Laboratory scale Cheddar type cheese were made from 411 milk samples originating from Ayrshire, Brown Swiss, Canadienne and Jersey with different phenotypes of kappa-casein (kappa-CN) and beta-lactoglobulin (beta-LG). From the milk input, cheese and whey outputs, the cheese yield, cheese composition and cheesemaking efficiency and other parameters were determined. The overall 37% moisture adjusted cheese yield and cheese yield efficiency were 11.19g, 10.19g, 11.97g, 11.46g and 98.91%, 90.10%, 90.76% and 90.92% for Ayrshire, Brown Swiss, Canadienne and Jersey respectively. The milk of the four respective breeds contained 12.91, 12.69, 13.50, 14.57% total solids; 3.97, 3.58, 4.40, 4.61% fat; 3.61, 3.73, 3.81, 4.00% protein. In Ayrshire, the combination BB/BB and BB/AA (kappa-CN/beta-LG) were associated with higher 37% moisture adjusted cheese yield with the values of 12.51 and 12.83 g/100 g milk respectively. The cheese composition for these two types of milk were 62.28 and 63.96% total solids, 24.22 and 20.40% protein; 32.75 and 37.92% fat. For Brown Swiss, type AA/BB was associated with higher cheese yield (11.18g) with composition of 62.15% total solids, 22.54% protein, 33.23% fat. The phenotype with the highest cheese yield for Canadienne is BB/AB (12.45g) with cheese composition of 63.61% total solids, 23.27% protein and 63.61% fat. In Jersey, the phenotype combination with higher cheese yield (14.59g) is BB/BB. The cheese composition corresponding to this phenotype was 58.64% total solids, 22.96% protein and 29.59% fat. Phenotypes associated with better coagulating properties for Ayrshire, Brown Swiss, Canadienne and Jersey were BB/AB, BB/BB, BB/BB and BB/BB for kappa-CN/beta-LG respectively.

This study was based on the 462 milk samples collected from approximately 2000 cows registered in Dairy Herd Analysis Service (DHAS). Milk samples from fresh milks were phenotyped by gel electrophoresis. Milk samples were selected according to the nine possibilities of phenotype combination of $ kappa$-casein AA, AB, BB and $ beta$-lactoglobulin AA, AB and BB. Selected milk samples from fresh milks were heated at 25$ sp circ$C, 60$ sp circ$C, 70$ sp circ$C, 80$ sp circ$C and 90$ sp circ$C, respectively. Whole casein and whey protein were separated by adjusting the pH to 4.6. Quantitative determination of milk protein were performed by reverse-phase HPLC. Whole casein was separated to $ kappa$-casein ($ kappa$-Cn), $ beta$-casein ($ beta$-Cn) and $ rm alpha sb{s}$-casein ($ rm alpha sb{s}$-Cn). Whey protein was separated as immunoglobulin (Ig), bovine serum albumin (BSA), $ alpha$-lactalbumin ($ alpha$-La) and $ beta$-lactoglobulin ($ beta$-Lg). Individual milk protein fraction was quantitatively determined by relative peak area and their ratios to whey protein or casein. The denaturation of individual milk protein at different heating temperature was investigated. (Abstract shortened by UMI.)

Casein – the main albumen constituent of milk. Food casein is used in the production of caseinat. Caseinats are used in the production of food concentrates, medicines, and cheese products. In addition, they may be used as casein glue. Goals of thesis. To determinate total bacterial contamination of acid casein edible, isolate and identify pathological microorganisms. 1. To determine the general bacterial contamination of edible acid casein samples. 2. To determine the influence of thermophylic bacteria on the general bacterial contamination. 3. To determine the general bacterial contamination of repeatedly researched edible acid casein samples and the presumable quantity of coliformic germs. 4. To define and identify the patological microorganisms out of edible acid casein samples. 5. To determine the chemical composition of edible acid casein samples. Results. Micro flora of crude milk constitutes certain part of micro flora, found in powdered milk. However, the increased level of general contamination and coliform germs shows the signs of secondary contamination. The enlarged bacteriological contamination, which exceeded the preset limit of 3.0x104 CFU/g, was identified in 3 per cent of analyzed acid casein edible samples. This was caused by impurity of crude milk. During the acid casein edible casein production process, the temperature of pasteurization was reached twice and in addition to that, comparatively low pH was maintained. These conditions are not hospitable for... [to full text]

Dresden, Techn. Univ., Diss., 2003.

Hohenheim, Univ., Diss., 2006.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains v, 49 p. Vita. Includes abstract. Includes bibliographical references (p. 38-42).

Made available in DSpace on 2015-06-17T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-02. Added 1 bitstream(s) on 2015-06-18T12:48:23Z : No. of bitstreams: 1 000834199_20160202.pdf: 110591 bytes, checksum: 9b4d763896b837f183fbb81b557d4619 (MD5) Bitstreams deleted on 2016-02-03T15:35:13Z: 000834199_20160202.pdf,. Added 1 bitstream(s) on 2016-02-03T15:35:54Z : No. of bitstreams: 1 000834199.pdf: 1278335 bytes, checksum: 9ed66d4ca576eca0681d0113a356d68a (MD5) / Dentre as proteínas do leite, as caseínas (alfa-s1, alfa-s2, beta- e kapa-caseína) assumem papel de destaque devido ao alto valor nutritivo e às características físico-químicas que favorecem a fabricação de derivados do leite. Essas proteínas são codificadas pelos genes CSN1S1, CSN1S2, CSN2 e CSN3. A fim de realizar análise comparativa dos genes das caseínas de búfalo, o presente trabalho teve como objetivo a identificação, caracterização e sequenciamento de clones da biblioteca genômica de búfalo, visando analisar a estrutura molecular de genes das caseínas. Dentre os 33.792 clones avaliados, foram identificados dois clones positivos para genes das caseínas, um para o gene CSN1S1 (clone A/2) e outro para o gene CSN3 (clone L/8). Na sequência de DNA obtida a partir do clone A/2, foram identificados os genes CSN1S1 inteiro e CSN2 parcial, enquanto que nas sequências de DNA do clone L/8 identificou-se o gene CSN3 partial. O gene CSN1S1 apresentou 17.008 bp organizados em 19 éxons com tamanhos variando de 24 bp a 380 bp e 18 íntrons com tamanhos de 90 bp a 1.710 bp. As análises comparativas revelaram que os éxons e íntrons desse gene apresentaram conservação acima de 85% entre búfalo e boi. As porções do gene CSN2 identificadas incluíram o éxon 9 e parte do íntron 8, os quais mostraram conservação acima de 98% com as sequências correspondentes em boi. Já as sequências parciais do gene CSN3 abrangeram parte dos íntrons 2 e 3 e o íntron 4 completo, além dos éxons 3, 4 e 5. Estas sequências apresentaram conservação acima de 94% com as correspondentes em boi. As análises de identificação de sequências repetitivas mostraram que 43,83% e 44,98% das sequências de DNA do clone A/2 e L/8, respectivamente, são representadas por elementos retrotransposons. Nas análises comparativas, tanto o gene CSN1S1 quanto o gene CSN3 parcial apresentaram sequências repetitivas búfalo específicas. A sequência ... / Among milk proteins, the caseins (alpha-s1, alpha-s2, beta- and kappa-casein) play a crucial role considering their high nutritional value and physicochemical characteristics which contribute to the manufacture of dairy products. These proteins are encoded by the CSN1S1, CSN1S2, CSN2 and CSN3 genes, respectively. In order to analyze the buffalo casein genes and compare the sequences with other species, the goal of the present study was to identify, characterize and sequence clones from a buffalo genomic library. A total of 33,792 clones were evaluated, and two clones were identified as positive, one for the CSN1S1 gene (clone A/2) and other for the CSN3 gene (clone L/8). The DNA sequence from clone A/2 identified the whole CSN1S1 and a partial sequence from the CSN2 genes. The DNA sequence from clone L/8 revealed a partial sequence from the CSN3 gene. The CSN1S1 gene presented a total of 17,008 bp organized in 19 exons ranging from 24 bp to 380 bp and 18 introns ranging from 90 bp to 1,710 bp. Comparative analysis showed sequence conservation higher than 85% on exons and introns of the CSN1S1 gene when compared with the cattle gene sequence. The partial sequence from the CSN2 gene included exon 9 and part of intron 8, with conservation higher than 98% when compared with the cattle sequence. The partial sequences of the CSN3 gene included parts of the introns 2 and 3, the whole sequence of intron 4 and exons 3, 4 and 5. These sequences showed conservation higher than 94% with cattle. The identification of repetitive sequences showed that 43.83% of DNA sequence from clone A/2 and 44,98% from clone L/8 were represented by retrotransposable elements. Further comparative analysis showed buffalo specific repetitive sequences in the CSN1S1 gene and the partial CSN3 gene with when compared with other bovids species. The coding sequence of the buffalo CSN1S1 gene showed 98%, 93%, and 90% of identity with the correspondent sequences in cattle ...

Misturas aquosas de polissacarídeos e proteínas são normalmente instáveis e separam-se em fases devido às interações repulsivas ou atrativas existentes entre os polímeros. O efeito da temperatura, do pH e da concentração polimérica no comportamento de misturas de pectina/caseína foi estudado nesse trabalho. Um diagrama de fases construído em pH 7 revelou que a mistura é estável apenas em baixas concentrações. Concentrações mais elevadas levam à incompatibilidade termodinâmica, governada por forças puramente entrópicas, e ao aparecimento de duas fases: uma rica em caseína (inferior) e outra rica em pectina (superior). A decomposição espinodal pôde ser visualizada nos estágios iniciais da separação de fases e, nos estágios intermediários, observou-se a formação de emulsões água/água. Quando o pH dessas emulsões é reduzido para abaixo de 6, a pectina é atraída para a fase de caseína, resultando na formação de partículas de complexo pectina/caseína que não coalescem e são resistentes à adição de sal (NaCl 100 mM), apresentando um diâmetro médio aproximado de 4 m. As micropartículas de pectina/caseína produzidas por este método demonstraram ser capazes de encapsular com alta eficiência tanto substâncias hidrofóbicas quanto hidrofílicas, possibilitando sua aplicação na encapsulação de compostos variados para fins diversos. Neste trabalho, as micropartículas foram utilizadas para encapsular cristais de metronidazol e sua utilização na obtenção de filmes de aplicação intra-bolsa periodontal foi avaliada in vitro. As dispersões de pectina/caseína contendo as micropartículas carregadas foram submetidas à secagem para a obtenção dos filmes. Estes, reticulados ou não com cálcio, sustentaram a liberação in vitro do fármaco por pelo menos 7 dias in vitro. A reticulação foi importante para reduzir a desintegração dos filmes, contribuindo para aumentar o tempo de permanência deles no local de aplicação e para melhorar suas propriedades mecânicas, facilitando seu manuseio e inserção na bolsa periodontal. Com esses resultados, conclui-se que os filmes de micropartículas de complexo pectina/caseína contendo metronidazol desenvolvidos neste trabalho são excelentes candidatos a sistemas de liberação local para o tratamento da doença periodontal. / Aqueous mixtures of polysaccharides and proteins are usually unstable and phase-separate either because of repulsive or attractive interactions. The effect of temperature, pH, and biopolymer concentration on the phase behavior of pectin/casein mixtures was investigated. A phase diagram built at pH 7 revealed that the mixture is stable at low polymer concentrations. Higher concentrations lead to thermodynamic incompatibility, driven purely by entropic forces, and to the appearance of two phases: one enriched with casein (lower) and the other, with pectin (upper). Spinodal decomposition was visualized in the early stages of phase separation. In the intermediate stages, water-in-water emulsions were observed. When the pH of these emulsions was lowered below 6, pectin was attracted by casein-rich phase, resulting in the formation of particles (diameter ~ 4 m) of pectin/casein complex, which do not coalesce and are insensitive to salt addition (100 mM NaCl). Pectin/casein microparticles obtained by this method were able to encapsulate with high efficiency either hydrophobic or hydrophilic substances and, due to that, could be applied in the encapsulation of a great variety of compounds for different purposes. In this work, the pectin/casein microparticles were used to encapsulate metronidazole crystals and the preparation of intra-periodontal pocket films with them was evaluated. Therefore, dispersions of loaded pectin/casein microparticles were dried in an oven. Films cross-linked or not with calcium sustained the in vitro drug release at least for 7 days. The cross-linking with calcium was important to reduce film disintegration, accounting for its permanence in the applied region, and to improve the mechanical properties, which facilitates manipulation and insertion into the periodontal pocket. With these results we conclude that the films formed by microparticles of pectin/casein complex loaded with metronidazole are excellent candidates for local drug delivery systems for the treatment of periodontal disease.

Os sistemas de liberação de fármacos são parte integrante da investigação farmacêutica. Grande ênfase tem sido dada à utilização de polímeros hidrofílicos naturais como carreadores devido às vantagens inerentes a seu baixo custo, biocompatibilidade e segurança de uso. Os objetivos principais deste trabalho foram a preparação e avaliação de sistemas microparticulados a base de pectina e caseína e o estudo da liberação in vitro do aciclovir contido nas micropartículas. Esses sistemas visam uma liberação prolongada do fármaco aumentando sua biodisponibilidade oral. O efeito de parâmetros como pH, força iônica, viscosidade, proporção e concentração total de polímeros foi avaliado. A melhor condição para ocorrência da coacervação foi determinada por mobilidade eletroforética, rendimento do coacervado e microscopia ótica. A pectina e a caseína podem interagir formando complexos insolúveis. A formação do complexo coacervado foi espontânea e ocorreu em condições brandas no intervalo de pH em que os polímeros encontram-se carregados com cargas opostas. As dispersões foram secas em Spray dryer, resultando em partículas bastante pequenas (6µm) e homogêneas. Através da microscopia ótica foi possível observar que o fármaco se encontrava no interior das micropartículas. O pH (4,0-5,0) do meio influenciou decididamente a formação dos complexos coacervados, e a melhor relação mássica para o par pectina/caseína foi 1:1. Proporções superiores ou inferiores reduziram significativamente a extensão da coacervação. O aumento no teor de sólidos totais (4-8% p/v) bem como a adição de sal (0-120 mMol) não suprimiu a formação ou a estabilidade do sistema. Foram preparadas matrizes hidrofílicas contendo as micropartículas encapsuladas com aciclovir. O estudo de dissolução in vitro demonstrou que a liberação do aciclovir foi mais lenta nos sistemas matriciais e microparticulados do que a do fármaco livre. Entretanto, as matrizes apresentaram perfis de liberação sustentada mais adequados do que os sistemas microparticulados. / Drug delivery systems became an integral part of pharmaceutical research. The use of natural hydrophilic polymers as drug carriers has received considerable attention in the last few years, especially from the viewpoint of cost, environmental concerns and safety. The main purpose of this study was to report and discuss the preparation of a microparticulate system by mixing the negatively charged pectin and the amphoteric casein and also the in vitro evaluation of polymeric microparticulate systems loaded with acyclovir. Such drug delivery system was conceived to prolong the therapeutic activity of acyclovir and increase its oral biovailability.The influence of pH, total biopolymers concentration, viscosity of dispersions, pectin/casein ratio and ionic strength were reported. Zeta potential measurements and dry coacervate yield were used to determine the optimal conditions for complex coacervation and were supplemented by optical microscopy. Pectin/casein in aqueous mixture may interact and form insoluble complexes. The complex formation was spontaneous and occurs under mild conditions. The phenomenon of complex coacervation mainly occurs at a pH range when both polyelectrolytes carry opposite charges. Microparticulate preparations were spray dried and results showed that the microparticles obtained were always quite small, the diameters of 80% of the particles did not exceed 6m, and physicochemical characterization showed that the drug was homogeneously dispersed inside the microparticles. Pectin/casein ratio and pH range were found to mainly affect the microparticles formation and encapsulation efficiency. The complex coacervation was dependent on pH (4,0-5,0) and the optimum pectin/casein ratio was 1:1. Superior or inferior proportion significantly decreased the coacervate yield. Increasing in total biopolymer concentration (4-8% w/v) and salt addition (0-120 mMol) did not inhibit the formation and stability of pectin/casein systems. Hydrophilic matrices containing acyclovir loaded microparticles were also prepared. The in vitro dissolution profile of acyclovir from the microparticulate systems and matrices were slower than that for the free drug. However, the sustained release characteristic was more prominent in matrices than in microparticles formulations

Orientador: Admar Costa de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T16:25:47Z (GMT). No. of bitstreams: 1 Rios_KarinaRibeiro_M.pdf: 519085 bytes, checksum: 22eba3b1a8c6784f7067751a10db8f1c (MD5) Previous issue date: 2003 / Resumo: O zinco é um mineral que desempenha inúmeras funções biológicas, como catalisador para a atividade de mais de 300 enzimas, constituinte estrutural de muitas proteínas e como regulador na prevenção da formação de radicais livres. Dado a esta multiplicidade funcional, a deficiência de zinco é especialmente crítica em estádios de rápido crescimento e desenvolvimento onde seu requerimento é aumentado, na ingestão alimentar deficiente ou quando ocorre baixa biodisponibilidade do zinco. Com a descoberta da deficiência do mineral em humanos na década de 60 devido ao elevado consumo de ácido fítico por populações do Oriente Médio, os estudiosos acreditavam ser este um fato isolado, até que na década de 90 foi reconhecido como um problema de carência nutricional de ocorrência freqüente em países desenvolvidos. Com vistas a determinar a influência da fonte de zinco da mistura mineral da dieta AIN-93G e de adições de ácido fítico no crescimento e estado nutricional de zinco em ratos Wistar, estudou-se o efeito da suplementação com carbonato de zinco (56 % Zn) e ácido fítico na forma de hexafosfato de mioinositol (IP6), utilizando-se adições crescentes na dieta de caseína. Os resultados mostraram que apesar de o carbonato de zinco (56 % Zn) ter sido removido por 32 dias, não foi observada diferença estatística (p>0,05) para os índices de crescimento (consumo de dieta e ganho de peso) e valor nutritivo da caseína, determinado pelo Quociente de Eficiência da Caseína (PER). A concentração sérica de zinco não diferiu entre os animais do grupo Controle (dieta AIN-93G, 12,2 % de caseína) e os animais do grupo com dieta basal, sem a fonte de zinco da mistura mineral (ZnC03, 56% Zn), sendo a zincemia assegurada pelos 4,2 mg Zn I kg de caseína. Adições crescentes de ZnC03, 56% Zn, até 129,2 mg de zinco I kg de dieta basal durante 8 dias, após a remoção do mineral por 32 dias, resultaram em valores maiores para ganho de peso, porém até o limite de 86,7 mg Zn I kg dieta, correspondendo a um valor máximo de 98,6 gramas de ganho pondera!. A eficiência alimentar apresentou valores maiores a partir de 33,1 mg Zn I kg dieta e a concentração de zinco no soro dos animais, valores maiores para as adições de 65,4 e 129,2 mg Zn/kg dieta. Adições crescentes de ácido fítico à dieta basal, sem o ZnC03, 56 % Zn, da mistura mineral, num período de 32 dias, ocasionaram redução constante nos índices de crescimento (consumo de dieta e ganho de peso), no valor nutritivo da caseína determinado pelo Quociente de Eficiência Líquida da Caseína (NPR) e Quociente de Eficiência da Caseína (PER), no valor nutritivo dietético, determinado pelo Quociente de Conversão Alimentar (QCA) e na concentração sérica de zinco dos ratos. Os valores das digestibilidades (Aparente e Corrigida pela Dieta Aprotéica) não foram comprometidos pelas adições crescentes de fitato. Pelo exposto, pôde ser inferido que o baixo teor de zinco da dieta basal (1,1 mg Zn I kg dieta) praticamente não afetou o crescimento dos ratos, enquanto a influência de adições crescente de ácido fítico teve um efeito de notável redução dos índices determinados, com exceção da digestibilidade da caseína, num período experimental de 32 dias / Abstract: Zinc is a mineral with a variety of biological functions such as catalyzing the activity of more than 300 enzymes, being a structural constituent of many proteins and as a regulator in the prevention of free radical formation. Due to this functional multiplicity, a deficiency of zinc becomes especially critical during rapid growth and development stages where the requirement is even greater, in cases of deficient feeding or in cases of low zinc bioavailability. In the sixties, when deficiency of this mineral was first discovered in humans, due to the high ingestion of phytic acid by Middle Eastern populations, researchers believed this to be an isolated case. However, in the nineties it was recognized as a malnutritional problem, occurring mainly in large countries. With the objective of determining the influence of the zinc source in the mineral mixture of the AIN-93G diet, and of additions of phytic acid on the growth and nutritional state of zinc in Wistar rats, the effect of supplementation with zinc carbonate (56% Zn) was studied, and also the addition of phytic acid in the form of myoinositol hexaphosphate (IP6), adding increasing amounts to the casein diet. The results show that despite the zinc carbonate (56% Zn) having been removed from the diet for 32 days, no significant (p>0.05) difference was observed with respect to the growth indexes (diet consumption and weight gain) or nutritive value of the casein, as determined from the Protein Efficiency Ratio (PER). There was no difference in serum zinc concentration between that of the Control group of animals (AIN-93G diet, 12.2% casein) and that of the animals on the basal diet, without the source of zinc in the mineral mixture (ZnCO3, 56% Zn), zincemia being guaranteed by the 4.2 mg Zn I kg casein. Increasing additions of ZnCO3, 56% Zn, up to 129.2 mg zinc I kg basal diet for 8 days, after removing the mineral for 32 days, resulted in an increased weight gain, although only up to a limit of 86.7 mg Zn I kg diet, corresponding to a maximum pondered weight gain of 98.6 grams. Higher values for food efficiency were shown as from 33.1 mg Zn I kg diet, and higher values for the concentration of zinc in the animal serum were shown with additions of from 65.4 to 129.2 mg Zn I kg diet. Increasing additions of phytic acid to the basal diet containing no ZnCO3, 56% Zn in the mineral mixture, for a period of 32 days, led to constant reductions in the growth indexes (diet consumption and weight gain), in the nutritive value of the casein as determined by the net protein ratio (NPR) and protein efficiency ratio (PER), in the dietary nutrition value as determined by the food conversion ratio (FCR) and in the serum zinc concentration of the rats. The values for digestibility (apparent and corrected according to the aproteic diet) were unaffected by the increasing additions of phytate. From the results, it can be inferred that the low level of zinc in the basal diet (1.1 mg Zn I kg diet) showed practically no influence on the growth of the rats, whereas in an experimental period of 32 days, there was a notable effect in the reduction of the indexes determined, with the exception of that of casein digestibility, with increasing additions of phytic acid / Mestrado / Mestre em Alimentos e Nutrição