• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 7
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Application of new technologies to cocoa alkalization

Valverde García, Damián 06 April 2020 (has links)
Tesis por compendio / [ES] «Aplicación de nuevas tecnologías a la alcalinización de cacao» es una tesis doctoral centrada, por un lado, en el estudio de los cambios fisicoquímicos y funcionales causados por dos técnicas de alcalinización alternativas a la convencional y, por otro, en la comparación de dichas propiedades con las de muestras comerciales. En el capítulo I, se describe un sistema de alcalinización basado en extrusión. Esta tecnología se ha aplicado a la alcalinización de cacao dada su capacidad de tratar la materia prima de forma rápida y continúa, y su bajo consumo energético. En primer lugar, se estudiaron los efectos de diversas variables de proceso sobre las propiedades fisicoquímicas y funcionales de cacaos en polvo. En general, de todas las variables, el tipo y la concentración de álcali fueron las principales responsables del incremento de pH, del oscurecimiento de las muestras y de la reducción en el contenido de compuestos funcionales. En cuanto a la humedad, fueron la temperatura y el contenido en agua las que mostraron causar los mayores efectos, llegando a producir reducciones de casi un 50%. Además de evaluarse el efecto de las diferentes variables, en este capítulo también se compararon los cacaos producidos mediante extrusión con los alcalinizados por el método convencional. Los resultados mostraron que la extrusión, en menos de cinco minutos, fue capaz de oscurecer y de producir cacaos en polvo con un perfil sensorial, una capacidad antioxidante y un contenido en polifenoles totales relativamente similar al de los productos comerciales. En cuanto al capítulo II, en este se ha estudiado la técnica de calentamiento por microondas como una alternativa al tratamiento de alcalinización tradicional. La tecnología microondas ha demostrado ser rápida, versátil y capaz de preservar las características funcionales y sensoriales, lo que ha hecho interesante su aplicación a la alcalinización de cacao. En los trabajos que forman este segundo capítulo, se estudiaron los efectos de diversas variables de proceso sobre el producto. En general, el tipo y la concentración de álcali fueron las variables principalmente responsables del oscurecimiento del cacao, del incremento del pH y de la reducción de las concentraciones de catequina y epicatequina. Sin embargo, el álcali empleado no redujo la actividad antioxidante ni al contenido en fenoles totales, propiedades que se vieron incrementadas por la presión, la potencia y la duración del tratamiento. Estos incrementos se relacionaron con la capacidad de estas variables para liberar a los polifenoles no extractables y para promover determinadas reacciones químicas. Además, también se estudió el efecto de las diferentes variables sobre la humedad. La potencia y la duración del tratamiento fueron las que se mostraron esenciales para lograr el secado del producto, llegando a producir reducciones de hasta el 70%. Por otro lado, además de estudiarse el impacto de las diferentes variables, también se compararon cacaos producidos por microondas con muestras producidas por el método convencional para evaluar su similitud con los cacaos comerciales. Los resultados mostraron que el microondas, en solo cuatro minutos, fue capaz de oscurecer el cacao y de mantener un perfil sensorial similar al producido por el método tradicional, a la par que conducía a una mejora en sus propiedades funcionales. En resumen, los métodos para la alcalinización de cacao desarrollados en el marco de la presente tesis doctoral han demostrado ser unas alternativas muy prometedoras a la tecnología convencional. Ambas técnicas no solo han sido capaces de oscurecer el cacao tanto como el método comercial en un tiempo mucho menor, sino que también han conseguido el secado parcial de la muestra y unas características sensoriales y funcionales comparables o incluso mejores que las del método convencional. / [CA] «Aplicació de noves tecnologies a l'alcalinització de cacau» és una tesi doctoral centrada, d'una banda, en l'estudi dels canvis fisicoquímics i funcionals causats per dos tècniques d'alcalinització alternatives a la convencional i, d'altra banda, en la comparació d'aquestes propietats amb les de mostres comercials. En el capítol I, es descriu un sistema d'alcalinització similar al convencional però basat en extrusió. Aquesta tecnologia s'ha aplicat a l'alcalinització de cacau per la seua capacitat de tractar la matèria primera de forma ràpida i continua, i pel seu baix consum energètic. En primer lloc, es van estudiar els efectes de diverses variables de procés sobre les propietats fisicoquímiques i funcionals de cacaus en pols. En general, de totes les variables, el tipus i la concentració d'àlcali van ser les principals responsables de l'increment de pH, de l'enfosquiment de les mostres i de la reducció en el contingut de compostos funcionals. Pel que fa a la humitat, van ser la temperatura i el contingut en aigua les que van causar els majors efectes, arribant a produir reduccions d'un 50%. A més d'avaluar l'efecte de les diferents variables, en aquest capítol també es van comparar els cacaus produïts mitjançant extrusió amb els alcalinizats pel mètode convencional. Els resultats van mostrar que l'extrusió, en menys de cinc minuts, va a ser capaç d'enfosquir i de produir cacaus en pols amb un perfil sensorial, una capacitat antioxidant i un contingut en polifenols totals relativament similar al dels productes comercials. Pel que fa al capítol II, en aquest s'ha estudiat la tècnica de calfament per microones com una alternativa a l'alcalinització tradicional. La tecnologia microones ha demostrat ser ràpida, versàtil i capaç de preservar les característiques funcionals i sensorials, el que ha fet interessant la seua aplicació a l'alcalinització de cacau. En els treballs que formen aquest segon capítol, es van estudiar els efectes de diverses variables de procés sobre el producte. En general, el tipus i la concentració d'àlcali van ser les variables principalment responsables de l'enfosquiment del cacau, de l'increment del pH i de la reducció de les concentracions de catequina i epicatequina. No obstant això, l'àlcali empleat no va reduir l'activitat antioxidant ni al contingut en fenols totals, propietats que es van incrementar per la pressió, la potència i la duració del tractament. Aquests increments es van relacionar amb la capacitat d'aquestes variables per alliberar els polifenols no extractables i per promoure determinades reaccions químiques. A més, també es va estudiar l'efecte de les diferents variables sobre la humitat. La potència i la duració del tractament van ser les que es van mostrar essencials per aconseguir la deshidratació del producte, arribant a produir reduccions de fins al 70%. D'altra banda, a més d'estudiar-se l'impacte de les diferents variables, també es van comparar els cacaus produïts per microones amb mostres produïdes pel mètode convencional per tal d'avaluar la seua similitud amb els cacaus comercials. Els resultats van mostrar que el microones, en només quatre minuts, va ser capaç d'enfosquir el cacau i de mantenir un perfil sensorial similar al produït pel mètode tradicional, al mateix temps que conduïa a una millora en les seues propietats funcionals. En resum, els mètodes per a l'alcalinització de cacau desenvolupats en el marc de la present tesi doctoral han demostrat ser unes alternatives molt prometedores per a substituir la tecnologia convencional. Les dos tècniques no només han estat capaces d'enfosquir el cacau tant com el mètode comercial en un temps molt menor, sinó que també han aconseguit la deshidratació parcial de la mostra i unes característiques sensorials i funcionals comparables a les del mètode convencional. / [EN] "Application of new technologies to cocoa alkalization" is a PhD thesis that aims to study the effects of two alternative techniques on the physicochemical and functional features of alkalized cocoa, and to evaluate their suitability to replace the traditional treatment. In chapter I, the conventional system for alkalization in closed and pressurized vessels has been replaced by extrusion. This technique has been proved to be a fast, continuous and less energy-consuming method, characteristics that the traditional system lacks and that have promoted its application to cocoa alkalization. On the one hand, the effects produced by temperature, water content and alkali type and concentration were evaluated on the physicochemical and functional features of cocoa. In general, alkali type and concentration were the main variables increasing the pH, darkening the sample, but also reducing the functional content, while water content and temperature exerted minor effects. On the other hand, the temperature and the water content were the variables exhibiting the greatest effect on the moisture content, leading to reductions of almost 50%. Moreover, the extrusion alkalization products were compared to traditionally produced cocoa powders based on physicochemical, functional and sensory criteria. The results revealed that extrusion was faster and able to dark cocoa in a greater extent than the conventional treatment and to produce sensory acceptable powders. These results confirm that extrusion is a feasible and promising alternative method able to alkalize cocoa in a fast, continuous and less energy-consuming manner. In chapter II, microwave heating has been studied as a substitute of the traditional alkalization treatment. This heating method has proven to be fast, versatile and able to preserve functional and sensory features of the treated products, which has made interesting its application to cocoa alkalization. The effects of the microwave heating technique on water content, power, duration, pressure application and alkali type and concentration were analyzed. In general, alkali type and concentration were the main variables inducing the darkening of cocoa, increasing its pH and reducing the concentrations of catechin and epicatechin. However, these variables did not affect the antioxidant activity and the total phenol content of the treated cocoas in comparison to the untreated one. Treatment pressure, power and duration exerted positive effects on the antioxidant activity, the total phenol content or both. These changes were related to the capacity of these variables, in combination with the alkali agent, to release non-extractable polyphenols from the matrix and to the induction of different chemical reactions. Additionally, the effects of the different variables were studied on the moisture content. Power and duration of the microwave heating treatment were decisive in the reduction of the water content, which was significantly reduced up to 70%. In terms of the evaluation of the suitability of the developed microwave heating alkalization method, the produced cocoas were compared to the traditionally alkalized ones in their physicochemical, functional and sensory characteristics. The developed fast microwave heating treatment showed to be able to dark cocoa as much as the traditional method, to produce sensory equivalent powders and to lead to the obtaining of cocoas with higher antioxidant activity and phenol content. In conclusion, this PhD thesis has applied extrusion and microwave heating as promising alternatives to cocoa alkalization. These technologies have demonstrated to dark cocoa in a significantly faster fashion than the traditional alkalization treatment, while keeping similar sensory profile and functional features, and substantially drying the product. / The authors would like to acknowledge the financial support of the Spanish Government and European Regional Development Fund (Project RTC-2016-5241- 2) / Valverde García, D. (2020). Application of new technologies to cocoa alkalization [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/140311 / TESIS / Compendio
2

Adhesion of Food Powders During Coating and the Effects of Alkalization and Roasting Conditions on Cocoa Volatile Compounds

Huang, Yang 01 November 2010 (has links)
No description available.
3

Rôles et régulations des canaux ioniques ASIC3 dans la douleur / Roles and regulation of ion channel ASIC3 in pain

Delaunay, Anne 30 October 2013 (has links)
Les douleurs chroniques, d’origine inflammatoire, neuropathique ou incisionnelle, affectent environ 20 % de la population adulte et jusqu’à 50 % de la population âgée. Elles représentent ainsi un véritable enjeu de santé publique. Malgré l’existence de grandes familles d’analgésiques, les traitements restent souvent inefficaces. Cela est dû en grande partie à un manque de connaissances des mécanismes physiopathologiques de la douleur. Durant ma thèse, je me suis intéressée aux rôles et aux régulations de senseurs moléculaires de la douleur récemment mis en évidence: les canaux ioniques ASIC (« Acid Sensing Ion Channels »). Les ASIC forment une famille de canaux cationiques, excitateurs. Les canaux ASIC3, en particulier, sont présents dans les neurones sensoriels qui innervent la peau, les muscles, les viscères et les articulations. Ils sont activés par de faibles acidifications extracellulaires qui se produisent au cours de nombreux mécanismes physiopathologiques comme l’inflammation, l’ischémie, le développement tumoral, ou encore les lésions tissulaires consécutives, par exemple, à une chirurgie. Dans une première étude, nous avons montré que les canaux ASIC3 jouent un rôle primordial dans le développement des douleurs post-opératoires, notamment dans les douleurs posturales, proches des cas cliniques. A partir d’un modèle d’incision plantaire chez le rat, nous avons mis en évidence une surexpression des canaux ASIC3 dans les neurones sensoriels qui innervent la patte opérée. L’inhibition pharmacologique (toxine) et génique (siARN) d’ASIC3 in vivo réduit le comportement douloureux. Notre seconde étude a porté sur le canal ASIC3 humain, peu étudié jusqu’ici. J’ai démontré que ce canal possède une propriété originale et inductible qui lui confère une sensibilité, non seulement à l’acidification, mais également à l’alcalinisation extracellulaire. Cette sensibilité alcaline est une caractéristique intrinsèque du canal. Elle implique deux résidus arginine spécifiques à la protéine humaine et présents sur sa boucle extracellulaire. Le canal ASIC3 humain, en adaptant son activité à différents environnements de pH, pourrait ainsi participer à la régulation fine du potentiel de membrane et à la sensibilisation neuronale. Plus récemment, j’ai étudié la régulation du canal ASIC3 par des lipides inflammatoires et ses conséquences sur la douleur. De manière très intéressante, je démontre que la lysophosphatidylcholine (LPC), un lipide issu de la dégradation membranaire lors de processus inflammatoires, est un nouvel activateur du canal ASIC3 en conditions normales de pH. De plus, en synergie avec une acidose modérée (pH 7,0), la LPC et son analogue non métabolisable produisent une douleur spontanée chez les rats, qui est réduite en présence de toxine inhibitrice d’ASIC3. / Chronic, inflammatory, neuropathic, or incisional pain is affecting about 20 % of the adult population and up to 50 % of the elderly population. It thus represent a real public health issue. Despite the existence of large families of analgesics, treatments are often ineffective. This is due in large part to a lack of knowledge of the patho-physiological mechanisms of pain. During my PhD, I have been interested in the roles and regulation of molecular sensors of the pain recently highlighted: ion channels (ASICs "Acid Sensing Ion Channels "). ASICs constitute a family of excitatory cationic channels. The ASIC3 channels, in particular, are present in sensory neurons that innervate the skin, muscles, organs and joints. They are activated by low extracellular acidification occurring in many patho-physiological mechanisms such as inflammation, ischemia, tumor growth, or the subsequent tissue damage, for example, surgery. In a first study, we showed that ASIC3 channels play a crucial role in the development of post -operative pain, including postural pain, close to clinical cases. From a plantar incision model in rats, we demonstrated an over-expression of ASIC3 channels in sensory neurons innervating the operated hindpaw. Pharmacological inhibition (with toxin) and invalidation (siRNA) of ASIC3 in vivo reduce pain behavior. Our second study focused on the human ASIC3 channel, not yet extensively studied. I demonstrated that this channel has a unique and inducible property which gives it a sensitivity not only to acidification, but also to the extracellular alkalinization. This alkaline sensitivity is an intrinsic characteristic of the channel. It involves two specific arginine residues in the human channel that are present in its extracellular loop.Thus the human ASIC3 channel adapts its activity at different pH environments, and could participate in the fine regulation of membrane potential and neuronal sensitization. More recently, I have studied the regulation of ASIC3 channel by inflammatory lipids and there effects on pain. Interestingly, I showed that lysophosphatidylcholine (LPC), a lipid produced from the degradation of the membrane during inflammation, is a new activator of ASIC3 channel under normal pH conditions. Moreover, in synergy with moderate acidosis (pH 7.0), the LPC and its non-metabolizable analogue produce spontaneous pain in rats. This pain is reduced in the presence of the ASIC3 inhibitory toxin.
4

Acidification trends in Swedish lakes : an assessment of past water chemistry conditions using lake sediments

Korsman, Tom January 1993 (has links)
This thesis presents temporal perspectives of lake acidification in Sweden. Sediment records have been used to study timing, trends and causes of acidification, and two different techniques for assessing past lake-water acidity are presented. A new technique for pH prediction, based on near-infrared (NIR) spectroscopy of surface sediments, is developed. This study shows that there is a pH related fraction of lake sediments that can be recorded by NIR analysis. Relationships between NIR spectra of surface sediment samples and measured lake-water pH values, and between NIR spectra of sediment cores and historical pH values inferred by diatom analysis, are modelled by partial least squares regression. The prediction errors of the models are comparable to those obtained by modelling of diatom and lake-water pH data. By further development NIR spectroscopy can become useful for inferring past pH, as well as several other lake-water parameters, from sediment cores. Diatom-based predictive models, using multivariate calibration methods, are developed for inferences of lake-water pH, alkalinity and colour. These models are used to provide a regional assessment of recent lake acidification in the provinces of Västerbotten and Norrbotten, northern Sweden. The study shows that a pH decline has occurred in some southeastern lakes, but that most of the lakes have not faced significant changes in lake-water pH, alkalinity and colour. The inferred water chemistiy changes are discussed in relation to atmospheric deposition and land-use. In a study of eight acid-sensitive Swedish boreal-forest lakes a past-analogue approach is used to test whether contemporary expansion of conifers could cause lake acidification. Water chemistry changes associated with the natural pre-historic colonization and expansion of spruce in Sweden (≈3000 years B.P.), at times of background atmospheric acidity, are inferred to evaluate the acidification ability of spruce per se on surface waters. This study shows that under natural, unpolluted conditions spruce colonization and expansion did not cause lake acidification. In a synthesis of palaeolimnological acidification research in Sweden a general model for pH- development for acid clear-water lakes in southern Sweden is presented. The pH-development from the last deglaciation to present time can be divided into four different periods; (i) a natural long-term acidification period (12000 B.P. - 2300 B.P., or later), with a gradual decrease in pH resulting from declining fluxes of base cations from catchment soils; (ii) a human induced alkalization period (2300 B.P. - 1900 A.D.), with a pH increase due to human activities in the catchments; (iii) the recent acidification period (about 1900 A.D. - present), when pH decreased towards 4.5 due to acid deposition and possibly ceased land-use; and (iv) the liming period (1970s - present), when pH often increases to values above 7 following lime treatment to counteract acidification. The implications of these past pH changes for the concept of contemporary lake acidification and for liming policy are outlined. / digitalisering@umu
5

Společenstva půdních hlístic při různých způsobech obnovy vřesovišť / Communities of terrestrial nematodes after different approaches to heathland restoration

Radochová, Petra January 2015 (has links)
Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification. Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation. In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to proove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. Key words: Nematoda,...
6

Efeito da agitação do EDTA por meio ultrassônico ou pelo laser diodo de alta potência quanto extrusão apical, alteração de temperatura, resistência à fratura radicular, e a variação de pH na estrutura dentinária. /

Oliveira, Luiz Fernando de Freitas. January 2020 (has links)
Orientador: Fábio Luiz Camargo Villela Berbert / Resumo: Objetivo: O objetivo desse estudo foi avaliar protocolos de agitação do EDTA aplicando dois diferentes tipos lasers de diodo de alta potência, comparando-os com os métodos de agitação convencional e com o ultrassom, quanto à extrusão apical, alteração de temperatura, resistência à fratura radicular e análise de pH na dentina radicular. Material e Métodos: Essa pesquisa experimental ex-vivo, utilizou 120 pré-molares inferiores, unirradiculados, com ráizes retas, com rizogênses completa e com tamanho radicular superior a 16mm, pré-selecionados por meio de radiografia digital. Suas coroas foram removidas, padronizando as raízes em 16 mm, seguido do preparo com a lima K#15 K#20 e o sistema reciproc R25, R40 e R50, 1 mm aquém do comprimento real do dente, com irrigação durante o preparo com NaOCl a 2,5%. Os espécimes foram distribuídos aleatoriamente em 6 grupos segundo protocolos de irrigação final: AD- água destilada (controle), CV- inundação com EDTA 17% e agitação com lima K #50, PUI- inundação com EDTA 17% agitado com ultrassom (Passive ultrasonic irrigation-PUI), PUI/CUI- inundação com EDTA 17% agitado com ultrassom (PUI) e irrigação com água destilada, agitada com ultrassom (Continuous ultrasonic irrigation-CUI), TL- inundação com EDTA 17% agitado com laser diodo Thera Lase Surgery, e GE- EDTA 17% agitado com laser diodo Gemini. Após irrigação final, todos os dentes foram irrigados com água destilada para remoção do EDTA. Resultados: Na avaliação da extrusão apical foi real... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objective: The objective of this study was to evaluate EDTA agitation protocols by applying two different types of high-power diode lasers, comparing them with conventional agitation methods and with ultrasound, in relation to apical extrusion, temperature change, fracture resistance root and pH analysis in root dentin. Material and Methods: This ex-vivo experimental research used 120 lower premolars, uniradicular, with straight roots, with complete rhizogenesis and with root size greater than 16mm, pre-selected by means of digital radiography. Their crowns were removed, standardizing the roots by 16 mm, followed by preparation with the K # 15 K # 20 file and the reciproc system R25, R40 and R50, 1 mm below the actual length of the tooth, with irrigation during preparation with NaOCl to 2.5%. The specimens were randomly distributed into 6 groups according to final irrigation protocols: AD- distilled water (control), CV- flood with 17% EDTA and agitation with K # 50 file, PUI- flood with 17% EDTA agitated with ultrasound (Passive ultrasonic irrigation-PUI), PUI / CUI- flooding with 17% EDTA stirred with ultrasound (PUI) and irrigation with distilled water, stirred with ultrasound (Continuous ultrasonic irrigation-CUI), TL- flooding with 17% EDTA stirred with laser diode Thera Lase Surgery, and GE-EDTA 17% stirred with Gemini diode laser. After final irrigation, all teeth were irrigated with distilled water to remove EDTA. Results: In the evaluation of the apical extrusion, the... (Complete abstract click electronic access below) / Mestre
7

Gut Health Benefits of Natural and Alkali-Processed Cocoa (Theobroma cacao) with and without Inulin

Essenmacher, Lauren Alexis 22 June 2020 (has links)
Chronic conditions such as obesity, inflammatory bowel disease (IBD), and colitis are associated with gastrointestinal (GI) inflammation and compromised GI barrier integrity. Cocoa may be a potential dietary strategy to mitigate gut-related conditions and been shown to elicit anti-inflammatory, antioxidant, and prebiotic effects. Alkali treatment of cocoa was once thought to reduce its bioactivity, but new evidence suggests it may enhance cocoa's health properties, through the formation of new, potentially bioactive high molecular weight compounds. Inulin, a fructose-containing plant polymer, exerts prebiotic effects and has also been investigated in the mitigation of IBD. This study aims to 1) investigate effects of alkali processing on gut health related bioactivity and phytochemical composition of cocoa and 2) evaluate potential additive benefits of combining cocoa and inulin. Polyphenolic and flavanol compounds in natural cocoa, alkalized cocoa, and inulin powders were characterized using Folin-Ciocalteu (total polyphenols) and 4-dimethylaminocinnamaldehyde (total flavanols) assays, thiolysis , and HILIC UPLC-MS/MS. Treatments of cocoa and inulin were made in 1:2 cocoa:inulin and 1:4 cocoa:inulin mixtures for both natural and alkalized cocoas. Cocoa mixtures, in addition to both cocoa powders and inulin alone, were subjected to an in-vitro digestion to generate material for an in-vitro fecal fermentation. Samples collected from the fermentation at 0, 6, 12, and 24 hours were analyzed via HPLC-MS for microbial metabolites, applied to HT-29 colon cancer cells to assess anti-inflammatory activity, and applied to a florescence assay measuring PLA2 inhibitory activity. The alkalized cocoa powder was found to have a significantly lower concentration of total polyphenols and total flavanols, as well as a lower mDP, suggesting that alkalization may affect larger procyanidins more than smaller flavanol compounds. Inulin enhanced the inhibition of the PLA2 enzyme and enhanced the IL-8 anti-inflammatory properties of cocoa, although the trends were weak. Overall, we did not see any clear, significant effects of alkalization or the addition of inulin to cocoa's colonic metabolite formation or its gut bioactivity in vitro. However, we have demonstrated that colonic fermentation of cocoa may have a negative effect on its bioactivity in vitro. Future research should further explore flavanol DP and bioactivity, fiber's interaction with polyphenols, colonic metabolism of cocoa, and cocoa's gut health effects in vivo. / Master of Science in Life Sciences / Gut conditions like obesity-associated inflammation and inflammatory bowel disease are highly prevalent, debilitating, and currently have no cure. Cocoa has been investigated as a possible dietary strategy for the mitigation and prevention of chronic inflammatory gut conditions due to its anti-inflammatory and enzyme inhibiting properties. Most attribute these effects of cocoa to its abundance of compounds called polyphenols. It is widely thought that the ability of cocoa to promote health is lost when cocoa beans are processed, because of the loss of polyphenols. Alkalization, or "Dutching", is an optional step in cocoa processing that some manufacturers perform to enhance flavor and color formation. Dutching cocoa can promote the polymerization of many smaller, flavanol, protein, and other compounds into larger, indigestible compounds. These indigestible compounds will not be absorbed in the small intestine and may be broken down in the large intestine by colonic bacteria, forming new metabolites. We obtained cocoa powders, one natural (not alkalized) and one alkalized and compared them in terms of content of polyphenols, bioactivities, and anti-inflammatory abilities. Additionally, we added a known prebiotic, inulin, to our cocoa formulations to determine if there are additive benefits of cocoa and inulin together. Ultimately, we found that alkalized cocoa contained lower concentrations of all polyphenolic compounds, even the larger compounds. Inulin enhanced the inhibition of digestive enzymes and the anti-inflammatory properties of cocoa, though not significantly. Inulin also reduced the pH (i.e. increased the acidity) of a simulated gut environment, which may be beneficial. Alkalization did not significantly affect cocoa's enzyme inhibitory activity or anti-inflammatory activity. Overall, the addition of inulin to cocoa does not seem to be effective in increasing cocoa's ability to treat and prevent gut diseases, but more information is needed.

Page generated in 0.0851 seconds