The present study was undertaken to analyze the vitamin E, total lipids, and cholesterol in regular and fat-reduced milk to assess whether decreases in fat result in lower vitamin E contents. Milk samples of varying fat contents (11%, 3.3%, 2%, 1% and 0.5% fat) were obtained from a local dairy on six different occasions, α-tocopherol was the major form of vitamin E found in different types of milk, γ-tocopherols and α-tocotrienol were found to a lesser extent in different milks. As the fat content of milk decreased from 11% to 0.3%, vitamin E content also decreased steadily. For example, raw milk as compared to non-fat milk had both a higher α-tocopherol contents (45.5 ± 4.59 μg/100 ml vs. 4.46 ± 0.54; p<0.0001) and a higher total lipids (3.46 ± 0.49 μg/100 ml vs. 0.30 ± 0.07 g/100 ml, (p [less than or equal to] 0.0001). The other detected forms of vitamin E, γ-tocopherol and α-tocotrienol, also varied as the total lipids. Vitamin E, cholesterol and total lipids increased as cream was added back to non-fat milk. For every 10 mg of cholesterol there was an increase of approximately 4 μg of α-tocopherol. For every 1 g increase in total lipid content, the α-tocopherol content increased by 17 μg. This study indicates that vitamin E; especially exotic forms of this vitamin are present in the dairy products analyzed. Also, vitamin E content varies with the total lipid and the cholesterol content. We suggest that vitamin E fortification of milk might be a reasonable approach to restore α-tocopherol intakes to those seen with whole milk. / Graduation date: 2000

A study was conducted to determine the relationship between the degree of glycosylation of $ kappa$-casein (CN) and physicochemical properties of milk: heat stability and ethanol stability. Morning milk samples from individual Holstein cows (genotype $ kappa$-CN AA, $ beta$-CN A$ sb1$A$ sb2$, $ alpha sb{ rm s1}$-CN BB, $ beta$-lactoglobulin AB) in midlactation were collected and analyzed for protein and somatic cell count. Samples of low somatic cell count ($<$150000 cells/ml) were skimmed and dialyzed overnight at 4$ sp circ$C against bulk tank milk to equilibrate soluble components. Three series of analyses were performed for the determination of thermostability of milk between pH 6.5 and 9. In the first 2 sections (A and B), the heat clotting time vs pH (HCT/pH) profiles of normal milk were measured. The effect of sialic acid (NANA) depletion on the HCT/pH profile was tested in a third series of experiments. And finally, a series of analyses were performed to determine the ethanol stability of milk. (Abstract shortened by UMI.)

No description available.

No description available.

Thesis (BTech (Food Technology))--Cape Technikon, 1999. / The Dairy industry, one of the larger food industries in South Africa processes probably the most perishable and possibly the most regulated foodstuff, namely mille The unique combination of vitamins, proteins, carbohydrates, lipids, moisture and near neutral pH, offers a suitable environment for the proliferation of microbes. Milk is therefore highly susceptible to microbiological activity resulting in the irreversible spoilage of this food (Frazier & Westhoff, 1988). The coliform group of organisms comprises all aerobic and anaerobic, gram-negative, non-spore-forming rods that are able to ferment lactose with the production of acid and gas at 32°C within 48 hours (Richardson, 1985). The primary purpose of the coliform detection test is to measure the quality of the practices used to minimise bacterial contamination of processed dairy products (Richardson, 1985). IDF Standard 132A: (1991) defines psychrotrophic organisms as organisms forming countable colonies when incubated aerobically at 6.5°C for 10 days under the conditions specified in IDF standard 101A. Shelf-life tests conducted in the fresh milk laboratory of a processing plant, revealed significant growth of coliforms in samples stored at 5°C. Luch, (1985) reported that other contaminating psychrotrophs together with the coliforms reduce the shelf-life of the milk when the storage temperature thereof is above 10°C.

In this work an attempt has been made to show the merit of some of the more rapid tests of milk quality, as compared with the plate count method. Results secured from the tests studied have not been compared with the actual keeping quality of the samples of milk used but with the results of the official plate counts secured from these same samples. This was taken as a basis for comparison because it is the recognized official method of determining quality. Though the official method, it mu.st be remembered that it is by no means a perfect method. As brought out by Ward (17) it is subject to many wide variations. It is the opinion of the writer that in many cases where lack of relation was shown between plate counts and some other tests, especially the methylene blue reduction test, that the lack of relation was due more to the inadequacy of the plate count method than to inadequacy of the other test. The methylene blue test showed good correlation with the plate count and is especially adapted to indicating milk of very poor quality as shown by results of its use under summer conditions. The writer is convinced by this study that the reductase test is just as good a test of quality of milk for fluid milk purposes as is the plate count. It is many times cheaper, quicker, and more adaptable to the use of the small milk plant and to inspection service. The pH test and catalase test showed little merit from results of this study. The catalase test seems to be of value in locating diseased udders when run on individual samples. The fermentation test proved valuable in showing the nature of bacterial flora present and is, for this reason, indispensable for judging quality of milk for cheese making. It seems that no one test yet in use will prove adequate to judge quality of milk for all purposes. Combinations of tests are often necessary; for bacterial numbers the methylene blue test and for cheese milk the methylene blue test and the fermentation test. / M.S.

O uso de ácidos orgânicos para conservação do leite é uma ferramenta importante para propriedades que não possuem equipamentos para refrigeração, ou que utilizam sistemas de criação que mantêm o leite sob temperatura ambiente durante longos períodos, principalmente em sistemas de aleitamento intensivo e à vontade e que fazem uso de aleitadores automáticos. O objetivo deste estudo foi avaliar a acidificação como método de conservação da dieta líquida em condições climáticas tropicais. Foram utilizados 45 bezerros machos e fêmeas da raça Holandesa em delineamento de blocos contendo os tratamentos: 1) Leite integral acidificado mantido a temperatura ambiente (LA); 2) Leite refrigerado mantido a 5°C (LR) e 3) Sucedâneo lácteo diluído a 12,5% de sólidos (S). Após o nascimento, os animais foram devidamente colostrados e a partir do segundo dia recebiam 6L de dieta líquida de acordo com o tratamento. Os bezerros eram mantidos em abrigos individuais, e a temperatura ambiente média variou entre 17 e 26°C durante o período experimental de 56 dias, quando os animais eram desaleitados. Os bezerros tiveram livre acesso a água e concentrado. O consumo de alimentos e o escore fecal foram monitorados diariamente. Semanalmente, os animais eram pesados e medidas corporais realizadas, assim como eram realizadas coletas de sangue para determinação de metabólitos. O consumo de concentrado e dieta líquida, peso corporal, ganho de diário e medidas corporais foi menor para animais aleitado com S, mas não diferiu entre os tratamentos LA e LR (P<0,05). O escore fecal foi menor para o tratamento LR (P<0,05) o que indica que esses animais apresentaram menor frequência de diarreia, contudo, o valor apresentado pelo tratamento LA (1,98) não sugere ainda um processo diarreico. Houve efeito de tratamento (P<0,05) para o hematócrito e concentrações de glicose, &beta;HBA, e proteína total, com valores inferiores para o tratamento S. Houve diferença (P<0,05) entre os tratamentos LA e LR, apenas para a concentração de lactato. A acidificação do leite demonstrou-se um método adequado de conservação da dieta bem como a refrigeração, não afetando negativamente o desempenho dos animais em comparação ao leite refrigerado. / The use of organic acids to preserve milk is an important method for farms that do not have refrigeration equipment, or that use feeding systems that keep milk at ambient temperature for long periods, especially in intensive feeding systems with the use of an automatic feeder. The objective of this study was to evaluate the acidification as a method of preserving the liquid diet in tropical climatic conditions. Forty-five male and female Holstein calves were blocked according to sex, date and weight of birth and randomly assigned tothe treatments: 1) Acidified whole milk kept at ambient temperature (AM); 2) Refrigerated milk kept at 5ºC (RM) and 3) Milk replacer diluted to 12.5% solids (MR). After birth, the animals were colostrum fed and from the second day they received 6L of liquid diet according to the treatment. Calves were kept in individual hutches, and the mean ambient temperature varied between 26 and 17 °C during the experimental period of 56 days, when the animals were gradually weaned. Feed intake and fecal scores were monitored daily. Weekly animals were weighed and body measurements were performed, as were blood samples collected for metabolites analysis. Concentrated and liquid diet, body weight, daily gain and body measurements were lower for MR-fed animals, but did not differ between treatments AM and RM (P <0.05). The fecal score was lower for the LR treatment (P <0.05), indicating that these animals presented less frequency of diarrhea, however, the value presented by the LA treatment (1,98) does not yet suggest a diarrheal process. There was a treatment effect (P <0.05) for hematocrit and concentrations of glucose, &beta;HBA, and total protein, with lower values for MR treatment. There was a difference (P <0.05) between LA and LR treatments, only for lactate concentration. Acidification of milk has been shown to be an adequate method of preserving milk as well as cooling, and does not adversely affect the performance of the animals compared to the refrigerated milk.

Objetivou-se com este trabalho avaliar a utilização da metodologia no infravermelho com Transformada de Fourier (ITF) na determinação do pH e ponto de congelamento (PC) no leite bovino. No primeiro estudo foram avaliados os efeitos das diferentes condições de conservação em amostras de leite para posterior análise do pH e do PC. Para tanto, foram coletadas, do tanque de 57 propriedades, amostras de três litros de leite. Cada amostra foi subdividida e transferida para 45 frascos de 40mL e distribuídas de acordo com a temperatura de armazenamento (-30C° - Congelado; 7°C - Resfriado; 25°C - Ambiente), idade da amostra (0, 3, 6 e 9dias) e níveis de adição de água (0, 2, 4 e 6%). Foram adicionadas pastilhas de bronopol (Microtabs®) aos 44 frascos, sendo que um foi mantido sem adição do conservante para tratamento controle. Os resultados obtidos, considerando as diferentes condições de conservação das amostras, e ainda, o efeito da adição do bronopol, foram avaliados por comparação de médias. As metodologias (referência e alternativa) foram correlacionadas em função da idade da amostra para o PC por análise de regressão linear. A sensibilidade e a especificidade foram calculadas para avaliação do desempenho do equipamento MilkoScanTM FT+ na detecção de água. A adição do bronopol não alterou as médias do pH, porém reduziu significativamente o PC. Para eliminação desse efeito, foram calculados fatores de correção para os resultados do PC nas duas metodologias empregadas nesse estudo. O aumento da temperatura de armazenamento reduziu significativamente as médias do pH e do PC em amostras com seis e nove dias de coleta. Não houve efeito significativo nas médias do pH e do PC com o aumento na idade da amostra a -30° e 7°C. As correlações entre as metodologias em função da idade da amostra para o PC foram altas e significativas. A sensibilidade e especificidade do equipamento MilkoScanTM FT+ na detecção de água, em relação ao crioscópio eletrônico, foram de 90,9% e de 86,8%, respectivamente. No segundo estudo, objetivou-se caracterizar a atual situação do ponto de congelamento (PC) em rebanhos brasileiros, e avaliar o efeito da lactose e da contagem bacteriana total (CBT) sobre os resultados do PC. Foram analisados 137.443 dados por meio de estatística descritiva e de análise da variância, para caracterizar a atual situação do PC e para avaliação dos efeitos da lactose e da CBT sobre o PC. A média e o respectivo desviopadrão do PC foi de -0,522 (0,011)°C, e, constatou-se que o percentual de amostras em conformidade com a Instrução Normativa nº 51 foi de 92,48%, enquanto que para amostras em não conformidade, com indicativo de adição de água ou de soluto, foi de 7,10% e 0,41% respectivamente. A lactose e a CBT influenciaram significativamente nos níveis do PC. / The objective of this study was to evaluate the use of the methodology Fourier Transform Infrared (FTIR) for determining the pH and freezing point (FP) in bovine milk. The first study evaluated the effects of different storage conditions on samples of milk for subsequent analysis of pH and the PC. For both, were collected from the tank of 57 properties, samples of three liters of milk. Each sample was divided and transferred to 45 vials of 40mL and distributed according to storage temperature (-30C°- Frozen, 7°C - Cold, 25°C - Environment), age of the sample (0, 3, 6 and 9 days) and levels of added water (0, 2, 4 and 6%). Tablets to bronopol (Microtabs®) were added to 44 bottles, of which one was maintained without addition of preservative for control treatment. The results, considering the different conditions of storage of samples, and the effect of adding bronopol were evaluated by comparison of means. The methods (reference and alternative) were correlated with age of the sample to the FP for linear regression analysis. The sensitivity and specificity were calculated to evaluate the performance of MilkoScanTM FT+ equipment for detecting water. The addition of bronopol did not alter the average pH, but significantly reduced the FP. To combat this effect, were calculated correction factors for the results of the PC in the two methodologies employed in this study. Increasing the temperature of storage significantly reduced the average pH and the FP samples with six and nine days of collection. There was no significant effect on mean pH and the PC with the increasing age of the sample at -30°C and 7°C. The correlations between the methods depending on the age of the sample for the FP were high and significant. The sensitivity and specificity of the equipment MilkoScanTM FT+ in the detection of water on the thermistor cryoscope were 90.9% and 86.8% respectively. While in the second study aimed to characterize the current state of the freezing point (FP) in Brazilian herds and Evaluated the effect of lactose and the total bacterial count (TBC) on the results of the FP. 137,443 data were analyzed using descriptive statistics and analysis of variance, to characterize the current state of the FP and to evaluated the effects of lactose and TBC on the FP. The mean and standard deviation of the FP was -0.522 (0.011)°C, and it was found that the percentage of samples in accordance with Normative Instruction nº 51 was 92.48%, while for samples not in accordance with an indication of added water and solute was 7.10% and 0.41% respectively. The lactose and TBC significantly influenced the levels of PC.

Made available in DSpace on 2014-06-11T19:31:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-04Bitstream added on 2014-06-13T21:02:23Z : No. of bitstreams: 1 garcia_acfz_dr_botfmvz.pdf: 369339 bytes, checksum: b2a846ac4500c2551e112251103250bd (MD5) / Universidade Estadual Paulista (UNESP) / Atualmente, a demanda por produtos lácteos processados e de alta qualidade é crescente por parte da população, provocando uma tendência progressiva de adaptação por parte da indústria leiteira a essas exigências ditadas pelo mercado consumidor. O valor nutricional e o rendimento industrial do leite pode ser avaliado por meio dos testes físico-químicos. O objetivo deste trabalho foi avaliar o efeito da suplementação com propionato de zinco a 16% ou com o produto homeopático Fator M&P® na qualidade do leite de vacas Holandesas. Foram utilizadas 40 vacas da raça holandesa variedade preta e branca, divididas em quatro grupos (Zn3-suplementadas com zinco + eliminação 3 jatos iniciais de leite, Zn - suplementadas com zinco + 3 jatos iniciais de leite, MP3- suplementadas com produto homeopático + eliminação 3 jatos iniciais de leite e MP - suplementadas com produto homeopático + 3 jatos iniciais de leite). As amostras de leite dos quatro tetos foram coletadas quinzenalmente em três momentos (M1-antes suplementação, M2-durante suplementação, e M3- após término suplementação),durante cinco meses e enviados à Clinica do Leite, no setor do Departamento de Zootecnia da Escola Superior de Agricultura “Luiz de Queiroz (ESALQ) da Universidade de São Paulo em Piracicaba – SP, para realização da CCS e das análises de percentagem de gordura, lactose e proteína, respectivamente. Com os resultados obtidos neste estudo, pode-se dizer que o fornecimento suplementar de zinco e do produto homeopático Fator M&P® para vacas lactantes, nas doses utilizadas, tem efeito e contribuem de forma eficaz nas caracteristicas fisico-quimicas e nos valores de CCS / Currently, the demand for processed milk products and high quality is increasing among the population, causing a progressive tendency of adaptation by the dairy industry these requirements dictated by the market. The physico-chemical quality of milk, aims to assess the nutritional value or its industrial output. The objective of this study was to evaluate whether there is improvement in the quality of milk from cows supplemented with zinc propionate to 16% and the homeopathic product Fator M & P ®. 40 Dutch cows were used, divided into four groups (Zn 3-supplemented with zinc + 3 jets disposal initial milk, Zn - supplemented with zinc + 3 jet initial milk, supplemented with MP3-homeopathic product disposal + 3 jet initial milk and MP - supplemented homeopathic product with initial milk + 3 jets). Milk samples from the four teats were collected biweekly at three moments (M1-before supplementation, M2-supplementation during and M3-after ending supplementation) for five months and sent to the Clinic of the Milk Industry in the Department of Animal Science School of the Agriculture Luiz de Queiroz (ESALQ), University of Sao Paulo in Piracicaba - SP, CCS and to perform the analyzes of percentage of fat, lactose and protein, respectively. With the results obtained in this study, we can say that providing supplemental zinc and homeopathic product Fator M & P ® to lactating cows at the doses used, is effective and contribute effectively in the physical-chemical characteristics and values of CCS

Made available in DSpace on 2014-06-11T19:27:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-03Bitstream added on 2014-06-13T20:56:01Z : No. of bitstreams: 1 motta_rg_me_botfmvz.pdf: 824097 bytes, checksum: 81156400b6e111a39e02d477352288c3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi avaliada a qualidade microbiológica, constituintes nutricionais, celularidade, presença de resíduos de antimicrobianos e micro-organismos patogênicos, em amostras de leite de vacas, com base na IN 51 do MAPA, obtidas de tanque de expansão individuais, tanques coletivos e leite informal, provenientes de propriedades da região sudeste do estado de São Paulo. Foram utilizadas 300 amostras de leite obtidas de 100 tanques individuais e 100 tanques coletivos colhidas nas propriedades, e 100 amostras de leite informal comercializadas na região. Foi verificado que 41% dos tanques individuais, 24% dos coletivos e 67% das amostras de leite informal estavam em desacordo com os valores máximos de CCS exigidos pela Instrução Normativa 51 (IN 51) do MAPA, Brasil. Foi observado que 10% das propriedades com tanques individuais, 71% dos coletivos e 86% de leite informal estão em desacordo com a IN 51, que prevê limite máximo de CBT de 750.000 UFC\mL. Em relação aos teores de sólidos totais, 48,0% dos tanques individuais, 89,0%, dos coletivos e 64,0% do leite informal apresentaram valores considerados normais. Em 32% do leite obtido dos tanques individuais, 5% dos coletivos e 3% do leite informal foram observados teores de proteína em desacordo com a IN 51, enquanto 54% do leite dos tanques individuais, 41% dos coletivos e 38% do leite informal, acusaram teores de gordura em desacordo com a legislação vigente. Para o extrato seco desengordurado, 52% do leite dos tanques individuais, 23% dos coletivos e 43% do leite informal, foram encontrados teores irregulares. Os teores de nitrogênio uréico foram considerados normais em 34% das amostras de leite dos tanques individuais, 50% dos tanques coletivos e 27% do leite informal. Em 42% das amostras de leite dos tanques individuais, 35% dos coletivos e 59% do leite... / Assorted tests were run on samples from cow milk based on Brazil's MAPA IN 51 (Normative lnstruction Nr. 51), obtained from individualbulk tanks, collective tanks and informal milk from breeders located in the southeast area of São Paulo state, Brazil. Their microbiological quality as well as their nutritional constituents, cellulous characteristics (SCC),presenceof anti-microbian residuais and pathogenic microorganisms was investigated. A total of three hundred samples of milk, comprised of 100 samples from individual tanks, one hundred from collective tanks plus one hundred samples of milk commercialized in the area mentioned above was utilized for the experiment. As a result we learnt that 41% of the individual tanks, 24% of the collective tanks and 67% of informal milk samples were in violative with SCC maximum limits values required by MAPA's IN 51. It has also been observed that 10% of the breeders with individual tanks, 71% of the collective tanks and 86% of informal milk were in disagreement with MAPA's IN 51, which requires maximum CBT levelllimit of 750,000 UFC/rnL. As for total solid contents 48% ofthe individual tanks, 89% ofthe collective tanks and 64% ofthe informal milk showed values considered normal. In terms of protein content, 32% ofthe milk from individual tanks, 5% of the collective tanks and 3% of the informal milk were in disagreement with MAPA's IN 51. On the other hand 54% of the individual tanks, 41% of the collective tanks and 38% of the informal milk failed to present fat content in accordance to legislations demands. As for the non-fit dry extract, in 52% of samples from individual tanks, in 23% of the collective tanks and in 43% of the informal milk, irregular contents have been found. The ureic nitrogen contents were considered normal in 34% of the samples from individual tanks, in 50% of the... (Complete abstract click electronic access below)