A mussarela de leite de búfala, principal queijo obtido a partir desse leite no Brasil, é um produto praticamente novo no mercado, com alta aceitação pelos consumidores e excelentes perspectivas. Seguindo tecnologia de produção tradicional italiana, caracteriza-se pela intensa manipulação durante a sua elaboração. No presente trabalho, avaliou-se a qualidade microbiológica de duas marcas comerciais de queijo mussarela de leite de búfala, sendo uma das marcas comercializada em embalagem com soro (A) e a outra em embalagem sem soro e a vácuo (B), adquiridas no comércio varejista da cidade de Piracicaba/SP. As análises microbiológicas compreenderam a determinação do NMP de coliformes totais e fecais, a pesquisa de Listeria spp., a contagem de Staphylococcus coagulase-positiva e a pesquisa de Salmonella spp. Com base nos resultados obtidos, pode-se afirmar que as duas marcas analisadas encontram-se em acordo com os padrões microbiológicos legais vigentes. No entanto, pôde-se notar que a qualidade microbiológica dos queijos comercializados em embalagem com soro mostrou-se inferior à dos oferecidos ao consumo em embalagem sem soro e a vácuo. / Buffalo mozzarella cheese, main cheese obtained from buffalo milk in Brazil, is practically a recent product in the market, showing high acceptance by consumers and excellent perspectives. Following traditional italian production tecnology, this cheese is intensely manipulated during its manufacture. In this study, the microbiology quality of two commercial brands of buffalo mozzarella cheese was evaluated, being one of the brands presented in bag with whey (A) while the other one is presented in bag without whey and under vacuum (B). The samples were acquired in the Piracicaba city commerce. Microbiology analysis comprehended the determination of the MPN of total and fecal coliforms, the Listeria spp. presence / absence, the coagulase-positive Staphylococcus accounting and the Salmonella spp. presence / absence. Based on the analysis results, both brands are according to current legal microbiology standards specifications. However, the microbiology quality of the cheeses packed in bag with whey was lower than the microbiology quality of those offered in bag without whey and under vacuum.

Mozzarella cheese is currently the highest consumed cheese in the United States. The popularity of mozzarella cheese is typically attributed to the high consumption rates of pizza cheese and string cheese; both of which are low moisture part skim (LMPS) mozzarella cheese. A single serving of LMPS mozzarella cheese contains approximately 8% of the daily value (DV) for sodium, a mineral which is currently consumed in excess among most Americans. On average, one in three Americans has hypertension. This condition is strongly associated with excessive sodium intake, and it is a leading risk factor for cardiovascular disease and stroke in the United States. Considering the popularity of LMPS mozzarella cheese, its sodium content, and the alarmingly high rates of hypertension among the American population, mozzarella cheese appears to be a product worth pursuing for sodium reduction. Salt (NaCl) provides several key benefits to cheese including: flavor enhancement, preservation, moisture control, and syneresis; thus reducing its concentration in cheese can result in multiple quality concerns. Previous research has investigated the effects of lower sodium in a variety of cheeses including: cheddar, feta, and imitation cheese. Typical methods for reducing sodium content in cheese include reduction of NaCl alone to a level which is still acceptable or partial substitution of NaCl with salt replacers including KCl. For assessing the consumer acceptability of low sodium cheeses, researchers have typically employed the use of traditional hedonic, preference, and ranking questions; however, consumer scientists have recently suggested the benefits of asking consumers questions which go beyond typical acceptability questions. Purchase intent and decision making have been associated with consumer emotions, and perhaps by better understanding consumer emotions toward nutritional alternative foods, including low sodium mozzarella cheese, a more successful low sodium cheese can be developed. The current study implemented a series of tests to progressively understand the role NaCl plays in mozzarella cheese and consumer opinion of low sodium cheese. A series of traditional sensory tests, including triangle, duo-trio, and hedonic tests, were performed to determine a sensory transparent antimicrobial and a consumer acceptable salt replacer. Based upon this sequence of tests, a single antimicrobial (SEA-i F75) and concentration (0.275%) were selected in addition to the most consistently preferred salt replacer in a low sodium mozzarella cheese system; however, the most preferred salt replacer was dependent upon the type of mozzarella cheese (direct acid or bacteria cultured). In order to address the potentially limited information from traditional sensory testing, a novel method for evaluating emotions was developed. The IMET (Image Measurement of Emotion and Texture) method utilized consumer provided images of emotions, researcher generated emotion images, and emotion words (the current industry standard) to aid in emotion testing, and the use of texture images and texture words (industry standard) for texture assessment. The IMET method was tested and validated across three commercial food product categories: orange soda, dairy beverages, and convenience cheeses. The IMET study indicated consumer selected emotion images were less variable than emotion words in a positive emotion, but the words only method was less variable in a negative emotion. Additionally, subjects were more likely to use images of themselves for positive emotions, and images of others for the negative emotions. After validation of the IMET method, the consumer emotion images method was used in conjunction with consumer acceptability testing and instrumental texture analysis in non-commercial low sodium mozzarella cheese. This study indicated the full sodium cheese was consistently liked most, followed by the 100% KCl cheese sample. Additionally, cheese with higher hedonic scores had increased changes in the positive emotions, while the disliked products had increased changes in the negative emotions across the eating experience. The instrumental texture analysis resulted in significant textural differences between the eight samples tested, and samples with higher mean scores for all texture attributes were associated with having higher mean hedonic scores. The studies performed in this thesis are important contributions for better understanding the role of NaCl in LMPS mozzarella cheese, and the consumer’s perception and potential acceptance of this nutritional alternative product. Additionally, the development of a novel emotion testing method may impact how researchers ask consumer questions, conduct consumer research, and investigate the effects of images on emotion testing with consumers.

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No. of bitstreams: 2 Dissertação - Flávia Carneiro Gonçalves - 2015.pdf: 3718226 bytes, checksum: 3024f921d7aec7030599eee358d0593f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study objectives to evaluate the effect of an inappropriate night cooling condition, it is practiced by some shops with processed mozzarella cheese and conventional mozzarella chemical profiles, using nuclear magnetic resonance technique (NMR). The simulation of inappropriate cooling was performed using a Styrofoam box with ice, not covered, and leaving the system to reach thermal equilibrium with the ambient temperature during the night. To make studies with processed mozzarella cheese was acquired two packages of the same batch, at local shops. Subjecting the spectral data, coming from the analysis made with HR-MAS, in the chemometric treatment was observed a tendency of discrimination in the samples exposed to different cooling conditions, and signals concerning lactose and some of fatty acids had greater influence in the observed separation. For the mozzarella cheese, in addition to NMR studies, it was also performed physical and chemical characteristics studies. For these studies, it has been acquired twenty-two trays containing sliced cheese, in the local market, which were divided into two sets with eleven trays each. Samples were analyzed in nature, using HR-MAS probe, and the crude extract using TBI probe. The identification of metabolites was done from the HSQC experiments, J-resolved and NMR ¹H, the last one being also used in the relative quantification of twelve metabolites. For the mozzarella cheese maintained under improper cooling conditions, there was a reduction in the galactose content and an increasing of amino acids and organic acids contents. The physicochemical analysis of pH, saturated fat and protein showed no significant differences that could be correlated with the different conditions of sample cooling. Finally, it has been concluded that NMR technique and chemometric tools are promising in identify the cheese samples submitted to different cooling conditions that has been studied, which could not be done using the physical and chemical parameters commonly used in cheese quality analysis. / Neste estudo vislumbrou-se avaliar a o efeito da condição de refrigeração noturna inadequada, praticada por alguns estabelecimentos comerciais, no perfil químico dos queijos tipo processados sabor mozarela e tipo mozarela convencional, fazendo uso da técnica de Ressonância Magnética Nuclear (RMN). A simulação da refrigeração inadequada foi realizada utilizando-se uma caixa de isopor contendo gelo, sem tampa, deixando o sistema atingir o equilíbrio térmico com o ambiente no decorrer da noite. Para os estudos com o queijo tipo mozarela processado adquiriu-se dois pacotes, pertencentes a um mesmo lote, no comércio local. Submetendo-se os dados espectrais, advindos das análises fazendo uso da sonda HR-MAS, ao tratamento quimiométrico, observa-se uma tendência de discriminação das amostras submetidas a diferentes condições de refrigeração, sendo que os sinais referentes a lactose e de alguns ácidos graxos tiveram maior influencia na separação observada. Já para o queijo tipo mozarela convencional, além dos estudos de RMN, realizou-se também estudos de características físico-químicas. Para isso, foram adquiridas no comércio local vinte e duas bandejas contendo queijo fatiado, as quais foram divididas em dois conjuntos com onze bandejas cada. Foram realizadas análises da amostra in natura, fazendo uso da sonda HR-MAS, e do extrato bruto, fazendo uso da sonda TBI. A identificação de metabólitos foi feita a partir dos experimentos HSQC, J-resolved e RMN de ¹H, sendo este último utilizado também na quantificação relativa de doze metabólitos. Para o queijo tipo mozarela mantido sob condições inadequadas de refrigeração observou-se uma redução no teor de galactose e aumento no teor de aminoácidos e ácidos orgânicos. As análises físicoquímicas de pH, gordura total e proteína total não mostraram diferenças significativas que pudessem ser correlacionadas com as diferentes condições de refrigeração das amostras. Nesse sentido, conclui-se que a técnica de RMN e ferramentas quimiométricas mostraram-se promissoras na identificação das amostras de queijo submetidas às diferentes condições de refrigeração estudadas, o que não pôde ser feito utilizando-se os parâmetros físico-químicos rotineiramente empregados em análises da qualidade de queijos.

A mussarela de leite de búfala, principal queijo obtido a partir desse leite no Brasil, é um produto praticamente novo no mercado, com alta aceitação pelos consumidores e excelentes perspectivas. Seguindo tecnologia de produção tradicional italiana, caracteriza-se pela intensa manipulação durante a sua elaboração. No presente trabalho, avaliou-se a qualidade microbiológica de duas marcas comerciais de queijo mussarela de leite de búfala, sendo uma das marcas comercializada em embalagem com soro (A) e a outra em embalagem sem soro e a vácuo (B), adquiridas no comércio varejista da cidade de Piracicaba/SP. As análises microbiológicas compreenderam a determinação do NMP de coliformes totais e fecais, a pesquisa de Listeria spp., a contagem de Staphylococcus coagulase-positiva e a pesquisa de Salmonella spp. Com base nos resultados obtidos, pode-se afirmar que as duas marcas analisadas encontram-se em acordo com os padrões microbiológicos legais vigentes. No entanto, pôde-se notar que a qualidade microbiológica dos queijos comercializados em embalagem com soro mostrou-se inferior à dos oferecidos ao consumo em embalagem sem soro e a vácuo. / Buffalo mozzarella cheese, main cheese obtained from buffalo milk in Brazil, is practically a recent product in the market, showing high acceptance by consumers and excellent perspectives. Following traditional italian production tecnology, this cheese is intensely manipulated during its manufacture. In this study, the microbiology quality of two commercial brands of buffalo mozzarella cheese was evaluated, being one of the brands presented in bag with whey (A) while the other one is presented in bag without whey and under vacuum (B). The samples were acquired in the Piracicaba city commerce. Microbiology analysis comprehended the determination of the MPN of total and fecal coliforms, the Listeria spp. presence / absence, the coagulase-positive Staphylococcus accounting and the Salmonella spp. presence / absence. Based on the analysis results, both brands are according to current legal microbiology standards specifications. However, the microbiology quality of the cheeses packed in bag with whey was lower than the microbiology quality of those offered in bag without whey and under vacuum.

The thesis deals with molecular gastronomy as an expanding culinary direction and is focused on the use in chemistry teaching in primary and secondary education. There are described home experiments which were verified, documented and explained.

The chemical composition of milk (specifically casein, fat, and calcium) is known to affect the quality and functional properties of Mozzarella cheese. Therefore, concentrations of total nitrogen, casein nitrogen, non-casein nitrogen, non-protein nitrogen, true nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, fat, total calcium, total solids, somatic cells, and pH were measured in silo milk samples collected weekly over 18-months from a large dairy plant in Central Valley, California from July 2008 to December 2009 to verify changes and correlate to low moisture part skim Mozzarella (LMPS) characteristics. LMPS mozzarella cheese from the same plant was also collected biweekly during the same period and analyzed five days post manufacture for total nitrogen, water soluble nitrogen, total calcium, water soluble calcium, salt, pH, fat in dry matter and total solids and texture properties (i.e., hardness (g), cohesiveness, springiness, chewiness (g), aggregation index (AGI), and percentage cheese loss during shredding). Significant seasonal variations of total nitrogen, non-protein nitrogen, casein nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, and total calcium in milk were explained using a linear model equivalent to a basic single cosinor model with sine and cosine of week (converted into radians) as predictors. Correlation studies were done between milk composition and cheese composition, milk composition and cheese textural characteristics as well as cheese composition and cheese texture, showing that concentration of total calcium and nitrogen fractions in cheese milk significantly affected the texture and composition of LMPS mozzarella. Also, the cheese total nitrogen, total calcium and water soluble calcium affected the cheese texture. The LMPS Mozzarella that was firmer and more cohesive had less loss during shredding and aggregated to a lesser extent. The milk total nitrogen, non-protein nitrogen, casein nitrogen, casein to total protein ratio, casein to true protein ratio, and total calcium had positive correlation with each other. However, the milk non-casein nitrogen did not significantly correlate with other nitrogen fractions and total calcium of milk. In addition, there was a significant increase of water soluble nitrogen, percent loss in shredding and aggregation index, and a significant decrease of hardness, and chewiness of LMPS Mozzarella ripened at 8.90 C in comparison to the cheese ripened at 3.30 C for 21 days.