Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 33-37). Also available on the World Wide Web.

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A low, but significant, fraction of the carbohydrate portion of herbaceous biomass may be composed of fructose/fructosyl-containing components (“fructose equivalents”); such carbohydrates include sucrose, fructo-oligosaccharides, and fructans. Standard methods used for the quantification of structural-carbohydrate-derived neutral monosaccharide-equivalents in biomass are not particularly well suited for the quantification of fructose equivalents due to the inherent instability of fructose in conditions commonly used for hemicellulose/cellulose hydrolysis (> 80% degradation of fructose standards treated at 4% sulfuric acid, 121oC, 1 hr). Alternative time, temperature and acid concentration combinations for fructan hydrolysis were considered using model fructans (inulin, β-2,1 and levan, β-2,6) and a grass seed straw (Tall Fescue, Festuca arundinacea) as representative feedstocks. The instability of fructose, relative to glucose and xylose, at higher acid/temperature combinations is demonstrated, all rates of fructose degradation being acid and temperature dependent. Fructans are shown to be completely hydrolyzed at acid concentrations well below that used for the structural carbohydrates, as low as 0.2%, at 121oC for 1 hr. Lower temperatures are also shown to be effective, with corresponding adjustments in acid concentration and time. Thus, fructans can be effectively hydrolyzed under conditions where fructose degradation is maintained below 10%. Hydrolysis of the β-2,1 fructans at temperatures ≥ 50oC, at all conditions consistent with complete hydrolysis, appear to generate difructose dianhydrides. These same compounds were not detected upon hydrolysis of levan, sucrose, or straw components. It is suggested that fructan hydrolysis conditions be chosen such that hydrolysis goes to completion, fructose degradation is minimized, and difructose dianhydride production is accounted for. / Graduation date: 2009

Dissertation (PhD)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Os objetivos do trabalho foram desenvolver um queijo petit-suisse simbiótico a partir de leite de cabra e polpa de açaí, com a cultura probiótica Lactobacillus paracasei LPC-37 e os prebióticos inulina e fruto-oligossacarideos (FOS), verificar a viabilidade e sobrevivência do probiótico no produto e frente às condições gástricas e entéricas simuladas in vitro e avaliar as características dos queijos ao longo de seu armazenamento a 4ºC, bem como comparar o queijo petit-suisse simbiótico de cabra com o similar produzido a partir de leite de vaca. O delineamento experimental consistiu-se de três tipos de queijo petit-suisse caprino, em triplicata, todos utilizando S.thermophilus TA-40 como cultura starter: QCC = controle; QCP = probiótico (com cultura probiótica LPC-37); QCS = queijo simbiótico (com LPC-37 + prebióticos). Os queijos foram armazenados a 4ºC e analisados semanalmente por até 28 dias. Adicionalmente, para fins de comparação com o QCS, foi, também, produzido um queijo similar com leite de vaca: QVS = queijo simbiótico de leite de vaca (com culturas starter e probiótica LPC-37 + prebióticos). A viabilidade dos probióticos e da cultura starter, a sobrevivência in vitro do probiótico incorporado aos produtos frente às condições gastrintestinais simuladas, bem como as análises de pH, acidez titulável e dureza instrumental dos queijos foram monitorados no produto final e semanalmente até 28 dias de armazenamento. A partir de amostras do dia 1 de armazenamento mantidas congeladas e liofilizadas, respectivamente, foi determinada a sua composição centesimal e de ácidos graxos. A aceitabilidade sensorial dos queijos frente a públicos de duas localidades distintas - de Sobral/CE e de São Paulo/SP foi realizada, respectivamente, aos 7, 14, 21 dias e aos 14 e 21 dias de armazenamento dos queijos. A avaliação sensorial em São Paulo foi conduzida somente em dois pontos, em virtude de dificuldades quanto à logística, envolvendo o transporte dos queijos até São Paulo. Os queijos petit-suisse caprinos apresentaram populações de LPC-37 superiores a 7,93 log UFC/g até 28 dias de armazenamento. As populações de S. thermophilus tiveram reduções significativas (p<0,05) de até 1 ciclo log ao longo do armazenamento nos queijos QCP e QCS. A sobrevivência in vitro de LPC-37 foi baixa, com uma taxa de sobrevivência decrescente ao longo do armazenamento de QCS (de 47,0 para 32,5%) e de QVS (de 48,8 para 30,0%) e crescente para QCP (de 26,5 para 55,9%) para na fase entérica. Quanto à sobrevivência in vitro da LPC-37 na fase gástrica, o queijo de leite de vaca mostrou maior queda da taxa de sobrevivência (de 54,5 para 44,4%) ao longo do armazenamento (p<0,05). A adição de prebióticos influenciou significativamente (p<0,05) o aumento da dureza do queijo QCS. Não foi observada diferença (p>0,05) entre a aceitabilidade dos queijos caprinos frente aos consumidores das duas localidades avaliadas, com exceção do QCS aos 21 dias, onde se observou uma menor aceitabilidade por parte dos consumidores de São Paulo, os quais também revelaram menores intenções de compra. Entre os queijos simbióticos, o de vaca (QVS) foi mais aceito que o seu equivalente de cabra (QCS) em ambas as localidades, com intenção de compra >80% e >55%, respectivamente, em Sobral e em São Paulo. Os resultados revelaram que os queijos petit-suisse caprinos apresentam-se como matrizes alimentares adequadas para a incorporação de L. paracasei LPC-37 em combinação com os prebióticos inulina e FOS, com boa aceitabilidade sensorial, principalmente pelos consumidores de Sobral/CE. / This study aimed to develop a synbiotic petit-suisse from goat milk and acai pulp, with the probiotic strain Lactobacillus paracasei LPC-37 and the prebiotic ingredients inulin and fructo-oligosaccharides (FOS), to verify the probiotic viability in the product and its survival under in vitro simulated gastric and enteric conditions and the characteristics of cheeses during storage at 4 ºC, and to compare the goat synbiotic petit-suisse cheese with the equivalent product produced from cow\'s milk. The experimental design consisted of three types of goat petit-suisse cheese, in triplicates, all of them produced using S.thermophilus TA-40 as the starter culture: CGC = control goat cheese; PGC = probiotic goat cheese (with LPC-37); SGC = synbiotic goat cheese (with LPC-37 + prebiotics). The cheeses were stored at 4 ºC and analyzed weekly for up to 28 days. Additionally, for comparison purposes with the SGC, a similar cheese produced from cow\'s milk: SCC = synbiotic cow cheese (with the starter and the probiotic culture LPC- 37 + prebiotics). The viability of the probiotic and of the starter culture, the probiotic survival under in vitro simulated gastrointestinal, as well as the pH, titratable acidity, and instrumental hardness of cheeses were monitored in the final product and weekly until 28 days of storage. Cheese samples were kept frozen and freeze-dried one day after production, respectively, for analyses of their chemical composition and their fatty acids profile. The sensory acceptability of cheeses by consumers from two different locations - Sobral/ CE and São Paulo/ SP was conducted, respectively, on days 7, 14, and 21 and on days 14 and 21 of storage. Sensory evaluation in São Paulo was conducted at two points due to difficulties regarding transportation of the cheeses to São Paulo.The petit-suisse goat cheeses LPC-37 populations were always above 7.93 log CFU/ g up to 28 days of storage. Populations of S. thermophilus presented significant reductions (p <0.05), up to 1 log cycle, during storage of cheeses PGC and SGC. The in vitro survival of LPC-37 was low, with a decreasing survival rate during storage of SGC (from 47.0 to 32.5%) and SCC (from 48.8 to 30.0%) and an increasing survival for PGC (from 26.5 to 55.9%) during the enteric phase. As for the in vitro survival of LPC-37 in the gastric phase, cheese from cow\'s milk showed a higher decrease in the survival rate (from 54.5 to 44.4%) during storage (p <0,05). The addition of prebiotics significantly increased (p <0.05) the hardness of SGC. No significant difference was observed (p> 0.05) between the acceptability of goat cheeses by the consumers of the two localitions evaluated, except for the SGC on day 21, for which a lower acceptability was observed for the consumers of São Paulo, who also revealed lower purchase intentions. Among the synbiotic cheeses, the cow cheese (SCC) was more accepted than the equivalent goat cheese (SGC) in both locations, with the purchase intentions above 80% and above 55%, respectively, in Sobral and in São Paulo. The results showed that the goat petit-suisse cheeses revealed to be suitable as food matrices for the incorporation of L. paracasei LPC-37 in combination with the prebiotics inulin and FOS, with good sensory acceptability, especially regarding consumers of Sobral/ CE.

Neste estudo foi avaliado o efeito de frutanos do tipo inulina (FTI) na biodisponibilidade de minerais em ratos, com particular enfoque para o Ca e o Fe. Foram realizados dois ensaios: no primeiro utilizou-se um modelo fatorial 2×2×2, com dois níveis de Fe (0 e 35 mg/kg), Ca (0 e 5 g/kg) e FTI (0 e 100 g/kg) nas rações; no segundo, utilizou-se um modelo de repleção de Hb em ratos anêmicos. As fontes de FTI foram a Raftilose P95 (ensaios 1 e 2), fonte purificada, e a farinha de yacón (FY; ensaio 2); os sais de Fe utilizados foram o Fe4(P2O7)3 (ensaios 1 e 2) e o FeSO4 microencapsulado com alginato (ensaio 2). No primeiro ensaio foram avaliados parâmetros bioquímicos de Fe, concentração de minerais nos ossos, fígado e baço, e parâmetros de resistência e histomorfometria óssea. Após 33 d, não foram observados efeitos na retenção óssea de Ca, porém observou-se maior volume trabecular ósseo e parâmetros histomorfométricos de formação óssea nos animais deficientes em Fe alimentados com os FTI. No segundo ensaio foram determinados parâmetros hematológicos, de biodisponibilidade de Fe, e parâmetros intestinais (balanço mineral; pH, ácidos graxos de cadeia curta e espécies de Fe no conteúdo intestinal). A FY recuperou os animais da deficiência de Fe mais rapidamente do que a Raftilose. Esse efeito ocorreu em função de alterações intestinais provocadas pelo aumento da fermentação desses carboidratos, que afetou a solubilidade do Fe da dieta. Concluiu-se que os FTI aumentaram a biodisponibilidade de minerais, possivelmente por influência da concentração do mineral e pelas interações entre os minerais presentes na ração, pelo tempo de ensaio, pela matriz alimentar, e pelo modelo experimental utilizado. / This study evaluated the effect of inulin-type fructans (ITF) on mineral bioavailability in rats, focusing mainly on Ca and Fe. Two experiments were carried out: the first one considered a 2×2×2 factorial model using two levels of Fe (0 and 35 mg/kg), Ca (0 and 5 g/kg) and ITF (0 and 100 g/kg) in the diets; the second experiment considered a Hb repletion model in anemic rats. Raftilose P95 (experiments 1 and 2; purified source) and yacon flour (YF; experiment 2) were used as ITF sources; the Fe salts used were Fe4(P2O7)3 (experiments 1 and 2) and microencapsulated FeSO4 with alginate (experiment 2). In the first experiment, Fe biochemical parameters, mineral concentration in the bones, liver and spleen, bone strength and histomorphometrical parameters were evaluated. After 33 d, no effects on bone retention were observed, but a larger bone volume and larger bone-formation parameters were observed on Fe-deficient animals fed with ITF. In the second experiment, hematological, Fe bioavailability and intestinal parameters (mineral balance, pH, short-chain fatty acids and Fe species in the intestinal content) were determined. Fe-deficient animals fed with YF recovered more rapidly than those fed with Raftilose. This effect took place as a function of intestinal alterations caused by the increased fermentation of these carbohydrates, which affected dietary Fe solubility. It can be concluded that ITF increased the bioavailability of minerals, possibly due to the influence of mineral concentration and interactions between minerals in the diet, experiment duration, food matrix and experimental model used.

Os objetivos do trabalho foram desenvolver um queijo petit-suisse simbiótico a partir de leite de cabra e polpa de açaí, com a cultura probiótica Lactobacillus paracasei LPC-37 e os prebióticos inulina e fruto-oligossacarideos (FOS), verificar a viabilidade e sobrevivência do probiótico no produto e frente às condições gástricas e entéricas simuladas in vitro e avaliar as características dos queijos ao longo de seu armazenamento a 4ºC, bem como comparar o queijo petit-suisse simbiótico de cabra com o similar produzido a partir de leite de vaca. O delineamento experimental consistiu-se de três tipos de queijo petit-suisse caprino, em triplicata, todos utilizando S.thermophilus TA-40 como cultura starter: QCC = controle; QCP = probiótico (com cultura probiótica LPC-37); QCS = queijo simbiótico (com LPC-37 + prebióticos). Os queijos foram armazenados a 4ºC e analisados semanalmente por até 28 dias. Adicionalmente, para fins de comparação com o QCS, foi, também, produzido um queijo similar com leite de vaca: QVS = queijo simbiótico de leite de vaca (com culturas starter e probiótica LPC-37 + prebióticos). A viabilidade dos probióticos e da cultura starter, a sobrevivência in vitro do probiótico incorporado aos produtos frente às condições gastrintestinais simuladas, bem como as análises de pH, acidez titulável e dureza instrumental dos queijos foram monitorados no produto final e semanalmente até 28 dias de armazenamento. A partir de amostras do dia 1 de armazenamento mantidas congeladas e liofilizadas, respectivamente, foi determinada a sua composição centesimal e de ácidos graxos. A aceitabilidade sensorial dos queijos frente a públicos de duas localidades distintas - de Sobral/CE e de São Paulo/SP foi realizada, respectivamente, aos 7, 14, 21 dias e aos 14 e 21 dias de armazenamento dos queijos. A avaliação sensorial em São Paulo foi conduzida somente em dois pontos, em virtude de dificuldades quanto à logística, envolvendo o transporte dos queijos até São Paulo. Os queijos petit-suisse caprinos apresentaram populações de LPC-37 superiores a 7,93 log UFC/g até 28 dias de armazenamento. As populações de S. thermophilus tiveram reduções significativas (p<0,05) de até 1 ciclo log ao longo do armazenamento nos queijos QCP e QCS. A sobrevivência in vitro de LPC-37 foi baixa, com uma taxa de sobrevivência decrescente ao longo do armazenamento de QCS (de 47,0 para 32,5%) e de QVS (de 48,8 para 30,0%) e crescente para QCP (de 26,5 para 55,9%) para na fase entérica. Quanto à sobrevivência in vitro da LPC-37 na fase gástrica, o queijo de leite de vaca mostrou maior queda da taxa de sobrevivência (de 54,5 para 44,4%) ao longo do armazenamento (p<0,05). A adição de prebióticos influenciou significativamente (p<0,05) o aumento da dureza do queijo QCS. Não foi observada diferença (p>0,05) entre a aceitabilidade dos queijos caprinos frente aos consumidores das duas localidades avaliadas, com exceção do QCS aos 21 dias, onde se observou uma menor aceitabilidade por parte dos consumidores de São Paulo, os quais também revelaram menores intenções de compra. Entre os queijos simbióticos, o de vaca (QVS) foi mais aceito que o seu equivalente de cabra (QCS) em ambas as localidades, com intenção de compra >80% e >55%, respectivamente, em Sobral e em São Paulo. Os resultados revelaram que os queijos petit-suisse caprinos apresentam-se como matrizes alimentares adequadas para a incorporação de L. paracasei LPC-37 em combinação com os prebióticos inulina e FOS, com boa aceitabilidade sensorial, principalmente pelos consumidores de Sobral/CE. / This study aimed to develop a synbiotic petit-suisse from goat milk and acai pulp, with the probiotic strain Lactobacillus paracasei LPC-37 and the prebiotic ingredients inulin and fructo-oligosaccharides (FOS), to verify the probiotic viability in the product and its survival under in vitro simulated gastric and enteric conditions and the characteristics of cheeses during storage at 4 ºC, and to compare the goat synbiotic petit-suisse cheese with the equivalent product produced from cow\'s milk. The experimental design consisted of three types of goat petit-suisse cheese, in triplicates, all of them produced using S.thermophilus TA-40 as the starter culture: CGC = control goat cheese; PGC = probiotic goat cheese (with LPC-37); SGC = synbiotic goat cheese (with LPC-37 + prebiotics). The cheeses were stored at 4 ºC and analyzed weekly for up to 28 days. Additionally, for comparison purposes with the SGC, a similar cheese produced from cow\'s milk: SCC = synbiotic cow cheese (with the starter and the probiotic culture LPC- 37 + prebiotics). The viability of the probiotic and of the starter culture, the probiotic survival under in vitro simulated gastrointestinal, as well as the pH, titratable acidity, and instrumental hardness of cheeses were monitored in the final product and weekly until 28 days of storage. Cheese samples were kept frozen and freeze-dried one day after production, respectively, for analyses of their chemical composition and their fatty acids profile. The sensory acceptability of cheeses by consumers from two different locations - Sobral/ CE and São Paulo/ SP was conducted, respectively, on days 7, 14, and 21 and on days 14 and 21 of storage. Sensory evaluation in São Paulo was conducted at two points due to difficulties regarding transportation of the cheeses to São Paulo.The petit-suisse goat cheeses LPC-37 populations were always above 7.93 log CFU/ g up to 28 days of storage. Populations of S. thermophilus presented significant reductions (p <0.05), up to 1 log cycle, during storage of cheeses PGC and SGC. The in vitro survival of LPC-37 was low, with a decreasing survival rate during storage of SGC (from 47.0 to 32.5%) and SCC (from 48.8 to 30.0%) and an increasing survival for PGC (from 26.5 to 55.9%) during the enteric phase. As for the in vitro survival of LPC-37 in the gastric phase, cheese from cow\'s milk showed a higher decrease in the survival rate (from 54.5 to 44.4%) during storage (p <0,05). The addition of prebiotics significantly increased (p <0.05) the hardness of SGC. No significant difference was observed (p> 0.05) between the acceptability of goat cheeses by the consumers of the two localitions evaluated, except for the SGC on day 21, for which a lower acceptability was observed for the consumers of São Paulo, who also revealed lower purchase intentions. Among the synbiotic cheeses, the cow cheese (SCC) was more accepted than the equivalent goat cheese (SGC) in both locations, with the purchase intentions above 80% and above 55%, respectively, in Sobral and in São Paulo. The results showed that the goat petit-suisse cheeses revealed to be suitable as food matrices for the incorporation of L. paracasei LPC-37 in combination with the prebiotics inulin and FOS, with good sensory acceptability, especially regarding consumers of Sobral/ CE.

Fructans are polysaccharides that are made up mainly of fructose. They are non-digestible carbohydrates and act as prebiotics to selectively promote the growth of colonic bifidobacteria, thereby improving human gut health. Fructans are present in the grain of wheat (Triticum aestivum L.), a staple food crop. Until now, there has been no research on genetic improvement of the concentration of fructans in wheat grain, partly because it has been difficult to accurately measure. One aim of this research project was to develop a simple and effective method to measure the fructan concentration in wheat grain. This was achieved by modifying a method that involves extraction of fructans from wheat grain followed by enzymatic hydrolysis to break down fructans into monosaccharides and quantification by anion-exchange liquid chromatography coupled with pulsed amperometric detection. The modified procedure is reliable and allows the handling of large numbers of flour samples at a relatively low cost, and can therefore be useful for assessing large numbers of wheat breeding lines. Using this method, grain samples taken from a diverse set of 117 wheat cultivars and breeding lines, including parents of mapping populations, were analysed for grain fructan concentration. There was significant genotypic variation among these materials, with grain fructan concentration ranging from 0.3 to 2.3% of grain dry weight. There was no evidence of strong genotype-byenvironment interaction; the fructan concentrations of the same genotypes were positively correlated over different environments in Australia. Genetic mapping was carried out to detect and map loci affecting grain fructan concentration in wheat using a doubled haploid population derived from a cross between Berkut (high fructan) and Krichauff (low fructan). Grain samples were obtained from two field sites in South Australia and one in Kazakhstan. Fructan concentration varied widely within the population (0.6-2.6% of grain dry weight), with heritability estimated as h² = 0.71. A linkage map of 528 molecular markers covering 21 wheat chromosomes was used for locating quantitative trait loci (QTL). Genetic mapping identified two major QTLs on chromosomes 6D and 7A, with the (high fructan concentration) alleles contributed from Berkut, contributing to a 30-40% increase in wheat grain fructan compared to the Krichauff alleles. Effects of these chromosome regions were validated in additional environments and in another mapping population, Sokoll/Krichauff, with the favourable alleles contributed from Sokoll. The major QTL on chromosome 7A was in the same region with a reported fructosyltransferase orthologue (AB029888), while the major QTL on chromosome 6D seemed to be co-located with a reported gene encoding for a fructan-degrading enzyme 1-exohydrolase (1-FEHw2). It is concluded that grain fructan concentration of wheat can be improved by breeding and that molecular markers could be used to select effectively for favourable alleles in two regions of the wheat genome. / Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2009

Fructans are polysaccharides that are made up mainly of fructose. They are non-digestible carbohydrates and act as prebiotics to selectively promote the growth of colonic bifidobacteria, thereby improving human gut health. Fructans are present in the grain of wheat (Triticum aestivum L.), a staple food crop. Until now, there has been no research on genetic improvement of the concentration of fructans in wheat grain, partly because it has been difficult to accurately measure. One aim of this research project was to develop a simple and effective method to measure the fructan concentration in wheat grain. This was achieved by modifying a method that involves extraction of fructans from wheat grain followed by enzymatic hydrolysis to break down fructans into monosaccharides and quantification by anion-exchange liquid chromatography coupled with pulsed amperometric detection. The modified procedure is reliable and allows the handling of large numbers of flour samples at a relatively low cost, and can therefore be useful for assessing large numbers of wheat breeding lines. Using this method, grain samples taken from a diverse set of 117 wheat cultivars and breeding lines, including parents of mapping populations, were analysed for grain fructan concentration. There was significant genotypic variation among these materials, with grain fructan concentration ranging from 0.3 to 2.3% of grain dry weight. There was no evidence of strong genotype-byenvironment interaction; the fructan concentrations of the same genotypes were positively correlated over different environments in Australia. Genetic mapping was carried out to detect and map loci affecting grain fructan concentration in wheat using a doubled haploid population derived from a cross between Berkut (high fructan) and Krichauff (low fructan). Grain samples were obtained from two field sites in South Australia and one in Kazakhstan. Fructan concentration varied widely within the population (0.6-2.6% of grain dry weight), with heritability estimated as h² = 0.71. A linkage map of 528 molecular markers covering 21 wheat chromosomes was used for locating quantitative trait loci (QTL). Genetic mapping identified two major QTLs on chromosomes 6D and 7A, with the (high fructan concentration) alleles contributed from Berkut, contributing to a 30-40% increase in wheat grain fructan compared to the Krichauff alleles. Effects of these chromosome regions were validated in additional environments and in another mapping population, Sokoll/Krichauff, with the favourable alleles contributed from Sokoll. The major QTL on chromosome 7A was in the same region with a reported fructosyltransferase orthologue (AB029888), while the major QTL on chromosome 6D seemed to be co-located with a reported gene encoding for a fructan-degrading enzyme 1-exohydrolase (1-FEHw2). It is concluded that grain fructan concentration of wheat can be improved by breeding and that molecular markers could be used to select effectively for favourable alleles in two regions of the wheat genome. / Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2009

Festuca novae-zelandiae (Hack.) Cockayne is an endemic New Zealand perennial tussock forming grass of the family Poaceae. Morphologically F. novae-zelandiae exhibits a number of leaf adaptations associated with dehydration postponement as reflected in the climatic distribution of this species and its occurrence as a physiognomic dominant grass in semi arid short-tussock grasslands. Biochemical studies into the drought tolerance of this species have indicated the occurrence of tissue specific responses with respect to abscisic acid (ABA) and proline accumulation and protein turnover suggestive of a preferential protection of the tiller base and associated meristematic zones at the expense of lamina tissues. Further tissue specific biochemical responses to water-deficit stress in F. novae-zelandiae have been investigated. Changes in water-soluble carbohydrates (WSC) were monitoured over a 49-day dry-down period (decline in soil water content from 30% to 4%) in consecutive leaf segments comprising the leaf base (meristem region), elongation zone, the enclosed and exposed lamina, as well as basal sheath segments from the two next oldest leaves. In fully hydrated leaf tissues polymers of fructose (fructans) were the main WSC present and were mainly low molecular weight fructans of the inulin and neokestose series with the average degree of polymerization (DP) of fructan pools from 6 to 9. The highest fructan concentrations were present towards the leaf base. Fructan concentrations decreased over the course of the dry-down, although remained significantly higher in the meristem region of the tiller base with respect to any other tissue, until tissue water content fell below 45%. By day 49 of the dry-down period, the average DP of the fructan pool in tissues was from 3 to 5. Sucrose content increased in each tissue during the course of the dry-down, and was highest at the leaf base, where a concentration of 200 µmol g-1 dry weight was measured after 49 days of dry-down. The negative correlation between fructan and sucrose content, which indicates an inter-conversion dependent on tissue water content, suggests that, in this specises, fructans serve as a carbohydrate storage pool, while sucrose stabilises the meristem during extreme water deficit.