Bioavailability of Ca, P and Zn and Bone Mineralization in Rats Fed Yoghurt and Soy-yoghurt Containing Bifidobacteria.

Bioavailability of calcium, phosphorus and Zinc from probiotic dairy foods and other food sources has been an important issue of studies over recent years. The aim of the present study was designed to asses and to compare therapeutic effect of milk yoghurt and soy yoghurt containing bifidobacteria with regards to their effect on the bioavailability of Ca, P and Zn and bone mineralization in rats. Eight groups of rats were fed basal diet, cow milk, probiotic-free or probiotic-containing milk yoghurts (Bifidobacterium lactis Bb-12 or Bifidobacterium longum Bb-46), soymilk and soy-yoghurts containing only the above mentioned probiotics for 45 days. Upon feeding probiotic-containing milk and soymilk yoghurts, rat's serum Ca and P content were about two fold that of control and surprisingly the rat's serum Zn content was about 19-21 fold that of control. The increment of apparent absorption % as compared with control was ranged between 24.7–26.6, 24–38 and 51-70% for Ca, P and Zn, respectively. The above mentioned results clearly demonstrate the enhancement of Ca, P and Zn bioavailability when probiotic diets were fed. A significant increase (n=6;p<0.05) was observed in ash content and breaking force of femur of rats fed probiotic milk-and soyyoghurts. Moreover probiotic milk yoghurts were much better than soy-yoghurts fermented by Bifidobacteria in enhancing bioavailability of Ca, P and Zn as well as bone mineralization. These results suggest that intake of probiotic milk-and soy- yoghurts may be useful in enhancing mineral bioavailability and bone properties.

Empleo de fitasas como ingrediente funcional en alimentos: [revisión] / Application of phytases as functional ingredient in foods: [review]

Algunos métodos empleados durante el procesado industrial de cereales y leguminosas producen una reducción en la concentración de ácido fítico presente, sin embargo, ésta reducción o inactivación es sólo parcial. Con la finalidad de mejorar la hidrólisis del ácido fítico, se ha comprobado que la adición de fitasas exógenas (myo-inositol hexafosfato fosfohidrolasas) procedente de diferentes orígenes puede tener una importante eficacia en alimentación animal. Diversos estudios sobre el empleo de fitasas exógenas en alimentación humana han demostrado un gran potencial para su empleo en mejora de la disponibilidad mineral, pudiendo esta capacidad ser utilizada para reducir el elevado riesgo que presentan ciertos grupos de la población expuestos a padecer déficits minerales como los vegetarianos, los niños alimentados con fórmulas infantiles elaboradas con soja o los habitantes de países en vías de desarrollo en los que alimentos ricos en ácido fítico como los cereales y las leguminosas son la base de su nutrición. No obstante, en los últimos años han surgido evidencias que demuestran que el ácido fítico ejerce una importante acción beneficiosa sobre el organismo.

Various food processing and preparation methods result in a reduction in the phytate content of cereals and legumes. However, in general during these processes, phytate is not fully hydrolysed. To alleviate the aforementioned problems in the production of animal feeds, exogenous phytases (myo-inositol hexaphosphate phosphohydrolases) have been widely used. There is great potential, therefore, to use this class of enzymes in the processing and manufacturing of food for human consumption given the capacity to improve mineral bioavailability. This is seen as a way to reduce the risk of mineral deficiency in vulnerable groups including; child-bearing women; strict vegetarians; babies consuming soy-based infant formulas; and the inhabitants of developing countries. There is, however, growing evidence to demonstrate the beneficial role played by phytic acid in all human organisms.

Evaluación de la influencia de distintos componentes de la dieta sobre la biodisponibilidad potencial de minerales en alimentos complementarios / Evaluation of the influence of different dietary components on potential mineral bioavailability in complementary foods

Iron (Fe), zinc (Zn) and calcium (Ca) potential bioavailability (Ba) was evaluated in complementary foods fortified with vitamins and minerals: a commercial infant cereal (IC), the mixture of IC with a commercial infant dessert (IC+ID) and a mixture of IC with orange (IC+O). Each sample was combined with 5 different beverages (tea, mate, chocolate milk, a cola soft drink and artificial orange juice). Mineral's dialysis ability (D%) as an indicator of potential Ba was assessed using an in vitro method. Fe D % showed no significant differences between IC (19.9) and IC+ID (17.8) but was significantly increased in the IC+O sample (35.4). The IC+ID mixture had the lowest Zn D% (11.4) while the IC+O sample showed a very high value (24). There were no significant differences in Ca D% among the three samples. Regarding the beverages, both chocolate milk and mate had a depressing effect on mineral dialysis ability in all cases. There was no modification due to cola soft drink. Artificial juice caused a considerable increase in D% for all of the minerals. Mineral potential bioavailability in these complementary foods may be significantly modified by other habitual dietary components.

Se evaluó la biodisponibilidad potencial (Bd) de hierro (Fe), zinc (Zn) y calcio (Ca) en alimentos complementarios fortificados con vitaminas y minerales: un cereal comercial infantil (CI), la mezcla de CI con un postre comercial infantil (CI+PI) y mezcla de CI con naranja (CI+N). Cada muestra se combinó con 5 bebidas diferentes (té, mate cocido, leche chocolatada, bebida cola y «jugo¼ artificial de naranja). La dializabilidad (D%) mineral como indicador de la Bd potencial, fue determinada con un método in vitro. La D % de Fe fue muy similar en CI (19,9) y CI+PI (17,8) pero mostró un aumento muy significativo en la mezcla CI+N (35,4). La muestra CI+PI presentó la menor D % Zn (11,4) mientras que en CI+N fue muy elevada (24). La D% de Ca no presentó diferencias significativas entre las tres muestras. En relación con las bebidas, la leche chocolatada y el mate cocido tuvieron un efecto depresor en todos los minerales. No se observaron modificaciones con la bebida cola. El «jugo¼ artificial provocó un incremento considerable en la D% de todos los minerales. La biodisponibilidad potencial de los minerales estudiados en estos alimentos complementarios puede verse significativamente modificada por otros componentes habituales de la dieta.

Biodisponibilidade de minerais / Mineral biovailability

A importância da determinação da biodisponibilidade de minerais em dietas está centralizada no estabelecimento das recomendações de ingestão destes elementos em função das necessidades dos indivíduos. Assim, os estudos de biodisponibilidade de nutrientes devem ser específicos para cada país, tendo em vista a grande diversidade de dietas e de indivíduos. Nesta abordagem, procurou-se discutir as metodologias disponíveis para avaliação da biodisponibilidade de minerais e os fatores que podem interferir nesta medida, visando motivar jovens pesquisadores a se interessarem por esta área de pesquisa que promete grandes descobertas

The importance of mineral bioavailability determination in diets is focused on the establishment of these minerals intake recommendations, considering the individual necessities. So, researche of nutrients bioavailability should be specific to each country, taking into account the numerous types of diets and individuals. The purpose of this article is to discuss the available methodologies for mineral bioavailability assessment and the variables that interfere with this evaluation, trying to make young researcher interested in this area which is quite promising in new discoveries