A. Barrado

Review article: is there a link between micronutrient malnutrition and Helicobacter pylori infection?

Helicobacter pylori causes a chronic gastric infection, which is usually life‐long. Many epidemiological studies have shown that this is probably one of the most common bacterial infections throughout the world involving 30% of the population living in developed countries and up to 80–90% of the population in developing regions. Concomitantly, developing regions also have high prevalence of micronutrient malnutrition. In the last few years, some studies have suggested that H. pylori infection may affect the homeostasis of different micronutrients including iron, vitamin B12, folic acid, α‐tocopherol, vitamin C and β‐carotene. In this article, we discuss the current scientific information of the effect that H. pylori infection may produce on micronutrient malnutrition.

Modification of the ferrozine technique to analyze iron contents in different foods: comparative study using an internal standard as reference methodology.

A methodology for the determination of iron in foods fortified with this element or in nutritional products is important and has to be sensitive and rapid. In developing countries, an inexpensive and reliable methodology is also required. For this purpose, the Gordon’s Ferrozine technique was slightly modified and assayed with yogurt, dry powdered milk, and cereal mixtures, all of them fortified with iron, using an internal standard as the reference methodology. The obtained results demonstrate a close correlation between the standard curve interpolation method and the internal standard reference method (correlation coefficient r2= 0.9950) in a wide range of concentrations. The slope (0.9998 ± 0.0040) demonstrates that both procedures measure equal amounts of iron. The conclusion is that the proposed technique is a reliable, practical, and inexpensive methodology for iron determination in different foods fortified with iron.

Dietary zinc effects on zinc, calcium, and magnesium content in bones of growing rats

The aim of the present study was to assess dietary zinc effects on femur weight and mineral content in growing rats. For this purpose, 70 weanling Sprague-Dawley rats were divided into four groups. Each group was subject to a diet containing 2 (BZ), 5 (DZ), 10 (MZ), and 30 (CZ) ppm zinc. The calcium and magnesium content in all diets was 5 g/kg and 507 mg/kg, respectively. The animals were kept on this regime for 28 d and then sacrificed and their femurs were removed for analysis using atomic absorption spectrophotometry.The weights of the BZ and DZ groups were significantly different from the MZ and CZ groups (38.5±10.5, 89.9±13.7, 118.6±13.6 and 134±19.9 g, p<0.01) respectively. There were no differences between the MZ and CZ groups. Femur weight also varied with dietary zinc, as it was significantly different among all groups (BZ, 265±49 mg; DZ, 380±40 mg; MZ, 452±54 mg; CZ, 735±66 mg; p<0.01). The femur zinc content varied with diets, following a different pattern than the above parameters. Femur zinc from the BZ group (51.5±5.4 ppm) was significantly different from the MZ and CZ groups (115.9±14.2 and 175.0±13.5 ppm, respectively), whereas the DZ group (62.5±11.3 ppm) did not differ from the other three groups. The femur content of calcium (BZ, 83.2±9.8 mg/g; DZ, 88.0±9.2 mg/g; MZ, 90.2±13.6 mg/g; CZ, 83.1±14.7 mg/g) and magnesium (BZ, 1.82±0.13 mg/g; DZ, 1.98±0.09 mg/g; MZ, 1.93±14 mg/g; CZ, 1.83±0.19 mg/g) were not significantly different among the groups, nor was the calcium-magnesium ratio. These results suggest that although dietary zinc deficiency retards growth and causes bone fragility, bone deposition of calcium and magnesium and its ratio are not affected.

Determination of relative bioavailability of zinc in a petit suisse cheese using weight gain and bone zinc content in rats as markers

The aim of the study was to determine the relative bioavailability of zinc gluconate stabilized with glycine in a Petit Suisse cheese from an infant dessert. Weight gain and bone zinc content were the nutritional responses evaluated for the diets of different zinc content: 2 ppm (basal) and 5, 10, and 30 ppm from zinc gluconate stabilized with glycine and zinc sulfate. Nonlinear regression analysis of the fitted curves for weight gain determined a relative zinc bioavailability of 100% for the Ymax ratio and 96% for Ymax/t1/2 ratio for zinc gluconate stabilized with glycine (R2=0.7996 for zinc sulfate and 0.8665 for zinc gluconate stabilized with glycine). The slope ratio analysis from linear regression of femur zinc determined a relative zinc bioavailability of 93% for zinc gluconate stabilized with glycine (R2=0.8693 for zinc sulfate and 0.8307 for zinc gluconate stabilized with glycine). Zinc gluconate stabilized with glycine has similar bioavailability as zinc sulfate in a Petit Suisse cheese nutritional matrix, with the advantage that the stabilized compound does not modify the sensorial characteristics of the fortified cheese.

Iron bioavailability from fortified petit suisse cheese determined by the prophylactic-preventive method

In this research, we measured the iron bioavailability of ferrous gluconate stabilized with glycine (SFG) when it is used to fortify petit suisse cheese using the prophylactic-preventive method in rats. Three groups of male, weaned rats received a basal diet (control diet; 5.2 ppm Fe), a reference standard diet (SO4Fe; 9.2 ppm Fe), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 8.8 ppm Fe) for 22d. The iron bioavailability was calculated as the ratio between the mass of iron incorporated into hemoglobin and the total iron intake per animal during the treatment. These values (BioFe) were 68% and 72% for SFG and ferrous sulfate, respectively. The value of the Relative Biological Value (RBV) was 95% for SFG in petit suisse cheese. These results show that according to this method, the iron bioavailability from industrial fortified petit suisse cheese can be considered as a high bioavailability rate.

Normal growth rate in rats is recovered after a period of zinc deficiency by restoration of zinc supply by means of a zinc-fortified Petit Suisse cheese

Fortification of a Petit Suisse cheese with zinc sulfate and zinc gluconate stabilized with glycine was used as a tool to overcome zinc-deficiency effects on total-body growth and skeletal growth. Animals were divided in 4 groups of 10 rats: basal (B), control (C), depletion-repletion 1 (DR1), and depletion-repletion 2 (DR2). These four groups were fed with four diets: basal (2 ppm Zn), control (30 ppm Zn), DR1, and DR2; they received a basal diet for 14 d and a control diet for the other 14 d of the experiment, using zinc sulfate for DR1 and zinc gluconate stabilized with glycine for DR2. After 28 d of the experiment, total-body weight and weight gain of the control and DR1 and DR2 animals were not statistically different (p<0.05), Femur weight and femur zinc content of DR1 and DR2 did not achieve the values of control animals (p<0.05), but they were higher than that of basal animals. Our results show that restoration of dietary zinc levels by means of food fortification normalized weight gain, as an indicator of total-body growth, and presented a trend to normalize bone weight, as a marker of skeletal growth, in young rats and independently of the zinc source used.

Iron bioavailability from fortified fluid milk and petit suisse cheese determined by the prophylactic-preventive method

In this research, we measure the iron bioavailability of micronized ferric orthophosphate when it is used to fortify low-fat fluid milk enriched with calcium and petit suisse cheese using the prophylactic-preventive method in rats. Four groups of male weaned rats received a basal diet (control diet; 6.5 ppm Fe), a reference standard diet (SO4Fe; 18.2 ppm Fe), a basal diet using iron-fortified fluid milk as the iron source (milk diet; Fe ppm 17.9), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 18.0 ppm Fe) for 22 d. The iron bioavailability of the different sources was calculated as the ratio between the mass of iron incorporated into hemoglobin during the experiment and the total iron intake per animal. The relative biological values with regard to the reference standard (RBV%) were 61% and 69% for the milk and cheese diet, respectively. These results show that according to this method, the iron bioavailability in both fortified foods can be considered as medium bioavailability rates.

Nutritional and technological behavior of stabilized iron-gluconate in wheat flour

Food fortification has been shown to be an effective strategy to overcome iron malnutrition. When a new iron compound is developed for this purpose, it must be evaluated from a nutritional and technological point of view before adding it into foods. In this way, we have evaluated ferrous gluconate stabilized by glycine as a new iron source to be used in wheat flour fortification. We performed biological studies in rats as well as sensory perceptions by human subjects in wheat flour fortified with this iron source. The productions of pentane as a rancidity indicator as well as the change of the sensorial properties of the biscuits made with stabilized ferrous gluconate-fortified wheat flour were negligible. Iron absorption in water from this iron source was similar to the reference standard ferrous sulfate. Nevertheless, because of the phytic acid content, iron absorption from fortified wheat flour decrease 40% for both iron sources. The addition of zinc from different sources did not modify iron absorption from ferrous sulfate and stabilized ferrous gluconate in water and wheat flour. The iron absorption mechanism as well as the biodistribution studies demonstrate that the biological behavior of this iron source does not differ significantly from the reference standard. These results demonstrate that the iron source under study has adequate properties to be used in wheat flour fortification. Nevertheless, more research is needed before considering this iron source for its massive use in food fortification.