Orientador: Nelson Horacio Pezoa Garcia / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T13:00:47Z (GMT). No. of bitstreams: 1 Efraim_Priscilla_D.pdf: 3005113 bytes, checksum: 644805cbb4b729e262d0a9e849b572b8 (MD5) Previous issue date: 2009 / Resumo: Este trabalho buscou contribuir com o Programa Brasileiro de Melhoramento Genético de Cacau por meio do processamento e caracterização dos principais derivados de nove clones estudados e utilizados comercialmente na Bahia por sua resistência à vassoura-de-bruxa: CEPEC 42, EET 397, TSA 654, TSA 656, TSAN 792, TSH 516, TSH 565, TSH 774, TSH 1188 e do cacau Comum, tradicional na região e suscetível à doença. Os frutos foram colhidos em um mesmo período, fermentados simultaneamente em lotes de 50 Kg e secos naturalmente ao sol. As amêndoas obtidas foram quebradas em nibs, que foram torrados em 3 diferentes tempos em forno elétrico rotativo a 150 ºC e moídos até 25 µm para obtenção dos liquors. A análise sensorial de preferência definiu o tempo de torração de cada material. A manteiga de cacau foi obtida por prensagem hidráulica dos liquors. Chocolates amargos foram produzidos pelo método convencional. A caracterização física dos frutos e sementes demonstrou diferenças entre os materiais quanto ao peso total dos frutos e rendimento de sementes com polpa por fruto. O monitoramento de temperatura e pH da massa em fermentação e a avaliação dos teores de umidade, atividade de água, pH, acidez total titulável, açúcares, ácidos orgânicos, proteínas, compostos fenólicos totais e da contagem microbiológica, durante a fermentação e ao término da secagem, demonstraram que a evolução do processo fermentativo foi distinta para cada material. A caracterização da manteiga de cacau quanto à composição em triacilgliceróis e curva de sólidos indicou que os todos os cultivares estudados, exceto o TSH 774, apresentaram melhorias em relação ao cacau Comum. A análise sensorial descritiva quantitativa dos liquors por duas equipes treinadas e de aceitação dos chocolates, por painel não treinado de consumidores, indicaram diferenças entre os materiais para alguns atributos avaliados de acordo com sua ascendência genética, sendo que os materiais descendentes dos grupos Trinitário e Forastero apresentaram maior preferência em relação aos descendentes apenas do grupo Forastero. Apesar das diferenças físicas e químicas verificadas nos liquors e chocolates, observou-se a viabilidade industrial de todos dos materiais estudados. Estudou-se ainda a influência da mistura de 0, 30, 50 e 100% de sementes danificadas pela vassoura-de-bruxa com sementes sadias na fermentação às características de amêndoas, liquors, manteiga e pó de cacau obtidos. Os perfis de temperatura e pH da massa em fermentação, os teores de açúcares e ácidos orgânicos e a análise da fração volátil demonstraram que reações que normalmente ocorrem na fermentação podem ter se iniciado nos frutos, antes da colheita. O teor de polifenóis totais das sementes danificadas foi maior que o de sementes sadias, porém, as perdas na fermentação foram maiores. Os teores de lipídios e proteínas das amêndoas e liquors foram menores quanto maior a proporção de sementes danificadas. A vassoura-de-bruxa não causou alterações nas propriedades físicas e químicas avaliadas nas manteigas de cacau. A análise da fração volátil das sementes, amêndoas e liquors indicou que o aumento do teor de sementes danificadas levou à diminuição ou ausência de importantes alquilpirazinas, indicando que o uso destas, nas porcentagens estudadas, pode prejudicar a qualidade sensorial dos derivados de cacau / Abstract: The aim of this study was to contribute with the Brazilian Genetic Improvement Program of cocoa by processing and characterizing the main cocoa-derived products from nine clones studied and used commercially in Bahia due to their resistance to ¿witches¿ broom¿: CEPEC 42, EET 397, TSA 654, TSA 656, TSAN 792, TSH 516, TSH 565, TSH 774, TSH 1188 and Comum cocoa, traditional in the area and susceptible to the disease. The fruits were harvested in the same period, fermented in 50 kg batches and sun-dried. The cocoa beans obtained were broken into nibs, roasted during 3 different times in a rotative electric oven at 150ºC and milled to 25 µm to obtain the liquors. A preference sensory evaluation defined the specific roasting time for each material. Cocoa butter was obtained by hydraulic pressing of the liquors. Bitter chocolates were produced by the conventional method. The physical characterization of the fruits and seeds demonstrated differences among the materials regarding total weight of the fruits and yield of seeds with pulp per fruit. Temperature and pH monitoring of the mass during fermentation and evaluation of moisture content, water activity, pH, total acidity, sugars, organic acids, proteins, total phenolic compounds and microbiological count during fermentation and at the end of drying demonstrated that the evolution of the fermentation process was different for each material. The triacylglycerol composition and the solid fat content of the cocoa butters from all the cultivars studied, except TSH 774, presented improvements compared to Comum cocoa. The quantitative descriptive analysis of the liquors carried out by two trained panels and the acceptance of the chocolates by an untrained consumer panel indicated differences for some of the parameters evaluated among the materials studied according to their genetic ascendance. The cultivars descending from Trinitario and Forastero groups presented greater preference in relation to the descendants of the Forastero group only. The physical and chemical characterization of the liquors and chocolates demonstrated differences among the materials studied; however, it also showed their industrial viability. The influence of the mixture of 0, 30, 50 and 100% of seeds damaged by ¿witches¿ broom¿ with healthy seeds during the fermentation process on the characteristics of cocoa beans, liquors, cocoa butter and powder was also studied. The temperature and pH profiles of the mass during fermentation, the amounts of sugars and organic acids and the analysis of volatile compounds demonstrated that some reactions that usually occur during fermentation might have been initiated in the fruits before harvesting. The total content of polyphenols in the damaged seeds was higher than in the healthy seeds; however, losses during fermentation were also greater. Lipid and protein contents of cocoa beans and liquors decreased with the increase of the proportion of damaged seeds. ¿Witches¿ broom¿ did not cause changes in the physical and chemical properties evaluated in the cocoa butters. The analysis of the volatile compounds of the seeds, beans and liquors showed that the increase of the content of damaged seeds led to the decrease or absence of the main alkylpyrazines, indicating that their use in the percentages studied may negatively affect the sensory quality of cocoa-derived products / Doutorado / Doutor em Tecnologia de Alimentos

Depuis plusieurs années, les programmes de recherche chez le cacaoyer ont mis l'accent sur l'étude des bases génétiques des caractères agronomiques d'intérêt, notamment concernant la résistance aux maladies et la qualité des fèves de cacao, qui représentent deux attributs importants pour la cacaoculture et la production de chocolat. Ce travail présente, par l'exploration du transcriptome et du génome du cacaoyer, la constitution de ressources moléculaires et l'analyse des voies de biosynthèse impliquées dans plusieurs de ces caractères agronomiques d'intérêt. L'étude du transcriptome a permis l'identification de plusieurs dizaines de milliers de gènes exprimés dans divers organes et pour différentes conditions environnementales et ont fourni de nombreux marqueurs moléculaires qui ont été utilisés pour réaliser des cartes génétiques haute densité. Les informations apportées par ce travail ont permis d’engager le séquençage du génome de la variété Criollo du cacaoyer. Son analyse et son annotation ont apporté un ensemble d'informations biologiques cruciales, depuis le catalogue des gènes et éléments mobiles jusqu'aux aspects évolutifs qui a révélé une structure du génome peu remanié par rapport à l'ancêtre commun aux dicotylédones. Par la suite, les travaux que nous avons menés pour améliorer la séquence complète ont conduit à une réduction considérable de la fragmentation chromosomique observée dans la première version. Par ailleurs 97% de la séquence assemblée et 99% des gènes sont désormais ancrés sur les chromosomes du cacaoyer. Pour commencer à exploiter cette nouvelle séquence du génome, nous avons conduit une étude QTL à partir d'une descendance entre Trinitario implantée en Guyane, permettant de localiser les régions génomiques impliquées dans la variation de la couleur des fèves de cacao. En s'appuyant sur la version améliorée du génome du Criollo, nous avons identifié deux gènes potentiellement impliqués dans la voie de biosynthèse des anthocyanines et flavonoïdes dans la principale région génomique concernée. Un des deux gènes, situé proche du marqueur situé au pic du QTL et codant pour une chalcone synthase, semble être un gène candidat prometteur. L'étude comparative de sa structure dans le génome du Criollo (à fève blanche) et du génome de l'Amelonado (à fève violette) a mis en évidence des différences structurales pouvant être à l'origine d'une modification fonctionnelle. L'ensemble des résultats présentés dans ce travail de thèse apporte une connaissance et des outils variés qui peuvent être exploités par de multiples approches intégrées pour étudier la génétique du cacaoyer. / For several years, cocoa research programs have focused on studying the genetic basis of agronomic traits of interest, especially for disease resistance and quality of cocoa beans, two important attributes for cocoa farmers and chocolate production. This work presents, by exploring the transcriptome and cocoa genome, the constitution of molecular resources and the analysis of biosynthesis pathways involved in several of these agronomical traits. The transcriptome study allowed the identification of several tens of thousands of genes expressed in various organs and for different environmental conditions and provided numerous molecular markers, used to produce high-density genetic maps. The information provided by this work led to the genome sequencing of a cocoa Criollo variety. Its analysis and annotation have provided a set of crucial biological information, from the catalog of genes and transposable elements to evolutionary aspects, which revealed a close evolutionary relationship to the eudicot putative ancestor, showing a limited number of recombination between ancestral chromosomes. Subsequently, the work we carried out to improve the complete sequence led to a considerable reduction of the chromosomal fragmentation observed in the first version. In addition, 97% of the assembled sequence and 99% of the genes are now anchored on the cocoa chromosomes. To exploit this new sequence of the genome, we conducted a QTL study from a progeny between Trinitario clones established in French Guiana, allowing to identify genomic regions involved in color trait variation observed in cocoa beans. Based on the improved version of the Criollo genome, we identified two genes potentially involved in the biosynthesis pathway of anthocyanins and flavonoids in the main genomic region concerned. One of the two genes is located nearby the QTL peak and encoding a chalcone synthase, appears to be a promising candidate gene. The comparative study of its structure in the Criollo genome (white bean) and in the Amelonado genome (purple bean) revealed several variations that could be responsible for functional modifications. The results presented in this thesis provide a variety of knowledge and tools useful to conduct multiple integrated approaches to studying cocoa tree genetics.

An intensification of 200 000 tonnes of cacao is planned for the Colombian cacao production until 2021. This could lead large negative effects on the Colombian nature and biodiversity if the current smallholdings of agroforestry were abandoned in favour for large monocultures. The main objective for this study was to get general overview regarding sustainability and development challenges of the current cacao farming in Huila, Colombia. This was conducted through a minor field study in the area over eight weeks were five farms were documented together with semi-structured interviews and participatory evaluations with the farmers based on the three dimensions; environmental, economical and human. The participatory evaluations were presented by an AMOEBA methodology and even if the subjectivity of the result is a concern for the reliability, the farmers evaluations have highlighted areas of concern as well as for possibilities. Currently, practical improvements such as equipment and low income seemed to be of the greatest concerns but deeper rooted problems, such as the corruption and mistrust to the institutions could probably make a greater impact on the future development of the studied farms. On the positive side, working together in cooperatives has implicated to risen the social sustainability due to more contact and support between farmers.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-01-03T12:27:54Z No. of bitstreams: 1 texto completo.pdf: 682821 bytes, checksum: 252f4f3303c2480d714227ccfa7bc851 (MD5) / Made available in DSpace on 2017-01-03T12:27:54Z (GMT). No. of bitstreams: 1 texto completo.pdf: 682821 bytes, checksum: 252f4f3303c2480d714227ccfa7bc851 (MD5) Previous issue date: 2016-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As sementes fermentadas e secas do cacaueiro (Theobroma cacao L.) constituem a matéria-prima para a produção de chocolate, cuja cadeia produtiva envolve 60 bilhões de dólares anuais. A coleta, avaliação e conservação de germoplasma de cacau são muito importantes para os programas de melhoramento. Todavia, o nível e a distribuição da variação em populações silvestres são pouco conhecidos. Dessa forma, os objetivos do presente estudo foram: Avaliar a diversidade e o padrão de distribuição da mesma, entre e dentro de populações de cacau de diferentes bacias hidrográficas; avaliar a hipótese de diferenciação das populações por bacia e avaliar o potencial dos acessos clonais de cacau para o melhoramento. Para a avaliação foram coletados, durante quatro anos consecutivos, dados morfológicos de 145 acessos clonais provenientes de nove bacias hidrográficas: 1. Delta/estuário-PA, 2. Ji-Paraná- RO, 3. Solimões/Amazonas-PA, 4. Jamari-RO, 5. Clones alienígenas-TTO, 6. Clones alienígenas-PER, 7. Solimões/Amazonas-AM, 8. Acre-AC e 9. Clones melhorados-RO. Foram avaliadas 11 características, das quais nove relativas ao fruto, por planta: NTFC (Número total de frutos colhidos), NTFS (Número total de frutos sadios), MSUFS (Massa de sementes úmidas dos frutos sadios, em g), MMUSFS (Massa média de sementes úmidas por fruto sadio, em g), MSSFS (Massa de sementes secas dos frutos sadios, em g), MMSSFS (Massa média de sementes secas por frutos sadios, em g), PFVB (Percentagem de frutos com vassoura-de-bruxa), PFBR (Percentagem de frutos com broca), PFGE (Percentagem de frutos com sementes germinadas), NRVB (Número de ramos com vassoura-de-bruxa) e NAFVB (Número de almofadas florais com vassoura- de-bruxa). Os acessos pertencem ao Banco Ativo de Germoplasma da Estex- OP, localizado em Ouro Preto do Oeste-RO. Dados de oito das 11 características foram submetidos às análises de variância (ANAVAs) e ao cálculo distância de Mahalanobis (D2) entre as bacias. Com base nas ANAVAs, houve diferenças significativas (P<0,05) para todas as características e a maior variabilidade foi detectada dentro das populações de cacau. Sendo assim, recomenda-se que a coleta de materiais botânicos silvestres priorize maior número de plantas de poucas populações das bacias mais divergentes. Valores significativos (P<0,05) de D2 evidenciaram maior divergência entre as bacias Ji- Paraná-RO e Solimões/Amazonas-PA (27,7) e maior semelhança entre Ji- Paraná-RO e Jamari-RO (1,39), com relação as suas populações. A análise multivariada revelou também que a diferenciação dos acessos ocorreu de acordo com o sistema de bacias hidrográficas. Utilizando-se dados das 11 características foram processadas a correlação de Pearson e as análises de variância (ANAVAs). As maiores correlações significativas (P<0,05) foram observadas entre NTFC e NTFS (0,94), NTFS e MSUFS (0,86), NRVB e NAFVB (0,542) e entre NTFC e MSUFS (0,84). Com base nas ANAVAs, houve diferenças significativas (P<0,05) entre acessos para todas as características, o que amplia as possibilidades de ganho com a seleção. / The fermented and dried seeds of the cacao tree (Theobroma cacao L.) are the raw material for the production of chocolate, whose production chain involves 60 billion annually. The collection, evaluation and cocoa germplasm conservation are very important for breeding programs. However, the level and distribution of variation in wild populations are unknown. Thus, the objectives of this study were to evaluate the diversity and distribution pattern of the same, between and within cacao populations in different river basins; assess the possibility of differentiation of populations by basin and assess the potential of clonal cocoa accessions to improvement. For the evaluation were collected for four consecutive years, morphological data of 145 clonal access from nine river basins: 1. Delta/estuário- PA, 2. Ji-Paraná-RO, 3. Solimões/Amazonas-PA, 4. Jamari-RO, 5. Clones alienígenas-TTO, 6. Clones alienígenas-PER, 7. Solimões/Amazonas-AM, 8. Acre-AC e 9. Clones melhorados-RO. We evaluated 11 characteristics, nine of which related to fruit, per plant: NTFC (Total number of fruits), NTFS (total number of healthy fruits), MSUFS (Mass wet seeds of healthy fruits, g), MMUSFS (Massa average wet seed for healthy fruit, g), MSSFS (Mass dry seeds of healthy fruits, g), MMSSFS (average mass of dry seeds for healthy fruits, g), PFVB (fruit Percentage of witches' -bruxa) PFBR (Percentage of fruit with drill), PFGE (Percentage of fruits with seeds germinated), NRVB (number of branches with witch's broom) and NAFVB (number of flower cushions with witch's broom). Accesses belong to the Active Germplasm Bank of Estex-OP, located in Ouro Preto do Oeste-RO. Data from eight of the 11 characteristics were submitted to analysis of variance (ANAVAs) and calculate Mahalanobis distance (D2) between the basins. Based on ANAVAs, there were significant differences (P <0.05) for all features and greater variability was detected within the cocoa populations. Therefore, it is recommended that the collection of wild botanical materials prioritizes greater number of plants of a few populations of the different basins. Significant values (P <0.05) D2 showed greater divergence between basins Ji- Paraná-RO and Solimões/Amazonas-PA (27.7) and greater similarity between Ji- Paraná-RO and Jamari-RO (1.39 ), regarding their populations. Multivariate analysis also revealed that the differentiation of access took place according to the system of watersheds. Using data from 11 characteristics were processed Pearson's correlation and analysis of variance (ANAVAs). The higher significant correlation (P <0.05) were observed between NTFC and NTFS (0.94), NTFS and MSUFS (0.86), and NRVB NAFVB (0.542) and between NTFC and MSUFS (0.84). Based on ANAVAs, there were significant differences (P <0.05) access to all features, which increases the gain of possibilities with the selection.

nÃo hà / Diversos efeitos benÃficos sÃo associados ao consumo de cacau em pÃ, como propriedade antioxidante e efeito cardioprotetor. No entanto, devido a algumas desvantagens como amargor e presenÃa de substÃncias estimulantes e alergÃnica, vÃrios produtos tÃm sido testados como substitutos do cacau, dentre os quais se destaca a alfarroba em pÃ. O produto nÃo apresenta tais desvantagens, alÃm de ser naturalmente adoÃada e fonte de fibras. Diante do exposto, o objetivo desta pesquisa foi verificar a viabilidade de substituiÃÃo total do cacau em pà pela alfarroba em pà em bebida sem lactose a base de amÃndoas da castanha de caju (ACC) e avaliar as alteraÃÃes das caracterÃsticas sensoriais, da aceitabilidade e do comportamento reolÃgico da bebida otimizada. A pesquisa foi realizada em duas fases, onde na primeira adotou-se um planejamento fatorial do tipo 2 para avaliar, atravÃs de superfÃcie de resposta, os efeitos da substituiÃÃo do cacau por alfarroba em pà (concentraÃÃo total de 2 g/100 mL), do teor de sacarose e de carragena no pH e no teor de sÃlidos solÃveis da bebida. Na segunda fase, as amostras otimizadas foram submetidas Ãs anÃlises microbiolÃgicas e à determinaÃÃo de atividade de Ãgua (aw), visando garantir a inocuidade para as anÃlises sensoriais. Aplicou-se a anÃlise descritiva quantitativa (ADQ) para verificar as principais propriedades sensoriais da bebida. Na medida de aceitabilidade das amostras, utilizaram-se os testes com escala hedÃnica e escala relativa ao ideal. O comportamento reolÃgico foi avaliado a 10 ÂC utilizando reÃmetro com placas paralelas. A proporÃÃo de cacau/alfarroba influenciou sutilmente somente o pH da bebida. Desta forma, decidiu-se pela substituiÃÃo total do cacau pela alfarroba em pÃ. As contagens microbianas estavam em nÃveis baixos aceitÃveis, garantindo a seguranÃa do produto, e a atividade de Ãgua situou-se em torno de 0,9838-0,9958. As propriedades sensoriais que apresentaram maior variaÃÃo entre as amostras foram cor marrom, aparÃncia viscosa, aroma de torrefaÃÃo, gosto doce e textura encorpada. As sete formulaÃÃes alcanÃaram boa aceitaÃÃo sensorial. No entanto, as duas amostras com menores teores de sacarose apresentaram menor aceitaÃÃo indicando a grande influÃncia da doÃura para a aceitaÃÃo da bebida. Recomenda-se 16% de sacarose para obter a doÃura ideal. As amostras apresentaram comportamento nÃo Newtoniano. Conclui-se que a substituiÃÃo do cacau pela alfarroba em pà na bebida de ACC (2 g/100 mL) à viÃvel, resultando em um produto de boa aceitaÃÃo sensorial. / Several benefits are associated with cocoa powder consumption as antioxidant properties and cardioprotective effect. However, due to some disadvantages, such as bitterness and the presence of stimulating and allergenic substances, many other products have been tested as a cocoa substitute, and among them carob powder has stood out. The product does not have the same disadvantages of cocoa, besides being naturally sweetened and source of fiber. According to the informations presented, the objective of this research was to investigate the feasibility of full replacement of cocoa powder by carob powder in lactose-free beverage cashew nut almond (CNA)-based as well as to evaluate changes in sensory characteristics, acceptability and rheological behaviour of the optimized beverage. The survey was conducted in two phases, in the first phase a factorial planning type 2 was carried out in order to evaluate, through response surface, the effects of cocoa replacement by carob powder (total concentration of 2 g/100 mL), of sucrose and carrageenan content in the pH and also in the soluble solids content of the beverage. As for the second phase, the optimized samples were subjected to microbiological analyzes, just as well to the determination of water activity (aw), in order to ensure safety for the sensory analysis. A quantitative descriptive analysis (QDA) was applied to verify the main sensory properties of the beverage. Tests with hedonic scale and just about right scale were used to verify the acceptance level of the samples. The rheological behaviour was evaluated at 10 ÂC with a rheometer with parallel plates. The proportion of cocoa/carob just slightly influenced the pH of the beverage. Thus, it was decided to full substitution of the cocoa by carob powder. Microbial counts were in low acceptable levels, ensuring product safety, and water activity stood at around 0.9838 to 0.9958. The sensory properties which presented greater variation among the samples were brown color, viscous appearance, roasting aroma, sweet taste and thickness. The seven formulations achieved good sensory acceptance. However, the two samples with lower sucrose levels presented a lowers acceptance indicating the great influence of sweetness level to the acceptance of the beverage. It is recommended the use of 16% sucrose for optimal sweetness. The samples presented a non-Newtonian behaviour. Finally it was possible to conclude that the replacement of cocoa by carob powder (2 g/100 mL) in lactose-free beverage CNA-based is feasible, resulting in a product of good sensory acceptance.

La cacaoculture est aujourd'hui considérée comme un des principaux facteurs de déforestation en milieu tropical. Dans de nombreux pays, elle repose en effet sur un modèle technique peu durable de monoculture intensive impliquant le déplacement des zones de production. Souvent délaissés par la recherche en raison de leurs faibles rendements en cacao marchand, les systèmes agroforestiers à base de cacaoyer apparaissent aujourd'hui comme une alternative crédible pour faire face aux nouveaux enjeux de la cacaoculture mondiale. Au Centre-Sud du Cameroun, la cacaoculture repose en grande partie sur des cacaoyères agroforestières anciennes, ce qui pose l'hypothèse qu'un modèle de cacaoculture durable basé sur des systèmes de culture agroforestiers est possible. Notre objectif est de mieux comprendre le fonctionnement de ces systèmes agroforestiers à base de cacaoyer, à travers leurs caractéristiques, leurs évolutions et leurs déterminants, ainsi que les conditions de leur production en cacao marchand sur le long terme. Notre démarche articule à la fois une évaluation des systèmes agroforestiers complexes à l'échelle de la parcelle et une analyse compréhensive des pratiques techniques sur le temps long. La thèse repose sur un dispositif de recherche mis en place dans la région du Centre, dans trois zones de culture différenciables par leurs conditions pédo-climatiques (Bokito, Zima et Ngomedzap). Une enquête d'agriculteurs a été réalisée à grande échelle (1 171 exploitations regroupant 1 638 cacaoyères), complétée par des observations spécifiques réalisées dans un réseau de 61 cacaoyères exploitées par 40 agriculteurs. Résultats. (1) Nos résultats d'enquête, complétés par des observations spécifiques, ont confirmé la durabilité des systèmes agroforestiers à base de cacaoyer aux plans agro-écologique et socio-économique. (2) Dans la zone de transition forêt-savane, considérée comme sub-optimale pour la cacaoculture, nous avons montré que le modèle technique adopté par les agriculteurs leur permet d'installer sur savane des cacaoyères viables sur le long terme. (3) Une méthode participative de quantification de la valeur d'usage des espèces par les agriculteurs, appliquée sur le réseau d'observation, a confirmé la multifonctionnalité des systèmes agroforestiers et mesuré la place qu'y occupe la composante cacaoyère. (4) L'évaluation des peuplements cacaoyers, réalisée en adaptant la méthode de diagnostic agronomique régional aux systèmes complexes, a permis d'identifier les facteurs limitant le rendement en cacao marchand. Celui-ci s'avère étroitement lié à la structure des peuplements cacaoyers et à celle des peuplements associés. (5) Enfin, l'analyse compréhensive des pratiques des agriculteurs sur le long terme, en lien avec l'évolution technique des peuplements cacaoyers a confirmé la flexibilité des systèmes agroforestiers à base de cacaoyer. Cette flexibilité peut être traduite par des trajectoires d'évolution des pratiques et des trajectoires de structures spécifiques. Ce travail fournit une nouvelle base méthodologique pour l'analyse et l'évaluation des systèmes agroforestiers complexes. L'ensemble des résultats et des connaissances produites dans ce travail permet de formuler des propositions pour la mise au point d'un nouveau modèle technique en cacaoculture. / Cocoa cultivation is generally considered as one of the main deforestation factors in the Tropics. Indeed, in many countries it is based on a low-sustainability technical model of intensive monocrops with shifting production zones. Cocoa agroforests, which are often neglected by research due to their low fermented dried cocoa yields, now appear to be a credible alternative for taking up the new challenges facing world cocoa production. In Centre-South Cameroon, cocoa cultivation is largely based on old cocoa agroforests, which suggests that a sustainable cocoa growing model based on agroforestry systems is possible. Our aim was to more effectively understand how these cocoa agroforests function, through their characteristics, their evolution and their determinants, along with the conditions for their long-term fermented dried cocoa production. Our approach consisted of an evaluation of cocoa agroforests on a plot scale and a comprehensive analysis of technical practices over the long term. The thesis is based on an experimental design set up in the Centre region, in three growing zones that could be differentiated through their pedo climatic conditions (Bokito, Zima and Ngomedzap). A large-scale survey was undertaken (1,171 farms grouping 1,638 cocoa plantations) completed by specific observations collected in a network of 61 cocoa agroforests managed by 40 farmers. Results. (1) Our survey results, completed by specific observations, confirmed the sustainability of the cocoa agroforestry systems from an agro ecological and socio-economic viewpoint. (2) In the forest-savannah transition zone, which is considered sub-optimum for cocoa cultivation, we confirmed that the technical model adopted by the farmers enabled them to set up cocoa agroforests on savannah that were viable over the long term. (3) In the network, a participatory method applied to quantify the use value given to the species by the farmers confirmed the multi-functionality of cocoa agroforests and measured the place occupied in it by cocoa. (4) The evaluation of the cocoa tree stands, achieved by adapting the regional agronomic diagnosis method to complex systems, revealed the factors limiting cocoa yield. It was proved that cocoa yield is closely linked to the structure of the cocoa tree stand and that of the intercropped stands. (5) Lastly, a comprehensive analysis of farmer practices over the long term, in association with the evolution of the technical management of the cocoa tree stands, confirmed the flexibility of cocoa agroforestry systems. This flexibility was reflected in the evolution pathways for specific practices and structures. This work provides a new methodological basis to assess the performance of complex agroforestry systems. All the results and knowledge produced by this work make it possible to draw up proposals for developing a new technical model for cocoa growing.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-11-09T17:58:22Z No. of bitstreams: 1 2017 - Mariana de Albuquerque Almeida.pdf: 2619920 bytes, checksum: 48c00262629bac9a7779fc4ea9ec94a6 (MD5) / Made available in DSpace on 2017-11-09T17:58:22Z (GMT). No. of bitstreams: 1 2017 - Mariana de Albuquerque Almeida.pdf: 2619920 bytes, checksum: 48c00262629bac9a7779fc4ea9ec94a6 (MD5) Previous issue date: 2017-05-10 / CAPES / This dissertation presents the evaluation of four thiosemicarbazones, from extracts of species of vegetables Talinum triangulare, Physalis angulata e Theobroma cacao L. besides formulation obtained from the combination extract of thiosemicarbazones vegetables as corrosion inhibitor in the presence of carbon steel AISI 1020. Thiosemicarbazones were obtained with good level of purity, satisfactory throughput and identified by NMR of 1H and 13C. The watery extract of Talinum triangulare was obtained using ultrasound device. The extracts of Physalis angulata species were obtained by maceration in water and the other one in ethyl acetate. The watery extracts of Theobroma cacao L. species were obtained using ultrasound device and decoction and hydroalcoholic extract was obtained by maceration in ethanol:water (80:20). The thiosemicarbazones, the vegetable extracts and their formulation were tested in the presence of corrosion of carbon steel AISI 1020 in solution 1 mol. L-1 of HCl. For this evaluation it was used the gravimetric techinique of weight loss and electrochemical techiniques of potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that the presence of thiosemicarbazones, as well as, the formulation increased significantly the resistence of carbon steel AISI 1020 in acidic medium. The results obtained in different used essays (weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy) show that these techniques are complementary in relation to the evaluation of corrosion inhibition. The best anti-corrosion efficiency was observed for thiosemicarbazone chloro and hydroxy-substituted and its formulations with the extract of T. triangulare achieving 88% and 87% of efficiency, by electrochemical impedance spectroscopy, respectively. / Nesta Tese ? apresentada a avalia??o de quatro tiossemicarbazonas, dos extratos das esp?cies vegetais Talinum triangulare, Physalis angulata e Theobroma cacao L., al?m de formula??es obtidas pela combina??o extrato vegetal:tiossemicarbazonas, como inibidores de corros?o frente ao a?o carbono AISI 1020 em meio de ?cido cloridr?co. As tiossemicarbazonas foram obtidas com bom grau de pureza, em rendimentos satisfat?rios e, caracterizadas por IV, RMN de ^1H e ^13C. O extrato aquoso de Talinum triangulare foi obtido em aparelho de ultrassom, os extratos da esp?cie Physalis angulata, foram obtidos sob macera??o em ?gua e o outro em acetato de etila; j? os extratos aquosos da esp?cie Theobroma cacao L. foram obtidos em aparelho de ultrassom e decoc??o e, finalmente, o extrato hidroalco?lico foi obtido por macera??o em etanol:?gua (80:20). As tiossemicarbazonas, os extratos vegetais e suas formula??es foram testadas frente ? corros?o de a?o carbono AISI 1020 em solu??o 1mol.L-1 de HCl. Para tal avalia??o foi utilizada a t?cnica gravim?trica de Perda de Massa e as t?cnicas eletroqu?micas de Polariza??o Potenciodin?mica e Espectroscopia de Imped?ncia Eletroqu?mica. Os resultados mostraram que a presen?a de tiossemicarbazonas, bem como, das formula??es aumentam significativamente a resist?ncia do a?o carbono AISI 1020 em ?cido. Os resultados obtidos nos diferentes ensaios utilizados (Perda de Massa, Polariza??o Potenciodin?mica e Espectroscopia de Imped?ncia Eletroqu?mica) mostraram que estas t?cnicas s?o complementares quanto a avalia??o da inibi??o da corros?o. A melhor efici?ncia anticorrosiva foi observada para as tiossemicarbazonas cloro e hidroxi-substitu?das e, para suas formula??es com o extrato da T. triangulare obtendo-se 88% e 87% de efici?ncia por espectroscopia de imped?ncia eletroqu?mica, respectivamente.