L'électro-activation (EA) est une approche novatrice qui permet l'isomérisation du lactose en lactulose directement in situ du lactosérum. Cependant, le lactosérum électro-activé (LA-EA) possède un pH hautement alcalin. Alors, l'objectif de ce travail est de contribuer au développement d'un procédé électrolytique pour la neutralisation du LA-EA. La détermination de l'effet des paramètres opératoires et physico-chimiques du milieu électro-activé sur la formation du lactulose a montré qu'un rendement maximum en lactulose de 34,71% est obtenu en utilisant une solution de lactosérum d'une concentration de 7% et 60 min de temps d'électro-activation sous une intensité du courant de 1000 mA après un temps de relaxation de 48 h. Trois configurations électrolytiques ont été étudiées pour la neutralisation de la solution du lactosérum: (1) en neutralisant avec l'anolyte généré dans le compartiment anodique; (2) en inversant les deux électrodes (cathode et anode) et (3) en introduisant le LA-EA dans le compartiment central du réacteur. Les résultats ont montré la faisabilité du processus d'électro-neutralisation. En effet, le pH de la solution a diminué soit en ajoutant des ions H⁺ (cas des configurations 1 et 2), ou en éliminant les ions OH⁻ de la solution (cas de la configuration 3). De plus, il a été révélé que l'électro-neutralisation est ralentie lorsque (I) augmente pour les deux configurations 1 et 2, tandis que pour la configuration 3, elle est accélérée. Les résultats de l'évaluation de l'effet de ce processus sur les propriétés du LA-EA ont montré que la neutralisation de la solution après un temps de relaxation de 48 h n'a pas affecté la composition glucidique du LA-EA, notamment le lactulose. De plus, elle a permis d'améliorer les propriétés techno-fonctionnelles des poudres résultantes en particulier en termes de reconstitution instantanée. / Electro activation (EA) is a novel approach that allows the isomerization of lactose to lactulose in situ from whey. However, electro-activated whey (LA-EA) has a highly alkaline pH. Therefore, the objective of this work is to contribute to the development of an electrolytic process for the neutralization of LA-EA. The determination of the effect of physico-chemical parameters on the formation of lactulose showed that the maximum lactulose yield (34.71%) is obtained for a feed concentration of 7% at 60 min of electro-activation, under a current intensity of 1000 mA after a relaxation time of 48 h. Three electrolytic configurations were studied for neutralization of the whey solution: (1) neutralizing with the anolyte generated at the anode compartment; (2) reversing the two electrodes (cathode and anode) and (3) introducing LA-EA into the central compartment of the reactor. The results showed the feasibility of the electro-neutralization process. Indeed, the pH of the solution decreased either by adding H⁺ ions (case of configurations 1 and 2), or by removing OH⁻ ions from the solution (case of configuration 3). Furthermore, it was revealed that electro-neutralization is slowed down when (I) increases for both configurations 1 and 2, while for configuration 3, it is accelerated. The results of the evaluation of the effect of this process on the properties of LA-EA showed that the neutralization of the solution after a relaxation time of 48 h did not affect the carbohydrate composition of LA-EA, especially lactulose. Moreover, it improved the techno-functional properties of the resulting powder in particular in terms of instant reconstitution.

L'électro-activation (EA) est une approche novatrice qui permet l'isomérisation du lactose en lactulose directement in situ du lactosérum. Cependant, le lactosérum électro-activé (LA-EA) possède un pH hautement alcalin. Alors, l'objectif de ce travail est de contribuer au développement d'un procédé électrolytique pour la neutralisation du LA-EA. La détermination de l'effet des paramètres opératoires et physico-chimiques du milieu électro-activé sur la formation du lactulose a montré qu'un rendement maximum en lactulose de 34,71% est obtenu en utilisant une solution de lactosérum d'une concentration de 7% et 60 min de temps d'électro-activation sous une intensité du courant de 1000 mA après un temps de relaxation de 48 h. Trois configurations électrolytiques ont été étudiées pour la neutralisation de la solution du lactosérum: (1) en neutralisant avec l'anolyte généré dans le compartiment anodique; (2) en inversant les deux électrodes (cathode et anode) et (3) en introduisant le LA-EA dans le compartiment central du réacteur. Les résultats ont montré la faisabilité du processus d'électro-neutralisation. En effet, le pH de la solution a diminué soit en ajoutant des ions H⁺ (cas des configurations 1 et 2), ou en éliminant les ions OH⁻ de la solution (cas de la configuration 3). De plus, il a été révélé que l'électro-neutralisation est ralentie lorsque (I) augmente pour les deux configurations 1 et 2, tandis que pour la configuration 3, elle est accélérée. Les résultats de l'évaluation de l'effet de ce processus sur les propriétés du LA-EA ont montré que la neutralisation de la solution après un temps de relaxation de 48 h n'a pas affecté la composition glucidique du LA-EA, notamment le lactulose. De plus, elle a permis d'améliorer les propriétés techno-fonctionnelles des poudres résultantes en particulier en termes de reconstitution instantanée. / Electro activation (EA) is a novel approach that allows the isomerization of lactose to lactulose in situ from whey. However, electro-activated whey (LA-EA) has a highly alkaline pH. Therefore, the objective of this work is to contribute to the development of an electrolytic process for the neutralization of LA-EA. The determination of the effect of physico-chemical parameters on the formation of lactulose showed that the maximum lactulose yield (34.71%) is obtained for a feed concentration of 7% at 60 min of electro-activation, under a current intensity of 1000 mA after a relaxation time of 48 h. Three electrolytic configurations were studied for neutralization of the whey solution: (1) neutralizing with the anolyte generated at the anode compartment; (2) reversing the two electrodes (cathode and anode) and (3) introducing LA-EA into the central compartment of the reactor. The results showed the feasibility of the electro-neutralization process. Indeed, the pH of the solution decreased either by adding H⁺ ions (case of configurations 1 and 2), or by removing OH⁻ ions from the solution (case of configuration 3). Furthermore, it was revealed that electro-neutralization is slowed down when (I) increases for both configurations 1 and 2, while for configuration 3, it is accelerated. The results of the evaluation of the effect of this process on the properties of LA-EA showed that the neutralization of the solution after a relaxation time of 48 h did not affect the carbohydrate composition of LA-EA, especially lactulose. Moreover, it improved the techno-functional properties of the resulting powder in particular in terms of instant reconstitution.

<p>Farm animals face a variety of stressors during commercial production practices, and economic necessities and ethical considerations require mitigation strategies to help animals cope with stressors that might otherwise reduce animal performance or lead to morbidity. In swine production, arguably the most stressful period of a pig’s life is the first several weeks following weaning (nursery period), where pigs must rapidly adapt to a host of environmental and physiological stressors. In broiler chickens, exposure to environmental temperatures above their comfort zone is a considerable stressor. Accordingly, several studies were conducted with the objective of developing alternative ways to measure physiological stress in nursery pigs and broiler chickens. These alternative methods may improve the ability of animal scientists to measure physiological stress and thereby aid in development of mitigation strategies. Nursery pigs frequently struggle with diarrhea and other intestinal diseases characterized by increases in intestinal permeability. Therefore, several studies were conducted to evaluate the use of non-metabolizable carbohydrates (lactulose and mannitol) as a non-invasive measure of intestinal health in weanling pigs. In Exp 2.1 and Exp 2.2, an aspirin-induced model of intestinal permeability was explored and the excretion pattern of lactulose and mannitol in urine over a 48 h urine collection period was determined. Aspirin at 15 mg/kg BW increased the excretion of lactulose over that of pigs given 0 or 30 mg/kg of aspirin, and therefore has potential to be used to induce intestinal permeability in nursery pigs. The excretion of lactulose and mannitol peaked at 4 h post-oral dose with a solution of lactulose and mannitol and was primarily complete by 8 h post-oral dose. In the few published reports of the lactulose and mannitol test of intestinal health in weanling pigs, the dose of lactulose and mannitol has varied considerably, raising questions as to the comparability of the results. Accordingly, in Exp 3.1, the impact of variation in the dose of lactulose and mannitol was explored, and pigs given the lowest dose at 0.2 g/kg BW lactulose and 0.02 g/kg BW mannitol had large numerical decreases in lactulose excretion warranting further investigation. Pigs in Exp 3.1 also demonstrated low urine recovery rates (50% successful urine collection averaged over the 3 urine collection time points) which were postulated to be due to the stresses associated with urine collection in metabolism cages combining with the stresses of weaning. Therefore, in Exp 3.2, an alternative urine collection procedure was developed that utilized a urine collection pad held in place by an elastic wrap. Results from Exp 3.2 with urine collected either by metabolism cages or via the urine collection pads indicated that the urine collection pad held promise as an alternative urine collection method that would not require the use of metabolism cages. Accordingly, the use of the collection pad was evaluated as part of a lactulose and mannitol test of intestinal health in group-housed nursery pigs in Exp 5.1. In brief, in Exp 5.1, pigs were weaned, transported for 12 h in a livestock trailer, and fed five treatment diets for 14 d post-weaning. The treatment diets were designed to evaluate the additive effects of L-glutamine and a combination of prebiotics and probiotics as potential antibiotic alternatives to aid in mitigating stress associated with weaning and transport. After two weeks of treatment diets, common diets were fed through market-weight. Urine collection pads were used on 40 pigs (8 pigs per treatment) on d 5 and d 12 post-weaning, with pigs allowed to remain in their familiar group pen during the urine collection period, and urine collection success rates averaged 84% across collection days. This improvement over that of Exp 3.1 may indicate that the use of a urine collection pad may improve the ability to obtain urine from pigs shortly after weaning. Considerable variation in the excretion of lactulose and mannitol was still observed similarly to that seen in Exp 3.1 and precluded statistical differences among dietary treatments. An increase in urine collection length was postulated to be one potential way to reduce that variation. Additional responses to the nursery diets fed in Exp 5.1 are discussed in Chapters 4 and 5. In broiler chickens, measurement of physiological heat stress is limited by the existing techniques which have considerable disadvantages. Therefore, in Chapter 6 a simple surgical procedure is detailed that allows small data loggers to be placed into the abdominal cavity of anesthetized broiler chickens. After a period to allow the chickens to recover from the surgery, these data loggers can record the internal temperature of the chicken at user-defined intervals and have the ability to gather large amounts of internal body temperature data in a wide variety of research settings. A more traditional measure of physiological heat stress in chickens is measurement of the temperature of the cloaca with a thermometer. Therefore, to compare the two methods, values from implanted data loggers were compared to values obtained by measuring the temperature of the cloaca in Exp 6.1 and Exp 6.2, and in general, the two methods yielded similar results. Since surgery to implant data loggers is not always possible or practical, in Chapter 7 the development and evaluation of an equation to predict the internal temperature of broiler chickens was investigated. In Exp 7.1, broiler chickens were exposed to four ambient temperatures each day for four days. The surface temperature of the chicken’s face was measured with a thermal imaging camera, while internal temperature was measured with data loggers as in Chapter 6. The resulting prediction equation contained the significant explanatory variables of the surface temperature of the face, the sex of the chicken, and the number of days of heat stress exposure. Accordingly, the accuracy of the prediction equation was evaluated in Exp 7.2, where chickens were exposed to the same 4 ambient temperatures and temperatures of the face and the internal body measured as in Exp 7.1. The prediction equation developed in Exp 7.1 was then used with the inputs of the facial surface temperature, sex of the birds, and number of days of heat stress exposure from chickens in Exp 7.2 to calculate a predicted internal temperature. This predicted internal temperature was then compared to the internal temperature as measured with data loggers in Exp 7.2. While the accuracy varied by experimental day and ambient temperature, the predicted internal temperature averaged 0.32°C greater than the measured internal temperature. Therefore, while the prediction equation shows considerable promise as a non-invasive metric of physiological heat stress in broiler chickens, refinement of the equation may be required in future studies before internal temperature may be predicted with the accuracy desired in a research setting. In conclusion, the lactulose and mannitol urinary test of intestinal health requires more research before wide-spread use but has considerable promise as a non-invasive test. Surgical implantation of data loggers to measure internal temperature of broiler chickens enables precise measurement of physiological heat stress in broiler chickens, and further research may enable accurate prediction of internal body temperature of broiler chickens without requiring invasive measurement techniques. <br></p><p> </p>

The development of processes for the preparation of prebiotic compounds, namely inulin from tubers of Jerusalem artichoke (JA-Helianthus tuberosus L.), and lactulose from milk concentration permeate (MCP) was examined. Inulin was extracted from the whole JA tubers using hydrothermal extraction process, followed by clarification and concentration. The concentrate was fractionated using two different procedures i.e. ethanol fractionation and cold precipitation (+4 and/or -24C) into high- and low-molecular-weight components. The most satisfactory method was cold fractionation wherein the insoluble heavier inulin fractions were found to settle to the bottom and were separated and spray-dried to obtain inulin powder. Lactose in MCP was isomerised into lactulose using carbonate-based catalysts (oyster shell and egg shell powders) followed by clarification and concentration. The high-performance liquid chromatography with refractive index detector (HPLC-RID) chr omatograms and changes in pH and colour values confirmed the conversion of lactose into lactulose and decomposition of lactulose into by-products. The results obtained showed the suitability of oyster shell powder for lactose isomerisation in lieu of egg shell powder. For preparing lactulose-enriched MCP with acceptable lactulose yield of 22%, the optimum reaction conditions were found to be catalyst loading of 12 mg per mL of MCP and isomerisation time of 120 min at 96C. The resulting products i.e. JAI concentrate and powder and lactulose-enriched MCP syrup (40B) were tested for their prebiotic power in media broth and in fermented milk models. Prebiotic properties of these compounds were observed as supplementation levels increased from 0-2% to 3-4%. Based on the growth and acidification abilities of the probiotic strains tested, the combination of Lactobacillus casei LC-01 with JAI, and Lactobacillus acidophilus LA-5 with lactulose-enriched MCP syrup were found to be the best for development of synbiotic yoghurt. The prebiotic effect of JAIP was then compared with the two commercial chicory inulin products (Raftiline GR and Raftilose P95). Probiotic yoghurts supplemented with 4% inulin powders were prepared from reconstituted skim milk using mixed cultures of Lactobacillus casei LC-01, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (1:0.5:0.5, w/w). The survival and acidifying activity of probiotic and lactic acid cultures were investiga ted during the shelf life of 28 days at 4C. Incorporation of JAIP and chicory inulins resulted in a significant improvement in viability of LC-01 compared with non-supplemented yoghurt, maintaining more than 107 CFU g-1 throughout storage time. Additionally, the suitability of JAIP as fat replacer was determined in a set of fat-free yoghurt in comparison to three commercial chicory inulin products. Results of large deformation tests revealed that the firmness of JAIP-supplemented yoghurt was reduced to a similar level as the full-fat control yoghurt. However, small deformation results showed that the JAIP could not fully mimic milk fat to the same extent as Raftiline HP with an average DP of 23. The rheological effects of JAIP addition were comparable to those of short-chain (Raftilose P95 with an average DP of 4) and medium-chain inulins (Raftiline® GR with an average DP of 12).

Universiẗat, Diss., 2004--Leipzig.

Ce projet a démontré la faisabilité de fabrication de pain à base de farine riche en son de blé additionnée de lactulose jusqu'à 5%. La pâte enrichie de lactulose est caractérisée par une acidité titrable légèrement inférieure au témoin. Ceci est attribuable à l'incapacité des levures à fermenter le lactulose. La cuisson a montré que l'ajout de lactulose à la formule de pain à un niveau allant jusqu'à 5% n'a pas d'incidence négative sur la qualité du pain. L'évaluation visuelle et sensorielle a montré que l'ajout de 5% de lactulose à la formulation de pain de blé ne modifie pas le profil de texture du produit. La structure de la mie du pain témoin est légèrement plus poreuse que celle du pain additionné de lactulose à 5%. Le volume massique du pain est également plus faible, ce qui indique que des changements de texture se sont produits, mais restent acceptables.

Dans le présent travail, l’électro-isomérisation du lactose en lactulose a été étudiée. Les variables indépendantes mises à l’étude dans ce projet sont : 1) l’effet de la concentration du lactose (5 et 10%), l’effet de la densité du champ électrique appliqué au réacteur d’électro-activation (100 et 200 mA). L’électro-isomérisation du lactose à 5% a été également comparée à celle observée dans du lactosérum ayant une concentration de lactose ≈ 5%. Les variables réponse principales (variables dépendantes) mises à l’étude étaient le taux de conversion du lactose en lactulose, le taux de formation de sous-produits de la réaction et l'efficacité du procédé exprimée en termes de résistance électrique globale du système d’électro-activation. Une surface totale de l’aire cathodique de 21,5 cm2 a été utilisée, donnant ainsi des densités de courant électrique de 4,65 et 9,30 mA/cm2, respectivement. Les analyses statistiques des données obtenues ont montré que l’effet du temps d’électro-activation sur le taux d’électro-isomérisation du lactose (rendement de formation de lactulose) ainsi que la résistance électrique du réacteur électro-activation était significatif. Le processus d’électro-activation a été réalisé pendant 60 min et des échantillons ont été prélevés chaque 10 min. Les résultats obtenus ont montré la grande efficacité de l'électro-activation, en tant qu’approche novatrice, pour transformer le lactose en lactulose. Après 60 min d’électro-activation à température ambiante (23 +/- 1 °C), 25% de rendement d’électro-isomérisation a été obtenu. En excluant le lactose, la pureté du produit final était de 96,28 +/- 0,18%. En outre, aucune formation d’epilactose n’a été observée. De façon non systématique, du galactose a été détecté dans certains échantillons (&lt; 1,5%) et seulement quelques traces de fructose ont été observées (&lt; 0,31%). La résistance électrique globale du réacteur d’électro-activation diminuait avec l’augmentation du temps d'électro-activation, indiquant une grande efficacité énergétique de cette nouvelle technologie d’isomérisation du lactose en lactulose. / In the present work, electro-isomerization of lactose into lactulose has been studied. Effects of lactose concentration (5 and 10%) and applied DC-electric field (100 and 200 mA) on the electro-isomerization of lactose into lactulose and on process efficiency were investigated. Total cathode area of 21.5 cm2 was used; giving electric current density of 4.65 mA/cm2 and 9.30 mA/cm2, respectively. Milk whey permeate (4.7 +/- 0.15% lactose) obtained by ultrafiltration was also used as feed solution in the electro-activation reactor. The effect of processing time on lactose electro-isomerization rate (lactulose formation yield), by-product (glucose, galactose, epilactose and fructose) formation, and global electric resistance of the electro-activation reactor has been investigated. The process was run during 60 min and samples were taken every 10 min. Obtained results showed the high effectiveness of the developed electro-activation technology to convert lactose into lactulose. After 60 min electro-activation at ambient temperature (23 +/- 1 °C), 25% electro-isomerisation yield was obtained. By excluding lactose, the end product purity was 96.28 +/- 0.18%, which is similar to the pharmakopoeia requirements for lactulose powder. Moreover, no epilactose was formed. Not systematically, galactose was detected in some samples (&lt; 1.5%) and only some traces of fructose were detected (&lt; 0.31%). The global electric resistance of the electro-activation reactor decreased as the electro-activation time was increased indicating the high energetic effectiveness of this new electro-isomerization technology.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-25T13:09:16Z No. of bitstreams: 2 Tese - Felix André Sanches Penhavel - 2014.pdf: 2537517 bytes, checksum: 2edff02f8a1f3fa50c180c2222a53b17 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-25T13:34:49Z (GMT) No. of bitstreams: 2 Tese - Felix André Sanches Penhavel - 2014.pdf: 2537517 bytes, checksum: 2edff02f8a1f3fa50c180c2222a53b17 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-25T13:34:49Z (GMT). No. of bitstreams: 2 Tese - Felix André Sanches Penhavel - 2014.pdf: 2537517 bytes, checksum: 2edff02f8a1f3fa50c180c2222a53b17 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-12-15 / American Tripanosomiasis is one of the most prevalente tropical disease in Latin America. One third of brazilian territory is considered endemic for Chagas disease. Vectorial transmission is not complitely interrupted. In Central Brazil, specially Goiás State, digestive forms with megasyndormes have a high frequence. The involvement of small bowel has been discribed with functional disturbances. Patients with acquired megacolon may have normal bowel movements or long lasting constipation. Until now the influence of small bowel on the frequence of bowel movements is not clear. This prospective study addressed the small bowel motility measuring the orocecal transit time (OCTT) and the occurence of small bowel intestinal bacterial overgrowth (SIBO) by hydrogen breath test. 45 patients with positive serology for Chagas disease were divided into four groups: A – without megacolon and no constipation (17); B – with megacolon and no constipation (8); C – with megacolon and constipation (10) and D – without megacolon and constipation (10). Constipation was defined by at least 7 days without bowel movements. 15 healthy volunteers were taken as a control group (CG). Non hydrogen producers: 10/45 patients and 1/15 controls. The OCTT (medium time in minutes) was longer in patients than in controls: A=108.18, B=108.0, C=112.5, D=130.0 and CG=68.46. Patients together showed difference compared to controls (P=0.001). No difference was found among groups (P>0.05). The prevalence of SIBO was: 66.7% in constipated patients (C and D), 25% in non constipated patients (A and B) and 8.3% in controls. Significant statistical difference was found only comparing constipated patients and controls (P=0.017). The presence of megacolon did not show influence the frequence of SIBO (P=0.181). Lactose and D-xylose malabsorption was higher in controls. The number of patients with symptoms during the test was the same for chagasic and controls independently of the test result. Patients with Chagas disease have a prolonged OCTT and those with constipation showed a higher prevalence of SIBO and both factors are not related to megacolon. Chagasic patients showed a less frequency of lactose and D- xylose malabsorption. / A Tripanossomíase Americana é uma das doenças tropicais mais prevalentes na América Latina. Mais de um terço do território brasileiro é área endêmica, e a transmissão vetorial ainda não se interrompeu em todos os estados. Em Goiás, as megassíndromes do tubo digestivo são muito frequentes. O comprometimento do tubo digestivo não se restringe à víscera dilatada e alterações funcionais têm sido descritas no intestino delgado. O objetivo geral deste estudo foi investigar alterações de motilidade e de absorção de carboidratos no intestino delgado de pacientes chagásicos com e sem constipação e megacólon. Avaliou-se 45 pacientes com sorologia positiva para doença de Chagas, divididos em quatro grupos: A - sem constipação, sem megacólon (17); B - sem constipação, com megacólon (8); C - com constipação, com megacólon (10) e D - com constipação, sem megacólon (10). Quinze voluntários sadios foram usados como controles (GC). Todos os pacientes e controles realizaram três testes respiratórios com os substratos: lactulose, lactose e D-xilose. Identificou-se não produção de hidrogênio em 10 pacientes e um controle. O tempo de trânsito orocecal (TTOC) (média em minutos) foi maior nos pacientes do que nos controles: A=108,18; B=108,0; C=112,5; D=130,0 e GC=68,46 (P=0,001). Não houve diferença no TTOC entre os grupos de pacientes (P<0,05). A prevalência de supercrescimento bacteriano no intestino delgado (SBID) foi de 66,7% nos pacientes constipados (C e D), 25% nos não constipados (A e B) e de 8,3% nos controles (P=0,017). A presença de megacólon não influenciou a frequência de SBID (P=0,181). A má absorção de lactose foi maior entre os controles. O número de pacientes que apresentava sintomas ou não durante o teste da lactose foi igual para pacientes e controles, independentemente do resultado do teste. A má absorção de D-xilose foi mais frequente no grupo controle. Concluiu-se que os pacientes chagásicos têm o tempo de trânsito orocecal prolongado e que aqueles com constipação apresentam uma maior prevalência de SBID, ambos os fatores não sofrem influência da presença do megacólon. A má absorção de lactose e D-xilose foi maior entre controles.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-10T15:07:06Z No. of bitstreams: 1 leandranataliadeoliveiraneves.pdf: 2553405 bytes, checksum: ca2d010014f08aa1f723b669f468fc96 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-15T18:59:47Z (GMT) No. of bitstreams: 1 leandranataliadeoliveiraneves.pdf: 2553405 bytes, checksum: ca2d010014f08aa1f723b669f468fc96 (MD5) / Made available in DSpace on 2016-06-15T18:59:47Z (GMT). No. of bitstreams: 1 leandranataliadeoliveiraneves.pdf: 2553405 bytes, checksum: ca2d010014f08aa1f723b669f468fc96 (MD5) Previous issue date: 2015-04-17 / O leite é considerado um alimento rico nutricionalmente por ser fonte de proteínas, carboidrato, vitaminas e minerais. Durante o processamento térmico do leite, reações químicas podem ocorrer gerando modificações de compostos pré-existentes ou formação de novos compostos, os quais se comportam como indicadores do tratamento térmico utilizado. O monitoramento destes indicadores em leite UHT é de grande importância uma vez que permite traçar o perfil do produto e do processo, podendo sugerir intervenções tecnológicas capazes de minimizar custos de produção bem como reduzir a ocorrência de eventuais perdas nutricionais e descaracterização do produto. O presente trabalho teve como objetivo quantificar os indicadores índice de soroproteína não desnaturada – WPNI, 5-hidroximetilfurfural – HMF e lactulose em amostras de leite UHT, com teor regular e reduzido de lactose, comercializadas no mercado nacional. Metodologias analíticas para WPNI e HMF, ambos determinados por métodos espectrofotométricos, foram implantadas e os modelos estatísticos foram ajustados. Dois métodos analíticos de separação para determinação de lactulose foram desenvolvidos e validados utilizando cromatografia líquida de alta eficiência (HPLC) com detecção por índice de refração e eletroforese capilar de zona (CZE) com detecção indireta no ultravioleta. Os resultados obtidos no teste de comparação de médias do teor de lactulose pelos métodos por HPLC e CZE indicaram não haver diferença significativa entre os métodos propostos. A média do índice de WPNI indicou que 76% das amostras em estudo são classificadas como “médio tratamento térmico”. Os índices de HMF livre e total mostraram-se capazes de discriminar amostras com teor regular e com teor reduzido de lactose. Flutuações nos índices de WPNI e HMF livre e no teor de lactulose das amostras analisadas sugeriram a ocorrência de falta de uniformidade do processamento adotado pelas indústrias nacionais processadoras de leite UHT, o que foi confirmado pelo efeito de marca sobre estes índices no produto. Verificou-se que os métodos analíticos implantados e desenvolvidos são capazes de atender à demanda de métodos de controle aptos em avaliar o processo e oferecer suporte para desenvolvimento e estudo do processamento. Os indicadores monitorados remetem a ocorrência de despadronização do perfil químico do leite UHT atualmente comercializado no mercado nacional, refletindo a necessidade de um maior controle do processamento pelas indústrias processadoras. / Milk is considered a nutritionally rich food because it is a source of protein, carbohydrate, vitamins and minerals. During milk heat treatment, chemical reactions can occur causing changes of pre-existing compounds or formation of new compounds, which can be used as indicators of heat treatment used. The monitoring of these indicators in UHT milk is very important since they allow to draw the product and process profile and can suggest technological interventions that can minimize production costs and reduce the occurrence of any nutritional losses and distortion of the product. This study aimed to quantify the indicators whey protein nitrogen index - WPNI, 5-hydroxymethylfurfural – HMF and lactulose in UHT milk samples, with regular and reduced lactose content, sold in the domestic market. Analytical methodologies for WPNI and HMF (both measured by spectrophotometric methods) were implemented and the statistical models were fitted. Two analytical methods of separation for lactulose determination were developed and validated using high performance liquid chromatography (HPLC) with detection by refractive index and capillary zone electrophoresis (CZE) with indirect UV detection. The results obtained in the mean comparison test of lactulose content by HPLC and CZE methods showed no significant difference between the proposed methods. The average WPNI index indicated that 76% of the samples studied are classified as "medium heat treatment". The contents of free and total HMF were able to discriminate samples with regular and reduced lactose content. Fluctuations in WPNI, free HMF and lactulose content of the examined samples suggested the occurrence of non-uniformity of processing adopted in processing UHT milk of national industries, which was confirmed by the effect of these indicators in the product. It was found that analytical methods studied are able to achieve the control methods demanded to evaluate the process and support the development and study of processing. The monitored indicators refer to the occurrence of lack of standardization in the chemical profile of UHT milk currently commercialized in Brazilian market, reflecting the need for greater control of processing by milk processing industries.

Le lactosérum et le perméat de lactosérum (WP) sont les principaux sous-produits du processus de fabrication du fromage et de la caséine. Ils sont considérés comme des polluants environnementaux en raison de leur charge organique élevée caractérisée par une haute demande biologique et chimique en oxygène. Ils créent un problème majeur d'élimination pour l'industrie laitière en raison des grands volumes de leur production annuelle. Par conséquent, il y a une demande constante de développer une approche durable pour leur utilisation afin d'éviter la pollution de l'environnement. Dans ce contexte, cette étude visait à comparer la technologie d'électro-activation (EA) à un processus d'isomérisation chimique, à alcalinité équivalente de la solution, pour produire du lactulose, qui est un prébiotique reconnu et éprouvé, en utilisant du lactose pur, du lactosérum et du perméat de lactosérum, comme matières premières sources de lactose, et de valoriser les produits électro-activés en produisant des métabolites à haute valeur ajoutée en utilisant une culture de kéfir et une culture pure de Kluyveromyces marxianus comme approche intégrée pour la valorisation complète de ces résidus de l'industrie laitière. La technologie d'électro-activation a été appliquée pour isomériser le lactose en lactulose dans un réacteur d'électro-activation modulé par des membranes échangeuses d'anions et de cations. L'électro-isomérisation du lactose en lactulose a été réalisée en utilisant des solutions de lactose (5, 10, 15 et 20 % p/v), de lactosérum (7, 14 et 21 % p/v) et de perméat de lactosérum (6, 12 et 18 % p/v) sous des intensités de courant électrique de 300, 600 et 900 mA pendant 60 min avec un intervalle d'échantillonnage de 5 min. L'isomérisation chimique conventionnelle a été réalisée à une alcalinité de la solution équivalente au KOH correspondant à celle mesurée dans les substrats électro-activés (lactose, lactosérum et perméat de lactosérum) à chaque intervalle de 5 min en utilisant de la poudre de KOH comme catalyseur à température ambiante (22 ± 2 °C). Les résultats obtenus ont montré que la production de lactulose en utilisant l'approche par électro-activation dépendait de l'intensité du courant électrique, de la concentration de la solution soumise à l'électro-activation et du temps de réaction. Les rendements les plus élevés de lactulose sont de 38 % en utilisant une solution de lactose de 10 % électro-activé pendant 40 min sous 900 mA, de 32 % en utilisant une solution de 7 % de lactosérum électro-activé sous 900 mA pendant 60 min et de 37 % en utilisant une solution de 6 % de perméat de lactosérum électro-activé sous 900 mA pendant 50 min. Parallèlement, les résultats ont montré qu'avec une approche chimique conventionnelle avec du KOH comme catalyseur, les rendements de lactulose étaient de ~27 % en utilisant une solution de 10 % de lactose pendant 60 min et de 25,47 % en utilisant une solution de 6 % de perméat de lactosérum pendant 50 min. Cependant, aucune formation de lactulose n'a été observée en utilisant du lactosérum dans le procédé chimique conventionnel à une alcalinité équivalente de la solution traitée par électro-activation. Les résultats de cette étude ont révélé que la technologie d'électro-activation est plus efficace pour la production du lactulose à partir du lactose pur, du lactosérum et du perméat de lactosérum par rapport au processus d'isomérisation chimique conventionnelle. Par la suite, la faisabilité d'utiliser les substrats à base de lactose électro-activé, du lactosérum électro-activé et du perméat de lactosérum électro-activé comme sources de carbone pour produire de la biomasse riche en protéines et métabolites à valeur commerciale élevée comme des acides organiques (lactique, acétique, citrique et propionique) et des biomolécules aux propriétés aromatiques et gustatives a été étudiée en utilisant une culture microbienne mixte provenant de grains de kéfir comme ferment et une culture pure de Kluyveromyces marxianus. La fermentation a été réalisée pendant 96 h à 30 °C en utilisant les substrats électro-activés et non électro-activés du lactose, du lactosérum et du perméat de lactosérum. Les résultats obtenus ont montré que les substrats électro-activés ont permis d'atteindre une croissance de la biomasse la plus élevée en un temps de fermentation réduit comparativement aux substrats non électro-activés en utilisant la culture de kéfir comme agent de fermentation. La croissance cellulaire la plus élevée (6,04 g/L) a été obtenue dans le lactosérum électro-activé après 72 h, qui était 1,7 fois supérieure à ce qui était obtenu dans le milieu clostridien renforcé (RCM). De plus, le lactosérum électro-activé a permis de produire un maximum de 8,46, 3,97, 0,60 et 1,02 g/L d'acide lactique, acétique, citrique et propionique, respectivement. De plus, le lactosérum électro-activé a permis la production de kéfiran la plus élevée de 2,99 g/L, suivi par le lactosérum (2,67 g/L), le perméat de lactosérum électro-activé (2,31 g/L), le perméat de lactosérum (1,88 g/L), le milieu RCM (1,42 g /L), le lactose électro-activé (1,37 g/L) et le lactose (0,91 g/L). Les résultats ont également démontré que divers composés aromatiques volatils étaient produits au cours de la fermentation du lactosérum électro-activé, ce qui peut améliorer les caractéristiques organoleptiques et la qualité sensorielle des produits fermentés. Également, K. marxianus a également montré une production satisfaisante de la biomasse dans tous les substrats utilisés et que le lactosérum électro-activé a permis d'atteindre une biomasse maximale (4,23 g/L) après 96 h de fermentation, suivie du milieu standard YM (4,85 g/L). La biomasse produite avait une teneur élevée en protéines et en lipides (24,43-57,83 et 15,44-25,64 %, respectivement) dépendamment des substrats utilisés et des conditions de fermentation. Plusieurs acides organiques majeurs comme les acides lactique, acétique, citrique et propionique ont été produits pendant la fermentation sur tous les milieux, avec des différences significatives entre les substrats électro-activés et non électro-activés. De plus, K. marxianus a produit divers composés aromatiques volatils aux propriétés organoleptiques appréciées. Le milieu de culture YM a entraîné la plus faible production d'éthanol (8,42 g/L à 48 h) tandis que la plus forte production d'éthanol a été produite dans le lactosérum non électro-activé (28,13 g/L à 48 h), suivi du lactose (27,85 g/L à 48 h), du lactose électro-activé (26,77 g/L à 36 h), du perméat de lactosérum (25,99 à 72 h), du perméat de lactosérum électro-activé (24,66 g/L à 36 h) et du lactosérum électro-activé(22,06 g/L à 48 h). De plus, un maximum de 393,85 à 988,22 mg/L de 2-phényléthanol a été atteint, selon les substrats utilisés. Par conséquent, les résultats de ce projet suggèrent que la technologie d'électro-activation peut être une approche durable émergente permettant d'atteindre le double objectif de production de lactulose, un prébiotique reconnu et éprouvé, et de valorisation intégrale du lactosérum et de ses dérivés en utilisant des bioprocédés à base de culture de kéfir et de K. marxianus pour produire des métabolites à valeur commerciale élevée pour différentes applications; y compris pour l'industrie de l'alimentation humaine et animale. Ainsi, les connaissances obtenues dans ce projet pourront servir à améliorer la valorisation du lactosérum. / Whey and whey permeate (WP) are the main agro-industrial by-products from cheese or casein production process that are regarded as environmental pollutants because of their high organic load (high biochemical and chemical oxygen demand) and are creating a major disposal problem for the dairy industry. Consequently, there is a serious demand of developing a sustainable approach for their utilization to evade environmental pollution. In this context, the study was intended to compare the electro-activation (EA) technology with a chemical isomerization process at equivalent solution alkalinity to produce a prebiotic lactulose using lactose, whey, and WP as feedstocks and to valorize the electro-activated materials into valuable metabolites using a whole Kefir culture and a pure culture of Kluyveromyces marxianus as an integrated approach for complete valorization of these waste products. The EA technique was applied to isomerize lactose into lactulose in an EA react or modulated by anion and cation exchange membranes. Electro-isomerization of lactose into lactulose was performed by using lactose (5, 10, 15, and 20%, w/v), whey (7, 14, and 21%, w/v), and WP (6, 12, and 18%, w/v) solutions under current intensities of 300, 600, and 900 mA during 60 min with a sampling interval of 5 min. The conventional chemical isomerization was carried out at the KOH-equivalent solution alkalinity corresponding to that measured in the electro-activated lactose (EA-lactose), electro-activated whey (EA-whey), electro-activated whey permeate (EA-WP) solutions at each 5 min interval using KOH powder as a catalyst at ambient temperature (22 ± 2 °C). The results showed that the production of lactulose using the EA approach was current intensity-, solution concentration-, and reaction time-dependent. The highest lactulose yields of 38 (at 40 min for a 900 mA and 10% lactose solution), 32 (at 60 min for a 900 mA and 7% whey solution), and 36.98% (at 50 min for a 900 mA and 6% WP solution) were achieved for lactose, whey, and WP, respectively. Whereas the maximum lactulose yields of ~27 (at 60 min for 10% lactose solution) and 25.47% (at 50 min for 6% WP solution) were obtained for lactose and WP, respectively. However, no lactulose was produced for whey using the chemical process at the equivalent solution alkalinity as in the EA technique. The outcomes of this study revealed that the EA technology is a more efficient technique for the enhanced production of lactulose from lactose, whey, and WP compared to the convention chemical isomerization process. Thereafter, the feasibility of using electro-activated whey-based substrates including EA-lactose, EA-whey, EA-WP as carbon sources to produce protein enriched biomass and valuable metabolites including organic acids (i.e., lactic, acetic, citric, and propionic acids) and biomolecules with aroma and flavor properties was studied using a mixed microbiota originated from whole kefir grains as a starter culture and a pure culture of Kluyveromyces marxianus ATCC 64884. Fermentation was performed for 96 h at 30 °C using both electro-activated (EA) and non-electroactivated (non-EA) substances of lactose, whey, and WP. The results showed that the EA-substrates achieved a higher biomass growth in a reduced fermentation time than their non-EA mediums using the kefir culture. The highest cell growth (6.04 g/L) was obtained for EA-whey after 72 h which was even 1.7-fold higher than a standard nutrition broth, the reinforced clostridial medium (RCM). Furthermore, EA-whey produced a maximum of 8.46, 3.97, 0.60, and 1.02 g/L of lactic, acetic, citric, and propionic acid, respectively. Moreover, EA-whey achieved the highest kefiran production of 2.99 g/L, followed by the whey (2.67 g/L), EA-WP (2.31 g/L), WP (1.88 g/L), RCM broth (1.42 g/L), EA-lactose (1.37 g/L), and lactose (0.91 g/L). The results also demonstrated that various aromatic volatile compounds were produced during the fermentation of EA-whey, which may increase the organoleptic characteristic/sensory quality of the fermented products. Nevertheless, K. marxianus also demonstrated a satisfactory biomass growth in all substrates used and EA-whey achieved a maximum biomass (4.23 g/L) at 96 h of fermentation followed by YM broth (4.85 g/L). The produced biomass had high protein and lipid content (24.43-57.83, and 15.44-25.64%) depending on the used substrates and fermentation conditions. Several major organic acids including lactic, acetic, citric, propionic acids were produced during the fermentation on all media, with significant differences between electro-activated and non-electro-activated substrates. Furthermore, K. marxianus produced various volatile aroma compounds with valued organoleptic properties. The YM-broth resulted in the lowest ethanol production (8.42 g/L at 48 h) while the highest ethanol was produced in the non-electro-activated whey (28.13 g/L at 48 h), followed by lactose (27.85 g/L at 48 h), EA-lactose (26.77 g/L at 36 h), WP (25.99 at 72 h), EA-WP (24.66 g/L at 36 h), EA-Whey (22.06 g/L at 48 h). Moreover, a maximum of 393.85 to 988.22 mg/L of 2-phenylethanol was achieved, depending on the substrates used. Therefore, the results of this work suggest that the EA technology can be an emergent sustainable technology for achieving dual objectives of prebiotic lactulose production and concurrent valorization of whey and its derivatives in Kefir culture and K. marxianus driven bioprocesses to produce valuable metabolites for different applications including in food and feed industry. Thus, this knowledge is not only helpful to reduce the production cost of dairy industries, but also provide an eco-friendly alternative for the disposal of whey/WP as a part of integrated approach for complete valorization.