Evaluation of ED-XRF for the detection of inorganic adulterants in turmeric, paprika and oregano.

Herbs and spices are known to be prone to food fraud and accurate analytical tools are needed to detect adulterants. Amongst the potential adulteration, dilution with bulking agents has regularly been reported, especially with inorganic materials such as talc or brick powder. Energy Dispersive X-Ray Fluorescence (ED-XRF) spectrometry is a well-established non-destructive analytical technique for qualitative and quantitative elemental analysis of a wide variety of samples. ED-XRF was here evaluated for the detection of inorganic adulterants in turmeric, paprika and oregano, which were selected as representative for the herbs & spices food category. Magnesium, silicon, and calcium were identified as elements to detect talc, soapstone, brick/clay powder, and chalk inorganic adulterants. ED-XRF successfully detected adulterated samples when spiked down to 5% (w/w) in the selected herbs and spices. With its ease-of-use and speed, ED-XRF is well adapted for the monitoring of inorganic adulteration of herbs and spices along the supply chain.

Mode of Neonatal Delivery Influences the Nutrient Composition of Human Milk: Results From a Multicenter European Cohort of Lactating Women.

Background: The effect of the mode of neonatal delivery (cesarean or vaginal) on the nutrient composition of human milk (HM) has rarely been studied. Given the increasing prevalence of cesarean section (C-section) globally, understanding the impact of C-section vs. vaginal delivery on the nutrient composition of HM is fundamental when HM is the preferred source of infant food during the first 4 postnatal months. Objective: This study aimed to evaluate the association between mode of delivery and nutrient composition of HM in the first 4 months of life. Design: Milk samples were obtained from 317 healthy lactating mothers as part of an exploratory analyses within a multicenter European longitudinal cohort (ATLAS cohort) to study the HM composition, and its potential association with the mode of delivery. We employed traditional mixed models to study individual nutrient associations adjusted for mother's country, infant birth weight, parity, and gestational age, and complemented it, for the first time, with a multidimensional data analyses approach (non-negative tensor factorization, NTF) to examine holistically how patterns of multiple nutrients and changes over time are associated with the delivery mode. Results: Over the first 4 months, nutrient profiles in the milk of mothers who delivered vaginally (n = 237) showed significantly higher levels of palmitoleic acid (16:1n-7), stearic acid (18:0), oleic acid (18:1n-9), arachidic acid (20:0), alpha-linolenic acid (18:3n-3), eicosapentaenoic acid (20:5n-3), docosahexenoic acid (22:6n-3), erucic acid (22:1n-9), monounsaturated fatty acids (MUFA)%, calcium, and phosphorus, whereas the ratios of arachidonic acid/docosahexaenoic acid (ARA/DHA) and n-6/n-3, as well as polyunsaturated fatty acids (PUFA)% were higher in milk from women who had C-sections, in the unadjusted analyses (p < 0.05 for all), but did not retain significance when adjusted for confounders in the mixed models. Using a complementary multidimension data analyses approach (NTF), we show few similar patterns wherein a group of mothers with a high density of C-sections showed increased values for PUFA%, n-6/n-3, and ARA/DHA ratios, but decreased values of MUFA%, 20:1n-9, iodine, and fucosyl-sialyl-lacto-N-tetraose 2 during the first 4 months of lactation. Conclusion: Our data provide preliminary insights on differences in concentrations of several HM nutrients (predominantly fatty acids) among women who delivered via C-section. Although these effects tend to disappear after adjustment for confounders, given the similar patterns observed using two different data analytical approaches, these preliminary findings warrant further confirmation and additional insight on the biological and clinical effects related to such differences early in life.

A nutritional supplement containing zinc during preconception and pregnancy increases human milk zinc concentrations.

Introduction: During pregnancy and lactation minerals such as zinc are required to support maternal and infant health. Zinc is involved in various cellular processes, with requirements increasing in pregnancy and lactation. In the setting of a randomized trial, we investigated the effects on human milk (HM) zinc concentrations of a micronutrient-containing supplement including zinc in the intervention (but not control) group, started preconception and taken throughout pregnancy until birth. Additionally, we characterized longitudinal changes in HM concentrations of zinc and other minerals (calcium, copper, iodine, iron, magnesium, manganese, phosphorus, potassium, selenium, and sodium). Methods: HM samples were collected across 7 time points from 1 week to 12 months from lactating mothers from Singapore (n = 158) and New Zealand (n = 180). HM minerals were quantified using sector field inductively coupled plasma mass spectrometry. Potential intervention effects on HM mineral concentrations were assessed using linear mixed models with a repeated measures design and time-weighted area-under-the-curve analyses. Results: Over the first 3 months of lactation, HM zinc concentrations were 11% higher in the intervention group compared to the control group (p = 0.021). Higher HM zinc concentrations were most evident at 6 weeks of lactation. The intervention had no effect on HM concentrations of other minerals, which were not differently supplemented to the control and intervention groups. Temporal changes in HM minerals over 12 months of lactation were studied in the New Zealand mothers; HM zinc and copper concentrations progressively decreased throughout 12 months, while iron, potassium, sodium, and phosphorus decreased until 6 months then plateaued. HM calcium and magnesium initially increased in early lactation and iodine remained relatively constant throughout 12 months. HM manganese and selenium fell over the initial months of lactation, with a nadir at 6 months, and increased thereafter. The contrasting patterns of changes in HM mineral concentrations during lactation may reflect different absorption needs and roles at different stages of infancy. Discussion: Overall, this study indicates that HM zinc concentrations are influenced by maternal supplementation during preconception and pregnancy. Further studies are required to understand the associations between HM zinc and other minerals and both short- and long-term offspring outcomes. Trial registration: ClinicalTrials.gov, identifier: NCT02509988, Universal Trial Number U1111-1171-8056. Registered on 16 July 2015. This is an academic-led study by the EpiGen Global Research Consortium.

Detection and characterization of small-sized microplastics (≥ 5 µm) in milk products.

Microplastics (MPs) have gained a high degree of public interest since they are associated with the global release of plastics into the environment. Various studies have confirmed the presence of MPs throughout the food chain. However, information on the ingestion of MPs via the consumption of many commonly consumed foods like dairy products are scarce due to the lack of studies investigating the "contamination" of this food group by MPs. This lack of occurrence data is mainly due to the absence of robust analytical methods capable of reliably quantifying MPs with size < 20 µm in foods. In this work, a new methodology was developed to accurately determine and characterize MPs in milk-based products using micro-Raman (µRaman) technology, entailing combined enzymatic and chemical digestion steps. This is the first time that the presence of relatively low amounts of small-sized MP (≥ 5 µm) have been reported in raw milk collected at farm just after the milking machine and in some processed commercial liquid and powdered cow's milk products.

Vitamin B12 quantification in human milk - Beyond current limitations using liquid chromatography and inductively coupled plasma - Mass spectrometry.

Vitamin B12 plays a key role in human biological functions and is vital in the neurological development of infants. The assessment of the vitamin B12 intake in exclusively breastfed babies depends on the reliability of its determination in milk. In this report, we present a new accurate and robust method for quantification of vitamin B12 in human milk. A highly specific sample preparation is applied, associated with chromatographic separation and detection by ICP-MS. Excellent sensitivity and accuracy are reported, with recovery values well within acceptability limits (80-120%), within- and between-day variability are lower than 10% and 15% respectively. Strong correlation with a microbiological assay was observed (r2 = 0.9) within the validation range (40-1000 pmol/L, corresponding to 54 to 1355 ng/L). The method can be used to routinely monitor vitamin B12 in clinical or population observational studies, determine infant's intake or assess efficacy of mother's supplementation.

Impact of Ascorbic Acid on the In Vitro Iron Bioavailability of a Casein-Based Iron Fortificant.

A new iron-casein complex (ICC) has been developed for iron (Fe) fortification of dairy matrices. The objective was to assess the impact of ascorbic acid (AA) on its in vitro bioavailability in comparison with ferrous sulfate (FeSO4) and ferric pyrophosphate (FePP). A simulated digestion coupled with the Caco-2 cell culture model was used in parallel with solubility and dissociation tests. Under diluted acidic conditions, the ICC was as soluble as FeSO4, but only part of the iron was found to dissociate from the caseins, indicating that the ICC was an iron chelate. The Caco-2 cell results in milk showed that the addition of AA (2:1 molar ratio) enhanced iron uptake from the ICCs and FeSO4 to a similar level (p = 0.582; p = 0.852) and to a significantly higher level than that from FePP (p < 0.01). This translated into a relative in vitro bioavailability to FeSO4 of 36% for FePP and 114 and 104% for the two ICCs. Similar results were obtained from water. Increasing the AA to iron molar ratio (4:1 molar ratio) had no additional effect on the ICCs and FePP. However, ICC absorption remained similar to that from FeSO4 (p = 0.666; p = 0.113), and was still significantly higher than that from FePP (p < 0.003). Therefore, even though iron from ICC does not fully dissociate under gastric digestion, iron uptake suggested that ICCs are absorbed to a similar amount as FeSO4 in the presence of AA and thus provide an excellent source of iron.

The bioavailability of iron picolinate is comparable to iron sulfate when fortified into a complementary fruit yogurt: a stable iron isotope study in young women.

PURPOSE: A technological gap exists for the iron (Fe) fortification of difficult-to-fortify products, such as wet and acid food products containing polyphenols, with stable and bioavailable Fe. Fe picolinate, a novel food ingredient, was found to be stable over time in this type of matrix. The objective of this study was to measure the Fe bioavailability of Fe picolinate in a complementary fruit yogurt. METHODS: The bioavailability of Fe picolinate was determined using stable iron isotopes in a double blind, randomized cross-over design in non-anemic Swiss women (n = 19; 25.1 ± 4.6 years). Fractional Fe absorption was measured from Fe picolinate (2.5 mg 57Fe per serving in two servings given morning and afternoon) and from Fe sulfate (2.5 mg 54Fe per serving in two servings given morning and afternoon) in a fortified dairy complementary food (i.e. yogurt containing fruits). Fe absorption was determined based on erythrocyte incorporation of isotopic labels 14 days after consumption of the last test meal. RESULTS: Geometric mean (95% CI) fractional iron absorption from Fe picolinate and Fe sulfate were not significantly different: 5.2% (3.8-7.2%) and 5.3% (3.8-7.3%) (N.S.), respectively. Relative bioavailability of Fe picolinate versus Fe sulfate was 0.99 (0.85-1.15). CONCLUSION: Therefore, Fe picolinate is a promising compound for the fortification of difficult-to-fortify foods, to help meet Fe requirements of infants, young children and women of childbearing age.

Longitudinal Changes of Mineral Concentrations in Preterm and Term Human Milk from Lactating Swiss Women.

An adequate mineral supply to preterm infants is essential for normal growth and development. This study aimed to compare the mineral contents of human milk (HM) from healthy mothers of preterm (28-32 weeks) and full term (>37 weeks) infants. Samples were collected weekly for eight weeks for the term group (n = 34) and, biweekly up to 16 weeks for the preterm group (n = 27). Iron, zinc, selenium, copper, iodine, calcium, magnesium, phosphorus, potassium, and sodium were quantitatively analyzed by Inductively Coupled Plasma-Mass Spectrometry. The mineral contents of both HM showed parallel compositional changes over the period of lactation, with occasional significant differences when compared at the same postpartum age. However, when the comparisons were performed at an equivalent postmenstrual age, preterm HM contained less zinc and copper from week 39 to 48 (p < 0.002) and less selenium from week 39 to 44 (p < 0.002) than term HM. This translates into ranges of differences (min-max) of 53% to 78%, 30% to 72%, and 11% to 33% lower for zinc, copper, and selenium, respectively. These data provide comprehensive information on the temporal changes of ten minerals in preterm HM and may help to increase the accuracy of the mineral fortification of milk for preterm consumption.

Subclinical Mastitis in a European Multicenter Cohort: Prevalence, Impact on Human Milk (HM) Composition, and Association with Infant HM Intake and Growth.

Background: Subclinical mastitis (SCM) is an inflammatory condition of the mammary gland. We examined the effects of SCM on human milk (HM) composition, infant growth, and HM intake in a mother-infant cohort from seven European countries. Methods: HM samples were obtained from 305 mothers at 2, 17, 30, 60, 90, and 120 days postpartum. SCM status was assessed using HM Sodium (Na): Potassium (K) ratio >0.6. Levels of different macro- and micronutrients were analyzed in HM. Results: SCM prevalence in the first month of lactation was 35.4%. Mean gestational age at delivery was lower and birth by C-section higher in SCM mothers (p ≤ 0.001). HM concentrations of lactose, DHA, linolenic acid, calcium, and phosphorous (p < 0.05 for all) was lower, while total protein, alpha-lactalbumin, lactoferrin, albumin, arachidonic acid to DHA ratio, n-6 to n-3 ratio and minerals (iron, selenium, manganese, zinc, and copper) were higher (p < 0.001 for all) in mothers with SCM. There were no differences in infant growth and HM intake between non-SCM and SCM groups. Conclusion: We document, for the first time, in a large European standardized and longitudinal study, a high prevalence of SCM in early lactation and demonstrate that SCM is associated with significant changes in the macro- and micronutrient composition of HM. Future studies exploring the relation of SCM with breastfeeding behaviors and developmental outcomes are warranted.

Validation of a dilute and shoot method for quantification of 12 elements by inductively coupled plasma tandem mass spectrometry in human milk and in cow milk preparations.

Nutritional information about human milk is essential as early human growth and development have been closely linked to the status and requirements of several macro- and micro-elements. However, methods addressing whole mineral profiling in human milk have been scarce due in part to their technical complexities to accurately and simultaneously measure the concentration of micro- and macro-trace elements in low volume of human milk. In the present study, a single laboratory validation has been performed using a "dilute and shoot" approach for the quantification of sodium (Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo) and iodine (I), in both human milk and milk preparations. Performances in terms of limits of detection and quantification, of repeatability, reproducibility and trueness have been assessed and verified using various reference or certified materials. For certified human milk sample (NIST 1953), recoveries obtained for reference or spiked values are ranged from 93% to 108% (except for Mn at 151%). This robust method using new technology ICP-MS/MS without high pressure digestion is adapted to both routinely and rapidly analyze human milk micro-sample (i.e. less than 250 µL) in the frame of clinical trials but also to be extended to the mineral profiling of milk preparations like infant formula and adult nutritionals.

Simultaneous Determination of 10 Ultratrace Elements in Infant Formula, Adult Nutritionals, and Milk Products by ICP/MS After Pressure Digestion: Single-Laboratory Validation.

A single-laboratory validation (SLV) is presented for the simultaneous determination of 10 ultratrace elements (UTEs) including aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), molybdenum (Mo), lead (Pb), selenium (Se), and tin (Sn) in infant formulas, adult nutritionals, and milk based products by inductively coupled plasma (ICP)/MS after acidic pressure digestion. This robust and routine multielemental method is based on several official methods with modifications of sample preparation using either microwave digestion or high pressure ashing and of analytical conditions using ICP/MS with collision cell technology. This SLV fulfills AOAC method performance criteria in terms of linearity, specificity, sensitivity, precision, and accuracy and fully answers most international regulation limits for trace contaminants and/or recommended nutrient levels established for 10 UTEs in targeted matrixes.

Comparative study of the mesostructure of natural and synthetic polyisoprene by size exclusion chromatography-multi-angle light scattering and asymmetrical flow field flow fractionation-multi-angle light scattering.

This paper presents results from the first analyses of the mesostructure of natural rubber (NR) by asymmetrical flow field flow fractionation (AF4). The results are compared with those obtained by size exclusion chromatography (SEC) in terms of average molar masses, radius of gyration and insoluble part (or gel quantity). Comparable results were obtained for the sample not containing gel. Conversely, for samples with gel, significant differences were found due to the presence of microaggregates. Contrary to SEC, AF4 fractionation enables partial fractionation of polyisoprene chains and microaggregates in a single run without preliminary treatment. The results presented here also highlight the special structure (very compact spheres) of microaggregates in NR compared to chemical crosslinked microaggregates in synthetic polyisoprene. The advantages and drawbacks of both techniques for analysing NR samples are also discussed.

Characterization of oxidized tannins: comparison of depolymerization methods, asymmetric flow field-flow fractionation and small-angle X-ray scattering.

Condensed tannins are a major class of plant polyphenols. They play an important part in the colour and taste of foods and beverages. Due to their chemical reactivity, tannins are not stable once extracted from plants. A number of chemical reactions can take place, leading to structural changes of the native structures to give so-called derived tannins and pigments. This paper compares results obtained on native and oxidized tannins with different techniques: depolymerization followed by high-performance liquid chromatography analysis, small-angle X-ray scattering (SAXS) and asymmetric flow field-flow fractionation (AF4). Upon oxidation, new macromolecules were formed. Thioglycolysis experiments showed no evidence of molecular weight increase, but thioglycolysis yields drastically decreased. When oxidation was performed at high concentration (e.g., 10 g L(-1)), the weight average degree of polymerization determined from SAXS increased, whereas it remained stable when oxidation was done at low concentration (0.1 g L(-1)), indicating that the reaction was intramolecular, yet the conformations were different. Differences in terms of solubility were observed; ethanol being a better solvent than water. We also separated soluble and non-water-soluble species of a much oxidized fraction. Thioglycolysis showed no big differences between the two fractions, whereas SAXS and AF4 showed that insoluble macromolecules have a weight average molecular weight ten times higher than the soluble ones.

Single walled carbon nanotube length determination by asymmetrical-flow field-flow fractionation hyphenated to multi-angle laser-light scattering.

Asymmetrical flow field-flow fractionation (AFlFFF) hyphenated to multi-angle laser-light scattering (MALS) was evaluated in order to determine single walled carbon nanotube (SWCNT) length distribution. Fractionation conditions were investigated by examining mobile phase ionic strength and pH, channel components and cross-flow rate. Ammonium nitrate-based mobile phase with 10(-5)molL(-1) ionic strength and pH 6 allows the highest sample recovery (89±3%) to be obtained and the lowest loss of the longest SWCNT. A cross-flow rate of 0.9mLmin(-1) leads to avoid any significant membrane-sample interaction. Length was evaluated from gyration radius measured by MALS by comparing SWCNT to prolate ellipsoid. In order to validate the fractionation and the length determination obtained by AFlFFF-MALS, different SWCNT aliquots were collected after fractionation and measured by dynamic light scattering (DLS). AFlFFF is confirmed to operate in normal mode over 100-2000nm length. MALS length determination after fractionation is found to be accurate with 5% RSD. Additionally, a shape analysis was performed by combining gyration and hydrodynamic radii.

Colloidal organic matter from wastewater treatment plant effluents: Characterization and role in metal distribution.

Colloidal organic matter from wastewater treatment plants was characterized and examined with respect to its role in metal distribution by using tangential flow ultrafiltration, liquid chromatography coupled with organic carbon and UV detectors, and an asymmetrical flow field-flow fractionation (AFlFFF) multidetection platform. Results revealed that a humic-like fraction of low aromaticity with an average molar mass ranging from 1600 to 2600Da was the main colloidal component. High molar mass fractions (HMM), with molar mass ranges between 20 and 200kDa, were present in lower proportions. Ag, Cd, Cu, Cr, Mn and Zn were found mainly in the dissolved phase (<0.45microm) and their distribution between colloidal and truly dissolved fractions was strongly influenced by the distribution of dissolved organic carbon. AFlFFF coupled to ICP-MS showed that Ag, Cd, Cu, Cr, Mn and Zn associate to the low molar mass fraction of the colloidal pool, whereas Al, Fe and Pb were equally bound to low and high molar mass fractions.

Colloidal transport of uranium in soil: Size fractionation and characterization by field-flow fractionation-multi-detection.

The aim of this study was to characterize colloids associated with uranium by using an on-line fractionation/multi-detection technique based on asymmetrical flow field-flow fractionation (As-Fl-FFF) hyphenated with UV detector, multi angle laser light scattering (MALLS) and inductively coupling plasma-mass spectrometry (ICP-MS). Moreover, thanks to the As-Fl-FFF, the different colloidal fractions were collected and characterized by a total organic carbon analyzer (TOC). Thus it is possible to determine the nature (organic or inorganic colloids), molar mass, size (gyration and hydrodynamic radii) and quantitative uranium distribution over the whole colloidal phase. In the case of the site studied, two populations are highlighted. The first population corresponds to humic-like substances with a molar mass of (1500+/-300)gmol(-1) and a hydrodynamic diameter of (2.0+/-0.2)nm. The second one has been identified as a mix of carbonated nanoparticles or clays with organic particles (aggregates and/or coating of the inorganic particles) with a size range hydrodynamic diameter between 30 and 450nm. Each population is implied in the colloidal transport of uranium: maximum 1% of the uranium content in soil leachate is transported by the colloids in the site studied, according to the depth in the soil. Indeed, humic substances are the main responsible of this transport in sub-surface conditions whereas nanoparticles drive the phenomenon in depth conditions.

Evaluation of a combined fractionation and speciation approach for study of size-based distribution of organotin species on environmental colloids.

Results relating to the first original application of an analytical approach combining asymmetric flow field-flow fractionation (As-Fl-FFF) with multi-detection and chemical speciation for determination of organotins in a landfill leachate sample are presented. The speciation analysis involved off-line head-space solid-phase microextraction (HS-SPME)-gas chromatography with pulsed-flame photometric detection (GC-PFPD) performed after three consecutive collections of five different fractions of interest from the As-Fl-FFF system and cross-flow part (assumed to be representative of the <10 kDa phase). After 0.45 microm filtration and without preconcentration before fractionation and speciation analysis, limits of detection (LOD) were 4-45 ng (Sn) L(-1) in the sample, with relative standard deviations (RSD) of 3-23%. The As-Fl-FFF fractionation of this sample enables characterization of two distinct populations-organic-rich and inorganic colloids with gyration radius up to 120 nm. Total Sn and mono and dibutyltins (MBT and DBT) appear to be distributed over the whole colloidal phase. Tributyl, monomethyl, monooctyl, and diphenyltins (TBT, MMT, MOcT, and DPhT) were also detected. Quantitative speciation analysis performed on the two colloidal populations and in the <10 kDa phase revealed concentrations from 130 +/- 10 (MMT) to 560 +/- 50 ng (Sn) L(-1) (DPhT).