This study presents the applicability of monochromatic wavelength dispersive X-ray fluorescence spectrometry (MWD-XRF) to quantify low range of concentrations, from 0.2 to 10 mg/kg of total chlorine in vegetable oils and bleaching clays effluents. The combination of total chlorine analysis by MWD-XRF and monochloropropanediol fatty acid esters (MCPDE) analysis by LC-MS of vegetable oils at different steps of the refining process allows to identify clays and technical aids used for bleaching as entry points of chlorine, potentially resulting in MCPDE formation during heat treatment of vegetable oils. Efficient washing of clays and technical aids monitored by chlorine measurement in successive effluents by MWD-XRF demonstrates the impact of washing by keeping total 3- MCPD content at low level in bleached vegetable oil. Further investigation on pH of the bleaching clays effluents shows that acidity is a key parameter during the formation of MCPD.

This talk will discuss synergistic opportunities between the effects of recently explored MCPD mitigation concepts in palm oil and sunflower oil. The discussed laboratory concepts will include dry versus wet removal of residual sediments, various degumming conditions and the role the bleaching clay in mitigating or catalyzing the formation of MCPD. The effects of the discussed mitigation concepts were studied by integrating them into the physical refining of crude oil, including water-based degumming and sealed ampoule tests mimicking the thermal conditions of edible oil deodorization. Key experiments were also reproduced in laboratory benchtop deodorizer. The MCPD levels were monitored by both direct LC-HRMS and indirect GC-MS based approaches. Beyond reviewing the MCPD mitigation effects and pros/cons of the investigated concepts, particular emphasis will be put on assessing whether the observed effects are due to correlation or causality between the refining parameters and the MCPD levels.

This study reports the benefits of auxiliary degumming (Aux.D) and pressurized high temperature (165 degrees C) water washing (PHTW) to mitigate the formation of monochloropropanediols (MCPD) during labscale physical refining of palm oil. Water-based degumming in combination with bleaching and deodorization are performed as the selected physical refining process. The mitigation concepts Aux.D and PHTW are integrated into the refining protocol and the ultimately observed MCPD levels in the fully refined oils are determined. Aux.D is performed by extracting the hydratable gum from pressed sunflower oil and using it as a degumming agent to further purify palm oil that has been previously subjected to centrifugation and water degumming. This approach enables the mitigation of 3-MCPD from the water washed reference 2.4-0.9 mg kg(-1) in ampoules. Even stronger mitigation is obtained when Aux.D is combined with bleaching and executed twice allowing a mitigation from the reference 1.9-0.6 mg kg(-1), in ampoules. PHTW is shown to decrease the 3-MCPD content of the refined oil from the reference 2.4-1 mg kg(-1), in ampoules and when combined with bleaching and executed twice showing a decrease from the reference 1.9-0.9 mg kg(-1). Practical applications: The benefits of these mitigation concepts are confirmed both in sealed ampoule tests and in deodorizer experiments at the lab scale. A combined application of Aux.D or PHTW with physical refining may represent new insights that can help to potentially further mitigate the formation of MCPD in physically refined palm oil beyond the limits achievable with current refining practices.

The aim of this study was to identify the chlorine source during sunflower oil production and propose mitigation strategies in order to prevent monochloropropane-diol ester (MCPDE) formation. Whole sunflower seeds, the separated kernel, hulls, and pressed cake were studied to pinpoint the location of chlorine donors originating from the crop. Acid-water-based degumming, bleaching, cooling, and heat treatment were performed to mimic the current refining process practices. Various oil extraction and refining scenarios were tested. MCPDE and total monochloropropane-diol (MCPD) content of the heat-treated samples were determined by liquid chromatography-HRMS and by an AOCS Official method. The results show that the oil produced from crop hulls and the bleaching clay used are the strongest chlorine sources boosting the MCPDE formation. Using a mixture of pressed and solvent extracted cake oil as model, total 3-MCPD decreased by a factor of 2 when applying static cooling in combination with a washed bleaching clay.

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.

The two objectives were 1) to evaluate the solubility of two iron casein complexes (ICCs) under a condition mimicking gastric pH, 2) to evaluate the impact of ascorbic acid (AA) on the in vitro iron absorption of ICCs after incorporation in reconstituted whole milk powder. The in vitro solubility was determined over time after addition of diluted HCl (pH 1.7), ultracentrifugation and measurement of iron appearing in the supernatant by ICP-OES (n = 2). The impact of AA on iron uptake from the Fe compounds in reconstituted milk was determined using the in vitro digestion coupled with the Caco-2 cell model and the measurement of ferritin/total protein produced by the cells (n = 3). The molar ratio of AA to iron of 2 to 1 recommended by the WHO for iron absorption optimization has been tested with an iron level corresponding to 3.3 mg Fe/serving of milk. Ferrous sulfate (FeSO4), the reference compound for iron bioavailability and micronized ferric pyrophosphate (FePP), main salt used for milk fortification were used as references. The dissolution test showed a rapid solubilization of iron from the ICCs i.e., >75 ± 19.3% at 5 min and >89 ± 0.3% at 90 min. The kinetics of soluble iron from the complexes were like that from FeSO4. The solubility of FePP was only 37.6 ± 4.7% at 90 min. Without AA, the iron uptake from FeSO4 was lower than expected translating into a relative in vitro bioavailability (iRBA) of FePP and of the two ICCs to FeSO4 of 66, 169 and 215%. This might be explained by a rapid conversion of soluble iron from FeSO4 into Fe3+ and insoluble iron hydroxide when the pH increased from 2 to >7 during in vitro digestion. However, with the addition of AA in the milk, iron uptake by the cells was found to be increased to levels of 341.8 ± 8.9, 124 ± 12.2, 403.1 ± 117.8 and 362.9 ± 36.9 ng ferritin/mg protein for FeSO4, FePP and the two ICCs respectively. This translates into iRBAs to FeSO4 of 36% for FePP and of 118 and 106% for the two ICCs. The solubility and the demonstrated impact of AA on Fe uptake suggest that ICCs are absorbed to a similar amount as FeSO4 and thus provide an excellent source of Fe. Société des Produits Nestlé, NPTC Konolfingen, Switzerland.

This study investigates whether the formation of monochloropropane diol fatty acid esters (MCPDE) can be mitigated by removing the residual sediments from vegetable oils. Settling and centrifugation were conducted in crude sunflower and palm oil and the purified oils and their sediment-rich fractions were heated and analyzed for their MCPDE content. Increased MCPDE levels by factors of x2 to x6 were found in the sediment-rich fractions of settled sunflower oils compared to the sediment-free oil. The sediment-containing fraction could be however purified by ultracentrifugation resulting in the mitigation of MCPDE levels by a factor of 10. The effect of residual sediment on the MCPDE formation was also confirmed in the case of palm oil showing x2 to x10 more MCPDE formation in the sediment containing fractions compared to the purified oil. These results confirm that the mechanical removal of the trace sediments from crude vegetable oils results in reduced MCPDE levels.

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 aim of this study is to assess the synergy of mitigating main chlorine sources in palm oil and the oil refining conditions in a lab-scale physical refining process. Mitigation concepts including centrifugation and washing steps are integrated into the physical refining protocol and the MCPD levels in the fully refined oils are determined. The endogenous chlorine content of the crude oil and that of the bleaching clay is confirmed to predominantly impact MCPD formation in this refining process. Residual sediments are shown to induce up to 1 ppm MCPD in the fully refined oils. Residual chlorine content of bleaching clay is shown to increase MCPD content of the oil twofold.t-Test statistical analysis confirms significant effect of centrifugation, phosphoric acid content, clay type and clay washing on the formation of MCPD. Centrifugation is shown to effectively reduce the chlorine source coming from the sediments, while clay washing is shown to effectively reduce the chlorine source coming from the bleaching clay. These mitigation effects are confirmed both in sealed ampoule tests and in deodorizer experiments. Practical Applications: A combined application of strong centrifugation and clay washing is recommended to potentially improve the MCPD content of physically refined palm oil.

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.

This paper reports the first results on depleting certain organochlorines from vegetable oils without the use of any solvent in order to mitigate monochloropropanediol diesters (MCDPE). The concept is based on separating the organochlorines from the bulk oil by using trapping agents (e.g. monoacylglycerols) that can be easily separated from the oil. The process starts by mixing and homogenizing crude vegetable oils with the trapping agent and subsequently separating the trapping agent from the oil bulk via crystallization. The proof-of-concept of the approach is demonstrated on a spiked sunflower model system, solvent extracted crude sunflower oil, industrially produced crude soybean and corn oils. The depletion of organochlorines in the crude oils and its beneficial effect on the MCPDE content in the heat treated samples is measured by LC-MS. The depletion efficacy of the monitored organochlorines was estimated to be in the 60-95 % range. Both the melting point and polarity of the trapping agents affected the depletion efficacy of the organochlorines. Trapping agents with higher melting point and polarity, such as monostearin were more effective in comparison to high melting point but less polar agents such as palm stearin or agents rich in polar but low melting point monolinolein/monoolein. The effect of organochlorine depletion on the subsequent MPCDE levels in heat treated oil was in the range of 60-90 % reduction depending on the type of the studied oil.

A simple and fast method for the quantification of a series of macro elements (Na, Mg, P, Cl, K and Ca) and trace elements (Mn, Fe, Cu and Zn) by Energy Dispersive X-Ray Fluorescence (ED-XRF) was developed and validated using samples of commercial dry pet foods. All samples were systematically analyzed by reference methods (i.e. Potentiometry for chloride and Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for other elements) and by ED-XRF. A calibration set of 33 samples was selected to uniformly cover the concentration ranges of each element and their reference method values were used to calibrate the ED-XRF device. A second set (the validation set) was composed of 46 other samples, which were analyzed as unknowns. During this validation step, the elemental concentrations obtained by ED-XRF were systematically evaluated against those obtained from the reference methods. Using robust statistics, for the 10 investigated analytes, the bias between both methods was found to be not significantly different from 0 and the relative uncertainties RSD(u) were found to be lower than 15 %. This study demonstrated that ED-XRF is a fast and reliable method for minerals quantification in dry pet foods.

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.

A fully validated and rapid quantitative method is presented for determination of inorganic arsenic [arsenite, As(III) and arsenate, As(V)] and organic arsenic species (methylarsonic acid, dimethylarsinic acid, and arsenobetaine) by ion chromatography paired with inductively coupled plasma/MS after ultrasonic-assisted enzymatic extraction (UAEE) in rice- and seafood-based raw materials and finished products. This method gives toxicological meaning to arsenic analysis, since the sum of the toxic chemical forms As(III) and As(V) can be determined. In contrast to classical water-methanol extraction, UAEE enables drastic acceleration of sample extraction (5 min instead of several hours), while total arsenic extraction efficiency is improved without species conversion. Validation was performed to evaluate the method for selectivity, linearity, LOD/LOQ (0.007-0.020 mg/kg), trueness, precision (HorRat values, 0.2-0.6), recovery (93-122%), and uncertainty. The method was also satisfactorily tested using two proficiency tests. Performance characteristics are reported for four certified reference materials, standard reference material (SRM) 1568a (rice flour), Institute for Reference Materials and Measurements 804 (rice flour), SRM 2976 (mussel tissue), certified reference material-627 (tuna fish), and several commercial food samples populating five AOAC triangle food sectors. The results indicated that this speciation method is cost-efficient, time-saving, and accurate, as well as fit-for-purpose, according to International Organization for Standardization/International Electrotechnical Commission 17025:2005 standard, and could be used for routine analysis.

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.

The application of a dynamic reaction cell inductively coupled plasma mass spectrometer (DRC ICP-MS) for interference-free Cr determination was validated for different foods. The working conditions were optimized and the method as such validated using certified reference materials and internal food samples. For the latter, reference data obtained from graphite furnace atomic absorption spectrometry (GFAAS) were used for comparison. Samples were prepared using microwave-assisted acid hydrolysis and high-pressure ashing. Both methods yielded residual carbon that leads to an over-estimation of Cr concentrations when using the ICP-MS in standard mode. The DRC however reduced this interference efficiently making accurate and precise measurements of Cr in routine samples possible. The use of the DRC was especially justified for samples that were prepared by microwave-assisted acid hydrolysis because the interference was most pronounced in those samples.