Acute intake of fructooligosaccharide and partially hydrolyzed guar gum on gastrointestinal transit: A randomized crossover clinical trial.

OBJECTIVES: Dietary fibers, such as fructooligosaccharide (FOS) and partially hydrolyzed guar gum (PHGG) have several gastrointestinal functions. The aims of this study were to evaluate the effect of acute ingestion of FOS and PHGG on the percentage of gastric emptying and small intestinal transit and to evaluate the effect of these dietary fibers on the levels of intestinal hormones-active glucagon-like peptide-1, pancreatic polypeptide, and gastric inhibitory peptide-and their effect on feelings of hunger and satiety and the desire to eat. METHODS: In this crossover, randomized controlled clinical trial, we compared the effects of these two fibers on gastrointestinal transit. The tests were performed using scintigraphy. On three different days, healthy participants consumed a test meal containing 20 g of digestible maltodextrin (placebo), 20 g of FOS, or 20 g of PHGG. RESULTS: The gastric emptying of the FOS-based diet (84.2 ± 9.4%) within 2 h was statistically increased compared with the placebo and PHGG-based diets (78 ± 10.2% and 74 ± 15.3%, respectively; P < 0.05). However, a reduction in small intestinal transit was observed after consumption of both FOS- and PHGG-based diets (28.5 ± 15.56% and 24.2 ± 13.7%, respectively) compared with the placebo diet (41.20 ± 15.4%; P < 0.05). There were no changes in the levels of intestinal hormones, feeling of hunger and satiety, or desire to eat after consuming the three diets (P > 0.05). CONCLUSION: The acute intake of FOS increased gastric emptying, whereas both FOS and PHGG reduced small intestine transit without altering the levels of intestinal hormones, hunger feelings and satiety, or the desire to eat.

Calcium Bioavailability in the Soluble and Insoluble Fibers Extracted from Opuntia ficus indica at Different Maturity Stages in Growing Rats.

Childhood and adolescence are crucial stages of life for bone health. Therefore, an adequate calcium intake and a healthy life style constitute the main strategies to prevent the risk of osteoporosis-related fractures during adulthood. It has been demonstrated that inclusion of indigestible carbohydrates in foods can help improve calcium absorption in growing stages. The objective of this study was to evaluate the effect of supplementation of soluble and insoluble fibers extracted from O. ficus indica cladodes on calcium bioavailability. Male Wistar rats 4-week old were fed diets added with soluble and insoluble fibers extracted from O. ficus indica cladodes at early and late maturity stages, as the only source of calcium. The mineral content, bone mineral density (BMD), physical, microstructural, and biomechanical properties of rat femurs were determined. The bones of rats fed with diets containing a soluble fiber extracted from O. ficus indica at early and late maturity stages exhibited better bone properties (resistance to fracture, microarchitecture, and calcium content) than control rats and rats fed with an insoluble fiber from O. ficusindica cladodes at both maturity stages. As expected, based on these results, the BMD values were higher in adolescent and pubertal rats fed with a diet containing the O. ficus indica soluble fiber. These results demonstrate that the soluble fiber from O. ficus indica cladodes is indeed a valuable source of bioavailable calcium, which contributes to improve physical, densitometric, biomechanical, and microstructural properties of bone in growing rats.

Effect of the Addition of Soluble Dietary Fiber and Green Tea Polyphenols on Acrylamide Formation and In Vitro Starch Digestibility in Baked Starchy Matrices.

Starch digestibility may be affected by food microstructural changes, as well as by specific interactions with some biomolecules, such as soluble dietary fibers (SDFs). It is well-known that acrylamide (AA) is a toxic and potentially carcinogenic compound formed in starchy food products processed at temperatures above 120 °C. This study aimed to investigate the effect of the addition of SDF and green tea polyphenols (GTP) on AA formation and in vitro starch digestibility in baked starchy matrices. The formulations were prepared using gluten and wheat starch, ensuring ~40 ± 2% (wet basis, w.b.) moisture in the doughs. In some samples, 7.5% (dry basis, d.b.) of starch was replaced with inulin (IN), polydextrose (PD) or partially hydrolyzed guar gum (PHGG), and/or with GTP at 1% (d.b). Acrylamide was determined by gas chromatography-mass spectrometry, and the in vitro starch digestibility using the Englyst method. The GTP was able to reduce AA content by ~48%, and a combination of IN-GTP allowed it to be reduced by up to ~64%, revealing the lowest rapidly available glucose content (~17 mg/g glucose). While a PD-GTP mixture reduced the AA content by around ~57% and gave the highest unavailable glucose fraction (~74 mg/g glucose) compared to the control. This study showed how functional ingredients could be used to develop successfully healthier starchy bakery foods.

Micronization and extrusion processing on the physicochemical properties of dietary fiber / Efeito dos processos de micronização e extrusão nas propriedades físico-químicas da fibra alimentar

Dietary fiber plays an important physiological role, which is directly linked to its physicochemical properties, water-holding, oil-binding, and cation-exchange capacities. These properties can be altered by employing enzymatic, mechanical, and physical processes. Enzymatic and chemical processes require solvents and special conditions that make it unfeasible to use. Thus, the use of physical methods, such as micronization and extrusion, make promising options to change the physicochemical properties of dietary fiber. In this way, this review aimed to approach relevant information about the use of physical processes, specifically micronization and extrusion, for this purpose. Furthermore, conceptual aspects, such as definition, classification, and properties of dietary fiber and mainly characteristics about the micronization and extrusion processes, are reported. Micronization and extrusion are based on the decrease of the particle size to a micro scale and on the combination of high temperature, mechanical shearing and pressure, respectively. Applying these methods, modifications on the food matrix occurred by increasing the surface area and disruption of the glycosidic bonds. Consequently, there is a change in physicochemical properties of dietary fiber, which predict the physiological effect associated with dietary fiber consumption, such as decrease in blood cholesterol and glucose levels and improvement of intestinal transit. Moreover, these changes increase the bio accessibility of bioactive compounds present in the food matrix and improve the antioxidant capacity of products.(AU)

A fibra alimentar desempenha importante papel fisiológico, o qual está diretamente ligado às suas propriedades físico-químicas de capacidade de retenção de água, ligação ao óleo e a cátions. Estas propriedades podem ser alteradas empregando-se métodos enzimáticos, químicos e físicos. Métodos enzimáticos e químicos requerem solventes e condições específicas que inviabilizam sua utilização. Assim, o emprego dos métodos físicos, tais como micronização e extrusão, tornam-se alternativas promissoras para alterar as propriedades físico-químicas da fibra alimentar. Desta forma, este trabalho visa abordar informações relevantes sobre o uso dos processos físicos, especificamente micronização e extrusão para essa finalidade. Além disso, aspectos conceituais como definição, classificação e propriedades da fibra alimentar e as principais características dos processos de micronização e extrusão são relatados. Micronização e extrusão baseiam-se na diminuição do tamanho de partícula para microescala e na combinação de alta temperatura, pressão e força de cisalhamento, respectivamente. Aplicando-se estes métodos, modificações na matriz alimentícia ocorrem pelo aumento da área superficial e rompimento das ligações glicosídicas da matriz alimentar. Consequentemente, são observadas alterações nas propriedades físico-químicas da fibra alimentar, as quais predizem o efeito fisiológico associado ao seu consumo, como diminuição dos níveis de colesterol e glicose sanguíneos e a melhora do trânsito intestinal. Ademais, essas alterações aumentam a bioacessibilidade dos compostos bioativos presentes na matéria-prima alimentícia e melhoram a capacidade antioxidante dos produtos obtidos.(AU)

Micronization and extrusion processing on the physicochemical properties of dietary fiber / Efeito dos processos de micronização e extrusão nas propriedades físico-químicas da fibra alimentar

ABSTRACT: Dietary fiber plays an important physiological role, which is directly linked to its physicochemical properties, water-holding, oil-binding, and cation-exchange capacities. These properties can be altered by employing enzymatic, mechanical, and physical processes. Enzymatic and chemical processes require solvents and special conditions that make it unfeasible to use. Thus, the use of physical methods, such as micronization and extrusion, make promising options to change the physicochemical properties of dietary fiber. In this way, this review aimed to approach relevant information about the use of physical processes, specifically micronization and extrusion, for this purpose. Furthermore, conceptual aspects, such as definition, classification, and properties of dietary fiber and mainly characteristics about the micronization and extrusion processes, are reported. Micronization and extrusion are based on the decrease of the particle size to a micro scale and on the combination of high temperature, mechanical shearing and pressure, respectively. Applying these methods, modifications on the food matrix occurred by increasing the surface area and disruption of the glycosidic bonds. Consequently, there is a change in physicochemical properties of dietary fiber, which predict the physiological effect associated with dietary fiber consumption, such as decrease in blood cholesterol and glucose levels and improvement of intestinal transit. Moreover, these changes increase the bio accessibility of bioactive compounds present in the food matrix and improve the antioxidant capacity of products.

RESUMO: A fibra alimentar desempenha importante papel fisiológico, o qual está diretamente ligado às suas propriedades físico-químicas de capacidade de retenção de água, ligação ao óleo e a cátions. Estas propriedades podem ser alteradas empregando-se métodos enzimáticos, químicos e físicos. Métodos enzimáticos e químicos requerem solventes e condições específicas que inviabilizam sua utilização. Assim, o emprego dos métodos físicos, tais como micronização e extrusão, tornam-se alternativas promissoras para alterar as propriedades físico-químicas da fibra alimentar. Desta forma, este trabalho visa abordar informações relevantes sobre o uso dos processos físicos, especificamente micronização e extrusão para essa finalidade. Além disso, aspectos conceituais como definição, classificação e propriedades da fibra alimentar e as principais características dos processos de micronização e extrusão são relatados. Micronização e extrusão baseiam-se na diminuição do tamanho de partícula para microescala e na combinação de alta temperatura, pressão e força de cisalhamento, respectivamente. Aplicando-se estes métodos, modificações na matriz alimentícia ocorrem pelo aumento da área superficial e rompimento das ligações glicosídicas da matriz alimentar. Consequentemente, são observadas alterações nas propriedades físico-químicas da fibra alimentar, as quais predizem o efeito fisiológico associado ao seu consumo, como diminuição dos níveis de colesterol e glicose sanguíneos e a melhora do trânsito intestinal. Ademais, essas alterações aumentam a bioacessibilidade dos compostos bioativos presentes na matéria-prima alimentícia e melhoram a capacidade antioxidante dos produtos obtidos.

Characterization of dietary fiber and pectin of cassava bread obtained from different regions of Venezuela / Caracterización del contenido de fibra dietaria y pectina de casabe obtenido de diferentes regiones de Venezuela

Three varieties of cassava bread were analyzed by proximal analysis and biochemical methods. The content of protein, fat, carbohydrate, ash, crude fiber and dietary fiber (DF) differed significantly between each sample (p< 0.05). The cassava variety "Puerto Ayacucho" showed a higher content of insoluble DF (4.7%), soluble DF (1.6%), total DF (6.3%) and pectin (0.61%)) in comparison with the varieties of "Rio Chico" and "Caripito". Soluble DF retains significant amounts of water in the digestive tract, and this fact, combined with its reported effect of lowering human serum cholesterol its low moisture plus a high carbohydrate content confirm the suitability of this bread as an important nutritional food.

Tres variedades de casabe de yuca fueron analizados mediante el análisis proximal y métodos bioquímicos. El contenido de proteínas, grasas, hidratos de carbono, ceniza, fibra cruda y fibra dietética (FD) difieren significativamente entre cada muestra (p <0,05). La variedad de casabe "Puerto Ayacucho" mostró un mayor contenido de FD insoluble (4,7%), FD soluble (1,6%), FD total (6,3%) y pectina (0,61%)) en comparación con las variedades de "Rió Chico" y "Caripito ". FD soluble retiene grandes cantidades de agua en el tracto digestivo, y este hecho, combinado con su efecto ya reportado de bajar el colesterol del suero humano, así como el casabe de contener un bajo contenido de humedad aunado a un alto contenido de hidratos de carbono; confirma la idoneidad del mismo, como un importante alimento nutricional.