforms a variation of < 3 a > 1100 NMP/g was verified. Escherichia coli was found in all samples positive for heat resistantt coliforms. Salmonella spp. was not found. From the ten establishments 4 (40%) improved the salads quality with mayonnaise added and 1 (10%) stopped this food production after inspection and the technicians of Sanitary Survellance guidance. In relation to the isolated yeasts, Debaryomyces hansenii var. fabryii species was the most frequent, in 19 cultures (76,0%) followed by Cryptococcus laurentii with 4 (16%), Arxula adeninovorans with 1 (4,0%). The species Arxula adeninovorans and Candida edax were not sensitive to potassium sorbate conserver. In relation to...(Complete abstract click electronic access below)

Page generated in 0.0461 seconds