Aluminium levels in milk and infant formulae.

Aluminium levels in infant formulae purchased in 1990 and prepared as for consumption were in the range 530 micrograms/l to 640 micrograms/l for soya-based products and 27 micrograms/l to 120 micrograms/l for cows' milk-based formulae. Mean aluminium concentrations in these soya and cows' milk-based samples were, on average, 37% and 45% lower, respectively, than those of the same brands purchased between 1985 and 1987. Levels of aluminium in breast milk were in the range 3 micrograms/l to 79 micrograms/l. In the case of retail cows' milk, values ranged from 4 micrograms/l to 33 micrograms/l whilst more variable amounts of between 5 micrograms/l and 285 micrograms/l were detected in retail soya milk.     

Aluminium content of Spanish infant formula

Levels of aluminium in 82 different infant formulae from nine different manufacturers in Spain were determined by acid-microwave digestion and graphite furnace atomic absorption spectrophotometry. The influence of aluminium content in tap water in reconstituted powder formulae was examined and an estimate was made of the theoretical toxic aluminium intake in comparison with the provisional tolerable weekly intake (PTWI). Possible interactions between aluminium and certain essential trace elements added to infant formulations have been studied according to the type or main protein-based infant formula. In general, the infant formulae contained a higher aluminium content than that found in human milk, especially in the case of soya, preterm or hydrolysed casein-based formulae. Standard formulae gave lower aluminium intakes amounting to about 4% PTWI. Specialized and preterm formulae resulted in a moderate intake (11-12 and 8-10% PTWI, respectively) and soya formulae contributed the highest intake (15% PTWI). Aluminium exposure from drinking water used for powder formula reconstitution was not considered a potential risk. In accordance with the present state of knowledge about aluminium toxicity, it seems prudent to call for continued efforts to standardize routine quality control and reduce aluminium levels in infant formula as well as to keep the aluminium concentration under 300 μg l^-1 for all infant formulae, most specifically those formulae for premature and low birth neonates.     

Aluminium levels in Canadian infant formulate and estimation of aluminium intakes from formulae by infants 0-3 months old

Aluminium was determined in 282 cans of infant formulae and evaporated milks sold in Canada using graphite furnace atomic absorption spectrometry. Milk-based formulae contained average (range) concentrations of 0.129 (0.010-0.36), 0.217 (0.17-0.56) and 0.717 (0.19-2.49) micrograms/g ('as sold') in ready-to-use, concentrated liquid and powder formulae, respectively. The corresponding concentrations in the soy-based formulae were 1.98 (0.40-6.4), 1.41 (0.59-2.29) and 9.44 (3.15-18.0) micrograms/g. Evaporated milk contained 0.093 (0.022-0.34) micrograms/g. The levels varied extensively according to formula brand; e.g. for ready-to-use formulae, the range of average concentrations by formula brand were 0.42-3.28 micrograms/g for soy-based and 0.020-0.22 micrograms/g for milk-based products. Estimated aluminium ingestion from formula or milk by infants up to 3 months old ranged from 0.5 microgram per kg body weight per day (microgram/kg/day) or 2 micrograms/day for 0-1 month olds fed cow milk exclusively to 219 micrograms/kg/day (1260 micrograms/day) for 1-3 month olds fed only soy-based formulae. Consumption of only the formulae brand having the highest mean aluminium level (3.28 micrograms/g) by 1-3 month old infants could result in an intake of 363 micrograms/kg/day (2088 micrograms/day). The estimates assume that the sole source of aluminium is the formula or milk and do not include any potential contribution from other foods or water.     

Leaching of aluminium from aluminium dishes and packages.

A study was carried out of the leaching of aluminium from aluminium cooking vessels and packages. Very small or undetectable levels of aluminium leached from packaging materials into foodstuffs. In boiling tests with neutral porridge no migration of aluminium into the test matrix was observed from the pan. When boiling milk, the leaching of aluminium was 0.2-0.8 mg/kg. The aluminium content of tap water in aluminium pans when reaching boiling point was 0.54-4.3 mg/l and increased with increasing boiling time to 6.3-17 mg/l. Aluminium dissolved in foods based on acidic fruit juice rose to levels of 2.9-35 mg/kg when the foods were boiled in aluminium pans. Steaming of currant berries in an aluminium vessel gave aluminium concentrations of 19-77 mg/kg in the resulting juice. The highest aluminium concentration of 170 mg/kg was measured in rhubarb juice prepared in the steaming vessel. Aluminium dissolved in water to levels of 0.81-1.4 mg/l when heated for the first time in new coffee percolators. The aluminium concentration of water heated in older percolators was 0.09-0.78 mg/l.     

Aluminium content in milk powders by inductively-coupled argon plasma--optical emission spectrometry.

Forty-four brands of milk powders and simulated milk powders were analysed for aluminium content using Inductively Coupled Plasma Spectroscopy (ICP-OES) technique. The samples covered the full range of infant food items available in Singapore--full-cream milk formula, infant formula, fortified infant formula and milk-free soy protein formula. ICP-OES technique was employed for the analysis. Most samples analysed were found to contain less than 1 mg aluminium per kg powder. The highest aluminium content found was 15.0 mg aluminium per kg powder in a milk-free soy protein formula. The study found that ICP-OES is a convenient and accurate technique for trace metal analysis. However, considerable care needs to be exercised in the selection of emission lines of the metal under analysis to avoid error caused by emission from other metal present in the sample.     

Pesticide content of infant formulae and weaning foods available in New Zealand

A survey of the pesticide content of 25 commercially available infant formulae and 30 weaning foods available in New Zealand was undertaken in 1996. It included a representative mixture of imported and New Zealand manufactured infant foods. Three different pesticide screening techniques were used: a high-sensitivity organochlorine screen was carried out on all infant formulae, while a multiresidue screen (organochlorine and organophosphorus pesticides, synthetic pyrethroids, carbamate pesticides, fungicides and herbicides), and a specific screen for dithiocarbamate fungicides were both carried out on all weaning foods and on soy-based infant formulae. All results are expressed on a ready-to-feed basis. Extremely low levels of residues of three organochlorine compounds (p,p'-DDE, p,p'-DDT and dieldrin) were detected in infant formulae samples. Residues of p,p'-DDE were found in seven of 20 milk-based infant formulae at concentrations ranging from 0.03 to 0.5 μg kg^-1. Residues of p,p'-DDT were found in one imported milk-based infant formula at 0.7 μg kg^-1, and dieldrin residues were detected in four of five soy-based infant formulae at concentrations ranging from 0.05 to 0.08 μg kg^-1. The multiresidue pesticide screen detected low levels of residues of two organophosphorus pesticides; azinphos-methyl in one soy-based infant formula at a level of 22 μg kg^-1 and pirimiphos-methyl in two cereal-based weaning foods at concentrations of 5 and 14 μg kg^-1. None of the other approximately 140 pesticides (including fungicides and herbicides) included in the multiresidue screen were detected in any weaning foods or soy-based infant formulae, at a detection limit of 10 μg kg^-1. No residues of dithiocarbamate fungicides were detected in any product analysed, at a detection limit of 100 μg kg^-1.     

Selenium concentrations in soya based milks and infant formulae available in the United Kingdom

A simple hydride generation atomic absorption spectrometric method previously described for bovine infant formulae has been successfuly applied for the analysis of selenium in UK soya based milks and infant formulae. Levels reported for the first time ranged from 0.011 to 0.040 μg/g (wet wt) for soya milks and from 0.023 to 0.089 μg/g (dry wt) for soya isolate infant formulae. No matrix interferences were encountered and the mean recovery was 100.1%. These values exhibit variation between batches, hence routine QC analysis and fortification by manufacturers is recommended.     

Determination of nitrates in milk by ion-chromatography

A method is described for the determination of nitrates in cow milk, human milk, milk powder or milk-based infant formulae using liquid chromatography on Spheron DEAE and a direct photometric detection (205 nm). The influence of removing proteins by precipitation with Carrez reagent on the accuracy of determination was studied. The proposed method gives identical results with the reference method (photometry after reduction of nitrate to nitrite) but is more rapid. Its limit of determination is 0.5 mg NO3-/l of milk, its reproducibility is 4% (relative standard deviation).     

Hydride generation atomic absorption spectrometric (HGAAS) determination of selenium in term and preterm infant formulae available in the United Kingdom

A simple and sensitive hydride generation atomic absorption spectrometry method is described for the determination of total selenium in infant formulae. Decomposition of the composite sample matrix involved overnight digestion with a nitric-perchloric acid mixture (10:2 ml) then heating at 150 °C (30 min) and 220 °C (60 min). No apparent matrix interferences were encountered. The selenium levels in infant formulae, reported for the first time, ranged from 0.034 to 0.093 μ/g (dry wt) for bovine casein and whey-based term powdered infant products, 0.023–0.093 μg/g (dry wt) for preterm powdered formulae and 0.027–0.049 μ/g (wet wt) for hospital administered low birth weight ready-to-feed formulae. These values are dependent on geographic origin of bovine milk and exhibit variation between batches. Routine QC analysis and fortification by manufacturers is recommended.     

Plasticizers in total diet samples, baby food and infant formulae

The plasticizers di-n-butylphthalate (DBP), butylbenzylphthalate (BBP), di-2-(ethylhexyl)phthalate (DEHP) and di-2-(ethylhexyl)adipate (DEHA) were analysed in 29 total diet samples, in 11 samples of baby food and in 11 samples of infant formulae. In all of the total diet samples the presence of one or more of the plasticizers was demonstrated. Maximum and minimum mean concentrations in the total diet samples were: 0.09-0.19mg DBP/kg, 0.017-0.019mg BBP/kg, 0.11-0.18mg DEHP/kg and 0.13-0.14mg DEHA/kg. One or more of the phthalates was also found in about 50% of the samples of baby food as well as in infant formulae. The calculated mean maximum intakes of the individual compounds from the total diet samples were below 10% of the restrictions proposed by the EU Scientific Committee for Food (SCF), and the spread in individual intakes was considerable. DEHP was the plasticizer determined most frequently and contributed the highest fraction of its tolerable daily intake (TDI). Hence, the maximum calculated intake of DEHP from single samples of the foodstuffs analysed could be up to one-third of the TDI. The calculated mean intake of DEHA was about 1% of the TDI with a maximum value of 13% of the TDI. Violations of the restrictions proposed by the EU Scientific Committee for Food (SCF) in the form of TDI values or specific migration limits were not found in this investigation.     

Lead levels in retail samples of Spanish infant formulae and their contribution to dietary intake of infants

Lead concentrations in 82 different types of infant formulae (cow's milk and soy based) marked in Spain were analysed by acid-microwave decomposition and anodic stripping voltammetry. Dietary lead intake from infant formula and tap water used for powder formula reconstitution were estimated in comparison with the provisional tolerable weekly intake (PTWI). Additionally, the influence of physical state (powder and ready-to-use formulae), the type of container used and the impact of the industrial process from different manufacturers on lead levels were evaluated. According to the results, lead exposure from drinking water was negligible with respect to formulae investigated; where soya formulae contributed the highest intake (58-73% PTWI), non-adapted starter and specialized formulae gave an moderate intake (31-42 and 26-37% PTWI, respectively), and, finally, pre-term, adapted starter and follow-up formulae provided the lowest lead intake (22-25, 22-26 and 16-22% PTWI, respectively). Based on the current state of knowledge about lead toxicity, manufacturers are called to make an additional effort in order to keep a maximum lead level at 20 µg l^-1 for all infant formulae, although it is recommendable that these formulations supply the upper limit (5 µg l^-1) of 'normal' human milk.     

Manganese in natural mineral waters from Germany

154 commercially available natural mineral waters were analysed for their content of dissolved manganese (Mn(II)). 114 bottles were marked “deironized” (geogenic iron removed). Unexpectedly, waters rich in mangenese were more frequent among the deironized waters than among the non-deironized ones. Almost 20% of all waters contained more than 0,20 mg/l Mn(II), a toxicologically justified limit value with respect to formula-fed infants. Two waters which were declared as “adapted for the preparation of infant food” contained even more than 1,0 mg/l Mn(II). It is proposed to legally prescribe the declaration of manganese on the bottle. For reasons of preventive public health care, waters with more than 0,20 mg/l Mn(II) are not considered as suitable for the preparation of infant food.     

Design and preparation of market baskets of European Union commercial baby foods for the assessment of infant exposure to food chemicals and to their effects

The assessment of acute and chronic dietary exposure to contaminants in baby foods is needed to ensure healthy infant growth. Monthly European Union market baskets of commercial baby foods were designed for the first 9 months of life by the ‘babyfood’ study group of the CASCADE Network of Excellence for the specific purpose of assessing exposure to potentially toxic substances in infants fed with such foods. The present paper reports the different steps that led to the preparation of monthly pooled samples of commercial baby foods (‘Infant formulae and follow-on formulae’ and ‘Other baby foods’) that may constitute the extreme case of the diet for an infant who would not be breast fed at all. Several market baskets were generated for an ‘average European Union infant’ and for infants of four selected countries (Italy, Sweden, Spain, and the Slovakia), fed with either milk infant formulae, soy infant formulae or hypoallergenic infant formulae and weaned (at the fifth month) with commercial baby foods and beverages available on the European Union market. Market share data for 2007 for baby foods were used to design the baskets. Holding companies and the name of all their products were identified. Monthly diets for European Union infants were elaborated in terms of food categories (e.g. infant cereals) of typologies of products (e.g. infant cereals without gluten) and of a specific product. The number of baskets generated was 30 for ‘Infant formulae and follow-on formulae’ (including 62 products) and 13 for ‘Other baby foods’ (including 35 products). These market baskets were designed to be used for the determination of certain contaminants and nutrients in the diet of European Union infants and for the assessment of their effects on infant health.     

Availability of aluminium from tea and coffee

 The amount of aluminium in different kinds of tea and ground coffee was analysed, the transfer of aluminium into the infusion was determined and aluminium intake via tea and coffee was calculated within the framework of our investigations. Aluminium concentrations amounted to (in μg/g dry matter): black tea, 899; flavoured black tea, 763; peppermint tea, 477; mountain herbal tea, 419; fruit tea, 292; ground coffee, 19. About 30% of the aluminium stored in black tea’s dry matter was transferred into the infusion, which contained 4.2 mg Al/l. In contrast, the availability of aluminium from peppermint and fruit tea as well as from ground coffee was very low (about 5%). The calculated aluminium intake via tea and coffee was 0.2 to 0.3 mg/day and contributed about 5% to the total aluminium intake. Only black tea infusions are a significant source of aluminium intake via beverages. Received: 9 January 1997     

Chromium content in different kinds of Spanish infant formulae and estimation of dietary intake by infants fed on reconstituted powder formulae.

Chromium is well documented as an essential element for humans. Trivalent chromium, the main chemical form found in foods, is essential for maintaining normal glucose metabolism. Owing to analytical difficulties, several literature reports of chromium content of foods, especially for the lower levels, show large variability and should be interpreted with caution. Zeeman background correction, transversely heated graphite furnace atomic absorption spectrometry was used to determine the chromium content of 104 different infant formulae (cow's milk and soy protein based) marketed in Spain following an acid-digestion sample preparation procedure in a closed, pressurized and microwave digestion unit. The mean and range of chromium values, regarding types and main protein-based infant formulae are presented. Additionally, the influence of the type of container used, the impact of industrial process from different manufacturers and the physical state (powder and liquid formulae) on chromium levels is also discussed. In general, the infant formulae contain a higher chromium concentration than that found in human milk (reference range: 0.20-8.18 microg l-1), particularly in the case of hypoallergenic (18.16 +/- 7.89 microg l-1), lactose-free (11.37 +/- 3.07 microg l-1), pre-term (11.48 +/- 3.15 microg l-1) and soya (10.43 +/- 4.05 microg l-1) formulae. The maximum theoretical estimated intake of infants fed on the studied formulae was lower than the upper limit safety for trivalent chromium of 1 mg kg-1 (14 microg kg-1 b.w. day-1) recommended by the experts of Council for Responsible Nutrition (Hathcock 2004; available at: http://crnusa.org/safety.html), amounting to about 10, 15-18 and 26% of the standard (adapted and follow-up) and toddler, soya, lactose-free and pre-term, and hypoallergenic formulae, respectively. Therefore, manufacturers are called upon to make continued efforts to routinely monitor chromium levels, particularly for specialised and pre-term formulae, and at the same time, might consider the inclusion of labelling the levels of chromium at least in these complex formulations.     

Updating on the lysinoalanine content of commercial infant formulae and beicost products

Since the safety issue of lysinoalanine (LAL) still remains unresolved, its concentration in infant formulae should be reduced to a minimum. Data collected in the 1980s indicated that LAL is formed in higher amounts in liquid than in powdered formulae. Recently the market of liquid infant formulae is increasing rapidly and there are no new data, so 23 commercial powdered or liquid samples were investigated. In powdered samples, LAL was below the detection limit, whereas liquid adapted formulae contained up to 86 μg/g protein, liquid follow-on formulae up to 390 μg/g protein, and liquid growing milks up to 514 μg/g protein. The concentration of LAL in liquid formulae is considerably lower than in the past; however, the level in a few products remains rather high, especially compared with normal UHT-treated milk. Great differences were observed among products of different companies, which suggests that labelling with the thermal treatment applied would be very advisable. The investigation of some beicost products indicates that LAL is present only in products certainly containing milk proteins. Considering the rather low levels in comparison with liquid infant formulae, the contribution of beicost products to the total LAL daily intake does not seem to be particularly relevant.     

Dynamic in vitro gastric digestion of infant formulae made with goat milk and cow milk: Influence of protein composition

The gastric digestion behaviours of infant formulae made with goat milk and cow milk, with different ratios of casein to whey protein, were investigated using an in vitro dynamic infant human gastric simulator. The goat milk infant formulae formed smaller flocs of aggregated protein and oil droplets under gastric conditions, leading to faster protein digestion in goat milk infant formulae than in cow milk infant formulae. The extent of coagulation of protein and the size of flocculated oil droplets were dependent on the protein composition of the formulae. The casein-dominated cow milk infant formula had greater aggregation initially during gastric digestion, but a lower rate of casein digestion. The results suggest that the different composition of the casein micelles in goat milk may play an important role in the lower extent of coagulation and the faster protein gastric digestion in goat milk compared with cow milk.     

Studies on iodine content in daily diets and selected dairy products

Poland's people have moderate – and in seaside areas mild – degrees of severity of iodine deficiency. A national program has been introduced for obligatory iodine prophylaxis and includes the iodination of household salt to the extent of 30 ±10 mg KI/kg. In order to assess the extent of iodine consumption, analytical studies were carried out on iodine content in average Polish diets. Taking into account the fact that milk formulae are frequently the basic source of iodine for infants, studies were performed on the iodine content in selected dairy products, mainly infant formulae. Iodine concentrations in samples were determined in duplicate by radioactive neutron activation analysis (RNAA). The iodine content in Polish diets without added iodinated kitchen salt was low and insufficient to provide the Polish RDA for this element. The results of the analytical investigations of the daily diets showed higher iodine content in comparison to theoretical calculations. The theoretical values accounted for 71–85% of the analytical ones. Study of iodine content in infant formula demonstrated differences between the analytically determined iodine content in products and that declared by producers. Received: 22 November 1999     

Does aluminium stimulate the immune system in male rats after oral exposure?

The influence of oral aluminium exposure on the immune system was studied in rats. Male rats were exposed to soluble and labile Al in acidic drinking water (0-500 mg Al/l) for 7-9 weeks. The concentration of Al in femur bone was higher in rats exposed to 50 and 500 mg Al/l (mean concentration 277 and 599 ng Al/g) than in control rats (150 ng Al/g). The Al concentration in blood plasma could only be quantified in the 500 mg/l group (mean 2.7 ng/ml), whereas the concentrations in the control and 50 mg/l groups were low (< 2 ng Al/ml). Exposure of 4-13-weeks-old rats to the highest Al concentration caused an increased number of splenocytes, whereas exposure of 9-16-weeks-old rats to 500 mg Al/l caused an increased number of thymocytes. Moreover, the proliferative response of splenocytes to the mitogen Con A (2 micrograms/ml) was increased by exposure of the 9-16-weeks-old rats to 500 mg Al/l as compared with the controls. The results indicate that oral Al exposure caused a slight stimulation of some immune functions in the rat at Al plasma concentrations normally found in the human population (< 10 ng Al/ml).