Optimization of a Slurry Dispersion Method for Minerals and Trace Elements Analysis in Infant Formulae by ICP OES and FAAS

Infant formula developed by manufacturers requires a rigorous control of composition, particularly those elements added routinely in an attempt to mimic the mineral composition of human milk. A total of 97 different types of powdered infant formulae (preterm, adapted starter, adapted follow-up, toddler, specialised and soy based formulae) commercially available in Spain were studied. It is noteworthy great differences in mineral (Ca, P, Mg) and trace element (Zn, Fe, Cu, Mn) contents found between analysed and listed in label information. The development of a fast, simple and direct slurry method for the determination of these essential micronutrients in infant formula by inductively coupled plasma optical emission spectrometry (ICP OES) and flame atomic absorption spectrometry (FAAS) was performed in order to help in quality control tasks. Infant formula samples were solubilised using different amounts of several different solvents. An addition of 250 L of a solution 10 % tetramethylammonium hydroxide and 25 % ammonium hydroxide were required for the accurate quantification of Ca and P, Mg, Zn, Fe, Cu and Mn, respectively. The standard reference material 1549 non-fat milk powder was solubilised to compare the validity of assayed methodology following slurry nebulisation and traditional microwave-assisted acid digestion method. Good agreement of the analytical results by both ICP OES and FAAS, with the certified values was obtained. Method performance parameters (accuracy, precision and methodological detection limits) were determined for studied elements to check the quality and usefulness of the optimised slurry method. The analytical procedure was applied successfully to the analysis of a representative group of infant formulae. Levels of analysed elements were graphically represented, showing an acceptable comparability between slurry and acid-mineralisation method set by linear correlation coefficients and slopes close to the unit. The described simple and slurry method is appropriate, as an attractive alternative, for routine control analysis of added essential elements in infant formulae regardless of predominant protein type used in manufacture

Surveillance of aflatoxin content in dairy cow feedstuff from Navarra (Spain)

Aflatoxins (B1, B2, G1 and G2) are produced by the fungi Aspergillus (A. flavus and A. parasiticus) in substrates used in cattle feed manufacturing. Aflatoxin M1 (AFM1) is a major metabolite of Aflatoxin B1 (AFB1) which may be present in milk from animals that consume contaminated feed. Levels of aflatoxins in 78 dairy cow feedstuff samples from 40 farms located in Navarra were determined by HPLC-FLD (High Performance Liquid Chromatography with fluorescence detection) and post-column derivatization. The influence of geographical location, season and type of feeding system on aflatoxin content was studied. The climatic profile of AFB1 pointed to spring as the season with the highest aflatoxin level (0.086 μg/kg), followed by winter and summer (0.075 and 0.030 μg/kg, respectively), and to a lesser degree, autumn (0.017 μg/kg). Moreover, wet and dry TMR (Total Mixed Ration) feeding systems (i.e. AFB1: 0.076 and 0.068 μg/kg; Aflatoxin G1 (AFG1): 0.050 and 0.011 μg/kg, respectively) showed a greater content of the analyzed aflatoxins in comparison with compound feed (i.e. AFB1: 0.039 μg/kg; AFG1: 0.007 μg/kg). The fact that the majority of the samples collected were based on compound feed shows that this type was preferred by most dairy farmers. The undetectable levels of aflatoxins in the organic homemade compound feedstuff are also worth mentioning. While none of the feedstuff samples contained amounts over those permitted under European legislation (5 μg/kg), the theoretical extrapolation of the carryover rate suggested in previously published experiments of AFB1 to AFM1 in secreted cow's milk predicts that only one of the feed samples studied had a positive aflatoxin level (53.4 ng/kg) higher than the legal limit for raw cow's milk

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

The essentiality of chromium in humans is well documented. Trivalent chromium, main chemistry form found in foods, is essential for maintaining normal glucose metabolism. Because of analytical difficulties, several literature reports of chromium content of foods, especially for the lower levels, show large variability and they should be interpreted with caution for a valid interpretation of reliable results. A 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) marked in Spain following an acid attack sample preparation procedure in a closed, pressurized and microwave digestion unit. Mean and range 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 g l-1), particularly in case of hypoallergenic (18.16 ± 7.89 g l-1), lactose-free (11.37 ± 3.07 g l-1), preterm (11.48 ± 3.15 g l-1) and soya (10.43 ± 4.05 g l-1) formulae. The maximum theoretical estimated intake of infant fed on studied formulae was lower than the upper limit safety for trivalent chromium of 1 mg kg-1 (14 g Kg-1 b.w. day-1) recommended by the experts of Council for Responsible Nutrition (CRN ULS, 2004), amounting to about 10 %, 15-18 % and 26 % for standard (adapted and follow-up) and toddler; soya, lactose-free and preterm; and hypoallergenic formulae, respectively. Therefore, manufacturers are called for continued effort to routinely monitor chromium levels, mainly for specialised and preterm formulae, and at the same time, might consider the inclusion of labelling value for chromium at least in these complex formulations

Survey of total mercury and arsenic content in infant cereals marketed in Spain and estimated dietary intake.

Due to the fact that infants and children are especially sensitive to mercury and arsenic 7 exposure, predominantly through diet, a strict control of the most widely consumed 8 infant foods, especially infant cereals, is of paramount importance. Levels of both total 9 mercury and arsenic in 91 different infant cereals from ten different manufacturers in 10 Spain were determined by flow injection adapted to cold vapor and hydride generation 11 atomic absorption spectrometry, respectively. Cereals were assessed in terms of the 12 different types, the predominating cereal in the formulation, the added ingredients, and 13 whether the cereal was organically or conventionally obtained. In general, the content of 14 toxic elements (median (Q1;Q3)) found in infant cereals based on conventionally obtained raw materials (n=74, Hg: 2.11 (0.42;4.58), As: 21.0 (9.4;50.9) μg·Kg-1 15 ) was 16 lower than in cereals produced by organic methods (n= 17, Hg: 5.48 (4.54;7.64), As: 96.3 (87.5;152.3) μg·Kg-1 17 ). Mercury content in infant cereals shows the higher values in 18 those formulations with ingredients susceptible to particulate contamination such as 19 gluten-free or cacao-based cereals. The highest arsenic content appears in the rice-based 20 cereals. The mercury and the inorganic arsenic dietary intakes for infants fed on the 21 infant cereals studied were assessed, taking into account the different stages of growth. 22 Organic infant cereals based on cocoa showed the highest risk intakes of mercury, very 23 close to exceeding the intake reference. Just the opposite, 95% of the organically 24 produced infant cereals and 70% of the conventional gluten-free infant cereals showed 25 an inadmissible risk of arsenic intake. Thus, it seems prudent to call for continued 26 efforts in standardizing routine quality control and in reducing arsenic levels in infant 27 cereals; in addition it is essential that relevant legislation be established and regulated 28 by EC regarding these two toxic elements

Estimation of dietary intake and content of lead and cadmium in infant cereals marketed in Spain

Lead and cadmium have become highly toxic metallic elements. There is an obvious 5 toxicological impact of these elements on infants since their intestinal absorption is 6 significantly higher than in adults, thus it is desirable to quantify lead and cadmium levels in 7 commonly consumed infant foods. Zeeman background correction, transversely heated 8 graphite furnace atomic absorption spectrometry, was used to determine both the lead and 9 cadmium content of 91 Spanish infant cereals. Cereals were assessed in terms of different 10 types, cereal predominant in formulation and whether it was obtained organically or 11 conventionally. Preliminary analysis revealed a noticeably higher content of lead and 12 cadmium (median, Q1-Q3) in organic cereals (n = 17, Pb: 26.07; 21.36-51.63; Cd: 18.52; 16.56-28.50 μg kg-1 13 ) in relation to conventional ones (n =74, Pb: 10.78; 6.43-19.33; Cd: 7.12; 4.40-11.77 μg kg-1 14 ). Three formulations exceeded European lead maximum levels. Added 15 ingredients (milk, cocoa, fruit and honey) to the cereal base provide lead enrichment. For 16 cadmium, this pattern was observed by cereal based on cocoa, but also the raw materials 17 contributed with a dilution phenomenon, decreasing the final cadmium concentration in infant 18 cereal. Apart from several organically produced cereals, lead content showed a narrow 19 variation, where gluten-free cereals provide lower cadmium content than formulations 20 containing gluten. Dietary intakes of both elements were assessed in comparison with the 21 reference intake values proposed by the EFSA Panel on Contaminants in the Food Chain. 22 Organic infant cereals based on honey and cocoa supplied the highest risk intakes of lead and 23 cadmium, respectively. In accordance with the actual state of knowledge on lead and 24 cadmium toxicity and attending to the upper limits calculated from risk intake values set by 25 EFSA, it seems prudent to call for a revision of both heavy metals content regulated by EC to set a maximum guideline values for infant cereal at 55 and 45 μg kg-1 26 , respectively

Chemometric analysis of minerals and trace elements in raw cow milk from the Community of Navarra

The concentrations of protein, fat, five minerals (Na, K, P, Ca and Mg) and nine trace elements (Fe, Zn, Cu, Mn, Se, Al, Cd, Cr and Pb) have been determined in 347 samples of raw cow milk from the community of Navarra, north Spain, using infrared analysis, atomic absorption spectrometry (flame and electrothermal atomisation) and inductively coupled plasma atomic emission spectroscopy. A preliminary chemometric study with the use of pattern recognition methods was carried out in order to characterise, classify and distinguish the different collected samples on the basis of their contents. Principal component analysis (PCA) has permitted the reduction of 16 variables to five principal components which interpret reasonably well the correlations of these studied variables. These variable associations may be attributed to intrinsic (lactogenesis) and other extrinsic factors, such as seasonal variation, animal feeding or geographical situation. Changes in these contents during different seasons were also assessed and consistently interpreted. Linear discriminant analysis (LDA) was used to explore cow milk samples, classifying according to season or geographical location, providing complementary information to PCA. This work shows that PCA and LDA are useful chemometric tools for the multivariate characterisation of raw cows’ milk

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

Lead concentrations in a total of 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 industrial process from different manufacturers on lead levels were evaluated. According to our 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 specialised 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 g l-1 for all infant formulae, although it is recommendable that these formulations supply the upper limit (5 g l-1) of “normal” human milk

Selenium Content of Spanish Infant Formulae and Human Milk: Influence of Protein Matrix, Interactions with Other Trace Elements and Estimation of Dietary Intake by Infants

The Selenium content of infant formulae varies as a result of differences in the amount of intrinsic selenium compounds. Manufacturers have been gradually changing the protein profile of infant formula to reflect human milk contents more closely. Because of these variations in infant formula composition and their potential impact on selenium content, this trace element was analysed with regard to the different protein sources. The aims of this study were to determine the selenium content in infant formulae sold commercially in Spain, to estimate a daily dietary intake for infants fed on formulae and to compare with the selenium provided by Spanish breast milk samples used as a reference. We have also identified certain trace elements added to formulae which interact with selenium according to type and protein matrix of infant formula. Selenium concentration was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) with a hydride generator. The selenium concentrations in human milk and infant formula determined in this study are similar to those found by other researchers in different countries. Daily intake of studied formulae was estimated according to recommended doses from manufacturers. Theoretical intake of lactating infants has been studied in relation to the Recommended Dietary Allowance (RDA: 10 μg Se/day) and the specific recommendations for infant formula nutrient contents (10 – 35 μg/L) set by Expert Panel of Life Sciences Research Office (LSRO) of the American Society for Nutritional Sciences. According to our results, on an overall view, infants fed on the studied infant formulae have an intake between the basal and normative requirements. This might be considered to provide an adequate selenium intake. However, several formulae included in this research could provide an intake of selenium that does not reach the RDA for the first month of neonate life

Niveles de concentración de aluminio en fórmulas infantiles

Los altos contenidos de aluminio encontrados en las fórmulas infantiles con mayor grado de procesamiento han llevado a las organizaciones pediátricas a solicitar una evaluación de estos niveles, especialmente los preparados para lactantes pretérmino. Los objetivos de este estudio son: valorar los contenidos de aluminio en los diferentes tipos de fórmula infantil comercializados en España; determinar los factores condicionantes de su preparación por parte de las diferentes casas comerciales; y, aportar un nivel máximo de aluminio recomendable para las fórmulas infantiles. La metodología empleada ha seguido un escrupuloso protocolo para evitar cualquier contaminación metálica durante el proceso de toma y tratamiento de la muestra. La digestión de las muestras se ha llevado a cabo con ácido nítrico subboiling en un sistema cerrado de microondas y bombas de digestión de teflón de alta presión. Los valores de concentración de aluminio se han determinado por espectrofotometría de absorción atómica con atomización electrotérmica. Los contenidos de aluminio obtenidos presentan una amplia variabilidad dependiendo del tipo de fórmula analizado. Globalmente, las fórmulas infantiles estudiadas proporcionan unos niveles de concentración muy superiores a los hallados en la leche materna, especialmente aquellas formulaciones de alta complejidad tecnológica (fórmulas especiales, de soja y para prematuros). A la luz de los resultados obtenidos, es conveniente solicitar de las diferentes casas comerciales continuados esfuerzos para reducir el nivel de aluminio, introducir programas rutinarios de control y observar el valor guía máximo de 300 g/L, principalmente en las fórmulas para lactantes pretérmino

Ingesta dietética y requerimientos nutricionales de elementos traza en la alimentación infantil

La deficiencia de elementos traza durante el periodo neonatal tiene gran influencia en el desarrollo posterior del lactante. Las cantidades diariamente requeridas de oligoelementos son mínimas, proporcionadas por la leche humana o de fórmula, única fuente nutricional durante la etapa de lactancia exclusiva. Los requerimientos de elementos traza son específicos para cada individuo. Considerando esta amplia variación interindividual, las recomendaciones dietéticas deben establecerse de una forma bastante amplia para cubrir las necesidades de la mayoría de la población. Por razones de ética, existen algunos datos que no pueden ser obtenidos de los lactantes en buen estado de salud sino por extrapolación de otros estudios, con todas las limitaciones inherentes a dicha deducción. La leche humana sirve de referencia en cuanto a los valores de elementos traza contenidos. En este estudio se revisan los valores de ingesta dietética diaria de elementos traza esenciales (Fe, Zn, Cu, Mn y Se) y potencialmente tóxicos (Al, Pb y Cd) proporcionada por la leche materna y las fórmulas infantiles, comparándolos con los valores de ingesta recomendados por organismos competentes. A pesar de los innumerables esfuerzos realizados por numerosos investigadores, permanecen existiendo discrepancias y desconocimiento en algunos aspectos relevantes de algunos elementos traza esenciales, manifestándose la gran necesidad de nuevos estudios relevantes con objeto de cubrir las necesidades nutricionales de elementos traza de todos los lactantes