Thesis--Wageningen--Wageningen agricultural university, 1998. / Bibliogr. p. 227-276.

Thesis (M.S.)--Universidad de Puerto Rico, Recinto Universitario de Mayagüez, 2004. / Tables. Printout. Abstract in Spanish and English. Includes bibliographical references (leaves 59-61).

No description available.

The non-starch polysaccharide (NSP) components from apple, oat, broccoli and plantain were tested as growth substrates for representatives of the major groups of intestinal bacteria, none of which was able to fully utilise the NSPs for growth.  More bacteria were able to use the soluble plantain NSP fraction for growth than any other NSP tested, with the <i>Bacteroides </i>group showing the strongest growth response.  <i>E. coli</i> strains isolated from healthy people and Inflammatory bowel disease (IBD) patients were all able to utilise the soluble plantain substrate to the same high extent. A wide range of commensal anaerobes were able to bind to the insoluble plantain NSP in a strain specific manner that was independent of the ability to utilize the soluble plantain NSP for growth, with <i>E. coli </i>binding in the highest numbers to the insoluble NSP. The effects of plantain NSP were monitored <i>in vivo</i>, and only the <i>Bacteroides </i>group increased significantly after soluble plantain supplementation.  <i>E. coli </i>populations were volunteer-specific and unaltered after plantain supplementation. <i>Bacteroides </i>and <i>E. coli</i> were the two main groups affected by plantain NSP after the <i>in vitro </i>work, both of which have been implicated in IBD.  Binding to, and growth on plantain may therefore selectively alter the composition of the gut microbiota in patients.  Despite the stimulation of <i>E. coli</i> growth, addition of plantain to the diet may help to prevent colonization of the gut wall by providing this alternative binding substrate.

This thesis evaluates the potential of Integrated Pest Management (IPM) technologies for plantain to benefit the poor in Ecuador. First, a socioeconomic analysis of plantain producers in the Ecuadorian coast is presented. Second, adoption rates for different size farms are estimated for use of various improved management practices. Projected adoption rates are then used in an economic surplus analysis to estimate potential benefits of IPM technologies. Results indicate that most producer benefits will accrue to medium-scale plantain farmers. However, we find plantain farmers to be in general poor. Adopting farmers increase their demand for labor, benefiting mostly poor rural landless households. Urban consumers and rural poor households also benefit from the induced plantain price reduction resulting from increased production. / Master of Science

Este trabalho teve o objetivo de propor uma metodologia adequada ao diagnostico nutricional e à avaliação da fertilidade do solo, dentro do contexto do balanço nutricional da cultura do plátano (Musa AAB subgrupo plátano cv. Hárton) no Sul do Lago do Maracaibo, Venezuela. O procedimento inicial foi, estratificar a área de amostragem por series semelhantes de solos da região. Desta maneira, selecionaram-se quatro lavouras com um histórico de melhor rendimento, na serie de solos de texturas francas. Em seguida fez-se a amostragem completamente ao acaso, entre os meses de julho a dezembro dos anos 2000 e 2001. O tamanho da amostra tirada por lavoura, foi de 30 unidades experimentais. Entretanto, por segurança acrescentaram-se cerca de 25%, dadas as possibilidades de perdas por rajadas de vento e chuva e outros infortúnios. A unidade experimental foi formada pela planta "mãe" e seu broto lateral "filho" em pleno desenvolvimento. Em cada unidade coletou-se a amostra foliar, na planta "mãe" de acordo a norma estabelecida pelo Método de Amostragem Internacional de Referencia (MEIR). Concomitantemente, tomou-se a amostra de solo, na faixa de adubação, em frente do "filho" em duas profundidades 0 - 20 cm e 21 - 40 cm. As amostras de folhas foram analisadas para N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn. Nas amostras de solo se determinou-se pH, condutividade elétrica, matéria orgânica, areia, silte, argila, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. Os dados foram avaliados por analises de regressão com as combinações lineares dos componentes principais, regressão múltipla e obtenção da media aritmética das plantas com maior rendimento. Os resultados demonstraram que o modelo de regressão das combinações lineares com o rendimento deu uma melhor avaliação e predição do rendimento do plátano Hárton, dentro do contexto do balanço nutricional. Com esse modelo, posteriormente estimou-se o rendimento e se separou a população em classes desde o menor até o maior rendimento. Observaram-se nos dados dos analises de solos e folhas, incrementos, decréscimos ou ausência da variação nas concentrações de nutrientes em relação com o rendimento. Isto permitiu realizar interpretações simultâneas das análises de solos e folhas sem a necessidade de valores de referência. Por conseguinte vê-se que o modelo de regressão do rendimento com as combinações lineares vai além do uso de valores de referência isolados, pois permitiu determinar e utilizar o balanço nutricional entre todas as variáveis estudadas. Os resultados assim obtidos, permitem que a metodologia utilizada, seja indicada como una proposta de interpretação dos resultados de análises de solos e folhas. / The aim of this work is to suggest an adequate methodology for the evaluation of the nutritional status and of the fertility of soil for plantain grown in the South of Lake Maracaibo, Venezuela. Initially the area to sample was split into similar soil series. Four high yielding plantations were selected within a soil series of intermediate texture. Afterwards a random sampling was carried out from July to December 2000 and 2001. The sample per plantation had 30 experimental units, plus 25 % for safety reasons, since losses could occur due to weather conditions and other adverse factors. The experimental unit consisted of the "mother" plant and its fully developed "daughter". In each unit leaf sampling was done according to the "Method of International Sampling for Reference"(MEIR). Soil Samples were colleted in front of he daughter in the fertilization band at the depths of 0-20 and 21-40 cm. Leaf samples were analysed for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo and Zn. pH, conductivity, organic matter, sand, silt, clay, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn were determined in the soil samples. Data were evaluated by regression analysis with the lineal combinations of the main components, and by multiple regression. Results have shown that the regression model of the lineal combination with yield gave a better evaluation and prediction of the plantain crop, within the context of nutritional balance. This, on its turn allowed for the assessment of yield and for the separation of the population in yield classes. It was possible to observe both in the soils and leaves concentrations of nutrients related and not related to yield. It was possible, therefore, to conduct simultaneous interpretation of soil and leaf analyses obviating the need for reference values. The model of regression of yield against lineal combinations goes farther the than the isolated reference values since it allowed for the determination and utilization of nutritional balance among all variables. This methodology could be proposed for the interpretation of the results of soil and plant analyses.

Este trabalho teve o objetivo de propor uma metodologia adequada ao diagnostico nutricional e à avaliação da fertilidade do solo, dentro do contexto do balanço nutricional da cultura do plátano (Musa AAB subgrupo plátano cv. Hárton) no Sul do Lago do Maracaibo, Venezuela. O procedimento inicial foi, estratificar a área de amostragem por series semelhantes de solos da região. Desta maneira, selecionaram-se quatro lavouras com um histórico de melhor rendimento, na serie de solos de texturas francas. Em seguida fez-se a amostragem completamente ao acaso, entre os meses de julho a dezembro dos anos 2000 e 2001. O tamanho da amostra tirada por lavoura, foi de 30 unidades experimentais. Entretanto, por segurança acrescentaram-se cerca de 25%, dadas as possibilidades de perdas por rajadas de vento e chuva e outros infortúnios. A unidade experimental foi formada pela planta "mãe" e seu broto lateral "filho" em pleno desenvolvimento. Em cada unidade coletou-se a amostra foliar, na planta "mãe" de acordo a norma estabelecida pelo Método de Amostragem Internacional de Referencia (MEIR). Concomitantemente, tomou-se a amostra de solo, na faixa de adubação, em frente do "filho" em duas profundidades 0 – 20 cm e 21 – 40 cm. As amostras de folhas foram analisadas para N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn. Nas amostras de solo se determinou-se pH, condutividade elétrica, matéria orgânica, areia, silte, argila, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. Os dados foram avaliados por analises de regressão com as combinações lineares dos componentes principais, regressão múltipla e obtenção da media aritmética das plantas com maior rendimento. Os resultados demonstraram que o modelo de regressão das combinações lineares com o rendimento deu uma melhor avaliação e predição do rendimento do plátano Hárton, dentro do contexto do balanço nutricional. Com esse modelo, posteriormente estimou-se o rendimento e se separou a população em classes desde o menor até o maior rendimento. Observaram-se nos dados dos analises de solos e folhas, incrementos, decréscimos ou ausência da variação nas concentrações de nutrientes em relação com o rendimento. Isto permitiu realizar interpretações simultâneas das análises de solos e folhas sem a necessidade de valores de referência. Por conseguinte vê-se que o modelo de regressão do rendimento com as combinações lineares vai além do uso de valores de referência isolados, pois permitiu determinar e utilizar o balanço nutricional entre todas as variáveis estudadas. Os resultados assim obtidos, permitem que a metodologia utilizada, seja indicada como una proposta de interpretação dos resultados de análises de solos e folhas. / The aim of this work is to suggest an adequate methodology for the evaluation of the nutritional status and of the fertility of soil for plantain grown in the South of Lake Maracaibo, Venezuela. Initially the area to sample was split into similar soil series. Four high yielding plantations were selected within a soil series of intermediate texture. Afterwards a random sampling was carried out from July to December 2000 and 2001. The sample per plantation had 30 experimental units, plus 25 % for safety reasons, since losses could occur due to weather conditions and other adverse factors. The experimental unit consisted of the "mother" plant and its fully developed "daughter". In each unit leaf sampling was done according to the "Method of International Sampling for Reference"(MEIR). Soil Samples were colleted in front of he daughter in the fertilization band at the depths of 0-20 and 21-40 cm. Leaf samples were analysed for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo and Zn. pH, conductivity, organic matter, sand, silt, clay, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn were determined in the soil samples. Data were evaluated by regression analysis with the lineal combinations of the main components, and by multiple regression. Results have shown that the regression model of the lineal combination with yield gave a better evaluation and prediction of the plantain crop, within the context of nutritional balance. This, on its turn allowed for the assessment of yield and for the separation of the population in yield classes. It was possible to observe both in the soils and leaves concentrations of nutrients related and not related to yield. It was possible, therefore, to conduct simultaneous interpretation of soil and leaf analyses obviating the need for reference values. The model of regression of yield against lineal combinations goes farther the than the isolated reference values since it allowed for the determination and utilization of nutritional balance among all variables. This methodology could be proposed for the interpretation of the results of soil and plant analyses.

De nombreuses bananes cultivées et consommées sont des hybrides interspécifiques triploïdes entre Musa acuminata (génome A) et Musa balbisiana (génome B). L'amélioration de ces cultivars nécessite de mettre en place des stratégies complexes liées à leur faible fertilité et leur niveau de ploïdie. De plus, le génome M. balbisiana porteur de caractères agronomiques intéressants est malheureusement porteur de séquences intégrées de Banana streak virus (ou eBSV pour endogenous BSV). Ces eBSV sont capables de produire, dans un contexte de croisements interspécifiques et sous conditions de stress abiotiques, des génomes viraux responsables de l'infection systémique du bananier. L'activation spontanée de ces eBSV est la contrainte majeure des programmes d'amélioration du bananier plantain depuis plus de 10 ans. La ségrégation des chromosomes A et B chez les clones polyploïdes interspécifiques de bananiers est encore très peu connue. Nous avons au cours de cette thèse analysé la recombinaison et la ségrégation chromosomique chez 184 plantes issues de la descendance AAAB (CRBP39) x AA (Pahang_Carbap) au moyen de 38 marqueurs SSR distribués sur les 11 chromosomes Musa et de 6 marqueurs PCR spécifiques des deux espèces BSV présentes chez CRBP39 (eBSGFV-7 et eBSOLV-1). Nous avons observé qu'au cours de la formation des gamètes chez l'allotétraploïde CRBP39, la plupart des marqueurs du tétraploïde AAAB CRBP39 ont une ségrégation de type tétrasomique et que les génomes A et B recombinent au niveau de tous les segments de chromosomes pour lesquels nous pouvions suivre les allèles du chromosome B. D'autre part, nous avons montré que 50% des descendants ont reçu, à un ou quelques loci, un ou trois allèles du parent AAAB (CRBP39) au lieu de deux. La composition allélique de ces gamètes aneuploïdes, la cartographie génétique et l'analyse des corrélations entre marqueurs suggèrent que cette particularité résulte d'une variation structurale entre génomes A et B. Un des chromosomes B correspondrait à une partie des chromosomes 1A et 3A. Nous avons également observé une distorsion de ségrégation des loci eBSV avec une surreprésentation d'individus possédant au moins une intégration eBSV (86%). La régulation des eBSV semble très complexe et nécessitera des études complémentaires pour tenter d'identifier le ou les facteurs génétiques impliqués. Finalement, notre travail a montré que des croisements de type AAAB x AA peuvent générer des plantes possédant du génome B sans aucune intégration BSV (13%). Ce résultat est important car il ouvre une voie de contournement à la contrainte eBSV dans les programmes d'amélioration génétique. / Many cultivated and consumed banana are interspecific triploid hybrids between Musa acuminata (A genome) and Musa balbisiana (B genome). The genetic improvement of these cultivars requires the implementation of complex breeding strategies due to their low fertility and ploidy level. In addition, the B genome of M. balbisiana which bears interesting agronomic traits unfortunately carries endogenous Banana streak virus sequences (eBSV). Under certain conditions such as interspecific crosses and abiotic stresses, these eBSV are able to produce infectious viral genomes responsible for systemic infection of banana. The spontaneous activation of these eBSV is the major constraint of plantains improvement programs for more than 10 years. The A and B chromosomes recombination and segregation in interspecific polyploids banana are still poorly understood. We here analyzed chromosomes recombination and segregation in 184 offspring from the cross AAAB (CRBP39) x AA (Pahang_Carbap) using 38 SSR markers distributed on the 11 Musa chromosomes and 6 specific PCR markers of both BSV species integrated in CRBP39 (eBSGFV-7 and eBSOLV-1). We noticed that during CRBP39 meiosis most of the SSR markers have tetrasomic segregation and that A and B genomes recombine at all chromosomes segments where we were able to follow chromosome B alleles. Besides, we showed that 50% of the offspring received at one or several loci, one or three alleles of the CRBP39 parent instead of two. The allelic composition of these aneuploid gametes, the genetic map and the analysis of correlations between markers suggest that this peculiar observation is due to a structural variation between A and B genomes. One of the B chromosomes would be part of chromosomes 1A and 3A. We also noticed a distorted segregation of eBSV loci with an overrepresentation of individuals harboring at least one of the eBSV (86%). eBSV regulation seems very complex and requires additional studies to identify the genetic factor(s) involved. Finally, we also showed that AAAB x AA crosses can generate plants with B genome but without eBSV. This is the case for 13% of the offspring. This result is important because it shows that we can overcome eBSV constraint in banana breeding programs.

La banane plantain est un fruit couramment consommé au Congo-Brazzaville sous la forme cuite en tant qu’accompagnement. Le procédé de friture profonde de la banane plantain est une pratique très répandue, souvent mal maitrisé, compte tenu de l’utilisation prolongée des huiles de friture entrainant la formation de composés néfastes à la santé. En effet, depuis un certain nombre d’années, la consommation d’huiles locales (soja, palme) et leurs dégradations après chauffage constituent une des préoccupations principales pour la sécurité sanitaire du consommateur. Les objectifs de cette thèse consistaient à étudier l’influence du procédé de la friture profonde appliqué à la banane plantain Musa AAB, variété « Harton » au stade de maturité 7, consommée sous la forme de disque. Nous avons dans un premier temps appliqué la méthodologie des surfaces de réponse au procédé de friture profonde, afin de déterminer l’influence de trois paramètres (temps / température / quantité) sur différentes réponses (couleur, dureté, teneurs en huile et en eau des produits frits) en fonction de la nature de l’huile utilisée (soja, palme, huile Frial). Une fois les conditions optimales obtenues sur la banane plantain en condition domestique, l’étude s’est focalisée sur l’évolution de la stabilité des huiles de friture par le suivi des paramètres physico-chimiques de dégradation de ces dernières (composés polaires totaux, acides gras libres, composés primaires et secondaires d’oxydation). Des analyses de la couleur, du point de cristallisation et de la viscosité sont venues compléter l’étude et ont permis d’établir la durée d’utilisation optimale de ces huiles en fonction de la quantité de banane plantain à frire. Enfin, les mécanismes de transfert d’eau et d’absorption d’huile dans la matrice ont été étudiés et modélisés en fonction de la température, de l’épaisseur et du temps d’immersion. / Plantain is a fruit commonly consumed in Congo - Brazzaville in its cooked form, as an accompaniment. The process of deep frying plantain is a widespread practice, often poorly mastered, given the prolonged use of frying oils, leading to the formation of compounds harmful to health. Indeed, for a number of years, the consumption of local oils (soybean, palm) and their degradation after heating are cause of major concern for consumer safety. The objectives of this study were to investigate the influences of the deep frying process applied on the Musa AAB plantain of "harton" variety, maturity level 7, as consumed in sliced form. We initially applied response surface methodology (RSM) to the deep frying process to determine the influence of three parameters (time / temperature / quantity) on different responses (color, hardness, oil uptake and water content) according to the type of oil used (soybean, palm, Frial oils). Once optimal conditions were obtained from the plantain in domestic conditions, the study focused on the evolution of frying oil stability, by monitoring physicochemical parameters of the degradation of the aforementioned (total polar compounds, free fatty acids, primary and secondary oxidation products). Analyses of color, crystallization point and viscosity, were added to the study and helped establish the optimal duration of use for these oils depending on the quantity of plantains fried. Lastly, the mechanisms of water transfer and oil uptake in the matrix has been studied and modeled according to temperature, thickness and immersion time.

Region specific foods in the Niger Delta like yam and cassava are consumed on a daily basis by at least 70% of the population. In addition to other commonly consumed foods, high volumes of unavoidable food wastes are generated. With 78% of the households in the region disposing their waste by burying, burning or in unauthorised heaps, environmental degradation is sustained. The region also suffers an infestation of Water Hyacinth (WH). Anaerobic Digestion (AD) presents a viable way of managing these wastes in addition to providing a clean source of energy. Limited research has been conducted on the characterisation and biogas potential of these exotic food wastes due to their localised availability, leading to a knowledge gap. My original contribution to knowledge is the Specific Waste Index (SWI), nutrient characterisation and biogas potential of the local food wastes and WH. Also novel is the design and optimisation of the AD process for mono and codigestion including the quarter hourly analysis of CH4 and CO2 content of the biogas composition over the complete duration of an AD test. The research approach was experimental and involved using conventional research methods in new fields of investigation. SWI was determined by replicating local food processing practices while nutrient composition was obtained using standard analytical methods. The Bio-Methane Potential (BMP) tests were carried out on the four most common food wastes, Yam Peel (YP), Cassava Peel (CP), Cocoyam Peel (CoP), Plantain Peel (PP), following VDI 4630 guidelines and using a newly designed cost-effective bioreactor. Laboratory scale batch reactors ran over 20 days at 37⁰C (310 K). The food wastes were anaerobically co-digested with WH in the ratio 2:1 g Volatile Solid (VS) with a total substrate mass of 8.4 g VS. The S:I ratio was 1:2 g VS and tests were carried out in duplicates to give an indication of repeatability. The results showed a wide range of SWI from 0.2-1.5. The Total Solid (TS) content varied from 7% for WH to 82% for Egusi Shell. Crude Protein and Crude Fibre were highest for Ugwu Stalk at 37% VS and Egusi Shell at 82% VS respectively. Cassava Peel had the highest oil content at 25% VS. NFE which was the major nutrient for 80% of the samples was highest for Yam Peel at 82% VS. YP+WH, CP+WH, CoP+WH and PP+WH had specific biogas yields of 0.42, 0.29, 0.39, and 0.38 m3/kg VS respectively. The yields represented 76%, 48%, 70% and 69% of their respective theoretical values. The samples had their highest methane content during the Technical Digestion Time (T80) period, which lasted up to the 8th day of digestion. The pH values ranged from 7.3 to 7.9 indicating that there was no inhibitory accumulation of organic acids. The results of the mono-digestion tests showed that co-digestion with WH reduced the biogas yields for YP, CP, CoP and PP by 16%, 22%, 7% and 7%. This drop in gas production was due to presence of complex molecules in the WH co-substrate, which cannot be digested by the anaerobic microbes. Further tests showed that fresh waste produced more biogas than dry samples, while a lower S:I produced more biogas due to increased microbial population. It was concluded that waste and nutrient content varied widely between different types of Niger Delta foods. In addition mesophilic digestion of food wastes have good biogas potentials which reduce when co-digested with water hyacinth. The methane content is shown to vary widely throughout an AD test. The findings of this research would provide valuable information to AD databases and its implementation would support clean energy production, environmental remediation and allow researchers in poor regions to perform BMP test on novel feedstock using cost-effective reactors. Key Words: Anaerobic Digestion, Co-Digestion, Water Hyacinth, Niger Delta, Yam, Cassava, Cocoyam, Food Waste, Specific Waste Index, Biogas.