Iron (Fe) bioavailability and the distribution of anti-Fe nutrition biochemicals in the unpolished, and bran fraction of five rice gei polished grain riotypes

Iron (Fe) bioavailability in unpolished, polished grain and bran fraction of five rice genotypes with a range of Fe contents was measured by in vitro digestion and cultured Caco-2 cells of cooked grain. There was a significant difference in Fe bioavailability among the five rice genotypes tested, in both the unpolished and polished grain. The range of Fe bioavailability variation in polished rice was much wider than that of unpolished, suggesting the importance of using Fe levels and bioavailability in polished rice grain as the basis for selecting high-Fe rice cultivars for both agronomic and breeding purposes. Milling and polishing the grain to produce polished (or white) rice increased Fe bioavailability in all genotypes. Iron bioavailability in polished rice was high in the UBON2 and Nishiki, intermediate in both IR68144 and KDML105, and low in CMU122. All genotypes had low bioavailability of Fe in bran fraction compared to unpolished and polished grain, except in CMU122. CMU122 contained the lowest level of bioavailable Fe in unpolished and polished grain and bran, because of the dark purple pericarp colored grain and associated tannin content. The level of bioavailable Fe was not significantly correlated with grain Fe concentration or grain phytate levels among these five genotypes tested. The negative relationship between Fe bioavailability and the levels of total extractable phenol was only observed in unpolished (r = -0.83**) and bran fraction (r = -0.50*). The present results suggested that total extractable phenol and tannin contents could also contribute to lowering bioavailability of Fe in rice grain, in addition to phytate. (c) 2006 Society of Chemical Industry

Insights on food and nutrition in the Federated States of Micronesia: a review of the literature

Background: Nutrition-related disorders, including vitamin A deficiency (VAD) and chronic diseases, are serious problems in the Federated States of Micronesia (FSM). Many suggest that these disorders are new problems related to dietary and lifestyle changes. In the past four decades, imported foods, such as white rice, flour, sugar, refined foods and fatty meats, have increasingly replaced local foods in the diet. Aim: A literature review was conducted to understand underlying issues related to dietary change and obtain insights for nutrition research and interventions. Method: Published and unpublished papers from different disciplines were reviewed and collated for information on food and nutrition in FSM. Topics covered were historical background, local foods, infant and child feeding, dietary assessment, and nutritional status. Particular focus was on information and data relating to VAD, the primary topic that led to the review of the literature. Conclusions: FSM, a tropical country of abundant agricultural resources, has suffered a great loss in production and consumption of local foods. Inconsistent external and internal government policies and food aid programmes have contributed to the problem. Further research on the nutrient content of local foods and factors affecting production, acquisition and consumption is needed, as well as a broad, well-planned, intersectoral intervention aimed at dietary improvement for all age groups in the population.

Timing, magnitude, and location of initial soluble aluminum injuries to mungbean roots

Despite a century's knowledge that soluble aluminum (Al) is associated with acid soils and poor plant growth, it is still uncertain how Al exerts its deleterious effects. Hypotheses include reactions of Al with components of the cell wall, plasmalemma, or cytoplasm of cells close to the root tip, thereby reducing cell expansion and root growth. Digital microscopy was used to determine the initial injuries of soluble Al to mungbean (Vigna radiata L.) roots. Roots of young seedlings were marked with activated carbon particles and grown in 1 mm CaCl2 solution at pH 6 for ca. 100 min (control period), and AlCl3 solution was added to ensure a final concentration of 50 muM Al (pH 4). Further studies were conducted on the effects of pH 4 with and without 50 muM Al. Four distinct, but possibly related, initial detrimental effects of soluble Al were noted. First, there was a 56-75% reduction in the root elongation rate, first evident 18-52 min after the addition of Al, root elongation continuing at a decreased rate for ca. 20 It. Decreasing solution pH from 6 to 4 increased the root elongation rate 4-fold after 5 min, which decreased to close to the original rate after 130 min. The addition of Al during the period of rapid growth at pH 4 reduced the root elongation rate by 71% 14 min after the addition of Al. The activated carbon marks on the roots showed that, during the control period, the zone of maximum root growth occurred at 2,200-5,100 mum from the root tip (i.e. the cell elongation zone). It was there that Al first exerted its detrimental effect and low pH increased root elongation. Second, soluble Al prevented the progress of cells from the transition to the elongation phase, resulting in a considerable reduction of root growth over the longer term. The third type of soluble Al injury occurred after exposure for ca. 4 h to 50 mum Al when a kink developed at 2,370 mum from the root tip. Fourth, ruptures of the root epidermal and cortical cells at 1,900-2,300 mum from the tip occurred greater than or equal to4.3 h after exposure to soluble Al. The timing and location of Al injuries support the contention that Al initially reduces cell elongation, thus decreasing root growth and causing damage to epidermal and cortical cells.

Awareness and use of caffeine by athletes competing at the 2005 Ironman Triathlon World Championships

This study assessed the knowledge, prevalence, and quantity of caffeine use by athletes competing at the 2005 Ironman Triathlon World Championships. Caffeine-related questionnaires were self-administered to 140 (105 male and 35 female, 40.3 +/- 10.7 y) athletes representing 16 countries. Fifty of these athletes further consented to immediate post-race blood samples for analysis of plasma caffeine and paraxanthine using high-performance liquid chromatography (HPLC). Seventy-two percent of 70 athletes correctly identified caffeine as being an unrestricted substance in triathlon. The majority of athletes [125 (89%)] were planning on using a caffeinated substance immediately prior to or throughout the race. Cola drinks (78%), caffeinated gels (42%), coffee (usually pre-race) (37%), energy drinks (13%), and NoDoz tablets (9%) were the most popular caffeinated choices. Mean standard deviation (and range) post race plasma caffeine and paraxanthine levels were 22.3 +/- 20 mu mol/L (1.7 to 98.4) and 9.4 +/- 6 mu mol/L (1.8 to 28.9), respectively. Seven athletes (14%) finished with plasma caffeine levels >= 40 mu mol/L. Plasma values from elite athletes did not differ from age group competitors. Despite the prevalence of its consumption and the training experience of this athletic group, over one quarter of athletes remained either confused or uninformed about caffeine's legality. Levels of plasma caffeine taken immediately post race indicated that athletes typically finish with quantities of caffeine that have been shown to improve endurance performance (i.e., approximate to 20 mu mol/L or a dose of >= 3 mg/kg body weight).