Biomedical subjects

H Robberecht

Publications and source records attributed to H Robberecht.

At least 19 recordsLinked to original sources

PubMed2002

Calcium, iron and zinc availability from weaning meals.

UNLABELLED: During the weaning period, solid foods are introduced in the diet to complement human milk or infant formula. Consequently, marginal deficiencies may easily develop because of inappropriate feeding and low bioavailability of nutrients. The objective of this study was to determine calcium, iron and zinc availability from weaning foods that contained a variety of ingredients but almost the same dietary fibre content, and to describe dietary factors that influence availability in a linear matter. Availability measurements from eight meals were made in vitro by a continuous-flow dialysis system with preliminary intraluminal digestion. Calcium, iron and zinc were analysed by flame atomic absorption spectrometry; ascorbic acid content was taken from food-composition tables; and macronutrient and mineral contents were obtained from the manufacturer. Calcium availability was higher in fruits (mean +/- SD, 39.2 +/- 4.1%) than vegetables (31.7 +/- 5.8%) (p < or = 0.001). Iron availability was marginally significant higher in vegetables (13.0 +/- 4.7%) than fruits (10.2 +/- 1.6%) (p = 0.027). Zinc availability showed higher availability in fruits (52.3 +/- 22.3%) than vegetables (22.1 +/- 5.6%) (p < or = 0.001). CONCLUSION: A major portion (47.8%) of the variance in calcium availability, as determined by multiple regression, could be explained by protein (p = 0.058, beta = -0.691). Major predictors of iron availability among the nutrients were iron content of the meal (p = 0.014, beta = -0.838), carbohydrates (p = 0.044, beta = -0.610) and dietary fibre (p = 0.235, beta = -0.285). Zinc availability was merely influenced by the protein (p = 0.010, beta = -0.876) and fat content of the meals (p = 0.295, beta = 0.255) in relation to other nutrients.

Calcium↗

PubMed2001

In vitro availability of zinc from infant foods with increasing phytic acid contents.

An in vitro method was used to determine the availability of Zn from infant foods containing increasing amounts of phytate, and to quantify the effect of the phytate:Zn molar ratio on the availability. During the in vitro assay, digestive conditions of infants, younger and older than 4 months of age, were carefully simulated since the solubility of phytate-Zn complexes during digestion is pH dependent. Availability was measured with a continuous flow dialysis in vitro procedure with previous intralumen digestive stage. Zn concentrations were determined with flame atomic absorption spectrometry. Phytic acid content was measured with HPLC. Adding phytate to infant formula lowered Zn availability to 2.84 (sd 0.17) % when the phytate:Zn molar ratio increased to 2.2 as compared with cows' milk-based formula (6.65 (sd 0.55) %). Availability from vegetables (23.83 (sd 2.17) %) significantly decreased at a ratio > 7.9 (15.12 (sd 1.63) %). Zn availability from soyabean-based formula (2.26 (sd 0.36) %) was lower compared with cows' milk-based formula (6.65 (sd 0.55) %). Availability between soyabean- and cows' milk-based formula was similar when a phytate:Zn ratio of 2.2 (2.84 (sd 0.17) %) was obtained in the cows' milk formula. The negative effect of phytic acid on Zn availability was dependent on the type of the food and the phytate content, and should be considered when using soyabean-based formulas during early infancy.

Analysis of Variance↗

PubMed2001

A method for in vitro determination of calcium, iron and zinc availability from first-age infant formula and human milk.

A method for in vitro determination of available calcium, iron and zinc content from infant food after digestion was evaluated. This method introduced an intraluminal digestive phase, adapted to the gastrointestinal conditions of infants younger than 6 months of age, prior to continuous flow dialysis of the resultant gastric digest. Precautions handling the method were discussed and enzymatic parameters were defined. Ruggedness of the method was determined from the availability of calcium, iron and zinc at different gastrointestinal conditions. Availability of all three elements was higher at gastric pH of 2 (20.0 +/- 1.1% for calcium, 4.06 +/- 0.66% for iron and 17.5 +/- 1.3% for zinc), than from the normal procedure (pH 4) (15.6 +/- 1.2% for calcium, 1.18 +/- 0.26% for iron and 8.2 +/- 0.9% for zinc). At pH 5, however, calcium availability appeared to be lower (11.7 +/- 1.0%) (P < 0.05). The intestinal pH also had a major influence on the availability. At low intestinal pH (5.5), availability was 40.5 +/- 2.3% for calcium, 3.01 +/- 0.58% for iron and 26.8 +/- 1.8% for zinc, which was higher compared with the normal procedure (P < 0.05). Moreover, other factors, such as digestion time, mixing and filtration pressure, also affected the availability. Recovery tests yielded mean values of 94 +/- 3% for calcium, 109 +/- 9% for iron and 106 +/- 4% for zinc. Mean intra- and inter-batch precision of the availability procedure was 4.1 CV% and 6.6 CV% for calcium, 14.5 CV% and 19.2 CV% for iron, and 4.0 CV% and 13.6 CV% for zinc. The method provides adequate accuracy, acceptable precision and good recovery. It offers the advantage of being simple, rapid and inexpensive, since it takes only 1 day to run the whole availability procedure (including four replicates per sample), and the low costs of the dialysis equipment. It can therefore be considered as suitable for predicting the availability of essential elements from foods used during the first months of infancy.

Analysis of Variance↗

PubMed2001

In vitro availability of calcium, iron, and zinc from first-age infant formulae and human milk.

BACKGROUND: Variation in the bioavailability of calcium (Ca), iron (Fe), and zinc (Zn) occurs because of interactions of food components in the gastrointestinal microenvironment. Bioavailability is preferably determined by in vivo tests, but these are expensive, labor-intensive, time consuming, and often unethical. As an alternative, in vitro methods can be used to predict bioavailability of nutrients from foodstuffs. METHODS: A continuous-flow dialysis model with preliminary intraluminal digestive phase, adapted to the gastrointestinal conditions of infants younger than 6 months, was used. Human milk was the reference standard. Ca, Fe, and Zn content of samples and dialysates after digestion were analyzed by atomic absorption spectrometry. RESULTS: Ca availability is similar in human milk (13.1%+/-0.8%), whey (13.3%+/-1.2%), and soy-based formulae (13.0%+/-1.2%; P > 0.05), and higher in casein-predominant formula (21.2%+/-0.6%; P < 0.05). Availability of Fe is highest in human milk (8.12%+/-0.27%: P < 0.05). Fe availability in whey (1.28%+/-0.28%) and soy formulae (1.48%+/-0.28%) is similar (P > 0.05), but availability is lower in casein-predominant formula (0.48%+/-0.22%; P < 0.05). Zn availability is also highest in human milk (13.1%+/-0.7%; P < 0.05). However, Zn availability is similar in whey (6.7%+/-0.6%) and casein formulae (8.5%+/-1.6%; P > 0.05), but lower in soy formula (2.3%+/-0.4%; P < 0.05). CONCLUSIONS: Our observations are in agreement with previous data from in vivo studies in term infants. This in vitro procedure is an inexpensive, simple, rapid, and reliable method that predicts the bioavailability of Ca, Fe, and Zn in foods.

Biological Availability↗

PubMed2001

Binding of mineral elements to locust bean gum influences availability in vitro.

Experiments were conducted to evaluate the extent to which element binding of locust bean gum (LBG) affects the availability of calcium, iron, and zinc in the gut. Infant formula was supplemented with increasing amounts of LBG and subjected to an intraluminal digestion procedure. Element binding was measured by eliminating the complexes by twofold centrifugation. Availability of the elements was determined using a validated continuous-flow dialysis technique. Elemental content of the samples, supematants, and dialysates was analyzed with validated atomic absorption spectrometry. LBG provided small amounts of intrinsic calcium (1.13+/-0.02 mg/g) and trace amounts of iron (0.02+/-0.00 mg/g) and zinc (0.01+/-0.00 mg/g), which were strongly bound to the LBG molecule (respectively: 76.6+/-3.3%, 83.4+/-1.2%, 96.7+/-6.6%). Correlation analysis, between percent element bound by LBG after centrifugation and percent trapped after dialysis, yielded significant correlation only for the data of zinc (r = 0.93). For calcium and iron, no correlation could be demonstrated; however, for iron a similar trend was observed. These findings suggest that element binding of LBG has a major influence on the availability of zinc and maybe of iron. For calcium, other factors might also be involved, affecting availability.

Biological Availability↗

PubMed2000

Thickening infant formula with digestible and indigestible carbohydrate: availability of calcium, iron, and zinc in vitro.

BACKGROUND: Regurgitation is common in infants and is usually due to gastroesophageal reflux. Often parental reassurance and dietary management by feeding thickened formulas are the only therapeutic steps necessary. Adding fibers may interfere with the absorption of micronutrients. METHODS: A continuous-flow dialysis in vitro method with a preliminary intraluminal digestive phase, modified to simulate the conditions of infants less than 6 months of age and children from 6 months of age on, was used to study the availability of calcium, iron, and zinc from thickened and nonthickened first-and second-age infant formulas. Pooled mature human milk was used as the reference standard. The elemental content of the samples and dialysate fractions of calcium, iron, and zinc after digestion was determined by atomic absorption spectrometry. RESULTS: In human milk, calcium, iron, and zinc were highly available for absorptive processes. Availability of calcium, iron, and zinc from nonthickened first- and second-age infant formulas tends to be significantly better than in the corresponding products thickened with locust bean gum. Thickening infant formulas with pregelatinized rice starch, however, does not affect the availability of calcium, iron, and zinc. CONCLUSIONS: It appears that human milk provides optimal conditions for the availability of calcium, iron, and zinc. Availability of calcium, iron, and zinc seems to lower when infant formulas are thickened with indigestible carbohydrates, whereas it does not by adding digestible carbohydrates.

Biological Availability↗

PubMed2000

Indication of silicon essentiality in humans: serum concentrations in Belgian children and adults, including pregnant women.

Serum silicon concentrations were determined in Belgian healthy children and adults, including pregnant women, by electrothermal atomic absorption spectrometry. Serum levels appeared to be significantly higher in healthy children (1-18 yr) than in healthy adults (19-60 yr). Especially, levels in infants (< 1 yr) were higher than in any other group. Compared to age-matched nonpregnants, the serum silicon content was very low in pregnant women. In addition to the fact that this study for the first time provides serum silicon values in adults and children in Belgium, the most important observation is that these serum profiles might be an indication of silicon essentiality in man.

Adolescent↗

PubMed1996

Daily dietary chromium intake in Belgium, using duplicate portion sampling.

Daily dietary chromium intake in Belgium has been evaluated by sampling duplicate portions of food, heating them at an acidic pH in a microwave oven and then quantifying the chromium by atomic absorption spectrometry. The mean intake value (53 +/- 31 micrograms/day) is similar to levels found for most other countries and is situated at the lower end of the recommended range for a safe and adequate daily dietary intake.

Belgium↗

PubMed1996

The influence of different food components on the in vitro availability of iron, zinc and calcium from a composed meal.

The availability of iron, zinc and calcium from a composed meal was studied by an in vitro method using equilibrium dialysis after simulated gastric digestion. Four different concentrations of four influencing factors (coffee, vitamin C, wheat bran and pectin) were added to the mixed meal and their effect on the relative index of availability was studied after elemental analysis by atomic absorption spectrometry. Apart from ascorbic acid, all other factors had a negative effect on availability of minerals and trace elements. Most pronounced effect, and for all three elements, was observed for the addition of wheat bran. Zinc was the trace element, which was most sensitive to increased spiking of food constituents.

Ascorbic Acid↗

PubMed1995

Daily dietary copper intake in Belgium, using duplicate portion sampling.

Daily dietary copper intake in Belgium has been evaluated by duplicate portion sampling, heating in a microwave oven and atomic absorption spectrometric determination of this element. The mean intake value (1.5 +/- 0.4 mg/day) is similar to levels found for most other countries, but is situated at the lower end of the recommended range for a safe and adequate daily dietary intake.

Adult↗

PubMed1995

Daily dietary intake of manganese by several population groups in Belgium: preliminary reports.

Atomic absorption spectrometry is used to determine manganese content of several duplicate meals consumed by different population groups in the Antwerp region (Belgium). Daily elemental intake, beverages not included, is calculated and proven to be within the recommended daily allowances (National Academy of Sciences, USA) except for a higher intake by macrobiotics (6.7 +/- 3.8 mg per day). Intake level of vegetarians is similar to that of omnivorous adults, 2.9 +/- 2.0 and 2.5 +/- 0.3 mg per day, respectively. Values obtained in this study are compared with scarce data on intake by similar groups in other countries.

Adult↗

PubMed1994

Copper, zinc, manganese, iron, lead, cadmium, mercury and arsenic in fish from Lake Tanganyika, Burundi.

Atomic absorption spectrometric determination of copper, zinc, manganese, iron, lead, cadmium, mercury and arsenic in two fish species from Lake Tanganyika, Burundi, provide values that are lower than most literature data, especially for cadmium, arsenic and mercury. Tissue analysis of Lates stapersii reveals that liver accumulates the highest amount of most elements. The data illustrates that Lake Tanganyika is still a non-polluted area at the time of analysis.

Animals↗

PubMed1994

Modification of an in-vitro method for estimating the bioavailability of zinc and calcium from foods.

A continuous flow in-vitro method for estimating the bioavailability of minerals and trace elements was modified. This modified method includes a simulated gastric digestion with pepsin, gradual pH change during the first 30 min of dialysis in an Amicon stirred cell, and a further 2 h of continuous dialysis accompanied by intestinal digestion with pancreatin-bile extract. The percentage of continuously dialysed minerals or trace elements (dialysability) is used to express the bioavailability. Comparison of different in-vitro methods by using the dialysability of zinc and calcium from milk- and soy-based formula samples revealed that with the modified method the results are closer to the in-vivo situation and could be used as a relative index for predicting the bioavailability of some minerals and trace elements.

Animals↗

PubMed1994

Factors influencing blood selenium concentration values: a literature review.

Various factors, that probably influence the blood selenium concentration level of people residing in a given geographical area are discussed. The literature is screened for the effects of age, gender, smoking and drinking habits, race, state of lactation, environmental exposure and medical treatment. The differences are mostly found to be small on the absolute scale, with only nutrition seeming to be a major factor.

Aging↗

PubMed1994

Capillary whole blood selenium determination in assessing selenium status of children.

Selenium levels in venous and capillary whole blood of children were assessed by direct graphite furnace atomic absorption spectrometry. Selenium data obtained for both blood samples did not differ statistically (p > 0.05). Capillary blood may therefore be used as an alternative to venous blood, which is more difficult to obtain from children. Whole-blood selenium data for children in the Antwerp region (Belgium) were compared with literature data for children from other countries.

Belgium↗

PubMed1994

Manganese content of European wines.

The manganese content of 35 different red, white and rosé wines, produced in several European countries, is determined by electrothermal atomic absorption spectrometry. A mean concentration of 2.7 +/- 1.7 mg l-1 (range: 0.5-7.3 mg l-1) is obtained. No statistically significant difference is observed between red and white wines. On the other side, the red Beaujolais wines reveal significantly (p < 0.01) higher manganese content. Since literature data on manganese content of wine could hardly be traced, factors, probably affecting the manganese content of this alcoholic beverage, are discussed.

Europe↗

PubMed1994

Selenium concentration in serum of healthy Greek adults.

Serum selenium levels of 160 healthy Greeks were determined by Zeeman-effect background-corrected atomic absorption spectrometry. Mean value for 101 men (70.7 +/- 16.2 micrograms/L) tended to be higher, but not statistically significant, compared to the mean value for 59 women (64.9 +/- 14.7 micrograms/L). When the subjects were divided into various age groups there appeared to be some increase as a function of age. Compared to the extensive literature data on serum Se levels for various countries healthy Greeks proved to be at the lower concentration range. The scarce, but conflicting literature data on serum Se values for Greeks is discussed.

Adult↗

PubMed1993

Daily dietary intake of copper, zinc and selenium by different population groups in Burundi, Africa.

Daily dietary intake of copper, zinc and selenium for different population groups in Burundi, Africa, has been determined, using different sampling strategies, by atomic absorption spectrometry. Recommended daily intakes (RDA, National Academy, USA) are met for copper and zinc. For selenium, especially the rural population risk a deficiency as observed with a daily intake of 17 micrograms. The importance of different types of food in daily intake is discussed. Legumes proved to be an important source of copper, while for selenium fish contributes in a large part in dietary intake. Calculated total daily intakes are compared with intakes recently published for other countries.

Burundi↗