[ES] Esta tesis aborda la caracterización y posible utilización de la goma de alholva (Trigonella foenum-graecum) (FSG, por sus siglas en inglés) en la nutrición de gazapos durante el período posterior al destete como una alternativa al uso de antimicrobianos, centrándose en el comportamiento de la goma extraída con diferentes niveles de fibra dietaria, tanto in vitro como in vivo. En el primer experimento, a partir de una dieta basal comercial de conejo, se formularon tres dietas experimentales con niveles graduales de inclusión de FSG (0, 0.25, 0.50%) administrados a tres grupos de conejos desde el destete a los 31 días hasta el sacrificio a los 94 días. Se estudió el efecto de las dietas experimentales sobre la digestibilidad fecal en dos edades (38-41 días y 56-59 días), además de los parámetros de fermentación cecal al final del experimento. Por otro lado, a partir de la misma dieta comercial de conejo, se formularon cinco dietas experimentales que contenían 0. 0.125, 0.25, 0.50 y 100% de FSG, que se sometieron a incubación in vitro con inóculo cecal de conejo durante 72 h. Se midieron la producción de gas y las variables de fermentación. La digestibilidad fecal aparente y los parámetros de fermentación cecal no se vieron afectados significativamente por la inclusión in vivo de FSG hasta 0.5%. Sin embargo, los animales alimentados con FSG mostraron valores de pH cecal más bajos. La inclusión gradual en la dieta de FSG aumentó la concentración in vitro de ácidos grasos volátiles (VFA, por sus siglas en inglés), mientras que el FSG puro aumentó la producción asintótica de gas y la tasa máxima de degradación del sustrato y disminuyó el tiempo de incubación en el que se forma la mitad de la cantidad asintótica de gas. La incubación in vitro de FSG puro disminuyó el valor del pH, la concentración de ácido láctico y la concentración de N-NH3, y aumentó la de VFA. En el segundo experimento, el FSG se caracterizó para determinar su composición química, su contenido de galactosa y manosa y su potencial como prebiótico. Se evaluaron tanto FSG puro como niveles graduales (0, 5, 10, 15 y 20 g/kg) incluidos en dietas ricas en fibra soluble (SF, por sus siglas en inglés) de pulpa de remolacha (incluida al 10%) y dietas ricas en fibra insoluble (IF, por sus siglas en ingles) de semilla de uva desengrasada (incluida al 10%). Se sometieron a digestión enzimática con pepsina y pancreatina y luego sus fracciones indigestibles se sometieron a fermentación usando inóculo cecal. Se midieron las fracciones no digestibles después de la digestión enzimática, así como las fracciones no fermentables y las variables de fermentación después del tiempo de incubación (48 h). La FSG se compone principalmente de galactosa y manosa (630 g/kg) en una proporción de 1: 1 y un nivel moderado de proteínas (223 g/kg). El FSG puro se vio poco afectado por la digestión enzimática, ya que solo se disolvieron 145 g/kg. Sin embargo, desapareció casi por completo (984 g/kg) durante el proceso de fermentación. En consecuencia, FSG aumentó la concentración de VFA, disminuyó el valor de pH y la concentración de N-NH3. La inclusión gradual de FSG en las dietas de conejos afectó la digestión de algunos nutrientes, como las fracciones fibrosas, el almidón y las proteínas, además de aumentar la fracción fermentada en la dieta SF, pero sin ningún efecto relevante en el perfil de fermentación. En el tercer experimento, se formularon cuatro dietas de acuerdo con un diseño factorial 2 x 2: una dieta convencional de conejo (C), la misma dieta C suplementada con 10 g / kg de FSG, una dieta de bajo riesgo (LR, por sus siglas en inglés) y la misma dieta LR suplementada con 10 g/kg de FSG. Las dietas C y LR se diferenciaban en el nivel de SF y proteína bruta (CP, por sus siglas en inglés) (104 vs 205 y 156 vs 121 g/kg de SF y CP respectivamente para dietas C y LR). Doscientos dieciséis conejos de la línea LP se alojaron en jaulas individuales, se dividieron aleatoriamente entre los cuatro tratamientos y se les permitió el libre acceso al alimento y al agua. La mortalidad, la morbilidad, el índice de riesgo sanitario (HRi, por sus siglas en inglés), la ingestión diaria de pienso (DFI, por sus siglas en inglés), la ganancia media diaria (ADG, por sus siglas en inglés) y el índice de conversión alimenticia (FCR, por sus siglas en inglés) se controlaron hasta los 63 días de edad. El coeficiente de digestibilidad aparente total del tracto digestivo (CTTAD, por sus siglas en inglés) de los nutrientes se determinó en doce conejos por tratamiento, entre los 49 y 53 días de edad y finalmente se midió el ambiente cecal a los 63 días de edad. La inclusión de FSG en la dieta a 10 g/kg de alimento no afectó al rendimiento durante el cebo ni al CTTAD de los nutrientes, pero aumentó ligeramente la digestibilidad de la fibra neutrodetergente (NDF, por sus siglas en inglés) y la fibra ácido-detergente (ADF, por sus siglas en inglés) en las dietas C. Del mismo modo, los parámetros cecales no se vieron afectados por la inclusión de FSG, excepto la concentración de ácido caproico en las dietas C. Sin embargo, las dietas LR disminuyeron la mortalidad, HRi, DFI, ADG y CTTAD de materia orgánica y CP pero aumentaron FCR y CTTAD de NDF y ADF con respecto a las dietas C. Además, las dietas LR aumentaron la concentración de VFA, la proporción de ácido acético, isobutírico e isovalérico mientras que disminuyeron la materia seca del contenido cecal, NNH3 y la proporción de ácidos butírico, caproico y valérico. En resumen, la FSG responde perfectamente a las dos primeras condiciones para ser un prebiótico, ya que no es digestible por las enzimas gastrointestinales antes del ciego y es altamente fermentado una vez que alcanza el ciego. Parece afectar selectivamente a la microbiota cecal debido a su efecto sobre la concentración de VFA y N-NH3, además de su efecto sobre la proporción de caproico y valérico en dietas convencionales. FSG podría aumentar la viscosidad de la digesta limitando la solubilización de algunos nutrientes como el almidón y la proteína. FSG parece ser más efectivo en dietas comerciales convencionales que en dietas de bajo riesgo. Finalmente, se confirmó que las dietas con alto nivel de SF y bajo de CP podrían ser una buena herramienta contra la enteropatía epizoótica del conejo (ERE, por sus siglas en inglés) en un sistema de producción no medicado, a costa de peores parámetros de crecimiento. / [EN] This thesis tackles the possible characterisation and utilisation of fenugreek (Trigonella foenum-graecum) seed gum (FSG) in the nutrition of young rabbits during the post-weaning period as an alternative to antimicrobials uses. The study was focussed on the behaviour of the extracted gum with different dietary fibre levels, both in vitro and in vivo. In a first trial, starting from a basal commercial rabbit diet, three experimental diets were formulated with gradual levels of inclusion of FSG (0, 0.25, 0.50 %) given to three groups of rabbits starting from weaning at 31 days old to slaughter 94 days old. The effect of the experimental diets was studied on the faecal digestibility of the diet in two ages (38-41 days and 56-59days) and on the caecal fermentation parameters at the end of the experiment. On the other hand, starting from the same commercial rabbit diet five experimental diets were formulated containing 0, 0.125, 0.25, 0.50 and 100% of FSG that were submitted to in vitro incubation with rabbit caecal inoculum during 72h. Gas production and fermentation traits were measured. Apparent faecal digestibility and caecal fermentation parameters were not significantly affected by the in vivo inclusion of FSG up to 0.5%. However, animals fed with FSG showed lower caecal pH values. Gradual dietary inclusion of FSG increased in vitro concentration of volatile fatty acids (VFA), while pure FSG increased the asymptotic gas production and the maximum substrate degradation rate and decreased the time after incubation at which half of the asymptotic amount of gas is formed. In vitro incubation of pure FSG decreased pH value, lactic acid concentration and N-NH3 concentration and increased that of VFA. In a second trial, FSG was characterised determining its chemical composition, galactose and mannose content and prebiotic potential. Pure FSG and gradual levels of FSG (0, 5, 10, 15 and 20 g/kg), included both in diets rich in soluble fibre (SF) from beet pulp (included at 10%) or in diets rich in insoluble fibre (IF) from defatted grape seeds (included at 10 %), were evaluated. They were submitted to enzymatic digestion with pepsin and pancreatin and then their indigestible fractions were submitted to fermentation using caecal inoculum. The indigestible fractions after enzymatic digestion were measured, as well as the nonfermentable fractions and the fermentation traits after incubation time (48 h). FSG was mostly composed of galactose and mannose (630 g/kg) in 1:1 ratio and a moderate protein level (223 g/kg). Pure FSG was weakly affected by enzymatic digestion, only 145 g/kg was dissolved. However, it was almost entirely disappeared (984 g/kg) during the fermentation process. Consequently, FSG increased VFA concentration and decreased both pH value and N-NH3 concentration. Th gradual inclusion of FSG in rabbit’s diets affected some nutrients digestion such as the fibre fractions, starch and protein, besides to increase the fermentation fraction in SF diet but without any relevant effect on the fermentation profile. In a last third trial, four diets were formulated according to 2 x 2 factorial design: a conventional rabbit diet (C), the same C diet supplemented by 10 g/kg of FSG, a low-risk diet (LR), and the same LR diet supplemented by 10 g/kg of FSG. C and LR diets differed in SF and crude protein levels (CP) (104 vs 205 and 156 vs 121 g/kg of SF and CP respectively for C and LR diets). Two hundred and sixteen weaned rabbits (28 days of age) of the LP line were allocated in individual cages and divided randomly between the four treatments and allowed free access to feed and water. Mortality, morbidity, health risk index (HRi), daily feed intake (DFI), average daily gain (ADG) and feed conversion ratio (FCR) were controlled until 63 days of age. Coefficient of total tract apparent digestibility (CTTAD) of nutrients, on twelve rabbits per treatment, was determined from 49 to 53 days of age and finally, caecal environment was measured at 63 days of age. FSG dietary inclusion at 10 g/kg did not affect performance or CTTAD of nutrients but did slightly increased neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) digestibility in C diets. Similarly, caecal parameters were not affected by FSG except caproic acid concentration in C diets. Nevertheless, LR diets decreased mortality, HRi, DFI, ADG and CTTAD of organic matter and CP but increased FCR and CTTAD of NDF and ADF respect to C diets. Moreover, LR diets increased VFA concentration, the proportion of acetic, isobutyric and isovaleric while decreased the dry matter of the caecal content, N-NH3 and the proportion of butyric, caproic and valeric acids. To summarise, FSG perfectly responds to the two first conditions to be prebiotic, being not digestible by gastrointestinal enzymes before the caecum and highly fermented once reached the caecum. It seems to affect selectively caecal microbiota due to its effect on VFA and N-NH3 concentration besides to its effect on caproic and valeric proportions in conventional diets. FSG could increase viscosity of digesta limiting the solubilisation of some nutrients such starch and protein. FSG seems to be more effective in conventional commercial diets than in low-risk diets. Finally, it was confirmed that diets with high SF level and low CP could be a good tool against epizootic rabbit enteropathy (ERE) in a nomedicated breeding system at the cost of impaired growth parameters. / [CA] Aquesta tesi aborda la caracterització i possible utilització de la goma de fenigrec (Trigonella foenum-graecum) (FSG, per les sigles en anglès) en la nutrició del conills durant el període posterior al deslletament com una alternativa a l'ús d'antimicrobians, centrant-se en el comportament de la goma extreta amb diferents nivells de fibra dietària, tant in vitro com in vivo. En el primer experiment, a partir d'una dieta basal comercial de conill, es van formular tres dietes experimentals amb nivells graduals d'inclusió de FSG (0, 0.25, 0.50%) administrats a tres grups de conills des del deslletament als 31 dies fins al sacrifici als 94 dies. Es va estudiar l'efecte de les dietes experimentals sobre la digestibilitat fecal en dues edats (38-41 dies i 56-59 dies), a més dels paràmetres de fermentació cecal a la fi de l'experiment. D'altra banda, a partir de la mateixa dieta comercial de conill, es van formular cinq dietes experimentals que contenien 0. 0.125, 0.25, 0,50 i 100% de FSG, que es van sotmetre a incubació in vitro amb inòcul cecal de conill durant 72 h. Es van mesurar la producció de gas i les variables de fermentació. La digestibilitat fecal aparent i els paràmetres de fermentació cecal no es van veure afectats significativament per la inclusió in vivo de FSG fins a 0.5%. No obstant això, els animals alimentats amb FSG van mostrar valors de pH cecal més baixos. La inclusió gradual en la dieta de FSG va augmentar la concentració in vitro d'àcids grassos volàtils (VFA, per les sigles en anglès), mentre que el FSG pur va augmentar la producció asimptòtica de gas i la taxa màxima de degradació del substrat i va disminuir el temps d'incubació en el qual es forma la meitat de la quantitat asimptòtica de gas. La incubació in vitro d'FSG pur va disminuir el valor del pH, la concentració d'àcid làctic i la concentració de N-NH3, i va augmentar la de VFA. En el segon experiment, el FSG es va caracteritzar per determinar la seva composició química, el seu contingut de galactosa i manosa i el seu potencial com prebiòtic. Es van avaluar tant FSG pur com nivells graduals (0, 5, 10, 15 i 20 g/kg) inclosos en dietes riques en fibra soluble (SF, per les sigles en anglès) de polpa de remolatxa (inclosa al 10%) i dietes riques en fibra insoluble (IF, per les sigles en anglès) de llavor de raïm desgreixada (inclosa al 10%). Es van sotmetre a digestió enzimàtica amb pepsina i pancreatina i després les fraccions indigeribles es van sotmetre a fermentació usant inòcul cecal. Es van mesurar les fraccions no digestibles després de la digestió enzimàtica, així com les fraccions no fermentables i les variables de fermentació després del temps d'incubació (48 h). La FSG es compon principalment de galactosa i manosa (630 g/kg) en una proporció de 1: 1 i un nivell moderat de proteïnes (223 g/kg). El FSG pur es va veure poc afectat per la digestió enzimàtica, ja que només es van dissoldre 145 g/kg. No obstant això, va desaparèixer gairebé del tot (984 g/kg) durant el procés de fermentació. En conseqüència, FSG va augmentar la concentració de VFA, va disminuir el valor de pH i la concentració de N-NH3. La inclusió gradual de FSG en les dietes de conills va afectar la digestió d'alguns nutrients, com les fraccions fibroses, el midó i les proteïnes, a més d'augmentar la fracció fermentada en la dieta SF, però sense cap efecte rellevant en el perfil de fermentació. En el tercer experiment, es van formular quatre dietes d'acord amb un disseny factorial 2 x 2: una dieta convencional de conill (C), la mateixa dieta C suplementada amb 10 g/kg de FSG, una dieta de baix risc (LR, per les sigles en anglès) i la mateixa dieta LR suplementada amb 10 g/kg de FSG. Les dietes C i LR es diferenciaven en el nivell de SF i proteïna bruta (CP, per les sigles en anglès) (104 vs 205 i 156 vs 121 g/kg de SF i CP respectivament per a dietes C i LR). Doscents setze conills de la línia LP es van allotjar en gàbies individuals, es van dividir aleatòriament entre els quatre tractaments i se'ls va permetre el lliure accés a l'aliment i a l'aigua. La mortalitat, la morbiditat, l'índex de risc sanitari (HRi, per les sigles en anglès), la ingestió diària de pinso (DFI, per les sigles en anglès), el guany mitjá diari (ADG, per les sigles en anglès) i l'índex de conversió alimentària (FCR, per les sigles en anglès) es van controlar fins als 63 dies d'edat. El coeficient de digestibilitat aparent total del tracte digestiu (CTTAD, per les sigles en anglès) dels nutrients es va determinar en dotze conills per tractament, entre els 49 i 53 dies d'edat i finalment es va mesurar l'ambient cecal als 63 dies d'edat. La inclusió de FSG en la dieta a 10 g/kg d'aliment no va afectar el rendiment durant l'engreix ni el CTTAD dels nutrients, però va augmentar lleugerament la digestibilitat de la fibra neutre-detergent (NDF, per les sigles en anglès) i la fibra àcid-detergent (ADF, per les sigles en anglès) en les dietes C. De la mateixa manera, els paràmetres cecals no es van veure afectats per la inclusió de FSG, excepte la concentració d'àcid caproic en les dietes C. No obstant això, les dietes LR van disminuir la mortalitat, HRi, DFI, ADG i CTTAD de matèria orgànica i CP però van augmentar FCR i CTTAD de NDF i ADF pel que fa a les dietes C. A més, les dietes LR van augmentar la concentració de VFA, la proporció d'àcid acètic, isobutíric i isovalèric mentre que van disminuir la matèria seca del contingut cecal, N-NH3 i la proporció d'àcids butíric, caproic i valéric. En resum, la FSG respon perfectament a les dues primeres condicions per ser un prebiòtic, ja que no és digestible pels enzims gastrointestinals abans del cec i és altament fermentat un cop que arriba al cec. Sembla afectar selectivament a la microbiota cecal pel seu efecte sobre la concentració de VFA i N-NH3, a més del seu efecte sobre la proporció de caproic i valéric en dietes convencionals. FSG podria augmentar la viscositat de la digesta limitant la solubilització d'alguns nutrients com el midó i la proteïna. FSG sembla ser més efectiu en dietes comercials convencionals que en dietes de baix risc. Finalment, es va confirmar que les dietes amb alt nivell de SF i baix de CP podrien ser una bona eina contra la enteropatia epizoòtica del conill (ERE, per les sigles en anglès) en un sistema de producció no medicat, a costa d'pitjors paràmetres de creixement. / Jihed, Z. (2020). In vitro and in vivo characterization of galactomannanes extracted from fenugreek seeds (Trigonella foenum-graecum) for young rabbit nutrition [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153714 / TESIS

Orientador: Edvaldo Aparecido Amaral da Silva / Resumo: Os oligossacarídeos da família rafinose (OFR), presentes nas sementes/grãos de soja, são açúcares solúveis considerados fatores antinutricionais para humanos e animais monogástricos, e por isso, limitam o uso da cultura para estes. Entretanto, estes compostos aparentam exercer um papel fundamental na aquisição da qualidade fisiológica das sementes de soja. Diante disso, genótipos mutantes que expressam o fenótipo de baixo ou ultrabaixo teor de OFR têm sido estudados visando à eficiência da alimentação humana e animal. Portanto, é preciso elucidar as funções dos OFR sobre as propriedades da qualidade fisiológica de sementes, a fim de preconizar materiais genéticos de alta qualidade, com capacidade de armazenamento e propagação. Todavia, a qualidade fisiológica e os teores de açúcares solúveis podem ser alterados em função da genética do genótipo ou do ambiente. Por isso, genótipos mutantes em OFR podem apresentar a aquisição da qualidade fisiológica distinta quando produzidos em diferentes ambientes. Objetivou-se com este trabalho elucidar a contribuição dos OFR na aquisição da qualidade fisiológica de sementes de soja em genótipos que expressam teores contrastantes destes. Para tal, foram utilizadas sementes com fenótipos para baixo e ultrabaixo teor de OFR, mutantes nas enzimas rafinose sintase (rs) 2 e rs2 rs3, respectivamente, em comparação a genótipos com alelos funcionais para RS2 (teores normais de OFR), produzidos em três safras. As sementes foram colhidas em diferente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The raffinose family of oligosaccharides (OFR), present in soybean seeds/grains, are soluble sugars considered as antinutritional factors for humans and monogastric animals, and therefore, they limit the use of the crop. However, these compounds seem to play a fundamental role in the acquisition of physiological quality of soybean seeds. Thus, mutant genotypes expressing phenotype of low or ultralow content of OFR have been studied aiming at the efficiency of human and animal feeding. Therefore, it is necessary to elucidate the functions of OFR on the properties of physiological seed quality, in order to recommend materials of high-quality genetic material with storability and propagation capacity. The physiological quality and soluble sugar content may be altered in genetic or environmental function. Therefore, mutant OFR genotypes may acquire distinct physiological quality when grown in different environments. The aim of this research was to elucidate the contribution of OFR in the acquisition of the physiological quality of soybean seeds in genotypes that express contrasting contents for these in three experimental crops. For this, seeds with low and ultralow OFR phenotypes, mutants in raffinose synthase (rs) 2 and rs2 rs3, respectively, were used in comparison to genotypes with RS2 functional alleles (normal OFR levels). The seeds were harvested at different phenological stages during their maturation. Subsequently, it was evaluated for all genotypes studied in all harves... (Complete abstract click electronic access below) / Mestre

Cowpeas (Vigna unguiculata L. Walp) are legumes recognised as a good source of proteins in developing countries. Cowpeas are mostly utilised as cooked whole seeds. This is often achieved only after boiling for up to 2 hours, resulting in high energy consumption and a long time for food preparation. Micronisation of pre-conditioned cowpeas (± 41 % moisture at 153 °C) reduces their cooking time. During micronisation, cowpea seeds are exposed to electromagnetic radiation with a wavelength range of 1.8 to 3.4μm. For biological materials, the penetration of infrared rays into the food material causes intermolecular vibration, this result in a rapid increase in temperature and water vapour pressure within the seed. Micronisation changes physico-chemical properties of cowpea seeds that may affect sensory properties of cooked cowpeas. Micronisation may also affect cowpea bioactive components such as phenolic compounds and hence their antioxidant properties and bioactive properties. This study aimed at (1) determining the effects of micronisation of pre-conditioned cowpeas on sensory properties of cooked cowpeas and (2) determining the effects of mironisation of pre-conditioned cowpeas on the phenolic compounds, radical scavenging properties and their protective effects against oxidative damage of biomolecules (i.e. low density lipoproteins (LDL), deoxyribonucleic acid (DNA) and red blood cells (RBC). © University of Pretoria vi Micronisation significantly reduced cowpea cooking time by 28 to 49 %, depending on cowpea type. There were significant (P<0.05) increases in roasted aroma and flavour, mushy texture and splitting in all micronised samples. Bechuana white, a light brown cowpea type, was more mushy and split than others. There were significant decreases in firmness, mealiness and coarseness after micronisation for all cowpea types. Micronised cowpeas were darker (lower L* values) than unmicronised cooked cowpeas. Darkening was more evident in light coloured than dark coloured cowpea types. Although micronisation reduces cowpea cooking time, it also affects sensory properties of cowpeas. This might have an influence on consumer acceptance of micronised cowpeas. Twenty seven phenolic compounds were identified in the cowpea types studied: 6 phenolic acids, 14 flavonols and 7 flavan-3-ols. Protocatechuic acid, p-coumaric acid, 4- hydroxybenzoic acid and ferulic acid were the major phenolic acids in cowpeas. Catechin, catechin-3-O-glucoside, myricetin, rutin, quercetin and its mono and diglycosides were present in all cowpea types analysed. Dr Saunders (701.7−849.2 μg/g) (red in colour) and Glenda (571.9−708.1 μg/g) (dark brown in colour) contained the highest total phenolic contents, followed by Bechuana white (361.5−602.3 μg/g) (light brown in colour) and Blackeye (152.0−224.5 μg/g) (cream in colour). More of the flavonols were identified in red and dark brown compared to light brown and cream cowpea types. The red cowpea type contained all the dimers and oligomeric flavan-3-ol species identified in this study. In all cowpea types, extracts from unmicronised (uncooked) cowpeas inhibited copperinduced LDL oxidation in a dose dependent manner. Extracts from all samples analysed exhibited protective effects against AAPH (2, 2'-azobis (2-amidinopropane) hydrochloride) induced RBC haemolysis and DNA damage. Extracts from more pigmented cowpeas, i.e. Dr Saunders, Glenda and Bechuana white, had significantly (P<0.05) higher levels of total phenolics, total flavonoids and radical scavenging properties than Blackeye (less pigmented). Extracts from more pigmented cowpeas also offered higher protection against AAPH-induced DNA and copper-induced LDL oxidation damage than extracts from less pigmented cowpeas. These results indicate protection of biomolecules e.g. DNA, LDL and RBC) from oxidative damage and have a potential to reduce oxidative stress implicated in the development of chronic diseases. This is because cowpea phenolic compounds possess the ability to reduce oxidative damage associated with development of these diseases. © University of Pretoria vii Pigmented cowpea types may be recommended for health applications as they show more potential as source of antioxidants compared to the less pigmented cowpeas. Extracts from micronised (uncooked and cooked) samples of Dr Saunders and Glenda cowpeas had significantly higher concentrations of ferulic acid and p-coumaric acid compared with unmicronised samples. Para-coumaric acid concentrations were higher in all micronised samples of Blackeye cowpeas than in unmicronised samples. The micronisation process could release cell wall bound ferulic acid and p-coumaric, increasing their concentrations in micronised samples. On the contrary, extracts from all micronised samples of Bechuana white and Glenda cowpeas had lower concentrations of catechin than unmicronised samples. Results indicated that total extractable phenolics were lower in micronised samples of cowpea types than unmicronised samples. Futhermore, extracts from micronised samples of all cowpea types showed less protective effect against LDL oxidation than extracts from unmicronised samples. However, for most cowpea types there was no significant difference in total flavonoid contents (TFC) and Trolox equivalent antioxidant capacity (TEAC) values of cooked samples of both micronised and unmicronised. Micronisation did not affect the protective effects of cowpeas against AAPH-induced RBC haemolysis and oxidative DNA damage. Micronisation, followed by cooking, may have generated heat-induced antioxidants such as Maillard reaction products contributing to radical scavenging properties in micronised (cooked) cowpea samples. Though micronised samples had lower concentrations of some phenolic compounds and total extractable phenolics than unmicronised samples, micronised cowpea samples still exhibited radical scavenging properties and offered protective effects against oxidative damage of LDL, DNA and RBC and therefore may offer potential health benefits to consumers. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Food Science / Unrestricted

Orientador: Edvaldo Aparecido Amaral da Silva / Banca: João Nakagawa / Banca: José Baldin Pinheiro / Resumo: Programas de melhoramento têm permitido a expansão e adaptação da soja frente aos problemas bióticos e abióticos. Contudo, pouca ênfase é dada à seleção de características associadas à qualidade fisiológica e desempenho de sementes, pois estas determinam uma germinação rápida e uniforme, que garantem o estabelecimento de plântulas normais em campo, refletindo alta produtividade, além de conferir a viabilidade das sementes para o armazenamento (longevidade). Deste modo, objetivou-se avaliar à qualidade fisiológica de sementes de soja a partir de linhagens endogâmicas recombinantes (RILs), a fim de identificar materiais contrastantes quanto a qualidade fisiológica de sementes. Foram estudados os genótipos parentais IAC-100 e CD-215, respectivamente, suscetível ou não ao ataque de percevejo, e 166 RILs obtidas através do método "Single Seed Descent" (SSD). Inicialmente, os parentais e as RILs foram avaliados em relação a germinação, vigor e longevidade, para verificar se havia contrastes entre os materiais com relação a qualidade fisiológica de sementes, permitindo a seleção de materiais de alta qualidade fisiológica. Com bases nos resultados obtidos foi possível observar contrastes entre os materiais em relação a germinação, vigor e longevidade, permitindo a seleção de materiais com características superiores e inferiores. As linhagens selecionadas como superiores foram as 3, 24, 44, 76, 113, 141, 143, 153, 155 e 164, e as inferiores 12, 18, 28, 47, 97, 98, 105, 107, 109, 112 e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Breeding programs have allowed the expansion and adaptation of soybeans to biotic and abiotic stress. However, few emphases is given to the selection of characteristics associated with the physiological quality and seed performance, since they determine a fast and uniform germination that guarantee the establishment of normal seedlings in the field, reflecting high productivity. Moreover, they confer the viability of the seeds for storage (longevity). The aim of this study was to evaluate the physiological quality of soybean seeds from recombinant inbred lines (RILs) in order to identify contrast materials on the physiological quality of seeds. The parental genotypes IAC-100 and CD-215, and 166 RILs obtained through the "Single Seed Descent" (SSD) method were studied. The genitors and RILs were evaluated for germination, vigor and longevity, to verify if there were contrasts between the materials in relation to the physiological quality of seeds, allowing the selection of high physiological quality materials. Based on the results obtained, it was possible to observe contrasts between the materials in relation to germination, vigor and longevity, allowing the selection of materials with superior and inferior characteristics. The lines selected as superior were 3, 24, 44, 76, 113, 141, 143, 153, 155 and 164, and the lines selected as inferior were 12, 18, 28, 47, 97, 98, 105, 107, 109, 112 and 163. / Mestre

Phosphoenolpyruvate carboxylase (EC 4.1.1.31; PEPC) is one of the carbon dioxide- fixing enzymes, which yields oxaloacetate from phosphoenolpyruvate and bicarbonate. Regulation of PEPC activity occurs at many levels. In addition to pH and concentration of activators and inhibitors, it is phosphorylation as well. Phosphorylation of PEPC causes a change of kinetic parameters, such as maximal reaction rate, sensitivity to activation or inhibition. Considering that, there is still little information like this about C3 plants and that regulation is in various plant species different, I have dealt with monitoring of the kinetic parameters and regulation possibilities of PEPC isolated from C3 plant sources (Cannabis sativa L., Chenopodium quinoa, Pisum sativum L., Lens culinaris). While the activity of PEPC from leaves of Cannabis sativa L. was decreased by alkaline phosphatase, the activity of PEPC from seeds of Chenopodium quinoa, Pisum sativum L., Lens culinaris was not affected by alkaline phosphatase. The affinity of PEPC from seeds Chenopodium quinoa, Pisum sativum L., Lens culinaris to the substrate PEP was higher than in the case of PEPC from leaves of Cannabis sativa L.. For PEPC from Cannabis sativa L. was found that the apparent dephosphorylation leads to decrease of sensitivity to the...

Despite evidence of pollinator declines from many regions across the globe, the threat this poses to plant populations is not clear because plants can often produce seeds without animal pollinators. Here, we quantify pollinator contribution to seed production by comparing fertility in the presence versus the absence of pollinators for a global dataset of 1174 plant species. We estimate that, without pollinators, a third of flowering plant species would produce no seeds and half would suffer an 80% or more reduction in fertility. Pollinator contribution to plant reproduction is higher in plants with tree growth form, multiple reproductive episodes, more specialized pollination systems, and tropical distributions, making these groups especially vulnerable to reduced service from pollinators. These results suggest that, without mitigating efforts, pollinator declines have the potential to reduce reproduction for most plant species, increasing the risk of population declines.

The application of a sequential test, the sequential probability ratio test, for the tolerances of noxious weed seeds is studied. It is proved that the sequential test can give a similar power curve to that of the current fixed sample test if the test parameters are properly chosen. The average sample size required by a sequential test, in general, is smaller than that of the existing test. However, in some cases it requires relatively a larger sample than current test. As a solution to the problem a method of truncation is considered. A kind of mixed procedure is suggested. This procedure gives almost an identical power curve to the standard one with great savings in sample size. The sample size is always less than that of the current test procedure.

Conditions required for seed germination are different among species. Some seed of tropical and subtropical plants may germinate before the maturation of their fleshy fruit, e.g. papaya species, while seed from most deciduous trees have a period of after-ripening before germination. The after-ripening period, also referred to as rest or dormancy has also been observed in some vegetable crops and ornamental flowers.

No study has been done in the western United States concerning dispersal of dwarf mistletoe by mammals. At the outset of the study it was determined that the red squirrel, the yellow pine chipmunk (Eutamias amoenus), the northern flying squirrel, and the bushy-tailed wood rat (Neotaoma cinerea), were all potential vectors of seeds. The red squirrel was chosen as the main object of study because it is diurnal and is closely associated with ponderosa pine (Pinus ponderosa), a heavily infected species. The study was undertaken to determine whether small mammals play a significant role in transporting mistletoe seeds to uninfected areas. Understanding their role can be helpful both in further understanding of the biology of dwarf mistletoe and in evaluating current control practices.

Germination, respiration, and photosynthesis in seeds of dwarf mistletoe (Arcenthobium) were studied. The effects of 1 hour soakings of seeds in aqueous solutions of 1, 2, or 3% H2O2 or 1, 2, 3, 4, or 5% Chlorox on germination of seeds were tested. Germination rates for seeds from three consecutive years (1975-1977) were obtained. Germination rates varied widely. This variance transcended subtle changes in treatment. Pretreatment of seeds with Chlorox resulted in significantly lower germination rates than those of the control. Chlorophyll concentrations were determined for seeds and aerial shoot tissue of four species. Seeds of A. douglasii had the highest chlorophyll concentration (0.39 mg/g fresh weight) while seeds of A. tsugense had the lowest concentration (0.25 mg/g fresh weight). Net O2 uptake by seeds of A. campylopodum in dark and in light was measured by manometric and polarographic methods. The mean values were 353 μl O2 g-1 h-1 in the dark and 201 O2 g-1 h-1 in the light. The difference between these rates is apparently due to O2 evolution during photosynthesis. In light the seeds can fix 43% of the CO2 produced by respiration. Experiments in which seeds were exposed to 14CO2 in light confirmed that the seeds are able to fix CO2. Extraction of seeds with ethanol showed that 97-99% of the incorporated 14C was ethanol soluble. Ten to sixteen percent of the ethanol fraction was chloroform soluble while the rest was H2o soluble. Ion exchange separation of the H2o phase showed that 11-25% of 14C activity was cationic, 15-29% anionic, and 53-67% neutral.