Determination of soluble dietary fibre content of Okara treated with high hydrostatic pressure and enzymes: a comparative evaluation of two methods (AOAC and HPLC-ELSD).

ABSTRACT: Okara is a promising by-product from soybean and a rich source of dietary fibre, chiefly insoluble (IDF). To increase its solubility and functionality, a treatment with high hydrostatic pressure (HHP) assisted by food grade enzymes -Ultraflo® L or Viscozyme® L- has been performed. To monitor the effectiveness, an analysis of dietary fibre, mainly the soluble fraction (SDF), was accomplished by the AOAC enzymatic-gravimetric method with dialysis followed by both, spectrophotometric methods and High Performance Liquid Chromatography with Evaporative Light Scattering Detector (HPLC-ELSD) analysis of the soluble fraction. A significant increase in SDF (≈1.5-times) to the expense of a decrease in IDF was shown and chromatograms revealed two peaks of 95 and 22 kDa. Thus, treated Okara possessed a more balanced and convenient ratio of soluble to insoluble dietary fibre, which could have health benefits as prebiotic. Inbuilt interferences of the official AOAC's method for dietary fibre were confirmed and the direct HPLC-ELSD approach was about twice more sensitive than spectrophotometric methods. Consequently, the direct HPLC-ELSD analysis of the supernatant is proposed as a cheaper, faster and reliable method. Combined HHP-treatments plus specific enzymes represent a promising alternative for the valorisation and preservation of agrofood by-products.

In vitro fermentability and prebiotic potential of soyabean Okara by human faecal microbiota.

At present, there is a huge interest in finding new prebiotics from agrofood industrial waste, such as the soyabean by-product Okara, rich in insoluble dietary fibre. A previous treatment of Okara with high hydrostatic pressure assisted by the food-grade enzyme Ultraflo ® L achieved a 58·2 % increment in its soluble dietary fibre (SDF) contents. Therefore, potential prebiotic effect of both treated and native Okara was assayed using 48 h, pH-controlled, anaerobic batch cultures inoculated with human faecal slurries, which simulate the human gut. Changes in faecal microbiota were evaluated using 16S rRNA-based fluorescence in situ hybridisation, whereas release of SCFA and lactic acid was assessed by HPLC. Both Okara samples exhibited potential prebiotic effects but Okara treated to maximise its SDF content showed higher SCFA plus lactic acid, better growth promotion of beneficial bacteria, including bifidobacteria after 4 and 48 h and lactobacilli after 4 h of fermentation, and a greater inhibition of potentially harmful bacterial groups such as clostridia and Bacteroides. Differences found between fructo-oligosaccharides and Okara substrates could be attributed to the great complexity of Okara's cell wall, which would need longer times to be fermented than other easily digested molecules, thus allowing an extended potential prebiotic effect. These results support an in vitro potential prebiotic effect of Okara.

[Prebiotics: concept, properties and beneficial effects]. / Prebiotics: concept, properties and beneficial effects.

Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits.

Los prebióticos son ingredientes alimentarios no digeribles (oligosacáridos) que llegan al colon y sirven de sustrato a los microorganismos, originando energía, metabolitos y micronutrientes utilizados por el hospedador y estimulando el crecimiento selectivo de determinadas especies beneficiosas (principalmente, bifidobacterias y lactobacilos) de la microbiota intestinal. En este artículo se realiza una revisión sobre los carbohidratos prebióticos desde diferentes perspectivas, comenzando por las definiciones de prebióticos formuladas a lo largo de los últimos treinta años por científicos y diferentes organismos internacionales. Se realiza una descripción detallada de los prebióticos aceptados, como tales, que presentan propiedades beneficiosas fundamentadas en estudios llevados a cabo en humanos (fructanos tipo inulina y FOS; GOS, lactulosa y oligosacáridos de leche humana), los que se consideran prebióticos emergentes y aquellos que se encuentran en fases iniciales de estudio. Además y teniendo en cuenta que la estructura química de los carbohidratos influye notablemente en sus propiedades prebióticas, se describen las técnicas más utilizadas para su análisis y caracterización. Asimismo, se detallan los modelos in vitro e in vivo más utilizados para estudiar la resistencia de los prebióticos a la digestión y la absorción gastrointestinal, la fermentación de los prebióticos en el colon así como los criterios a tener en cuenta para llevar a cabo ensayos de intervención en humanos. Por último se realiza una amplia descripción de los efectos beneficiosos de los prebióticos para la salud a nivel intestinal y sistémico. Como conclusión, podría decirse que la investigación existente hasta el momento, sobre prebióticos, es extensa y pone de manifiesto que es necesario considerar un gran número de factores para poder atribuir alegaciones de salud a un prebiótico.

Prebióticos; concepto, propiedades y efectos beneficiosos / Prebiotics: concept, properties and beneficial effects

Los prebióticos son ingredientes alimentarios no digeribles (oligosacáridos) que llegan al colon y sirven de sustrato a los microorganismos, originando energía, metabolitos y micronutrientes utilizados por el hospedador y estimulando el crecimiento selectivo de determinadas especies beneficiosas (principalmente, bifidobacterias y lactobacilos) de la microbiota intestinal. En este artículo se realiza una revisión sobre los carbohidratos prebió- ticos desde diferentes perspectivas, comenzando por las definiciones de prebióticos formuladas a lo largo de los últimos treinta años por científicos y diferentes organismos internacionales. Se realiza una descripción detallada de los prebióticos aceptados, como tales, que presentan propiedades beneficiosas fundamentadas en estudios llevados a cabo en humanos (fructanos tipo inulina y FOS; GOS, lactulosa y oligosacáridos de leche humana), los que se consideran prebióticos emergentes y aquellos que se encuentran en fases iniciales de estudio. Además y teniendo en cuenta que la estructura química de los carbohidratos influye notablemente en sus propiedades prebióticas, se describen las técnicas más utilizadas para su análisis y caracterización. Asimismo, se detallan los modelos in vitro e in vivo más utilizados para estudiar la resistencia de los prebióticos a la digestión y la absorción gastrointestinal, la fermentación de los prebióticos en el colon así como los criterios a tener en cuenta para llevar a cabo ensayos de intervención en humanos. Por último se realiza una amplia descripción de los efectos beneficiosos de los prebióticos para la salud a nivel intestinal y sistémico. Como conclusión, podría decirse que la investigación existente hasta el momento, sobre prebióticos, es extensa y pone de manifiesto que es necesario considerar un gran número de factores para poder atribuir alegaciones de salud a un prebiótico (AU)

Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits (AU)

Seaweed as a source of novel nutraceuticals: sulfated polysaccharides and peptides.

Seaweeds and seaweed-derived products are underexploited marine bioresources and a source of natural ingredients for functional foods. Nutritional studies on seaweeds indicate that brown and red seaweeds possess a good nutritional quality and could be used as an alternative source of dietary fiber, protein, and minerals. Moreover, bioactive sulfated polysaccharides are the main components of soluble fiber in seaweeds and also bioactive peptides can be prepared from seaweed protein. This chapter gives an overview of the main biological properties of sulfated polysaccharides and peptides from brown and red seaweeds. Recent studies have provided evidence that sulfated polysaccharides from seaweeds can play a vital role in human health and nutrition. Besides, peptides derived from algal protein are most promising as antihypertensive agents. Further research work, especially in vivo studies, are needed in order to gain a better knowledge of the relation structure-function by which bioactive compounds from seaweeds exert their bioactivity.

[Characterization of cocoa fiber and its effect on the antioxidant capacity of serum in rats]. / Caracterización de la fibra de cacao y su efecto sobre la capacidad antioxidante en suero de animales de experimentación.

OBJECTIVES: The aim of this study was to characterize the physico-chemical properties of cocoa fibre (CF), to analyze its polyphenolic content and antioxidant capacity in vitro, and to investigate the effect of the administration of a polyphenolic extract of this cocoa fiber on the antioxidant capacity of the serum in rats. METHODS AND MATERIALS: Dietary fiber (DF) composition and polyphenolic (PP) content of the cocoa fiber were analyzed. The antioxidant capacity of the CF was determined by means of its reduction power (FRAP) and the capacity to scavenge free radicals (ABTS). To evaluate the bioavailability and the antioxidant capacity in vivo of the phenolic compounds of CF, an extract of these compounds was administred in the stomach of the rats with a gastric probe (100 mg PP/kg), taking blood samples at different time intervals. Sera were analyzed by HPLC to determine the presence/absence of PP or PP-metabolites. In orther to evaluate the antioxidant capacity of the serum FRAP and ABTS methods were used. RESULTS: Cocoa fiber was an excellent source of DF, with a high content of total dietary fiber (TDF), over 60% of the dry matter, made up mainly of insoluble dietary fiber (IDF; 83% of TDF). This fiber had just 1.15% of polyphenols, with low antioxidant activity. After intragastric administration of the PP-rich fraction a fast and measurable absorption of the CF polyphenols was observed, being epicatechin the main PP in blood. The absorption of this PP confers a significant, although transitory increase of the serum antioxidant capacity 10-45 minutes post-gavage; after this time, the antioxidant capacity progressively decreased reaching basal levels after 6 h. CONCLUSIONS: Cocoa fiber can be considered as an excellent source of DF, mainly insoluble dietary fiber; therefore, it could be used as an ingredient in fiber-rich functional foods. Besides the benefits derived from its high fiber content, the CF would provide protection against oxidative damage by means of its content in phenolic compounds (epicatechin) wich are absorbed maintaining the antioxidant properties in vivo.

Caracterización de la fibra de cacao y su efecto sobre la capacidad antioxidante en suero de animales de experimentación / Characterization of cocoa fiber and its effect on the antioxidant capacity of serum in rats

Objetivos: El objetivo de este trabajo era caracterizar la composición de la fibra de cacao, estudiar su contenido en polifenoles y capacidad antioxidante in vitro, e investigar el efecto de la administración de un extracto polifenólico de dicha fibra sobre la capacidad antioxidante en suero de ratas. Material y métodos: Se analizó la composición en fibra dietética (FD) y el contenido polifenólico de la fibra de cacao (FC), así como la capacidad antioxidante mediante la determinación de su poder reductor (FRAP) y de secuestro de radicales libres (ABTS). Asimismo, se administró a ratas Wistar adultas mediante sonda gástrica un extracto rico en polifenoles de cacao (100 mg/kg de peso del animal) procedente de la FC, a fin de estudiar la biodisponibilidad de los mismos, tomándose muestras a distintos intervalos de tiempo. Resultados: La fibra de cacao mostró ser una excelente fuente de FD, con un alto contenido de fibra total, superior al 60% de masa seca, con predominio de fracción insoluble (83%). Esta fibra contuvo sólo un 1,15% de polifenoles, con reducidos valores de capacidad antioxidante. Tras la administración intragástrica de extractos ricos en polifenoles de FC se observó una rápida y apreciable absorción de los polifenoles de la fibra de cacao, siendo la epicatequina el principal polifenol detectado en sangre. Paralelamente se produjo un incremento significativo, aunque transitorio, de la capacidad antioxidante en suero, entre los 10-45 minutos postgavage, momento en que empezó a disminuir hasta alcanzar valores basales al cabo de 6 h. Conclusiones: La FC se puede considerar como una excelente fuente de FD, principalmente de fibra insoluble, por lo que podría ser utilizado como ingrediente en el desarrollo de alimentos funcionales enriquecidos en fibra dietética. Además de los beneficios asociados a su elevado contenido en fibra, este producto aportaría protección frente a estrés oxidativo gracias a su contenido en polifenoles (epicatequina) que son absorbidos tras su ingesta contribuyendo a la actividad antioxidante en sangre (AU)

Objectives: The aim of this study was to characterize the physico-chemical properties of cocoa fibre (CF), to analyze its polyphenolic content and antioxidant capacity in vitro, and to investigate the effect of the administration of a polyphenolic extract of this cocoa fiber on the antioxidant capacity of the serum in rats. Methods and materials: Dietary fiber (DF) composition and polyphenolic (PP) content of the cocoa fiber were analyzed. The antioxidant capacity of the CF was determined by means of its reduction power (FRAP) and the capacity to scavenge free radicals (ABTS·+). To evaluate the bioavailability and the antioxidant capacity in vivo of the phenolic compounds of CF, an extract of these compounds was administred in the stomach of the rats with a gastric probe (100 mg PP/kg), taking blood samples at different time intervals. Sera were analyzed by HPLC to determine the presence/absence of PP or PPmetabolites. In orther to evaluate the antioxidant capacity of the serum FRAP and ABTS methods were used. Results: Cocoa fiber was an excellent source of DF, with a high content of total dietary fiber (TDF), over 60% of the dry matter, made up mainly of insoluble dietary fiber (IDF; 83% of TDF). This fiber had just 1,15% of polyphenols, with low antioxidant activity. After intragastric administration of the PP-rich fraction a fast and measurable absorption of the CF polyphenols was observed, being epicatechin the main PP in blood. The absorption of this PP confers a significant, although transitory increase of the serum antioxidant capacity 10-45 minutes post-gavage; after this time, the antioxidant capacity progressively decreased reaching basal levels after 6 h. Conclusions: Cocoa fiber can be considered as an excellent source of DF, mainly insoluble dietary fiber; therefore, it could be used as an ingredient in fiber-rich functional foods. Besides the benefits derived from its high fiber content, the CF would provide protection against oxidative damage by means of its content in phenolic compounds (epicatechin) which are absorbed maintaining the antioxidant properties in vivo (AU)

Soybean oligosaccharides. Potential as new ingredients in functional food.

The effects of maturity degree and culture type on oligosaccharide content were studied in soybean seed, a rich source of non-digestible galactooligosaccharides (GOS). Therefore, two commercial cultivars of yellow soybeans (ripe seeds) and two of green soybeans (unripe seeds) were chosen. One yellow and one green soybean seed were from intensive culture, while one yellow and one green soybean seed were biologically grown. Low molecular weight carbohydrates (LMWC) in soybean seeds were extracted with 85% ethanol and determined spectrophotometrically and by high performance liquid chromatography. LWC in soybean seeds were mainly: stachyose, raffinose and sucrose. Oligosaccharide content was not affected significantly, either by biological or intensive culture technique. On the contrary, significant differences in GOS content were found depending on ripeness degree of soybean seeds. Ripe yellow soybean seeds showed a higher oligosaccharide content (1.84-1.95%), than unripe green seeds (1.43-1.61%). Other LMWC content was also affected by ripeness degree, thus making that the relative percentage of GOS was higher in immature (47-53%) than in matured soybean seeds (21-34%). Moreover, in order to purify soybean GOS, biologically grown yellow soybean seeds with a higher GOS content were selected and a previously reported method was followed. Although the GOS containing fraction was enriched, the yield obtained was low and an effective purification was not achieved. According to these results, yellow soybean seeds seem to be a good source of GOS but, in order to improve their purification, simple methods must be further developed and evaluated.

Soybean oligosaccharides. Potential as new ingredients in functional food / Oligosacáridos de la soja. Su potencial como ingredientes nuevos de los alimentos funcionales

The effects of maturity degree and culture type on oligosaccharide content were studied in soybean seed, a rich source of non-digestible galactooligosaccharides (GOS). Therefore, two commercial cultivars of yellow soybeans (ripe seeds) and two of green soybeans (unripe seeds) were chosen. One yellow and one green soybean seed were from intensive culture, while one yellow and one green soybean seed were biologically grown. Low molecular weight carbohydrates (LMWC) in soybean seeds were extracted with 85% ethanol and determined spectrophotometrically and by high performance liquid chromatography. LWC in soybean seeds were mainly: stachyose, raffinose and sucrose. Oligosaccharide content was not affected significantly, either by biological or intensive culture technique. On the contrary, significant differences in GOS content were found depending on ripeness degree of soybean seeds. Ripe yellow soybean seeds showed a higher oligosaccharide content (1.84-1.95%), than unripe green seeds (1.43-1.61%). Other LMWC content was also affected by ripeness degree, thus making that the relative percentage of GOS was higher in immature (47-53%) than in matured soybean seeds (21-34%). Moreover, in order to purify soybean GOS, biologically grown yellow soybean seeds with a higher GOS content were selected and a previously reported method was followed. Although the GOS containing fraction was enriched, the yield obtained was low and an effective purification was not achieved. According to these results, yellow soybean seeds seem to be a good source of GOS but, in order to improve their purification, simple methods must be further developed and evaluated (AU)

En este trabajo se estudia cómo afecta el grado de madurez y el tipo de cultivo al contenido de oligosacáridos en la semilla de soja, que es una fuente rica en galactooligosacáridos (GOS) no digeribles. Para ello se eligieron dos variedades comerciales de habas de soja amarilla (semillas maduras) y dos de soja verde (semillas inmaduras). Una de las muestras de soja amarilla y otra verde provenían de cultivo intensivo; mientras que una semilla amarilla y otra verde se han producido mediante cultivo biológico. Los GOS, junto con otros azúcares de bajo peso molecular, se extrajeron con etanol al 85% y se determinaron espectrofotométricamente y por cromatografía líquida de alta eficacia. Los principales carbohidratos de bajo peso molecular detectados en la soja fueron: estaquiosa, rafinosa y sacarosa. Los resultados obtenidos muestran que las técnicas de cultivo, ya sea biológico o intensivo, no afectan de manera significativa al contenido en GOS. En cambio, el grado de madurez de las semillas sí pone de manifiesto diferencias significativas, observándose un mayor porcentaje de GOS en las semillas maduras (1,84-1,95%), que en las inmaduras (1,43-1,61%). El grado de madurez afecta también en mayor proporción al contenido de los otros azúcares de bajo peso molecular, lo cual hace que el porcentaje relativo de oligosacáridos sea mas alto en las semillas inmaduras (47-53%), que en las maduras (21-34%). Además, para evaluar un protocolo de aislamiento y purificación de oligosacáridos descrito en la bibliografía, se seleccionaron las semillas de soja amarilla de cultivo biológico por su mayor contenido en GOS y aunque se consiguió enriquecer la fracción que los contenía, las recuperaciones fueron bajas y no se observó una purificación efectiva. De acuerdo con estos resultados, la semilla de soja amarilla parece ser una buena fuente para la obtención de GOS, pero se deben seguir desarrollando y evaluando metodologías sencillas que permitan su purificación (AU)

Morbilidad de la gastrectomía total. ¿Influye el tamaño del cartucho empleado en la anastomosis? / Morbidity in total gastrectomy. Is the size of the cartridge used in anastomosis of influence?

Introducción. La utilización de sutura mecánica en la anastomosis esofagoyeyunal es una técnica que si bien se ha impuesto sobre la sutura manual por sus mejores resultados, no está exenta de complicaciones. Queremos valorar si el tamaño del cartucho que se utiliza en estas suturas puede influir en la aparición de complicaciones locales. Pacientes y método. Se ha realizado un estudio prospectivo observacional en 151 pacientes gastrectomizados por adenocarcinoma gástrico. En todos los casos se practicó una gastrectomía total y una anastomosis esofagoyeyunal con sutura circular mecánica. El objetivo del estudio ha sido analizar la posible asociación entre el tamaño del cartucho empleado en la sutura y una serie de complicaciones intraoperatorias y postoperatorias a corto-medio plazo. Resultados. En 93 pacientes se utilizó un cartucho de 25 mm, y se registraron 12 complicaciones: 2 pacientes con desgarro de la pared esofágica, un caso de pinzamiento de la pared mesentérica, seis fugas anastomóticas, tres estenosis y una hemorragia en el área de la línea de sutura. En 54 pacientes se utilizó un cartucho de 28 mm, y se registraron 10 complicaciones: desgarro de la pared esofágica en un paciente, pinzamiento de la pared mesentérica en 3 casos durante la intervención quirúrgica y en la fase postoperatoria, dos estenosis y cuatro fugas anastomóticas. Conclusiones. No se encontró ninguna relación entre estas complicaciones y el tamaño del cartucho (AU)

Free radical scavenging capacity in the aging of selected red Spanish wines.

Free radical scavenging capacity by the DPPH(*) method and main physicochemical properties, polyphenols content by HPLC, color by a tristimulus colorimeter, and UV-vis spectra in the aging of selected red Spanish wines, were studied. As the wines age, they become darker (lower lightness, L) and increase their hue angle (lower red color) as well as the ratio of absorbance at 420 nm to that at 520 nm. Main polyphenolics identified in the samples were tannic acid, oenin, and gallic acid. The antiradical efficiency of the samples increased during aging, which could be related to an increase in the tannic acid concentration shown by the following correlationship: EC(50) = 1/(0.18 + 0.0011[tannic acid](mg/L)) with a correlation coefficient of 0.744.

[Abdominal pseudotumor and Whipple's disease]. / Seudotumor abdominal y enfermedad de Whipple.

Whipple's disease is an uncommon systemic disease which most often affects the intestine but may involve any other organ. The case of a woman who consulted for weight loss, fever of unknown origin, cutaneous eruptions and increase in the abdominal perimeter is presented. The ascitic fluid showed exudate infected by E. coli suggesting spontaneous bacterial peritonitis associated with chronic liver disease. Antibiotic treatment and diuretics were administered after which abdominal exploration demonstrated the presence of a mesogastric mass. Echographic and tomographic studies were unable determine the origin of the mass with the final diagnosis being achieved by exploratory laparotomy and biopsy.