Zinc, iron and phytic acid levels of some popular foods consumed by rural children in Sri Lanka

Zinc Accumulates in the Nodes of Wheat Following the Foliar Application of 65Zn Oxide Nano- and Microparticles

Using zinc (Zn) foliar fertilizers to enhance the grain quality of wheat (Triticum aestivum) can be an effective alternative or supplement to Zn soil fertilizers. However, knowledge about the mechanisms of Zn absorption and translocation following foliar application is scarce. Here, autoradiography and γ-spectrometry were used to investigate the behavior of ⁶⁵Zn applied to wheat leaves as soluble ⁶⁵Zn chloride (⁶⁵ZnCl₂), chelated ⁶⁵Zn (⁶⁵ZnEDTA), ⁶⁵Zn oxide nanoparticle (⁶⁵ZnO-NP) suspensions, and ⁶⁵ZnO microparticle (⁶⁵ZnO-MP) suspensions. The largest amount of ⁶⁵Zn absorption occurred in ⁶⁵ZnCl₂ treated leaves. However, this treatment (⁶⁵ZnCl₂) also had the lowest proportion of absorbed ⁶⁵Zn translocated away from the treated leaf after 15 d due to leaf scorching (p = 0.0007). Foliar-applied ⁶⁵ZnO-NPs and ⁶⁵ZnO-MPs had the lowest absorption, but ⁶⁵ZnO-NPs had the highest relative translocation. ⁶⁵Zinc EDTA was intermediate, with higher ⁶⁵Zn absorption than ⁶⁵ZnO treatments but similar translocation. Regardless, the majority of the foliar-applied ⁶⁵Zn remained in the treated leaf for all treatments. Furthermore, ⁶⁵ZnO-NPs and ⁶⁵ZnO-MPs accumulated in plant nodes, suggesting that Zn was absorbed as dissolved ⁶⁵Zn and particulate ⁶⁵ZnO. Overall, the form and amount of absorbed ⁶⁵Zn affected translocation.

Iron Content of Some Popular Cooked Foods Consumed by the Rural School Children in Sri Lanka

Iron is an important micronutrient that can be found in different food sources in varying quantities. Iron deficiency is common in populations consuming cereal-based diets with little or no animal-derived food products. Rice is the staple for Sri Lankans, which may not provide sufficient bioavailable iron. Sri Lankan food composition table does not contain data on iron in home-cooked foods. Aim of the present study was to determine the iron content in commonly consumed home-cooked foods (rice, vegetables, green leaves, pulses, fish, etc.) by children aged 15-16 years. The study was carried out in eight schools at the Divisional Secretariat, Horana. The average iron values of cooked rice, vegetables, green leaves, pulses, and fish were 23.29 ± 14.46, 19.34 ± 9.90, 29.56 ± 13.64, 45.16 ± 22.28, and 46.72 ± 14.53 mg/kg, respectively. A serving of cooked red raw rice (rathu kekulu) provided the highest Estimated Daily Intake (EDI) of iron. The total EDI per serving for all categories was 6.39 ± 1.06 mg, contributing to the recommended daily allowance (RDA) of 42.62% of girls and 58.12% of boys as defined by the United States Department of Agriculture. Meanwhile, based on the Sri Lankan RDA, dietary iron contribution per serving ranges from 16.39% to 17.76% in girls and 16.39% to 21.31% in boys in the 15-16 years age category. Therefore, these home-cooked foods which were prepared using local recipes have high iron content and can replenish a major proportion of recommended quotidian values for iron intake.

Estimation of annual effective dose due to ingestion of radioactive elements in Sri Lankan common meal plans

Dietary ingestion of radionuclides by human may lead to many hazardous effects such as cancers. No studies have been conducted to estimate the levels of radioactivity dosage received from Sri Lankan homemade foods. In order to find out the levels of radionuclides in Sri Lankan cooked foods, meal plans (n = 11) that are most commonly consumed were analyzed for the activity concentrations of the radioisotopes ²²⁶Ra, ²¹⁰Pb, ²³²Th, ¹³⁷Cs, and ⁴⁰K by means of gamma spectroscopy. ⁴⁰K had the highest activity concentration present in the meal plans with a range of 80.56 ± 17.53 to 143.41 ± 24.6 Bq kg^-1, and the radionuclides ²²⁶Ra, ²¹⁰Pb, ¹³⁷Cs, and ²³²Th were not detected in any of the analyzed meal plans. The annual intake of food was determined on the basis of their average annual consumption. The effective dose to an average adult who consumes the meal plans ranged from 0.030 to 0.051 mSv year^-1. However, the effective dose and activity concentrations of radionuclides were lower than the guideline limit specified by United Nations Scientific Committee on the Effects of Atomic Radiation^-1 and other countries. Hence, the consumption of cooked meal plans in Sri Lanka is safe in terms of radioactivity for the five radionuclides investigated in this study.

Differential iron-bioavailability with relation to nutrient compositions in polished rice among selected Chinese genotypes using Caco-2 cell culture model

Genotypic variation of iron bioavailability and the relationship between iron bioavailability and nutrient composition in polished rice among 11 rice genotypes were assessed using an in vitro digestion/Caco-2 cell model. The results indicated that significant differences in iron bioavailability were detected among tested rice genotypes, with a 3-fold range, suggesting a possibility of selecting high bioavailable iron by plant breeding. Although iron bioavailability was not significantly correlated with Fe concentration in polished rice among tested rice genotypes, the results also indicated that most of the iron dense genotypes showed relatively high ferritin formation in Caco-2 cell and transported iron. Additionally, iron bioavailability in polished rice was enhanced by addition of ascorbic acid, with a much wider range of Fe bioavailability variation in polished rice with addition of ascorbic acid than that without addition of ascorbic acid. The positive relationship between iron bioavailability in polished rice and cysteine concentration (R = 0.669) or sulfur (S) concentration (R = 0.744) among tested rice genotypes, suggests that cysteine and sulfur concentration in polished rice could be used as an indicator for high iron bioavailability.

Estimating the global prevalence of inadequate zinc intake from national food balance sheets: effects of methodological assumptions

Background

The prevalence of inadequate zinc intake in a population can be estimated by comparing the zinc content of the food supply with the population’s theoretical requirement for zinc. However, assumptions regarding the nutrient composition of foods, zinc requirements, and zinc absorption may affect prevalence estimates. These analyses were conducted to: (1) evaluate the effect of varying methodological assumptions on country-specific estimates of the prevalence of dietary zinc inadequacy and (2) generate a model considered to provide the best estimates.

Methodology and Principal Findings

National food balance data were obtained from the Food and Agriculture Organization of the United Nations. Zinc and phytate contents of these foods were estimated from three nutrient composition databases. Zinc absorption was predicted using a mathematical model (Miller equation). Theoretical mean daily per capita physiological and dietary requirements for zinc were calculated using recommendations from the Food and Nutrition Board of the Institute of Medicine and the International Zinc Nutrition Consultative Group. The estimated global prevalence of inadequate zinc intake varied between 12–66%, depending on which methodological assumptions were applied. However, country-specific rank order of the estimated prevalence of inadequate intake was conserved across all models (r = 0.57–0.99, P<0.01). A “best-estimate” model, comprised of zinc and phytate data from a composite nutrient database and IZiNCG physiological requirements for absorbed zinc, estimated the global prevalence of inadequate zinc intake to be 17.3%.

Conclusions and Significance

Given the multiple sources of uncertainty in this method, caution must be taken in the interpretation of the estimated prevalence figures. However, the results of all models indicate that inadequate zinc intake may be fairly common globally. Inferences regarding the relative likelihood of zinc deficiency as a public health problem in different countries can be drawn based on the country-specific rank order of estimated prevalence of inadequate zinc intake.