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Le but de ce projet était de déterminer la possibilité de produire du fromage mozzarella de type pasta-filata, à faible teneur en humidité, ayant une teneur réduite en sodium sans diminuer la qualité et les propriétés sensorielles du fromage. Dans un premier temps, les effets de 12 conditions salines sur la composition, les activités microbiologiques et enzymatiques, ainsi que sur différentes propriétés fonctionnelles du fromage mozzarella ont été évalués. La nature des sels a eu peu d’influence sur la composition, les activités microbiologiques et enzymatiques et sur les propriétés fonctionnelles du fromage mozzarella entreposé pendant 14 jours. Ensuite, l’impact de ces douze conditions salines sur l’évolution des activités biologiques et enzymatiques a été évalué sur deux souches de bactéries lactiques thermophiles dans des caillés modèles. La réduction du NaCl et sa substitution par du KCl et du MgCl2 a eu peu d’impact sur l’évolution des activités microbiologiques et enzymatiques des bactéries lactiques thermophiles utilisées. À la lumière de ces résultats, quatre conditions salines ont été sélectionnées pour être utilisées en vue d’une optimisation du procédé de fabrication. L’impact de ces quatre conditions salines sur les caractéristiques physico-chimiques, les activités microbiologiques et enzymatique, les propriétés fonctionnelles du fromage mozzarella et sur les propriétés sensorielles du fromage mozzarella frais et utilisé dans un aliment complexe (pizza) a été évalué. Il a été possible de produire du fromage mozzarella réduit en sodium ayant une composition et des caractéristiques fonctionnelles comparables à un fromage mozzarella régulier. Toutefois, la substitution du NaCl par du KCl peut entraîner l’apparition de défauts de goût dans le fromage frais. Ces fromages réduits en sodium pourraient être utilisés comme ingrédients dans des préparations alimentaires sans diminuer la qualité du produit final. / The goal of this project was to quantify the impact of sodium reduction and substitution by KCl and MgCl2 on the production of mozzarella cheese. The reduction of NaCl and its replacement by KCl or MgCl2 did not have an impact on the evolution of the growth and the enzymatic activities of thermophiles lactic bacteria in cheese slurry and mozzarella cheese. Mozzarella cheeses were salted in 12 brines solutions. The concentration of salts in the brine solutions had more impact on the cheese than the type of salts used in the brine. Low sodium mozzarella cheese may be produced without decreasing the quality and functional properties of the cheese, but the substitution of NaCl by KCl may induce a flavour defect in fresh mozzarella cheese, but this cheese could be used as food ingredient without modifying the quality of the final product.

The effects of starch-based anti-caking agents on the browning of Mozzarella cheese were evaluated in this experiment. Six commercially available anti-caking agent treatments were examined and color measurements indicated that the starch-based anti-caking agents produced a baked cheese with a greater degree of browning than the samples treated with cellulose based anti-caking agents or no treatment (control). The cellulose-based treatments and the control also had a significantly greater moisture loss than the potato starch-based treatments. A negative correlation between percent moisture loss and the amount of browning was found (R2=0.51). The average surface temperature was at least 16 °C higher for the treatments containing potato starch than for the cellulose-based treatments. A significant relationship between average surface temperature and browning was also found (R2=0.67). These relationships suggest that the starch-based treatments impeded moisture loss, which decreased the amount of evaporative cooling. An increase in surface temperature resulted from the decrease in the amount of evaporative cooling and thus the Maillard reaction was accelerated leading to increased browning. The effects of the starch source were examined using starches from corn, rice and wheat. These starches were compared to commercially available potato starch and cellulose anti-caking agents. All starch sources were found to produce a greater degree of browning on the cheese sample compared to the cellulose treatment and control. Four adjuncts treatments, including dimethypolysiloxane, lactic acid, partially hydrogenated sunflower oil, and a combination of the dimethylpolysiloxane and sunflower oil were added to cheese treated with potato starch to determine if a reduction in the degree of browning could be achieved. No differences in browning between the potato starch treatment and those with added adjuncts were found. / Master of Science

Mozzarella cheese production has been gaining market share due in part to increasing market for pizza and ready to eat food items. Anti-caking agents are utilized in the production of shredded cheese for reducing clumping and increasing the appearance of separate cheese shreds. Six anti-caking agents were applied to low moisture part skim Mozzarella cheese and examined for effects on three major functional properties of Mozzarella cheese; meltability, stretchability, and free oil formation. Meltability determination utilizing a fabricated UW Meltmeter resulted in no significant differences between untreated samples (control) and samples treated with anti-caking agents containing cellulose, potato starch or mixtures including dextrose. Stretchability measurements taken using a modified helical viscometry procedure also resulted in no significant differences between control and treated samples. Significant differences were found when comparing free oil percentages obtained from varying treatments of anti-caking agents. A mixture of potato starch and cellulose resulted in the lowest level of free oil among all samples tested. Because potato starch treated samples performed equally to cellulose treated samples in both meltability and stretchability testing, anti-caking agents containing potato starch could be considered as an alternative to cellulose-based anti-caking agents. In addition, the use of potato starch alone and in conjunction with powdered cellulose has been shown to be more effective for free oil control. By treating with potato starch, functional properties of shredded Mozzarella cheese have been positively altered in a way which may increase acceptability by consumers. / Master of Science

Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2016-2017 / Le fromage Mozzarella entre dans la composition de plusieurs mets populaires d’Amérique du Nord. L’aptitude de ce fromage à être râpé et ses propriétés caractéristiques de cuisson en font un ingrédient idéal. Ces qualités sont attribuées principalement aux propriétés physiques particulières de ce fromage sous certaines conditions de cisaillement et de température. Le but de ce projet était d’évaluer l’impact de différentes stratégies couramment mises en oeuvre dans l’industrie fromagère sur la composition, la microstructure et les propriétés physiques du fromage. Diverses stratégies ont été étudiées : les conditions de filage du caillé lors du procédé de « pasta filata », l’addition de protéines sériques dénaturées, le contrôle de la minéralisation et le vieillissement du fromage. Les résultats ont démontré que le contrôle de l’intensité mécanique et thermique fournie lors du filage permettait respectivement de réduire les pertes de solides et d’améliorer la répartition de la phase aqueuse dans la matrice fromagère. L’aptitude au râpage du fromage peut être optimisée en combinant l’utilisation de plusieurs stratégies dont la réduction du calcium colloïdal, un temps de vieillissement adéquat et un râpage à basse température. Par ailleurs, des changements aux facteurs mentionnés précédemment sont apportés lors de l’ajout de protéines sériques dénaturées, ces dernières ayant un impact sur la composition et la structure du fromage. Des modèles prédictifs de l’aptitude au râpage ont été développés en sélectionnant uniquement les descripteurs de composition et de texture pertinents. La perception sensorielle du fromage cuit sur pizza et les propriétés physiques du fromage fondu ont été considérablement influencées par l'évolution physico-chimique du fromage au cours du vieillissement. L’utilisation d’une nouvelle approche pour la caractérisation des propriétés rhéologiques du fromage fondu sous fortes contraintes a permis d’établir de bonnes relations avec les descripteurs sensoriels de texture. Ce travail a permis de valider l’hypothèse que l’utilisation d’une ou plusieurs stratégies simples et accessibles pouvait être mise de l’avant afin d’optimiser les propriétés physiques du fromage Mozzarella. Cela contribue à une meilleure compréhension des facteurs pouvant être contrôlés afin de développer des fromages avec des attributs spécifiques, lorsqu’utilisés comme ingrédient. / Mozzarella cheese is expected to perform various key attributes when used as a food ingredient. The shreddability and the melting properties of cheese during and after baking are mainly governed by the physical properties of cheese when subjected to external factors such as shear and temperature. Therefore, the goal of this project was to evaluate the impact of cheese-making strategies commonly used in the dairy processing industry on the cheese composition, microstructure, and physical properties. Various strategies were studied: pasta filata process conditions, addition of denatured whey protein (WP-D) to milk, control of curd mineralization, and cheese aging. Results showed that controlling the mechanical and thermal intensity during the pasta filata process can lead to reduced cheese solid losses and a better distribution of water within cheese microstructure, respectively. The ability of cheese to be shredded can be increased using a combination of multiple factors such as lowering colloidal calcium phosphate associated with casein, proper aging, and by reducing cheese temperature before shredding. However, an optimisation of the previous factors should be done if WP-D is added because of its impact on cheese composition and structure. Predictive models to assess cheese shreddability were built using only few relevant compositional and textural descriptors. Sensory perception of baked cheese texture and physical properties of melted cheese were dramatically influenced by the physico-chemical evolution of cheese during aging. Melted cheese texture was satisfactorily related to different sensory attributes using a novel approach to determine the rheological properties under the large stress experienced during mastication. This work validated the hypothesis that simple cheese-making strategies, alone or combined, can be used to optimize the cheese physical properties. This contributes to a better understanding of the factors that can be controlled to improve or develop cheese ingredient with specific attributes.

Mozzarella de búfala é um queijo de fácil fabricação e que tem grande aceitabilidade no mercado. Esses fatos, associados ao melhor rendimento de fabricação e maior valor agregado, quando comparado ao similar feito com leite de vaca, têm estimulado a fraudação. Embora a PCR já seja uma técnica reconhecida para garantir a autenticidade da mozzarella de búfala em outros países, é necessária sua validação para as condições do rebanho nacional. O presente trabalho teve como objetivo avaliar a PCR para a detecção de adulteração de queijo tipo mussarela de búfala no Brasil, em condições experimentais. Utilizou-se dois primer, já descritos na literatura, para detecção do gene citocromo b (cytb) de bovino e de bubalino. Esses primers foram testados em sangue das raças Nelore e Holandês (representantes, respectivamente, das espécies Bos indicus e Bos taurus), e em sangue da raça Mediterrânea (Bubalus bubalis). Também foram testados em leite e na mozzarella, tanto nos produtos puros como em misturas. Os primers reconheceram especificamente o DNA bovino e bubalino tanto no sangue quanto no leite e mozzarella. A técnica foi mais sensível para detectar a fraude na mozzarella que no leite. Na mozzarella foi possível detectar a presença de 0,01% de leite bovino adicionado ao de búfala, utilizando uma técnica de extração (Fenol/Clorofórmio) e 0,05% de adição, quando se fez outro método de extração (Kit Nucleospin Food). Os resultados mostraram que a técnica é muito sensível e pode ser empregada como método para assegurar a autenticidade do produto, especialmente se a fábrica produzir exclusivamente produtos de leite de búfala. No entanto, se o fabricante utilizar os mesmos equipamentos para a fabricação de produtos de búfala e de vaca, a técnica pode gerar resultados falsos positivos (quanto à fraude). / The buffalo mozzarella is a cheese of easy fabrication that has great acceptability in the market. These facts, associated to the best fabrication income and higher added value, when compared to the similar made with cow milk, has stimulated fraud. Although the PCR is an acknowledged technique that guarantees the authenticity of the buffalo mozzarella in other countries, its validation is necessary for the conditions of the national herd. The objective of the present study was to evaluate PCR for the detection of buffalo mozzarella adulteration in Brazil, in experimental conditions. Two primers were utilized, already described in literature, for the detection of bovine and bubaline citocrome b (cytb). These primers were tested in blood of Nellore and Holstein race (respectively representatives of Bos indicus and Bos taurus), and in blood of Mediterranean race (Bubalus bubalis). They were also tested in milk and mozzarella, in pure products and in mixtures. The primers specifically recognized the bovine and bubaline DNA, either in blood as in milk and mozzarella. The technique was more sensitive to detect fraud in mozzarella then in milk. In mozzarella, it was possible to detect the presence of 0,01% of cow milk added to the buffalo\'s, utilizing an extraction technique (Phenol/Chloroform) and 0,05% of addition when another extraction method was used (Kit Nucleospin Food). The results showed that the technique is very sensitive and can be applied as a method to assure the authenticity of the product, especially if the industry exclusively produces buffalo milk products. However, if the producer utilizes the same equipments for the fabrication of buffalo and cow products, the technique can generate false positive results (related to fraud).

Mozzarella de búfala é um queijo de fácil fabricação e que tem grande aceitabilidade no mercado. Esses fatos, associados ao melhor rendimento de fabricação e maior valor agregado, quando comparado ao similar feito com leite de vaca, têm estimulado a fraudação. Embora a PCR já seja uma técnica reconhecida para garantir a autenticidade da mozzarella de búfala em outros países, é necessária sua validação para as condições do rebanho nacional. O presente trabalho teve como objetivo avaliar a PCR para a detecção de adulteração de queijo tipo mussarela de búfala no Brasil, em condições experimentais. Utilizou-se dois primer, já descritos na literatura, para detecção do gene citocromo b (cytb) de bovino e de bubalino. Esses primers foram testados em sangue das raças Nelore e Holandês (representantes, respectivamente, das espécies Bos indicus e Bos taurus), e em sangue da raça Mediterrânea (Bubalus bubalis). Também foram testados em leite e na mozzarella, tanto nos produtos puros como em misturas. Os primers reconheceram especificamente o DNA bovino e bubalino tanto no sangue quanto no leite e mozzarella. A técnica foi mais sensível para detectar a fraude na mozzarella que no leite. Na mozzarella foi possível detectar a presença de 0,01% de leite bovino adicionado ao de búfala, utilizando uma técnica de extração (Fenol/Clorofórmio) e 0,05% de adição, quando se fez outro método de extração (Kit Nucleospin Food). Os resultados mostraram que a técnica é muito sensível e pode ser empregada como método para assegurar a autenticidade do produto, especialmente se a fábrica produzir exclusivamente produtos de leite de búfala. No entanto, se o fabricante utilizar os mesmos equipamentos para a fabricação de produtos de búfala e de vaca, a técnica pode gerar resultados falsos positivos (quanto à fraude). / The buffalo mozzarella is a cheese of easy fabrication that has great acceptability in the market. These facts, associated to the best fabrication income and higher added value, when compared to the similar made with cow milk, has stimulated fraud. Although the PCR is an acknowledged technique that guarantees the authenticity of the buffalo mozzarella in other countries, its validation is necessary for the conditions of the national herd. The objective of the present study was to evaluate PCR for the detection of buffalo mozzarella adulteration in Brazil, in experimental conditions. Two primers were utilized, already described in literature, for the detection of bovine and bubaline citocrome b (cytb). These primers were tested in blood of Nellore and Holstein race (respectively representatives of Bos indicus and Bos taurus), and in blood of Mediterranean race (Bubalus bubalis). They were also tested in milk and mozzarella, in pure products and in mixtures. The primers specifically recognized the bovine and bubaline DNA, either in blood as in milk and mozzarella. The technique was more sensitive to detect fraud in mozzarella then in milk. In mozzarella, it was possible to detect the presence of 0,01% of cow milk added to the buffalo\'s, utilizing an extraction technique (Phenol/Chloroform) and 0,05% of addition when another extraction method was used (Kit Nucleospin Food). The results showed that the technique is very sensitive and can be applied as a method to assure the authenticity of the product, especially if the industry exclusively produces buffalo milk products. However, if the producer utilizes the same equipments for the fabrication of buffalo and cow products, the technique can generate false positive results (related to fraud).

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Curso de Pós-Graduação em Ciência dos Alimentos / Made available in DSpace on 2012-10-18T07:00:21Z (GMT). No. of bitstreams: 0 / O objetivo deste trabalho foi verificar o efeito do congelamento e armazenamento do leite bubalino em congeladores domésticos (freezers) nas características fisico-químicas e sensoriais do queijo mussarela produzido em forma de bolas. Foram realizados três tratamentos: T1 utilizando leite fresco, que foi considerado o queijo referência (padrão); T2 com leite congelado e armazenado por 25 dias e T3 com leite congelado e armazenado por 50 dias. Tanto o congelamento quanto a armazenagem foram realizados à temperatura de -18oC (±1oC). O leite e os queijos resultantes dos tratamentos foram caracterizados físico-quimicamente. Do leite obteve-se os seguintes percentuais médios: proteína 3,7%; gordura 5,4 %; extrato seco total 16,1%; cinzas 3,5%; umidade 84,0%; acidez 13,8 OD; densidade 1,033 e pH 6,8. Dos queijos produzidos com leite fresco(padrão), congelado e armazenado a -18oC (±1oC) por 25 dias e 50 dias obteve-se respectivamente os seguintes percentuais médios: proteína 17,9, 19,1 e 23,5; gordura 22,9, 20,6 e 18,8; cinzas 0,8, 1,1 e 1,1; umidade 58,6 , 58,8 e 56,4; pH 5,5 , 6,0 e 6,0 e acidez 2,2 ,2,2 e 2,0. A análise sensorial através do teste de comparação pareada mostrou que os queijos elaborados a partir dos tratamentos T2 e T3 não apresentaram diferenças significativas entre si para os quesitos cor, sabor e textura, enquanto que para a aparência a diferença foi significativa. Porém, quando comparados com o T1 (padrão) todos os quesitos avaliados foram significativamente inferiores. A utilização de leite de búfala congelado não resultou num queijo mussarela de características idênticas ao produzido com leite fresco. No entanto, a aceitabilidade geral dos queijos resultantes dos tratamentos T2 e T3 através da análise sensorial foi considerada satisfatória.

Orientador: Germano Francisco Biondi / Resumo: O presente trabalho visou avaliar a qualidade microbiológica de queijos mussarela elaborados a partir de leite de búfala, adquiridos do comércio varejista, assim como, verificar a sua autenticidade, averiguando a possível presença de leite de vaca no produto. As análises microbiológicas compreenderam em contagem de coliformes totais e E. coli, contagem de Staphylococcus coagulase-positiva e pesquisa de Salmonella spp.; enquanto que, para a determinação da pureza das mussarelas, a técnica utilizada foi a eletroforese em gel de poliacrilamida. Com base nos resultados obtidos na avaliação microbiológica, pode-se afirmar que 98% das amostras estão dentro dos padrões microbiológicos legais vigentes, embora algumas delas tenham apresentado valores para coliformes totais entre 103-106 UFC/g, indicando provavelmente condições inadequadas de higiene durante a fabricação dos queijos. Entretanto, 2% das amostras encontram-se em desacordo com a legislação, uma vez que apresentaram populações de coliformes fecais acima do permitido, como resultado de uma alta contaminação por E. coli. Mediante a caracterização eletroforética, detectou-se a presença de leite de vaca em 22% das amostras, adicionado, provavelmente, de forma intencional. / Abstract: This study evaluated the microbiological of mozzarella cheese made from buffalo milk bought in retail outlets and validated their authenticity by checking the product for the possible presence of cow milk. Microbiological analysis included counts of E. coli, total coliform, positive coagulase Staphylococcus, and Salmonella spp. For the determination of mozzarella purity, we used polyacrylamide gel electrophoresis. Based on the results of the microbiological evaluation, we can state that 98% of samples are within the legal microbiological standards, although some have shown values of total coliforms between 103-106 UFC/g, which indicates poor conditions and hygiene during cheese manufacture. However 2% of samples showed fecal coliform populations outside the legal limits as a result of a high E. coli contamination. Electrophoresis detected cow milk in 22% of the samples which was probably added intentionally. / Mestre

Low-fat cheese faces great challenges associated with its texture being hard and rubbery, desirable flavors being missing, color being undesirably intense and translucent appearing, and melting being improper. In an effort of improving the quality of low-fat cheeses, several strategies have been tried to accomplish three major objectives, 1) improving the melting and baking properties of low-fat Mozzarella cheese, 2) improving the color of low-fat Cheddar cheese, and 3) investigating the feasibilities of enriching low-fat Cheddar cheese with dietary fibers. For objective 1, 4 batches of low-fat Mozzarella cheese with target fat of 6.0%, 4.5%, 3.0%, and 1.5% were made using a stirred curd method, comminuted in a bowl chopper and mixed with different levels of melted butter (0.0, 1.5, 3.0, and 4.5% (wt/wt), respectively) before pressing. This would made the cheese that had increased free oil, increased melting, and improved baking as the level of added butter increased. The added butterfat was present as free fat along the curd particle junctions as shown by laser scanning confocal microscopy while the fat droplets originating from the milk were distributed within the protein matrix of the cheese. In objective 2, consumer tests and flavor profile analysis were performed on 4 commercial brands of full-fat Cheddar cheese and 9 low-fat Cheddar cheeses manufactured at Utah State University with different colors. Low-fat cheeses were rated different (P < 0.05) for their liking by a consumer panel even though they were all made the same way except for addition of color. The only difference in flavor detected by a trained panel was for a slight variation in bitterness. Using a combination of annatto and titanium dioxide produced a cheese that was rated the highest. Annatto when added singly produced a low-fat cheese that was rated the lowest. Moreover, commercial cheeses were also ranked significantly different for liking and buying preference. For objective 3, several trials were conducted to enrich low-fat cheese with inulin, pectin, polydextrose, or resistant-starch either by incorporating them into cheesemilk, mixing with 15-d aged cheese followed by repressing, or by formulating a W/O/W emulsion with inulin and incorporating the emulsion into the milk prior to cheesemaking. Adding fibers directly to milk resulted in less or no retention of fibers in cheese, whereas fibers added to comminuted cheeses were too crumbly. Adding fiber as a W/O/W emulsion improved fiber retention in the cheese and produced an improved texture of low-fat cheese.