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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.
1

Capillary electrophoresis and kinetic studies of food biopolymers

Zhong, Huijuan January 1999 (has links)
No description available.
2

NMR relaxation studies of some carbohydrates solutions and gels

Fabri, Deborah January 2001 (has links)
No description available.
3

Efeito do enxague oral com carboidrato sobre o desempenho de cavalos da raça Mangalarga Marchador em teste incremental de esforço máximo / Effect of carbohydrate mouth rinse on Mangalarga Marchador breed performance in maximal exercise test

Bogossian, Paulo Moreira 10 April 2015 (has links)
Estudos em neurociência aplicada ao exercício tem demonstrado que a gustação do carboidrato pode estimular áreas cerebrais de recompensa e postergar a exaustão em atletas humanos. O presente estudo tem por objetivo investigar o efeito do enxague oral com maltodextrina sobre o desempenho de cavalos em teste incremental de esforço máximo a campo. Sete equinos da raça Mangalarga Marchador foram avaliados após enxague oral com maltodextrina a 6,4% (teste C) e placebo (teste P). Tempo até a exaustão (TAE), frequência cardíaca, glicose e lactato plasmáticos, e a atividade plasmática de creatinoquinase foram avaliados durante e após os testes. O TAE do teste C foi em média 31 segundos superior ao P. O valor pico de lactato do teste C foi 5,97 mg/dl superior ao teste P. O enxague oral com maltodextrina aumentou a capacidade de resistência dos animais avaliados neste estudo / Ergogenic effect of carbohydrate mouth rinse has been widely described in human runner and cyclists. This effect seems to be mediated by the activation of brain areas related to reward and motivation. The aim of the present study is to investigate the effect of maltodextrin mouth rinse on field maximal exercise test. Seven MM breed horses were evaluated after mouth rinse with maltodextrin 6, 4% (test C) and placebo (test P). Time to exhaustion, heart rate, plasmatic glucose and lactate, and serum creatinokinase were measured during and after tests. Time to exhaustion of the test C was 31 second higher than test P. Plasmatic lactate peak was 5,97 mmol/l higher in test C. No differences were observed in glucose and CK levels. Maltodextrin mouth rinse improved performance in maximal field test
4

The effect of carbohydrate mouthrinse on simulated XC-sprint performance

Kårström, Andreas January 2014 (has links)
The purpose with this study was to investigate the effect of a carbohydrate (CHO) mouth rinse protocol on simulated cross country (XC) sprint. The primaryaim was to investigate ifa 10 secCHO solutionmouth rinsingprotocolimprovedthe finish timein a simulated cross country (XC) sprint(800 meters for female and 1000 meters for male) compared with control (CON).The second aim was to examif post-finish blood lactateconcentrationwouldbe lowercompared with CONwith mouth rinsing. Seven participants(four males and three females)completed four simulated sprints, two CON and two experimentalrinse protocols, CHO solution and placebo (PLA).Time to completion was not different with CHO compared with CON or PLA (203.0 ±16.5 sec, 202.3 ± 15.7 sec, 203.3 ± 14.6respectively.p >.05).Mean power output was CON 264 ± 73, PLA 258 ± 65, CHO 261± 70.Blood lactateat 15 minweresimilar between CHO, CON and and PLA(9.9 ± 3.9 mmol 7.6 ± 4.0 mmol, 10.1 ± 3.7 mmol respectively.p >.05).We concludethat mouth rinsing a CHO solutionfor 10 sechave no effect on high intensity exercise with duration lasting between 3 and 4 minutes.
5

Efeito do enxague oral com carboidrato sobre o desempenho de cavalos da raça Mangalarga Marchador em teste incremental de esforço máximo / Effect of carbohydrate mouth rinse on Mangalarga Marchador breed performance in maximal exercise test

Paulo Moreira Bogossian 10 April 2015 (has links)
Estudos em neurociência aplicada ao exercício tem demonstrado que a gustação do carboidrato pode estimular áreas cerebrais de recompensa e postergar a exaustão em atletas humanos. O presente estudo tem por objetivo investigar o efeito do enxague oral com maltodextrina sobre o desempenho de cavalos em teste incremental de esforço máximo a campo. Sete equinos da raça Mangalarga Marchador foram avaliados após enxague oral com maltodextrina a 6,4% (teste C) e placebo (teste P). Tempo até a exaustão (TAE), frequência cardíaca, glicose e lactato plasmáticos, e a atividade plasmática de creatinoquinase foram avaliados durante e após os testes. O TAE do teste C foi em média 31 segundos superior ao P. O valor pico de lactato do teste C foi 5,97 mg/dl superior ao teste P. O enxague oral com maltodextrina aumentou a capacidade de resistência dos animais avaliados neste estudo / Ergogenic effect of carbohydrate mouth rinse has been widely described in human runner and cyclists. This effect seems to be mediated by the activation of brain areas related to reward and motivation. The aim of the present study is to investigate the effect of maltodextrin mouth rinse on field maximal exercise test. Seven MM breed horses were evaluated after mouth rinse with maltodextrin 6, 4% (test C) and placebo (test P). Time to exhaustion, heart rate, plasmatic glucose and lactate, and serum creatinokinase were measured during and after tests. Time to exhaustion of the test C was 31 second higher than test P. Plasmatic lactate peak was 5,97 mmol/l higher in test C. No differences were observed in glucose and CK levels. Maltodextrin mouth rinse improved performance in maximal field test
6

Secagem da polpa de maracujá por atomização com adição de maltodextrina e farinha da sua casca / Drying pulp of passion fruit for atomization containing maltodextrin and flour of your peel

Faria, Carolyne Bitencourt, 1981 26 August 2018 (has links)
Orientador: Flavio Luis Schmidt / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-26T09:05:26Z (GMT). No. of bitstreams: 1 Faria_CarolyneBitencourt_D.pdf: 4465395 bytes, checksum: f14b25e18870fa1f58207127c61810f1 (MD5) Previous issue date: 2014 / Resumo: Este trabalho teve como objetivo a avaliação da adição da farinha da casca de maracujá (FCM), em substituição parcial da maltodextrina utilizada como coadjuvante de secagem na atomização da polpa de maracujá. Foi realizado o estudo das características físico-químicas, tecnológicas e estruturais da farinha obtida da casca do maracujá amarelo. Esta apresentou alta porosidade, boa solubilidade em meio líquido e alta temperatura de transição vítrea (Tg), mostrando-se um produto com promissoras características tecnológicas. Para avaliar a quantidade de FCM adicionada em substituição a maltodextrina, foi realizado um estudo do seu comportamento reológico. Os parâmetros reológicos foram determinados a 25, 40, 60 e 80°C, por meio de um viscosímetro de cilindros coaxiais, com variação da taxa de deformação de 6,60 a 198,0 s-1. No ajuste dos dados foram utilizados os modelos matemáticos: Leis da Potência e Herschel-Bulkley. Para otimizar a quantidade máxima de FCM adicionada na polpa para se obter sua secagem por atomização, foi realizado um planejamento estatístico central rotacional 23, com 3 pontos centrais, totalizando 17 ensaios, onde as variáveis independentes foram a temperatura do ar de entrada (163 a 197°C), a vazão mássica de alimentação (340 a 540 mL/h) e a concentração de agente carreador (0/100% a 15/85% - FCM/maltodextrina p/p). As respostas analisadas foram densidade aparente, umidade do pó, teor de ácido ascórbico, rendimento do processo, tempo de dissolução e higroscopicidade do pó. A adição da FCM reduziu a umidade, aumentou o rendimento e a conservação do ácido ascórbico no produto final. Assim as melhores condições de secagem estabelecidas foram: 190°C, 500 ml/h e 11,6/88,4% de FCM/maltodextrina. O pó produzido no ponto ótimo apresentou boa aceitação sensorial, quando preparado na forma de néctar, com apenas redução do aroma. Foi avaliada sua higroscopicidade através de isotermas de adsorção. Observou-se que o pó permaneceu estável a baixas umidades e mostrou o mesmo comportamento dos pós contendo apenas maltodextrina. Os resultados obtidos neste trabalho mostraram a viabilidade da adição da FCM na secagem por atomização da polpa de maracujá, melhorando as características do pó e seu valor nutricional / Abstract: This work aimed to evaluate the addition of passion fruit peel flour (PFPF), as a substitute for part of maltodextrin used as an adjuvant in the spray drying of passion fruit pulp. The study of the physic-chemical, technological and structural characteristics of the flour obtained from the peel of yellow passion fruit was held. This having high porosity, good solubility in liquid medium and high glass transition temperature (Tg), being a product with promising technological characteristics. To assess the amount of PFPF added to replace maltodextrin, a study of the rheological behavior was performed. The rheological parameters were determined at 25, 40, 60 and 80°C via a coaxial cylinder viscometer, with variation of the strain rate from 6,60 at 198 s-1. In data fitting mathematical models of the: Laws of Power and Herschel-Bulkley. To optimize the maximum amount of PFPF was performed a rotational central statistical design 23, with 3 central points, totaling 17 tests, where the independent variables were the temperature of the incoming air (163 at 197°C), the mass flow rate (340 at 540 mL/h) and the concentration of maltodextrin (0/100% at 15/85% PFPF/maltodextrin w/w). The responses analyzed were bulk density, moisture powder, ascorbic acid content, process yield, dissolution time and hygroscopic powder. The addition of PFPF reduced moisture, increased yield and conservation of ascorbic acid in the final product. So the best drying conditions established were: 190°C, 500 mL/h and 11.6/88.4% PFPF/maltodextrin. The produced at optimum powder showed good acceptability, when prepared in the form of nectar, with only reduction of flavor. Its hygroscopicity was evaluated adsorption isotherms. It was observed that the powder was stable at low humidity and showed the same behavior of powders containing only maltodextrin. The results of this study show the viability of the addition of PFPF in spray drying of passion fruit pulp, improving the characteristics of the powder and its nutritional value / Doutorado / Tecnologia de Alimentos / Doutora em Tecnologia de Alimentos
7

Régulation des opérons Maltose/Maltodextrines et Gentiobiose induits en contexte d'infection chez Enterococcus faecalis / Regulation of Maltose/Maltodextrin and gentiobiose operons induced during infection in Enterococcus faecalis

Grand, Maxime 14 November 2019 (has links)
Les entérocoques sont des bactéries commensales de l'Homme majoritairement rencontrées dans le tractus digestif. En dépit du caractère bénéfique pour leur hôte, ces microorganismes sont retrouvés au deuxième rang des bactéries responsables d'infection nosocomiales en France ces dernières décennies. Diverses études tendent à montrer que le métabolisme énergétique constitue un facteur crucial pour le processus infectieux des microorganismes. Lors de ce travail, nous nous sommes intéressés à l'étude des métabolismes de différents polymères de glucoses chez Enterococcus faecalis : les maltodextrines et le gentiobiose. L'utilisation du maltose et des maltodextrines est, chez cette bactérie, directement coordonnée au niveau transcriptionnel par le répresseur MalR. L'activité de ce régulateur est rapidement modulée par le maltose qui représente l'inducteur du système et par un corépresseur protéique : la protéine P Ser HPr qui, à l'inverse, favorise la répression exercée par MalR. Le métabolisme des maltodextrines complexes, mais pas le métabolisme du maltose, est également réprimé par le régulateur pléiotrope CcpA en coordination avec son cofacteur P Ser HPr en présence de glucose. La répression catabolique de l'opéron genBA, impliqué dans le métabolisme du β glycoside gentiobiose, est aussi assurée par ce régulateur CcpA en présence de glucose. Cet opéron genBA est responsable de l'import du gentiobiose par un PTS ainsi que de son catabolisme grâce à une hydrolase. L'expression de cette structure opéronique nécessite la présence de l'activateur transcriptionnel GenR actif en présence de l'inducteur gentiobiose 6' P. / Enterococci are commensal bacteria of Humans predominantly encountered in the digestive tract. Despite their beneficial activity for their host, these microorganisms became the second leading bacterial cause of hospital acquired infections in France for last decades. Some studies showed that the central metabolism is a critical factor for microorganisms infection process. In this study, we worked on the characterisation of metabolisms of the different glucose polymers maltodextrins and gentiobiose in Enterococcus faecalis. The maltose and maltodextrins utilization is coordinated in this bacterium transcriptionally by the MalR repressor. The MalR activity is rapidly modulated by the inducer maltose and by the co repressor P Ser HPr which strengthens the MalR DNA binding. The metabolism of long maltodextrins is also repressed by the pleiotropic regulator CcpA in complex with its essential cofactor P Ser HPr in presence of glucose. The Catabolite repression of the operon genBA, involved in metabolism of the β glycoside gentiobiose, is assumed by CcpA in presence of glucose. This operon genBA allows the gentiobiose uptake with a PTS and its catabolism by a hydrolase. The expression of this latter operon requires both the GenR transcriptional activator and the inducer gentiobiose 6' P.
8

Baking enzymes and microencapsulation strategies for retardation of staling

Kaur, Harkirat, h_harkiratkaur@student.rmit.edu.au January 2008 (has links)
The staling of baked products remains a significant cause of economic loss due to the loss of enjoyment seen as crumb firming occurs. The aims of the current project have been to investigate the stability of amylases in bakery formulations. In addition, the impact of partial hydrolysis products of starch on staling is investigated. Specific assays were used to measure ƒÑ-amylase and ƒÒ-amylase, in the presence of the other potentially interfering activity. ƒÑ-Amylase activity levels appeared to gradually increase during the proofing stages and then to decline upon heating of the dough. However, the activity remaining in the final baked loaf was readily measurable indicating that not all of the enzyme had been inactivated. Free and total ƒÒ-amylase activities were also measured and most was found to be in the free form. ƒÒ-Amylase was unstable with only relatively low activities remaining in the final baked loaf. It appears that of the two amylolytic enzymes, ƒÑ-a mylase is sufficiently stable that it may exert some impact on the crumb characteristics in the freshly baked product and during subsequent storage. In order to assess the likelihood that amylolysis is of significance to crumb characteristics, HPLC was used to analyse aqueous extracts for sugars. Commercial flours were found to contain low levels of sugars with maltose being the predominant sugar present. A number of commercial breads were also analysed and the composition found to vary between the different samples. Typically maltose was present at higher levels than the other sugars. When experimental loaves were analysed, the patterns showed that other sugars declined during proofing whereas maltose remained at readily measurable levels. Upon baking and subsequent storage the amounts of maltose increased. These results are consistent with the findings that some amylolytic activity remains in the baked product. In the third phase of this study, a potential means of investigating the role of particular carb ohydrates in product textures and staling rates was examined. The approach of spray drying was used to prepare microencapsulated maltodextrin. The encapsulating agents used were based upon rice starch and guar galactomannan. When these microcapsules were incorporated into the breadmaking formulation and baked, it appeared that softer crumb characteristics were achieved. The data also indicates an effect of delay in the staling rates. In a preliminary evaluation of the potential of two X-ray scattering methods, it was found that both techniques appear useful. The differences seen for samples of bread crumb analysed at various stages of storage did not show large differences in the intensity patterns. Of the two approaches, small angle analysis (SAXS) appears to show greater potential for application in ongoing studies of staling. In conclusion, cereal grain ƒÑ-amylase may be more stable during breadmaking than previously thought. There appears to be an increase in the level of some low molecular weight sugars in the final, baked product. Microencapsulation may offer a useful technique for the study of the role of specific carbohydrates during baking and storage of breads.
9

DEVELOPMENT OF AN IN VITRO ASSAY TO EVALUATE ANTIMICROBIALS

OFORI, REGINA 06 July 2012 (has links)
In vitro assays were developed using small intestinal contents from broilers fed maltodextrin in preparation for shipping. This was done to establish an effective bactericidal dose of allicin or lysozyme as ingredients in maltodextrin-based feed. The antimicrobials were added to overnight cultures of gut material bacteria from maltodextrin fed broilers and a pure culture of Salmonella. Following this, lysozyme was incorporated into maltodextrin feed at 0, 10 and 20 g.kg-1 of feed and offered for 9 h to 4 pens of 20 birds per treatment. Bacterial numbers were analyzed using Proc Mixed of SAS. Allicin and lysozyme inhibited Enterobacteriaceae and Clostridium perfringens, respectively, in vitro. Lysozyme showed the most promise; it reduced bacterial numbers in nutrient broth. Feeding lysozyme-enriched maltodextrin for 9 h inhibited bacilli growth (P<0.05) when evaluated using next generation sequencing. Lysozyme was effective in reducing specific bacterial numbers in the gut of market-aged broilers / The project focused on ways to ensure poultry meat safety by controlling bacteria population in the gastrointestinal tract of market-aged broilers prior to shipping.
10

Utveckling av en fiberberikad probiotisk fruktdryck

Jonsson, Liza January 2014 (has links)
The purpose of this study was to investigate whether resistant maltodextrin is suitable as a fiber source in the probiotic fruit drink ProViva Mango without affecting the probiotic bacterium Lactobacillus plantarum 299v, viscosity or the sensory experience of the drink. Resistant maltodextrin is produced from hydrolyzed corn starch and is classified as a soluble dietary fiber. It is relatively resistant to digestion in the small intestine, where approximately 10% can be broken down, 50% can be fermented in the colon by the intestinal flora and 40 % is excreted in the faeces. Resistant maltodextrin has several important qualities when it comes to food processing. When added in a product, it does not affect the viscosity or taste and it is heat and acid stable. Three different fiber levels were added to ProViva Mango; 5 g, 10 g and 15 g/350 ml and they were compared against a reference beverage without added fiber. ProViva has a shelf life of 30 days and therefore analyses were planned to be performed at day 1 and after 15 and 32 days. Due to lack of time analyses were only performed at day 1 and 15. The study showed that resistant maltodextrin did not affect the viscosity or the probiotic bacteria L. plantarum 299v. The sensory analysis evaluated five different parameters: sweetness, fruitiness, grittiness, mouth feel and appearance. At day 1 and 15 there was no experienced significant difference between the fiber-enriched drinks and the reference drink in the evaluated sensory parameters. Brix test showed that the percentage of sugars increased with increasing fiber content. The conclusion of the study is that adding resistant maltodextrin to ProViva Mango doesn’t affect the physiological properties of ProViva. To obtain the same nutritional value as a standard ProViva Mango, the amount added sugar needs to be adjusted so that the amount of total sugars remain at the same level as the standard.

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