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

Composição e quantificação de ácidos graxos de leite UHT integral, desnatado, semidesnatado e em pó integral comercializados em supermecados da cidade de Campinas/SP / Profiles and quantification of full, skimmed, semiskimmed UHT milk and whole milk powder fatty acids commercializes in the city of Campinas/SP

Zancan, Natalia Andrade, 1984- 19 August 2018 (has links)
Orientador: Marcelo Alexandre Prado / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T14:21:19Z (GMT). No. of bitstreams: 1 Zancan_NataliaAndrade_M.pdf: 912567 bytes, checksum: 6a6667e8149251485644335a2fe44802 (MD5) Previous issue date: 2012 / Resumo: O presente trabalho teve como objetivo avaliar a composição em ácidos graxos, componentes principais das moléculas de lipídios de leites UHT desnatado, semidesnatado, integral e em pó integral de vaca, de algumas marcas comercializadas em supermercados de Campinas/SP. No estudo, foi dado ênfase na qualidade nutricional dos leites relacionado à presença e quantidade dos ácidos graxos considerados benéficos à saúde. Para tanto, observou-se as razões insaturados/saturados, ômega 3/ômega 6, quantidade de ácidos graxos de cadeia curta, média e com 18 carbonos utilizando parâmetros muito discutidos na literatura internacional. Para tal, foi utilizada a técnica de cromatografia a gás. No final do estudo, foram obtidos dados da existência ou não de diferença entre lotes de um mesmo fabricante e fabricantes diferentes, através do Teste de Tukey. No leite desnatado UHT, foram encontradas quantidades muito pequenas ou não foram detectados ácidos graxos benéficos à saúde encontrados normalmente no leite. No leite semidesnatado UHT fora detectados ácidos graxos essenciais (EPA e DHA) em pequena quantidade e não foi detectado ácido linolênico conjugado (CLA). No leite Integral UHT houve diferenças significativas nos ácidos graxos saturados e alguns insaturados. O CLA foi encontrado em todos os lotes de ambas as marcas, com exceção do lote 2 da marca 1. No leite em pó integral, não foi encontrado o CLA e foram encontradas baixas quantidades de EPA e DHA / Abstract: This study aimed to evaluate the fatty acid composition, major components of the lipid molecules of UHT skim , semi skimmed, full and powdered full cow¿s milk, some brands sold in supermarkets in Campinas / SP. In the study, emphasis was on the nutritional quality of milk related to the presence and quantity of fatty acids considered beneficial to health. For this, we observed the reasons unsaturated / saturated, omega 6/omega 3, amount of short chain fatty acids, medium, and 18 carbons using parameters discussed in the literature. To this end, we used the technique of gas chromatography. At the end of the study, data were obtained from the existence of differences between batches of the same manufacturer and different manufacturers, using the Tukey test. In UHT skim milk, were found too small and were not detected fatty acids health benefits normally found in milk. In the UHT semi-skimmed milk was found essential fatty acids (EPA and DHA) in small amounts and wasn¿t detected conjugated linoleic acid (CLA). In UHT full milk there were significant differences in saturated fatty acids and some unsaturated. CLA was found in all batches of both brands, with the exception of part 2 of a brand 1. In milk full powder, CLA wasn¿t found and found low amounts of EPA and DHA / Mestrado / Ciência de Alimentos / Mestre em Ciência de Alimentos
12

Mozzarella de búfala: avaliação da reação em cadeia pela polimerase (PCR) para detectar fraude devido à adição de leite de vaca ao de búfala / Buffalo mozzarella: assessment by polymerase chain reaction (PCR) to detect fraud due to the addition of cow milk to buffalo

Souza, Gisele Oliveira de 06 December 2010 (has links)
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).
13

A Comparative Study on the Physicochemical Parameters and Trace Elements in Raw Milk Samples Collected from Misurata- Libya

Elbagerma, Mohamed A., Edwards, Howell G.M., Alajtal, Adel I. January 2014 (has links)
No / This research work was carried out to compare the physicochemical parameters of milk samples from four different animal species namely cow, goat, camel and sheep. Milk samples were collected from different areas of Misurata, Libya and analyzed for the key physiochemical parameters, pH, titratable acidity, total solids, ash, fat, protein and lactose. Furthermore in this study the concentrations of Zinc (Zn), Cadmium (Cd), Chromium (Cr), Magnesium (Mg), Manganese (Mn), Potassium (K), Calcium (Ca) Copper (Cu), Iron (Fe) and Lead (Pb) in similar commercial milk specimens from the same area were determined using microwave plasma- atomic emission spectrometry In fresh cow’s milk, the mean concentrations of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K were 0.13± 0.19 (mg/l), 0.004± 0.001 (mg/l), 0.04± 0.01 (mg/l), 0.17± 0.11 (mg/l), 0.72± 0.02 (mg/l), 1.98± 0.04 (mg/l), 214.00± 0.20 (mg/l), 0.080± 0.05 (mg/l), 423.0± 3.5 (mg/l) and 427.0± 2.5 (mg/l), respectively. While the mean concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the goat’s milk were 0.761 ± 0.78 (mg/l), 0.085 ± 0.02 (mg/l), 1.253 ± 0.18 (mg/l), 0.400± 0.08 (mg/l), 1.23± 0.21 (mg/l), 3.110± 0.15 (mg/l), 140.0± 0.31 (mg/l), 0.097± 0.07 (mg/l), 473± 5.12 (mg/l) and 510± 6.05 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the camel’s milk were 0.025 ± 0.019 (mg/l), 0.091± 0.05 (mg/l), 0.069± 0.07 (mg/l), 0.080 ± 0.05 (mg/l), 1.680 ± 0.43 (mg/l), 5.380 ± 1.17 (mg/l), 120.0 ± 0.11 (mg/l), 0.094 ± 0.04 (mg/l), 520.0 ± 0.32 (mg/l) and 571.0± 0.81 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the sheep’s milk were 0.062± 0.03, 0.106± 0.11, 0.040± 0.01, 0.201± 0.10, 0.880± 0.31, 5.350± 0.50, 180± 1.20, 0.072± 0.01, 478± 3.10, and 593.96± 1.87, respectively.
14

Variation in milk protein composition and its importance for the quality of cheese milk /

Wedholm, Anna, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 5 uppsatser.
15

Milk progesterone as a tool to improve fertility in dairy cows /

Petersson, Karl-Johan, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.
16

Klinički i ultrazvučni pregled vimena krava nakon primenelaktoferina u periodu involucije

Galfi Annamaria 27 July 2016 (has links)
<p>Kontrola zdravlja vimena krava je bitan element u procesu proizvodnje zdravstveno<br />bezbednog mleka, te se na farmama visokomlečnih krava, kroz program kontrole mastitisa,<br />redovno sprovode mere otkrivanja i prevencije bolesti vimena. Klinički pregled vimena<br />predstavlja osnovni metod koji pruţa korisne informacije o zdravstvenom statusu vimena<br />krava, ali nailazi na pote&scaron;koće u otkrivanju patolo&scaron;kih promena unutar parenhima i papile<br />vimena. U cilju otkrivanja promena u parenhimu vimena moţe se primeniti ultrazvučni<br />pregled koji omogućava vizualizaciju strukturnih promena vimena nastalih kao posledica<br />upalnih procesa i tako olak&scaron;ava dijagnostiku oboljenja.<br />Tokom poslednjih godina, javio se problem povećanja rezistencije bakterija na<br />antimikrobne lekove, &scaron;to oteţava lečenje bolesti, ali i ugroţava zdravlje ţivotinja i ljudi.<br />Najče&scaron;ći uzroci toga su nepravilna upotreba i eventualna zloupotreba antimikrobnih lekova.<br />Mnoga istraţivanja vr&scaron;ena su u in vitro i in vivo uslovima na primeni laktoferina samog ili u<br />kombinaciji sa antibioticima u terapiji i prevenciji mastitisa krava. Laktoferin, gvoţĎe<br />vezujući antimikrobni glikoprotein koji se nalazi u mleku i drugim sekretima, predstavlja<br />bitan deo sistema odbrane mlečne ţlezde.<br />Cilj istraţivanja u okviru ove disertacije je procena dijagnostičke mogućnosti<br />ultrazvučnog pregleda u detekciji subkliničkog mastitisa i poremećene sekrecije vimena,<br />kao i razmatranje opravdanosti primene laktoferina u prevenciji i lečenju mastitisa.<br />Kliničkim pregledom izvr&scaron;ena je procena op&scaron;teg zdravstvenog stanja krava, kao i<br />ispitivanje mlečne ţlezde adspekcijom i palpacijom. Za otkrivanje poremećene sekrecije<br />vimena i subkliničkih mastitisa kori&scaron;ćeni su brzi testovi, Kalifornija mastitis test i<br />Draminski test, kao i ultrazvučni pregled mlečne ţlezde krava. OdreĎivanje broja somatskih<br />ćelija u uzorcima mleka uraĎeno je metodom protočne citometrije. Za identifikaciju<br />uzročnika mastitisa kori&scaron;ćene su klasične mikrobiolo&scaron;ke metode. Krave sa pozitivnim<br />bakteriolo&scaron;kim nalazom podeljene su u dve ogledne grupe. Krave ogledne grupe I su<br />tretirane intramamarnom aplikacijom antibiotika, dok je kravama ogledne grupe II<br />aplikovana kombinacija antibiotika i laktoferina. OdreĎivanje koncentracije imunoglobulina<br />G u mlečnom serumu krava vr&scaron;eno je metodom radioimunodifuzije, a odreĎivanje<br />koncentracije laktoferina u mleku krava ELISA testom.<br />U istraţivanjima u okviru ove disertacije, najče&scaron;će izolovani major mastitis patogeni<br />bile su bakterije Staphylococcus aureus i Streptococcus agalactiae, a najče&scaron;će izolovani<br />minor mastitis patogeni Corynebacterium spp. i koagulaza negativne stafilokoke.<br />Ultrasonografija mlečne ţlezde krava pokazala se kao efikasna metoda u dijagnostici<br />poremećaja sekrecije vimena. Veće vrednosti koncentracije imunoglobulina G u mlečnom<br />serumu krava uočene su tokom perioda predzasu&scaron;enja i zasu&scaron;enja, u odnosu na period rane<br />laktacije. Najveći uticaj na porast koncentracije laktoferina u mleku krava su imali<br />bakterijski uzročnici mastitisa. Efikasnost antibiotske terapije primenjene tokom perioda<br />zasu&scaron;enja kod krava ogledne grupe I iznosila je 52,7%, dok je efikasnost primenjene terapije<br />sa goveĎim laktoferinom i antibiotikom kod krava ogledne grupe II iznosila 60%. Aplikacija<br />laktoferina tokom perioda zasu&scaron;enja doprinela je efikasnosti terapije intramamarnih<br />infekcija, ali nije imala uticaj na koncentraciju laktoferina u mleku tokom perioda rane<br />laktacije.<br />Dalja istraţivanja su neophodna kako bi se u potpunosti potvrdila efikasnost<br />intramamarne terapije sa goveĎim laktoferinom i antibiotikom u cilju eliminacije uzročnika<br />mastitisa i da se precizno odredi terapijska koncentracija laktoferina.</p> / <p>Control of udder health is an essential element in the process of safe milk<br />production, thus, through the mastitis control program, dairy farms regularly conduct<br />measures of detection and prevention of udder diseases. Clinical examination of the udder<br />is a basic method that provides useful information about the health status of cow udders,<br />but this method is limited in its ability to detect pathological changes in the udder<br />parenchyma and teat. In order to detect changes in the parenchyma of the udder, an<br />ultrasound can be applied which allows visualization of udder structural changes incurred<br />as a result of inflammatory processes, thus facilitating diagnosis of diseases.<br />Over the last few years, the problem of increasing resistance to antimicrobial drugs<br />has appeared, making it difficult to treat disease and also threaten the health of animals and<br />humans. The incorrect and widespread use of antimicrobial drugs are the most common<br />cause of this. Many studies were conducted in vitro and in vivo conditions on the use of<br />lactoferrin alone or in combination with antibiotics in the treatment and prevention of<br />mastitis. Lactoferrin, an iron-binding antimicrobial glycoprotein which is found in milk<br />and other secretions, represents an important part of the mammary gland defense system.<br />The aim of the research within this thesis was to evaluate the diagnostic<br />possibilities of udder ultrasonography in the detection of subclinical mastitis and udder<br />secretion disorders, as well as considering the feasibility of lactoferrin application in the<br />prevention and treatment of mastitis.<br />The general condition of the animals was evaluated by clinical examination, as<br />well as udder examination by adspection and palpation. The California mastitis test,<br />Draminski test and ultrasound examination of the cow&#39;s mammary glands were used for<br />detection of udder secretion disorders and subclinical mastitis. Somatic cell count in milk<br />samples was determined by flow cytometry method. Classical microbiological methods<br />were used for the isolation and identification of mastitis causative agents. Cows with<br />positive bacteriological findings were divided into two experimental groups. Cows in<br />experimental group I were treated with intramammary applications of antibiotics, while the<br />cows in experimental group II were treated with a combination of antibiotics and<br />lactoferrin. Immunoglobulin G concentration in bovine milk serum was determined by the<br />immunodiffusion method, while lactoferrin concentration in bovine milk was determined<br />using the ELISA test.<br />In this study, the most common isolated major mastitis pathogens were<br />Staphylococcus aureus and Streptococcus agalactiae, while Corynebacterium spp. and<br />coagulase-negatice staphilococci were the most commonly detected minor mastitis<br />pathogens. Ultrasonography of the bovine mammary gland proved to be an effective<br />method in the diagnosis of udder secretion disorders. Higher immunoglobulin G<br />concentrations were observed in milk serum from cows during pre-dry and dry period,<br />relative to early lactation period. The biggest influence on the increase in the concentration<br />of lactoferrin in the bovine milk had mastitis pathogens. The efficacy of antibiotic therapy<br />during the dry period in cows of experimental group I was 52.7%, while the efficacy of the<br />applied therapy with lactoferrina and antibiotics in cows of experimental group II was<br />60%. Application of lactoferrin during the dry period contributed to the effectiveness of<br />the treatment of intramammary infections, but had no influence on lactoferrin<br />concentration in the milk during the early lactation period.<br />Further studies are necessary to in order to fully confirm the efficacy of<br />intramammary therapy with bovine lactoferrin and antibiotic to eliminate the mastitis<br />pathogens and to determine the therapeutic concentration of lactoferrin.</p>
17

Multiplex flow cytometric assays for markers of inflammation : development and application in bovine samples /

Dernfalk, Johanna, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.
18

Milk fat globule stability : lipolysis with special reference to automatic milking systems /

Wiking, Lars, January 2005 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
19

Contribution à l'étude de la structure-texture du lait de chamelle lors de la coagulation et du traitement thermique : comparaison avec le lait de vache / Contribution to the study of the texture-structure of camel milk during coagulation and heat treatment : comparison with cow milk

Kamal, Mohammad 21 December 2016 (has links)
Le lait de chamelle constitue l'une des principales ressources alimentaires pour les peuples nomades. Malgré sa richesse en différents composants et sa production non négligeable au niveau mondial, ce produit demeure relativement peu transformé à cause du manque d’études menées sur les caractéristiques et les aptitudes technologiques de ce lait.Dans la première partie de cette thèse, l’évolution de la structure au cours de la coagulation enzymatique et acide des laits de chamelle et de vache crus et chauffés (50 et 70 °C) enrichis en minéraux (calcium et phosphate) a été étudiée. Les cinétiques de coagulation enzymatique et acide des échantillons du lait ont été suivies aux moyens du test de cisaillement dynamique et de la spectroscopie de fluorescence frontale. Les résultats obtenus ont permis, d’une part, de montrer des différences significatives entre les propriétés du coagulum obtenu à partir du lait de chamelle et celui du lait de vache, et d’autre part, d’évaluer l'impact de l’ajout des minéraux (calcium et phosphate) sur les propriétés du coagulum. L’analyse des spectres de fluorescence par analyse en composantes principales (ACP) a permis de caractériser sur le plan moléculaire la structure des gels, et également de discriminer les différentes conditions de coagulation. Les résultats rhéologiques ont montré que l’enrichissement de ces deux types de lait avec le calcium améliorait la fermeté du gel et diminuait le temps de gélification, alors que des effets inverses ont été observés suite à l’ajout du phosphate. L’analyse conjointe des données spectrales et rhéologiques au moyen de l’analyse en composantes communes et poids spécifiques (ACCPS) a montré une forte relation entre la structure au niveau moléculaire et la texture au niveau macroscopique. La deuxième partie de cette thèse a porté sur l’impact du traitement thermique (55 à 75 °C à différents intervalles de temps) sur les changements moléculaires du lait de chamelle. L’application de l’ACCPS aux spectres de la vitamine A, des produits fluorescents de la réaction du Maillard (PFRM) et du NADH a montré une bonne discrimination des échantillons en fonction du couple température-temps. Les résultats obtenus montrent que, de par sa rapidité, la spectroscopie de fluorescence frontale couplée aux méthodes chimiométriques présente un potentiel intéressant pour la caractérisation du lait de chamelle dans différentes conditions. En outre, le spectre de fluorescence d’un lait pourrait être considéré comme une empreinte digitale de celui-ci permettant de l’identifier. / Camel milk is one of the main food resources for nomadic people. Despite its richness in different components and its production in the world, this product remains poorly processed because of the lack of studies conducted on the characteristics and the technological abilities of this milk. In the first part of this thesis, the evolution of the structure during the enzymatic and acid coagulation of raw and heated (50 and 70 °C) camel and cow’s milk following the addition of minerals (calcium and phosphate) was studied. The kinetics of acid and enzymatic-induced coagulation of milk were followed using shear dynamic testing rheology at the macroscopic level and front-face fluorescence spectroscopy at the molecular scale. The obtained results showed significant differences between the properties of the coagulum that depends on the milk species and the level of added minerals (calcium and phosphate). The analysis of spectral data by principal component analysis allowed to characterize the coagulum structure at the molecular level as well as the discrimination of different coagulation conditions. The rheological results showed that the enrichment of both types of milk with calcium improved the gels firmness and reduced the gelation time, while opposite trend was observed following the addition of phosphate. The joint analysis of fluorescence spectral data and rheological measurements by applying common components and specific weights analysis showed a strong relationship between the structure at the molecular scale and the texture at the macroscopic level. The second part of this thesis focused on the impact of heat treatment (55 to 75 °C at different times) on the molecular changes in camel milk. The application of common components and specific weights analysis to the vitamin A, fluorescent Maillard reaction products and NADH fluorescence spectra enabled the discrimination of milk samples according to the temperature and time. The obtained results showed that front-face fluorescence spectroscopy coupled with chemometric tools enabled the characterization of camel milk in different conditions. Additionally, the fluorescence spectrum recorded on milk could be considered as a fingerprint allowing its identification.
20

Potravinové alergie a intolerance - fakta a mýty / Food allergies and intolerances - facts and myths

Češková, Blanka January 2017 (has links)
Food-related diseases, including food allergies and food intolerances, are on the rise worldwide. According to the World Health Organisation (WHO), allergic diseases in the economically advanced countries of the WHO have become the largest child environmental epidemic. Dysregulation of immune tolerance is the basic mechanism involved in the development of food allergy. It is believed that the risk of developing allergies is more related to other lifestyle factors such as a diet, physical activity or obesity. Food allergies in children and adult populations vary both in the spectrum of triggering foods and also their symptoms and their severity. The prognosis also differs in allergies for different types of foods. One of the most important factors affecting the correct development of the baby's immune system is nutrition. In the first 4 - 6 months, the baby should only receive breast milk - for infants it is the most appropriate and allergenically safe diet. It strengthens their immune system. Its positive effect is observed especially on the occurrence of food allergies and atopic eczema. However, developing asthma and other allergies may not be prevented. Breastfeeding has an extraordinary importance and benefits in preventing many illnesses for both the child and the mother. Milk is a major food...

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