Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-09-05T12:40:23Z No. of bitstreams: 1 RaulinoCN_DISSERT.pdf: 941381 bytes, checksum: e4c8162091f05a4a15cd3b57ebcc36e3 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-06T15:20:38Z (GMT) No. of bitstreams: 1 RaulinoCN_DISSERT.pdf: 941381 bytes, checksum: e4c8162091f05a4a15cd3b57ebcc36e3 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-06T15:23:03Z (GMT) No. of bitstreams: 1 RaulinoCN_DISSERT.pdf: 941381 bytes, checksum: e4c8162091f05a4a15cd3b57ebcc36e3 (MD5) / Made available in DSpace on 2017-09-06T15:23:13Z (GMT). No. of bitstreams: 1 RaulinoCN_DISSERT.pdf: 941381 bytes, checksum: e4c8162091f05a4a15cd3b57ebcc36e3 (MD5) Previous issue date: 2017-04-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Wastewater from pisciculture has benn used in irrigation and tested in the production of fruitful seedlings. Seaweeds synthesize plant hormones and there are products based on extracts of macroalgae, which are used commercially as biostimulants to increase agricultural production. The objective of this work was to test the efficiency of the best dose of seaweed extract in the development of tamarind seedlings. The work was carried out, from May to October 2016, at the Federal Rural Semi-Arid University (UFERSA), East Campus, in Mossoró-RN. The substrate used was formulated with 30% manure and 70% soil. The experimental design used was in randomized complete blocks (DBC) in a 2x5 factorial scheme, with four replications, in both experiments: 2 (“Bioestimulante A” – “Bioestimulante B”) x 5 (0 ml L-1, 4 ml L-1, 8 ml L-1, 12 ml L-1 e 16 ml L-1de bioestimulante) on first experiment, on the second, 2 ( “Com Bioestimulante – Sem Bioestimulante”) x 5 (0%, 25%, 50%, 75% e 100% of wastewater from pisciculture). Morphological and physiological characteristics were analyzed. The biostimulant based on A. nodosum (Biostimulant "B"), at the dose 4.0 ml L-1, promoted the greatest increases in the dry biomass of tamarind tree and reached the highest values of total length. Biostimulant based on lithothannium (Bio-A) is superior to biostimulant based on Ascophyllum nodosum (Bio-B), with respect to stomatal conductance and high doses, above 5.54 ml L-1, compromise the photosynthetic rate of tamarind seedlings. High concentrations of wastewater from fish farming promote decline in the following evaluated characteristics: Number of leaves, length of the aerial part, total length, dry mass of the root system, dry mass of the aerial part, total dry mass, stomatal conductance and transpiration. The concentrations used in this experiment (25%, 50%, 75% and 100%) of aquaculture water were very high, not allowing to observe the beneficial effect of water. In this way, we suggest that the next surveys be carried out using smaller concentrations. The biostimulant based on Ascophyllum. nodosum (Biostimulant "B") at the dose 4.0 ml L-1 promoted the greatest increases in the aerial parts and dry biomass of tamarind seedlings / A água residuária da piscicultura vem sendo utilizada para irrigação e tem sido testada na produção de mudas de frutíferas. As algas marinhas sintetizam hormônios vegetais e existem produtos à base de extratos de macroalgas utilizadas comercialmente como bioestimulantes para aumentar a produção agrícola. O objetivo desta pesquisa foi avaliar diferentes concentrações de água residuária da piscicultura e doses de bioestimulantes naturais de algas marinhas na produção de mudas de tamarindeiro (Tamarindus indica L.). O trabalho foi realizado, no período de maio a outubro de 2016, no viveiro de mudas do Setor de Fruticultura da UFERSA, Mossoró – RN. O substrato utilizado foi formulado com 30% de esterco bovino e 70% de solo. O delineamento experimental utilizado foi o “DBC” em esquema fatorial 2x5, com quatro repetições, nos dois experimentos: 2 (“Bioestimulante A” – “Bioestimulante B”) x 5 (0 ml L-1, 4 ml L-1, 8 ml L-1, 12 ml L-1 e 16 ml L-1de bioestimulante) no primeiro experimento, e no segundo, 2 ( “Com Bioestimulante – Sem Bioestimulante”) x 5(0%, 25%, 50%, 75% e 100% de água residuária da piscicultura). Foram realizadas análises das características morfológicas e fisiológicas. O bioestimulante à base de Ascophyllum nodosum (Bioestimulante “B”), na dose 4,0 ml L-1, promoveu os maiores incrementos na biomassa seca de tamarindeiro e atingiu os maiores valores de comprimento total. O bioestimulante à base de lithothannium (Bioestimulante “A”) é superior ao bioestimulante à base de Ascophyllum nodosum (Bioestimulante “B”), na variável de condutância estomática e doses elevadas de bioestimulantes, acima de 5,54 ml L-1, comprometem à taxa fotossintética de mudas de tamarindeiro. Altas concentrações de água residuária da piscicultura promovem declínio nas seguintes características avaliadas: Número de Folhas, Comprimento da parte Aérea, Comprimento Total, Massa Seca do Sistema Radicular, Massa Seca da Parte Aérea, Massa Seca Total, Condutância Estomática e Transpiração. As concentrações utilizadas neste experimento (25%, 50%, 75% e 100%) de água residuária da piscicultura foram bastante elevadas, não permitindo se observar o efeito benéfico da água. Dessa forma, sugerimos que as próximas pesquisas sejam realizadas utilizando concentrações menores. A fertilização com bioestimulante da espécie Ascophyllum. nodosum na dose de 4,0 ml L-1 promove incrementos no diâmetro do colo, comprimento da parte aérea e no acúmulo de biomassa seca de mudas de tamarindeiro / 2017-09-05

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-06T20:54:56Z No. of bitstreams: 1 IzaelDeSousaCosta_DISSERT.pdf: 1172471 bytes, checksum: 10b2fd67da0043eb1fc836fa80793180 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-20T22:08:56Z (GMT) No. of bitstreams: 1 IzaelDeSousaCosta_DISSERT.pdf: 1172471 bytes, checksum: 10b2fd67da0043eb1fc836fa80793180 (MD5) / Made available in DSpace on 2017-11-20T22:08:56Z (GMT). No. of bitstreams: 1 IzaelDeSousaCosta_DISSERT.pdf: 1172471 bytes, checksum: 10b2fd67da0043eb1fc836fa80793180 (MD5) Previous issue date: 2017-08-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A obesidade ? uma epidemia mundial que pode ocorrer por fatores gen?ticos, ambientais e metab?licos / hormonais. Entre os fatores hormonais, sabe-se que, em humanos ou animais, em estado de obesidade, esses apresentam respostas alteradas a determinados horm?nios quando comparados aos eutr?ficos. Por ser uma condi??o de causas multifatoriais, seu tratamento, ocorre por diversas maneiras; entre elas, vem sendo estudada a utiliza??o de inibidores de tripsina. Neste estudo foi avaliado o efeito do ITT como secretagogo de CCK e seu sinergismo sobre leptina em ratos Wistar com obesidade. Inicialmente, ratos Wistar foram classificados quando ao estado nutricional zoom?trico. O estudo foi conduzido com quatro grupos de ratos Wistar, divididos em tr?s grupos de animais com obesidade e um grupo com animais eutr?ficos (n total=20), sendo utilizadas as dietas comercial padr?o (Labina?) e experimental de alto ?ndice glic?mico e alta carga glic?mica (Dieta HGLI), a mesma utilizada para indu??o da obesidade. O ITT (25 mg / Kg de peso) e a Labina? foram utilizadas como tratamentos para dois dos grupos de animais com obesidade, durante dez dias. Aos grupos com obesidade foram administradas: Dieta padr?o mais ?gua (Obeso / Dieta padr?o); Dieta HGLI mais ?gua (Obeso / Dieta HGLI); Dieta HGLI mais ITT (Obeso / Dieta HGLI + ITT); enquanto aos animais eutr?ficos foi oferecida a dieta comercial Labina? (Eutr?fico / Dieta padr?o). Foram verificadas, ao longo desse per?odo, o efeito do ITT sobre o estado nutricional zoom?trico, as concentra??es plasm?ticas de CCK e leptina e a express?o de genes relacionados a CCK em intestino e do gene ob da leptina em gordura subcut?nea. Observou-se que todos os grupos mantiveram seus estados nutricionais de acordo com o ?ndice de Lee por?m os ratos que passaram pelo tratamento com o ITT foram os ?nicos a apresentar uma discreta redu??o desse ?ndice mas, sem signific?ncia estat?stica. O ITT n?o alterou a CCK plasm?tica, n?o tendo sido observadas diferen?as estat?sticas entre os valores de express?o relativa de mRNA para o receptor de CCK-2R e a enzima PCSK1. O tratamento com o ITT aumentou a express?o relativa de mRNA de CCK-1R, assim como ocorreu no grupo sem tratamento que consumia a dieta HGLI, no entanto foi diferente, estatisticamente, dos animais eutr?ficos (p = 0.028). Ademais, foi observado que 60% dos animais, tratados com o ITT, apresentaram concentra??es plasm?ticas de leptina abaixo de 0,1 ng/?L, enquanto aqueles tratados com dieta padr?o, apenas 20% se encontravam nessa condi??o. Tal fato n?o foi observado no grupo eutr?fico e com obesidade. Ainda, relacionado ao efeito do ITT, esse n?o foi capaz de reduzir a express?o relativa de mRNA do gene ob da leptina. O estudo com a express?o relativa de mRNA de genes relacionados ? produ??o de CCK em intestino de ratos com obesidade ? inovador e sugere-se que, ao constatar o efeito do ITT na redu??o das concentra??es plasm?ticas de leptina, neste estudo, o ITT melhore a a??o da CCK em animais com obesidade resultando em discreta melhora do estado de obesidade, independente do aumento plasm?tico da CCK. / Obesity is a worldwide epidemic that can occur due to genetic, environmental and metabolic / hormonal factors. Among the hormonal factors, it is seen that, humans or animals, in state of obesity, present altered responses to certain hormones when compared to eutrophic. Once obesity presents multifactorial causes, its treatment also occurs by several means, among which the use of trypsin inhibitors. This study evaluated the effect of a Tamarindus indica L. seed isolated Trypsin Inhibitor (TTI) as a CCK secretagogue and its synergism with leptin in obese Wistar rats. The study was conducted with obese and lean rats (n = 20). Three groups of obese rats were feed 10 days one of the following diets: Standard diet (Labina?) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the Labina? for the 10 days. We evaluated nutritional status (zoometric measurements), plasma CCK and leptin, mRNA expression of intestinal CCK-related genes and the ob gene in subcutaneous adipose tissue. TTI treated animals had a slight reduction in the Lee index. TTI did not increase plasma CCK in obese animals and we found no significant effect of TTI in CCK-2R and PCSK1 gene expression. On the other hand, TTI treatment increased CCK-1R gene expression compared with the lean group (p = 0.028). Although TTI did not reduce the ob gene expression. Interestingly 60% of the TTI treated animals presented plasma concentrations below 0.1 ng / ?L, whereas those treated with standard diet, only 20% of the animals were in this condition. This was not observed in the lean and obese groups. Our study with relative mRNA expression of intestinal CCK-related genes in obese rats is a novel study and suggests that TTI by decreasing plasma leptin may improve CCK action in obese rats, since the expression of the CCK-1R gene in this group was higher when compared to lean rats, resulting in improvement of zoometric measurements, independently of plasma CCK increase.

This study expanded the knowledge on tamarind (Tamarindus indica L.) seedling production by analyzing the effects of different container sizes and vermiculite doses in a commercial substrate and seed size and different sowing depths in a nursery seedling production. The experiments were done at the experimental farm Água Limpa in the sector of Fruit Crops, in a nursery with anti-aphid screens, with 0.38 mm2 opening. The farm is located at 19º05 23 S and 48º21 28 W, at 792 m altitude, in the county of Uberlândia, Minas Gerais, Brazil. The experimental design of the trials were randomized blocks, in a 3 x 3 or 2 x 3 factorial. In the first trial, were utilizadas three vermiculite doses (0%, 10% or 20% v v-¹) in three container sizes (18 x 30 cm, 20 x 25 cm or 25 x 35 cm), and in the second trial, utilizou-se two seed sizes (small and large) and three sowing depths (1cm; 2cm or 3cm), both of them with 5 repetitions and 5 plants per plot. The experiments were done from December 26 2006 to June 4 2007. In the first trial, results indicated that tamarind seedlings were not affected by container size, nor by the use of vermiculite. However, the largest container (25 x 35 cm) yielded longer root length, although reducing stem diameter and above ground fresh and dry matter. Mixing vermiculite to the substrate yielded better results for stem diameter, number of leaves, fresh and dry matter of roots and above ground mass. In the second trial, the results indicated that bigger seeds yielded greater quality tamarind seedlings for plant height, stem diameter, fresh and dry matter for above ground mass and roots. There were no significant differences in the parameters evaluated as a function of sowing depth. CHAPTER I: This study evaluated the effects of different vermiculite doses and container sizes in the development and quality of tamarind seedlings. The experiment was done in a nursery with anti-aphid screens, with 0.38 mm2 opening, in the sector of fruit Experimental Farm Água Limpa, county of Uberlândia (MG), from December 26 2006 to June 4 2007. The experimental design was randomized blocks , in a 3 x 3 factorial, with 5 repetitions and 5 plants per plot. The factors were three vermiculite doses (0%, 10% or 20% v v-¹) and three container sizes (18 x 30 cm, 20 x 25 cm or 25 x 35 cm). The development of tamarind seedlings was evaluated by the determination of the number of leaves, stem diameter, plant height, root length, fresh and dry weight of roots and above ground matter. The results showed that tamarind seedling height was not affected by container sized nor by the use of vermiculite. The largest container (25 x 35 cm) yielded better root length; however, stem diameter and above ground fresh and dry matter were reduced. Mixing vermiculite to the substrate yielded better results for stem diameter, number of leaves, fresh and dry matter of roots and above ground mass. CHAPTER II: The effect of seed size and different sowing depths on tamarind (Tamarindus indica L.) seedling vigor and vegetative growth was evaluated in a trial done in a screened nursery, with 0.38 mm2 opening, at the experimental farm Água Limpa, in a nursery with anti-aphid screens, in the county of Uberlândia,. The farm is located at 18º55 33 S and 48º17 19 W, at 872 m altitude, Minas Gerais, from December 26 2006 to June 4 2007. The experimental design was randomized blocks, in a 2 x 3 factorial, with 5 repetitions and 5 plants per plot. The factors were two seed sizes, small and large (65.60 g and 94.54 g respectively), defined according to the weight of 100 seeds and three sowing depths (1cm; 2cm or 3cm). The number of leaves, stem diameter, plant height, root length, fresh and dry weight of roots and above ground matter were evaluated. The results indicate that tamarind seed size affected seedling initial development. There were no significant differences in the parameters evaluated as a function of sowing depth. / O trabalho teve como objetivo ampliar os conhecimentos na produção de mudas de tamarindeiro (Tamarindus indica L.) estudando os efeitos de diferentes tamanhos de recipientes e doses de vermiculita em substrato comercial e tamanho de semente em diferentes profundidades de semeadura na produção de mudas durante a fase de viveiro. Os experimentos foram conduzidos na Fazenda Experimental Água Limpa no setor de Fruticultura, em um viveiro com telado anti-afídios, malha de 0,38 mm2. A Fazenda está situada a 19º05 23 de latitude sul e 48º21 28 de longitude oeste, e altitude de aproximadamente 792 m, no município de Uberlândia-MG. Os delineamentos experimentais foram inteiramente casualizados, com os tratamentos distribuídos em esquemas fatoriais 3 x 3 e 2 x 3. No primeiro experimento, foram utilizadas três doses de vermiculita (0%, 10% e 20% vv ¹) em três tamanhos de recipiente (18 x 30 cm, 20 x 25 cm e 25 x 35 cm), e no segundo experimento, utilizou-se dois tamanhos de semente (pequenas e grandes) e três profundidades de semeio (1; 2 e 3cm), ambos com 5 repetições e 5 mudas por parcela. Os experimentos foram realizados no período de 26 de dezembro de 2006 a 4 de junho de 2007. No primeiro experimento, os resultados mostraram que a altura das mudas de tamarindeiro não foi influenciada pelos diferentes tamanhos de recipiente e uso de vermiculita. No entanto, o maior recipiente (25 x 35 cm) propiciou melhor comprimento de raiz. Todavia, diminuiu o diâmetro de caule e a massa seca da parte aérea das mudas de tamarindeiro. Já a mistura de vermiculita ao substrato promoveu melhores resultados quanto ao diâmetro de caule, número de folhas, massa seca da parte aérea e de raízes. No segundo experimento, os resultados mostraram que as sementes grandes propiciaram mudas de tamarindeiro de qualidade superior, em relação à altura de muda, diâmetro de caule, massa seca, tanto do sistema radicular, como da parte aérea. Quanto à profundidade de semeio, não houve diferença significativa para todas as características avaliadas. CAPITULO I: O objetivo do presente experimento foi avaliar o efeito de diferentes doses de vermiculita e o tamanho dos recipientes no desenvolvimento e na qualidade de mudas de tamarindeiro. O experimento foi conduzido em um viveiro com tela anti-afídios, malha de 0,38 mm2, no setor de Fruticultura da Fazenda Experimental Água Limpa, município de Uberlândia (MG), no período de 26 de dezembro de 2006 a 4 de junho de 2007. O delineamento experimental foi inteiramente casualizado, com os tratamentos distribuídos em esquema fatorial 3 x 3, com 5 repetições e 5 mudas por parcela, sendo os fatores três doses de vermiculita ( 0%, 10% e 20% vv ¹) e três tamanhos de recipiente (18 x 30 cm, 20 x 25 cm e 25 x 35 cm). Para a avaliação do desenvolvimento das mudas de tamarindeiro, foi determinado o número de folhas, diâmetro do caule, altura da muda, comprimento da raiz, peso da matéria seca da parte aérea e das raízes. Os resultados mostraram que a altura das mudas de tamarindeiro não foi influenciada pelos diferentes tamanhos de recipiente e uso de vermiculita. O maior recipiente (25 x 35 cm) propiciou melhor comprimento de raiz, todavia, diminuiu o diâmetro de caule e a massa seca da parte aérea das mudas de tamarindeiro. Já a mistura de vermiculita ao substrato promoveu melhores resultados quanto ao diâmetro de caule, número de folhas, massa seca da parte aérea e de raízes. CAPITULO II: Com o objetivo de avaliar a influência dos tamanhos de semente e a profundidade de semeadura sobre o vigor e o desenvolvimento vegetativo das mudas de tamarindeiro (Tamarindus indica L.), conduziu-se um experimento em um viveiro telado, de malha 0,38 mm2, na Fazenda Experimental Água Limpa, no setor de Fruticultura, município de Uberlândia (MG), no período de 26 de dezembro de 2006 a 4 de junho de 2007. O delineamento experimental foi inteiramente casualizado, com os tratamentos distribuídos em esquema fatorial 2 x 3, com 5 repetições e 5 mudas por parcela, sendo os fatores: dois tamanhos de semente, pequenas e grandes (65,60 g/100 sementes; 94,54 g/100 sementes) respectivamente, e três profundidades de semeio (1; 2 e 3cm). Avaliou-se o número de folhas, diâmetro do caule, altura da muda, comprimento da raiz, massas secas da parte aérea e das raízes. Os resultados obtidos mostraram que as sementes de tamarindo influenciaram o desenvolvimento inicial das mudas. Quanto à profundidade de semeio, não houve diferença significativa entre todas as características avaliadas nas mudas. / Mestre em Agronomia

Le taro (Colocasia esculenta L SCHOTT) est un tubercule d’une grande importance alimentaire au Tchad pour la consommation humaine et animale. La littérature sur les pratiques culturales et les technologies traditionnelles post-récolte des variétés tchadiennes demeure presque inexistante. Une enquête a donc été menée dans la région du Mayo-Kebbi (Tchad) où le taro est très cultivé. Il résulte qu’il existe principalement deux variétés de taro au Tchad : la variété « Gouning souol» ou variété locale qui est caractérisée par une âcreté importante et un temps de cuisson prolongé (6 à 8 h). Ces propriétés ont entraîné l’abandon de la culture de cette variété au profit de la variété « Gouning sosso » qui présente une âcreté moindre et un temps de cuisson plus court (45 à 60 minutes). Une technique traditionnelle pour réduire l’âcreté et diminuer le temps de cuisson consiste à tremper les tranches de taro frais soit dans l’eau, soit dans une solution de trempage de maïs ou soit dans une infusion de tamarin pendant 24 à 48 h selon l'intensité de l'âcreté. Après séchage au soleil, les cossettes sèches sont transformées en farine. Ces produits de transformation servent à la préparation de boules de pâtes, de bouillie, de soupes ou de beignets. Des analyses ont été effectuées sur une gamme d’échantillon de farine de taro produite conformément à la recette artisanale dans l’optique de comprendre l’effet de cette technologie traditionnelle. Des cossettes fraîches de taro ont été trempées pendant 0, 1 h, 3 h, 6 h, 12 h et 24 h dans de l’eau, ou dans une solution de trempage de maïs ou dans une infusion de tamarin. Chaque échantillon a ensuite été séché au soleil pendant 48 h puis broyé en farine. La matière sèche, les protéines brutes, les cendres, les fibres brutes, les macroéléments minéraux et oligoéléments ont été évalués dans le but de déterminer les effets du trempage traditionnel sur le profil nutritionnel du taro. La digestibilité in vitro de l’amidon sous l’action de l’α-amylase et la teneur en oxalates de différentes farines de taro ont été également déterminées. Il ressort de ces analyses que seul le trempage dans une infusion de tamarin a induit une baisse significative (P < 0,001) de la teneur en protéines brutes (de 3,26 % pour T0 à 2,68 % pour le traitement au tamarin à T24). L’infusion de tamarin n’a pas modifié la teneur en fibres brutes alors que les autres traitements l’ont assez significativement diminuée (P < 0,001). Toutes les méthodes de trempage ont entraîné une diminution significative des teneurs en minéraux, à l’exception d’une augmentation des teneurs en sodium (due à la qualité de l’eau des préparations) et en phosphore (probablement due à l’hydrolyse des phytates du maïs). Une perte significative en fer a été constatée passant de 144 mg/kg de MS (témoin) à 78 mg/kg de MS (échantillon traité à l’eau pendant 12 h), soit une perte de 45,83 %. La plus faible diminution de taux de fer est observée dans le cas de l'échantillon trempé dans l'infusion de tamarin avec une perte maximale de 31,25 % après 24 h. La teneur en zinc ne varie pas. Les procédés de trempage entraînent globalement une amélioration de la digestibilité du taro après une simple cuisson (95°C pendant 30 minutes) qui passe de 39,30 % (échantillon témoin non trempé) à 78,67 % pour le taro trempé dans l’eau. Après 3 h de trempage, la farine de taro traitée par la solution de maïs est significativement plus digestible (77,12 %) que les échantillons résultant de deux autres traitements [tamarin (60,86 %), eau (60,45 %)] qui sont statistiquement similaires. (...) / Colocasia esculenta L SCHOTT is a valuable tuber widely consumed in Chad by humans and livestock. There is very little available literature about the cultivation and the post-harvest traditional technologies of the Chadian varieties of taro. A survey was carried out in the Mayo-Kebbi region ( Chad) where taro is a widely cultivated. There are two main varieties of taro in Chad : the " Gouning souol " variety, a local variety characterized by an important level of acridity and the prolonged cooking time (6 to 8 hours). The presence of these properties led to the replacement of the cultivation of this variety by the " Gouning sosso " variety which presents a lower level of acridity and a shorter cooking time (45 to 60 minutes). A traditional process to reduce the acridity and decrease the cooking time consists in dipping the slices of fresh taro in the water, or in a corn solution or in a tamarind infusion for a period of 24 to 48 hours according to the intensity of the acridity. After drying in the sun, the dried chips are ground into flour. This flour is then used to prepare mixtures of porridge, soups and cakes. Analyses were carried out on samples of taro flour produced in accordance with the traditional methods of soaking to determine the effects of this traditional process. Fresh taro chips were dipped over a period of 0, 1, 3, 6, 12 and 24 hours in the water, or in the corn infusion or in the tamarind infusion. Each sample was then dried in the sun for 48 hours and ground into flour. Dry matter, crude protein, ash, crude fiber, minerals and various trace elements were assessed. The in vitro digestibility of taro starch using α-amylase enzyme and the amount of total oxalates in the different taro flour were also determined. The soaking in the tamarind infusion induced a significant (P < 0.001) decrease in protein content (from 3.26 % for the control sample to 2.68 % for the treatment with the tamarind infusion at T24). The other treatments (corn solution and water) reduced also the protein level of taro but not significantly. The crude fibre content was not affected by the tamarind infusion but decreased significantly in the other treatments at the threshold level of 5 %. All methods of soaking led to a significant decrease of the mineral contents, except for an increase in sodium (due to the quality of the water used to prepare solutions) and in phosphorus (probably due to the hydrolysis of phytates by the corn infusion). A significant loss in trace element (Iron) was observed, decreasing from 144 mg / kg of DM (control sample) to 78 mg / kg of DM (after 12 hours of water soaking) corresponding to a loss of 45.83 %. The lowest decrease in iron level was observed after the treatment by the tamarind infusion (31.25 % after 24 hours). All the soaking processes were seen to have improved the digestibility of taro flour. By simply cooking (at a temperature of 95°C for 30 minutes), the in vitro digestibility increased from 39.30 % for the control sample to 78.67 % for the water treated samples of taro. After three hours of soaking, the taro flour treated by the solution of corn becomes significantly more digestible (77.12 %) than by the two other treatments [tamarind (60.86 %), water (60.45 %)] that are statistically similar. (...)

Le taro (Colocasia esculenta L SCHOTT) est un tubercule d'une grande importance alimentaire au Tchad pour la consommation humaine et animale. La littérature sur les pratiques culturales et les technologies traditionnelles post-récolte des variétés tchadiennes demeure presque inexistante. Une enquête a donc été menée dans la région du Mayo-Kebbi (Tchad) où le taro est très cultivé. Il résulte qu'il existe principalement deux variétés de taro au Tchad : la variété " Gouning souol" ou variété locale qui est caractérisée par une âcreté importante et un temps de cuisson prolongé (6 à 8 h). Ces propriétés ont entraîné l'abandon de la culture de cette variété au profit de la variété " Gouning sosso " qui présente une âcreté moindre et un temps de cuisson plus court (45 à 60 minutes). Une technique traditionnelle pour réduire l'âcreté et diminuer le temps de cuisson consiste à tremper les tranches de taro frais soit dans l'eau, soit dans une solution de trempage de maïs ou soit dans une infusion de tamarin pendant 24 à 48 h selon l'intensité de l'âcreté. Après séchage au soleil, les cossettes sèches sont transformées en farine. Ces produits de transformation servent à la préparation de boules de pâtes, de bouillie, de soupes ou de beignets. Des analyses ont été effectuées sur une gamme d'échantillon de farine de taro produite conformément à la recette artisanale dans l'optique de comprendre l'effet de cette technologie traditionnelle. Des cossettes fraîches de taro ont été trempées pendant 0, 1 h, 3 h, 6 h, 12 h et 24 h dans de l'eau, ou dans une solution de trempage de maïs ou dans une infusion de tamarin. Chaque échantillon a ensuite été séché au soleil pendant 48 h puis broyé en farine. La matière sèche, les protéines brutes, les cendres, les fibres brutes, les macroéléments minéraux et oligoéléments ont été évalués dans le but de déterminer les effets du trempage traditionnel sur le profil nutritionnel du taro. La digestibilité in vitro de l'amidon sous l'action de l'α-amylase et la teneur en oxalates de différentes farines de taro ont été également déterminées. Il ressort de ces analyses que seul le trempage dans une infusion de tamarin a induit une baisse significative (P < 0,001) de la teneur en protéines brutes (de 3,26 % pour T0 à 2,68 % pour le traitement au tamarin à T24). L'infusion de tamarin n'a pas modifié la teneur en fibres brutes alors que les autres traitements l'ont assez significativement diminuée (P < 0,001). Toutes les méthodes de trempage ont entraîné une diminution significative des teneurs en minéraux, à l'exception d'une augmentation des teneurs en sodium (due à la qualité de l'eau des préparations) et en phosphore (probablement due à l'hydrolyse des phytates du maïs). Une perte significative en fer a été constatée passant de 144 mg/kg de MS (témoin) à 78 mg/kg de MS (échantillon traité à l'eau pendant 12 h), soit une perte de 45,83 %. La plus faible diminution de taux de fer est observée dans le cas de l'échantillon trempé dans l'infusion de tamarin avec une perte maximale de 31,25 % après 24 h. La teneur en zinc ne varie pas. Les procédés de trempage entraînent globalement une amélioration de la digestibilité du taro après une simple cuisson (95°C pendant 30 minutes) qui passe de 39,30 % (échantillon témoin non trempé) à 78,67 % pour le taro trempé dans l'eau. Après 3 h de trempage, la farine de taro traitée par la solution de maïs est significativement plus digestible (77,12 %) que les échantillons résultant de deux autres traitements [tamarin (60,86 %), eau (60,45 %)] qui sont statistiquement similaires. (...)