Introdução: A doença celíaca não tem cura e apresenta como único tratamento a dieta isenta de glúten. Frequentemente observa-se a má absorção de cálcio em celíacos, consequência dos menores níveis de transportadores de cálcio no enterócito desses indivíduos. Os celíacos têm dificuldade em dar sequência ao tratamento dietético devido à escassez de produtos isentos de glúten, tornando fundamental o desenvolvimento de produtos para esta população. Isso pode ser feito por meio do uso de matérias primas isentas de glúten e com valor nutritivo agregado, como o grão de amaranto, e de ingredientes que contribuem para o aumento da absorção de cálcio através de absorção passiva nos colonócitos, como os frutanos inulina e oligofrutose. Objetivo: Desenvolver e otimizar as propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção nutricional em celíacos. Metodologia: Foram elaborados snacks à base de milho e amaranto (50, 75 e 100%), barras e pães sem glúten, enriquecidos com 4 gramas de frutanos/ porção. Para maximizar a aceitabilidade das barras foi utilizado um planejamento experimental para misturas de amaranto extrusado, estourado e laminado. Para maximizar o valor nutritrivo e a aceitabilidade do pão sem glúten foi utilizado o planejamento experimental para misturas de farinha de arroz, fécula de batata e farinha de amaranto. Os produtos foram caracterizados quanto a composição centesimal, o índice glicêmico (IG) e a carga glicêmica (CG). Também foram avaliadas as propriedades físicas e a aceitabilidade (escala hedônica estruturada de nove pontos) durante o período de armazenamento. Resultados e discussão: Os snacks foram aceitos e apresentaram estabilidade de suas características físicas e da aceitabilidade durante os 135 dias de armazenamento. O efeito combinado do amaranto e dos frutanos gerou redução de 19% do IG e de 56% da CG dos snacks. O amaranto estourado e laminado apresentaram interações sinérgicas para a aceitabilidade das barras (R2(aj)>92%, p=0,00). A formulação à base de amaranto estourado e laminado (½,½) foi diversificada em seis diferentes sabores e apresentou estabilidade de suas propriedades físicas e da aceitabilidade durante os seis meses de armazenamento. A estimativa da resposta glicêmica revelou IG moderado e CG baixa das barras. Pães com 33 e 45% de farinha de amaranto apresentaram destacado valor nutritivo e aceitabilidade. A incorporação de amaranto e de frutanos ocasionou redução de 20% do IG e de até 53% da CG do pão sem glúten. Conclusão: Os produtos desenvolvidos (snacks, barras e pães sem glúten) apresentaram destacado valor nutritivo em relação aos produtos convencionais, atenuação da resposta glicêmica e alta aceitabilidade pelo consumidor, podendo contribuir para uma maior variação e adequação da dieta dos celíacos e também para auxiliar no aumento da absorção de cálcio / Introduction: Celiac disease does not have a cure and the only scientifically proven treatment is strict lifelong adherence to a gluten-free diet. Calcium malabsorption is frequently found in celiac, possibly due to negligible amounts of calcium-binding protein in their enterocytes. Compliance with dietary treatment is often difficult due to the lack of gluten-free products, so it is essential to develop specific products for this population. This can be done through the use of gluten-free raw materials of great nutritional value, such as amaranth grain, and ingredients that contribute to the calcium absorption increasement through passive absorption in colonocytes, such as the fructans inulin and oligofructose. Objective: Develop and optimize the nutritional and sensory properties of amaranth based products enriched with fructans, for nutritional intervention in celiac. Methods: Snacks from blends of corn and amaranth (50, 75 and 100%), amaranth bars and gluten-free bread, all enriched with 4 grams of fructans/ portion, were prepared. A mixture experiment of extruded, popped and flaked amaranth was used to optimize the sensory acceptability of the bars. A mixture experiment of rice flour, potato starch and amaranth flour was used to maximize the nutritional value and sensory acceptability of gluten-free bread. Products chemical composition, glycemic index (GI) and glycemic load (GL), were evaluated. The physical properties and sensory acceptability (nine point hedonic scale) were assessed during the storage time. Results and discussion: Snacks were sensory accepted and maintained their physical characteristics and sensory acceptability during the 135 days of storage. The combined effect of amaranth and fructans resulted in 19% reduction of GI and 56% of GL of snacks. Popped and flaked amaranth present synergistic interactions to sensory acceptability of the bars (R2(adj)>92%, p=0,00). Bars were produced with popped and flaked amaranth (½,½) in six different flavors and its physical properties and sensory acceptability were stable during the six months of storage. The predicted glycemic response showed moderate GI and low GL bars. Breads with 33 and 45% of amaranth flour had higher nutritional value and sensory acceptability. Amaranth and fructans addition led to a reduction of approximately 20% of GI and up to 53% of the GL of gluten-free breads. Conclusion: The developed products (snacks, bars and gluten-free breads) had superior nutritional composition than conventional products, reduced glycemic response, high consumer sensory acceptability, great potential to contribute to variation and adequacy of celiac diet and also help to increase calcium absorption.

In einer Zeit, in der eine Zunahme von ernährungsbedingten Erkrankungen in steigendem Maße zu beobachten ist, wird dem Getreide als Grundlage der menschlichen Ernährung erhöhte Aufmerksamkeit gewidmet. Ein hoher Verzehr von Ballaststoffen ist ein wesentlicher Aspekt in der präventiv-medizinischen Ernährung. Die von der Deutschen Gesellschaft für Ernährung vorgeschlagene tägliche Ballaststoffzufuhr liegt bei 30 g. Die Aufnahme von Ballaststoffen ist jedoch in Deutschland deutlich unterhalb dieser empfohlenen Menge.<br><br> Getreideprodukte, besonders vom Vollkorntyp, sind die wichtigste Quelle für Ballaststoffe. Deshalb sollten im Rahmen dieser Arbeit direkt verzehrsfähige, Ballaststoff-angereicherte Haferprodukte (vorwiegend Extrudate) mit hohen Gehalten an b-Glucanen und resistenter Stärke hergestellt, analysiert und nachfolgend auf relevante ernährungsphysiologische Wirkungen geprüft werden. Als Basis für die Produkte wurden Hafermehl und Haferkleie eingesetzt.<br> Der erste Teil der Arbeit beschäftigte sich mit der Analyse der Haferprodukte. Diese wiesen eine hohe Wasserbindungskapazität auf. Bei den Untersuchungen am Tiermodell wurde gezeigt, dass im Dünndarm eine größere Menge an Wasser durch die Haferprodukte gebunden wurde, was zu einem höheren Feuchtigkeitsanteil der gastrointestinalen Inhalte der Tiere führte, die ballaststoffreiches Futter erhielten.<br><br> Trotz der hydrothermischen Behandlung während der Extrusion wurden Produkte gewonnen, deren β-Glucane im hochmolekularen Zustand erhalten blieben und somit eine hohe Viskosität in wässrigen Lösungen beibehielten. In rheologischen Untersuchungen wurde bestätigt, dass die aus Haferprodukten isolierten β-Glucane ein pseudoplastisches Fließverhalten besitzen. Demgegenüber führte ein Autoklavieren der Produkte zu einer starken Depolymerisation der b-Glucane, was sich in einer Änderung der funktionellen Eigenschaften der b-Glucane widerspiegelte.<br><br> Im Mittelpunkt der Untersuchungen standen ernährungsphysiologische In-vitro- und In-vivo-Experimente mit Extrudaten und Proben auf der Basis von Hafer, die einen erhöhten Anteil an Ballaststoffen, speziell an b-Glucan und an resistenter Stärke, besaßen und die direkt verzehrbar sind. Diese Haferprodukte zeigten eine Reihe von ernährungsphysiologisch vorteilhaften und protektiven Wirkungen in In-vitro-Experimenten. So traten sie mit Gallensäuren unter den Bedingungen des Dünndarms in Wechselwirkung und waren gut mit Faecesflora vom Menschen fermentierbar. Die In-vitro-Verdauung von Maisstärke durch Pankreatin, wurde durch die ballaststoffreichen Haferprodukte partiell gehemmt. Dieser Befund lässt eine Abschwächung des postprandialen Glukoseanstieges erwarten.<br><br> In einem sechswöchigen Fütterungsversuch erhielten Ratten Diäten, die zu 50 % aus ballaststoffreichen Haferprodukten bestanden. Diese Haferprodukte bewirkten einen erhöhten Transport von Gallensäuren und neutralen Sterolen in den unteren Intestinaltrakt sowie deren verstärkte Ausscheidung. Durch den Verzehr der ballaststoffreichen Haferprodukte kam es zu Veränderungen in der Mikroflora, wobei sich besonders die coliformen Keime verminderten und die Keimzahlen der Lactobacillen sowie die Bifidobakterien erhöhten. Die Fermentation der Ballaststoffe führte zur erhöhten Bildung von kurzkettigen Fettsäuren einschließlich von Butyrat. Die Bildung der kurzkettigen Fettsäuren geht mit einer pH-Wert-Absenkung im Caecum und Colon einher, die wiederum für eine geringere Bildung von sekundären Gallensäuren verantwortlich ist.<br><br> Die Ergebnisse des Fütterungsversuchs an Ratten wurden prinzipiell durch eine vierwöchige Pilotstudie am Menschen, in der Probanden täglich 100 g Haferextrudat erhielten, bestätigt. Das Extrudat wurde von den Probanden gut akzeptiert. In der 4. Woche wurden eine geringe Abnahme der Cholesterolfraktionen im Serum, höhere Keimzahlen für Lactobacillen, Bifidobacterien und Bacteroides, geringere pH-Werte und Trockenmassegehalte in den Faeces, eine Zunahme der individuellen und Gesamt-SCFA sowie des Butyratanteils in den Faeces, eine erhöhte Ausscheidung an Steroiden, eine Zunahme der primären Gallensäuren und eine Abnahme des prozentualen Anteils an sekundären Gallensäuren sowie der Cholesterol-Metaboliten gefunden. Diese Parameter gingen 2 Wochen nach Beendigung der Intervention mit dem Haferextrudat wieder in Richtung der Ausgangswerte (0. Woche) zurück.<br><br> Die untersuchten Haferprodukte erwiesen sich als gut fermentierbare Substrate für die intestinale Mikroflora und können deshalb als ein Präbiotikum mit Ballaststoffcharakter eingeschätzt werden. Diese Produkte, die mit einem erhöhten Anteil an resistenter Stärke und wertvollen Haferballaststoffen hergestellt wurden, können dazu beitragen, die Ballaststofflücke in unserer Ernährung zu schließen und positive ernährungsphysiologische Effekte zu bewirken. / Cereal products, particularly from whole grains, are the most important source of dietary fibre in the western diet. A high intake of dietary fibre, which is an essential component in nutrition, is positively related to several physiological and metabolic effects. However, the daily intake of dietary fibre is below the recommended levels (30d/day) in most industrials country. Oat (Avena sativa L.) products are well accepted in human nutrition. Oats is an excellent source of different dietary fibre types, such as β-glucan, arabinoxylans and cellulose, and it contains high levels of proteins, lipids, vitamins, antioxidants and minerals.<br> A series of extrudates was prepared from oat meal, oat bran and Novelose 330®, differing in concentrations of individual dietary fibre components, such as β-glucan and resistant starch, as well as total dietary fibre.<br><br> The cereal dietary fibre, β-glucan, has outstanding functional and nutritional properties, because of its viscosity in aqueous systems and in the intestinal tract. The rheological behaviour of β-glucan (concentrations: 2% and 4%) isolated from extruded oat meal and from oat bran was evaluated using oscillatory and rheological measurements. In frequency sweep, the storage and loss moduli G′ and G″ of β-glucan preparations from extruded meal and from bran increased continuously with increasing frequency, showing a dominantly viscous behaviour. With increasing frequency, the elastic properties improved.<br><br> After simulated digestion, the digested dietary fibre-rich oat-based extrudates were used to evaluate their physiological effects in vitro. A strong interaction occurred between the digested extrudates and bile acids. The binding of bile acids increased with increasing proportions of oat bran, total dietary fibre, insoluble dietary fibre and β-glucan in the extrudates. Dihydroxy-bile acid was more strongly bound to the extrudates than trihydroxy- bile acid. Interactions at pH 5.0 were greater than at pH 6.5. During fermentation of digested extrudates with human faecal samples, concentrations of short-chain fatty acid formed and the molar proportion of butyrate increased continuously. Higher short-chain fatty acid concentrations were found when extrudates contained more oat bran, soluble and insoluble dietary fibre and β-glucan. Extrudates, on the basis of oat, have several beneficial nutritional and protective effects in vitro. Therefore, physiological effects occurring in the small and large intestine are also related to the dietary fibre composition of the cereal products.<br><br> The results found in vitro was examined in feeding experiments with animal models and in nutritional studies with human subjects.<br><br> Male Wistar rats were fed either an oat-free diet (control group) or diet containing 50% oat-based products (test groups) for 6 week. In most of the test group, following effects were observed compared with control group: higher water intake; slightly decreased total and LDL cholesterol in serum; higher count of Bifidobacteria as well as lower count numbers of Coliforms; greater mass of cecum walls and cecal contents; lower pH values in intestinal contents; higher concentration of acetate, propionate and butyrate in cecal contents and greater excretion of short-chain fatty acids; significantly more total bile acids in cecal contents; higher excretion of total bile acids and primary bile acids; lower proportion of secondary bile acids as well as higher concentration of neutral sterols in cecal contents, colonic contents and feces.<br><br> In the human study 12 volunteers consumed 100 g fiber-rich oat-based product (to the habitually diet) daily for 4 week. Following results were observed in the week 4 compared with the beginning of the experiment: higher water intake; slightly decreased total cholesterol in serum; lower pH values in feces; higher concentration of acetate, propionate and butyrate in feces; higher excretion of total bile acids and primary bile acids; lower proportion of secondary bile acids as well as higher concentration of neutral sterols in feces.<br><br> In conclusion, application of the dietary fiber-rich oat-based diets had a variety of beneficial physiological and protective effects in rats and human depending on their composition and amount, their technological pre-treatment and their functional properties. The major effects connected whit fermentation of dietary fibre components and their high formation of short-chain fatty acids as well as with higher excretion of steroids.

Introdução: A doença celíaca não tem cura e apresenta como único tratamento a dieta isenta de glúten. Frequentemente observa-se a má absorção de cálcio em celíacos, consequência dos menores níveis de transportadores de cálcio no enterócito desses indivíduos. Os celíacos têm dificuldade em dar sequência ao tratamento dietético devido à escassez de produtos isentos de glúten, tornando fundamental o desenvolvimento de produtos para esta população. Isso pode ser feito por meio do uso de matérias primas isentas de glúten e com valor nutritivo agregado, como o grão de amaranto, e de ingredientes que contribuem para o aumento da absorção de cálcio através de absorção passiva nos colonócitos, como os frutanos inulina e oligofrutose. Objetivo: Desenvolver e otimizar as propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção nutricional em celíacos. Metodologia: Foram elaborados snacks à base de milho e amaranto (50, 75 e 100%), barras e pães sem glúten, enriquecidos com 4 gramas de frutanos/ porção. Para maximizar a aceitabilidade das barras foi utilizado um planejamento experimental para misturas de amaranto extrusado, estourado e laminado. Para maximizar o valor nutritrivo e a aceitabilidade do pão sem glúten foi utilizado o planejamento experimental para misturas de farinha de arroz, fécula de batata e farinha de amaranto. Os produtos foram caracterizados quanto a composição centesimal, o índice glicêmico (IG) e a carga glicêmica (CG). Também foram avaliadas as propriedades físicas e a aceitabilidade (escala hedônica estruturada de nove pontos) durante o período de armazenamento. Resultados e discussão: Os snacks foram aceitos e apresentaram estabilidade de suas características físicas e da aceitabilidade durante os 135 dias de armazenamento. O efeito combinado do amaranto e dos frutanos gerou redução de 19% do IG e de 56% da CG dos snacks. O amaranto estourado e laminado apresentaram interações sinérgicas para a aceitabilidade das barras (R2(aj)>92%, p=0,00). A formulação à base de amaranto estourado e laminado (½,½) foi diversificada em seis diferentes sabores e apresentou estabilidade de suas propriedades físicas e da aceitabilidade durante os seis meses de armazenamento. A estimativa da resposta glicêmica revelou IG moderado e CG baixa das barras. Pães com 33 e 45% de farinha de amaranto apresentaram destacado valor nutritivo e aceitabilidade. A incorporação de amaranto e de frutanos ocasionou redução de 20% do IG e de até 53% da CG do pão sem glúten. Conclusão: Os produtos desenvolvidos (snacks, barras e pães sem glúten) apresentaram destacado valor nutritivo em relação aos produtos convencionais, atenuação da resposta glicêmica e alta aceitabilidade pelo consumidor, podendo contribuir para uma maior variação e adequação da dieta dos celíacos e também para auxiliar no aumento da absorção de cálcio / Introduction: Celiac disease does not have a cure and the only scientifically proven treatment is strict lifelong adherence to a gluten-free diet. Calcium malabsorption is frequently found in celiac, possibly due to negligible amounts of calcium-binding protein in their enterocytes. Compliance with dietary treatment is often difficult due to the lack of gluten-free products, so it is essential to develop specific products for this population. This can be done through the use of gluten-free raw materials of great nutritional value, such as amaranth grain, and ingredients that contribute to the calcium absorption increasement through passive absorption in colonocytes, such as the fructans inulin and oligofructose. Objective: Develop and optimize the nutritional and sensory properties of amaranth based products enriched with fructans, for nutritional intervention in celiac. Methods: Snacks from blends of corn and amaranth (50, 75 and 100%), amaranth bars and gluten-free bread, all enriched with 4 grams of fructans/ portion, were prepared. A mixture experiment of extruded, popped and flaked amaranth was used to optimize the sensory acceptability of the bars. A mixture experiment of rice flour, potato starch and amaranth flour was used to maximize the nutritional value and sensory acceptability of gluten-free bread. Products chemical composition, glycemic index (GI) and glycemic load (GL), were evaluated. The physical properties and sensory acceptability (nine point hedonic scale) were assessed during the storage time. Results and discussion: Snacks were sensory accepted and maintained their physical characteristics and sensory acceptability during the 135 days of storage. The combined effect of amaranth and fructans resulted in 19% reduction of GI and 56% of GL of snacks. Popped and flaked amaranth present synergistic interactions to sensory acceptability of the bars (R2(adj)>92%, p=0,00). Bars were produced with popped and flaked amaranth (½,½) in six different flavors and its physical properties and sensory acceptability were stable during the six months of storage. The predicted glycemic response showed moderate GI and low GL bars. Breads with 33 and 45% of amaranth flour had higher nutritional value and sensory acceptability. Amaranth and fructans addition led to a reduction of approximately 20% of GI and up to 53% of the GL of gluten-free breads. Conclusion: The developed products (snacks, bars and gluten-free breads) had superior nutritional composition than conventional products, reduced glycemic response, high consumer sensory acceptability, great potential to contribute to variation and adequacy of celiac diet and also help to increase calcium absorption.