Dietary exposure and health risk assessment for 11 minerals and trace elements in Yaoundé: the Cameroonian Total Diet Study

Dietary exposure to 11 elements was assessed by the Total Diet Study (TDS) method. Sixty-four pooled samples representing 96.5% of the diet in Yaoundé, Cameroon, were prepared as consumed before analysis. Consumption data were sourced from a household budget survey. Dietary exposures were compared with nutritional or health-based guidance values (HBGV) and to worldwide TDS results. Elevated prevalence of inadequate intake was estimated for calcium (71.6%), iron (89.7%), magnesium (31.8%), zinc (46.9%) and selenium (87.3%). The percentage of the study population exceeding the tolerable upper intake levels was estimated as <3.2% for calcium, iron, magnesium, zinc and cobalt; 19.1% of the population exceeded the HBGV for sodium. No exceedance of the HBGV for inorganic mercury was predicted in the population. The margin of exposure ranged from 0.91 to 25.0 for inorganic arsenic depending on the reference point. The “Fish” food group was the highest contributor to intake for calcium (65%), cobalt (32%) and selenium (96%). This group was the highest contributor to the exposure to total arsenic (71%) and organic mercury (96%). The “Cereals and cereal products” highly contributed to iron (26%), zinc (26%) and chromium (25%) intakes. The “Tubers and starches” highly contributed to magnesium (39%) and potassium (52%) intakes. This study highlights the dietary deficiency of some essential elements and a low dietary exposure to toxic elements in Yaoundé.     

Dietary exposure to pesticide residues in Yaoundé: the Cameroonian total diet study

Dietary exposure to pesticide residues was assessed in Yaoundé, Cameroon, using the total diet study (TDS) method. Sixty-three composite samples, representative of the foods as consumed in Yaoundé, were collected, prepared, and analysed for residues of pesticides including organochlorine, organophosphorous, and pyrethroids. A multi-residue method was used with a limit of detection (LOD) of 0.005 mg kg(-1). Additional analyses were performed for dithiocarbamates (LOD=0.050 mg kg(-1)), glyphosate (LOD=0.005 mg kg(-1)) and chlordecone (LOD=0.0008 mg kg(-1)) on certain composites samples. The overall contamination was low with 37 out of 46 pesticides below the LOD in all samples. The estimated upper bound (for values less than the LOD equal the LOD; and values less than the LOQ equal the LOQ) of the mean dietary exposures ranged from 0.24% (cypermethrin) to 3.03% (pirimiphos-methyl) of the acceptable daily intakes (ADIs) for pesticides for which at least one analysis was greater than the LOD. This study suggests a low dietary exposure to pesticide residues in Yaoundé.     

Dietary exposure to pesticide residues in Yaoundé: The Cameroonian total diet study

Dietary exposure to pesticide residues was assessed in Yaoundé, Cameroon, using the total diet study (TDS) method. Sixty-three composite samples, representative of the foods as consumed in Yaoundé, were collected, prepared, and analysed for residues of pesticides including organochlorine, organophosphorous, and pyrethroids. A multi-residue method was used with a limit of detection (LOD) of 0.005mgkg^?1. Additional analyses were performed for dithiocarbamates (LOD=0.050mgkg^?1), glyphosate (LOD=0.005mgkg^?1) and chlordecone (LOD=0.0008mgkg^?1) on certain composites samples. The overall contamination was low with 37 out of 46 pesticides below the LOD in all samples. The estimated upper bound (for values less than the LOD equal the LOD; and values less than the LOQ equal the LOQ) of the mean dietary exposures ranged from 0.24% (cypermethrin) to 3.03% (pirimiphos-methyl) of the acceptable daily intakes (ADIs) for pesticides for which at least one analysis was greater than the LOD. This study suggests a low dietary exposure to pesticide residues in Yaoundé.     

Total antioxidant activity and trace elements in human milk: the first 4 months of breast-feeding

The content of many nutrients in breast milk are dependent on the nutritional status of the lactating woman. This is particularly true for fat and water-soluble vitamins, some of which have antioxidant properties. The aim of the study entertained herein was to evaluate the changes in total antioxidant status of human milk during the first 4 months of lactation, and to correlate such changes with the contents in specific antioxidant oligoelements (Cu, Zn, Mn and Se). Milk samples were collected from (31) lactating women recruited at the Service of Obstetrics of the Hospital de São João in Porto, after 1, 4, 8, 12 and 16 weeks after birth. The total antioxidant status (TAS) of human milk was measured by the Randox^® commercial kit and trace metals by ICP-MS (inductively coupled plasma-mass spectrometry). The results found for TAS and oligoelements under study show a decrease in the concentration of these parameters from 7 days to 4 months of breast-feeding and significant correlations (p < 0.05) were found between TAS and Cu, Zn and Se (not Mn). The decreases of Cu, Zn and Se were also correlated, but not proportional between them, suggesting diverse excretion mechanisms for all. Between primipara and multipara women, a significant difference was found only for Cu and Zn concentrations at 7 days of lactation, but not for the other metals or TAS. With respect to the mother’s age, no correlation was found, either for trace metal concentrations or TAS.     

Potential of an in vitro toolbox combined with exposure data as a first step for the risk assessment of dietary chemical contaminants

In vitro risk assessment of dietary contaminants has become a priority in human food safety. This paper proposes an in vitro approach associating different complementary tools in an original toolbox and aims to improve the assessment of the toxicological impact of dietary contaminants at realistic human exposure levels, with a special focus on the intestinal compartment. The system is based on the use of four complementary cellular tools, namely stress gene induction in transgenic strains of Escherichia coli, modulation of the activity of key biotransformation enzymes (cytochrome P-450 (CYP) 1A1 and 3A4) in a human intestinal cell line, and activation of aryl hydrocarbon receptor (AhR) and oestrogenic receptor (ER)-dependent genes in agonistic and antagonistic assays with luciferase reporter cells. It was applied to four chosen model molecules: ochratoxin A (OTA) and deoxynivalenol (DON), two common food-borne mycotoxins, and imazalil (IMA) and benomyl (BEN), two fungicides widely occurring in foodstuffs. All these assays were performed at or around a realistic intestinal concentration, determined through a deterministic approach based on the calculation of a theoretical maximum daily intake (TMDI). Using the four model molecules, it is clearly highlighted that induction of CYP1A1 activity and inhibition of CYP3A4 activity occurred in Caco-2 cells at a realistic intestinal concentration of IMA. Furthermore, some bacterial stress genes were induced in a range of realistic concentrations, following exposure to DON and IMA. In addition, BEN clearly provoked an ER agonistic activity in a human oestrogen sensitive reporter cell line. All these results are in accordance with the literature, suggesting that the in vitro toolbox constitutes an interesting approach in order to obtain a first ‘fingerprint’ of dietary contaminants at realistic human exposure for further risk assessment.     

A review of the current situation of aflatoxin M1 in cow’s milk in Serbia: risk assessment and regulatory aspects

ABSTRACT

The aim of this systematic review is to provide information regarding the incidence and levels of aflatoxin M₁ (AFM₁) in raw and heat processed cow’s milk in Serbia during 2015–16 and to compare these with collected data on the occurrence of AFM₁ in raw milk and dairy products during the last decade in our region. Estimation of dietary exposure (EDI) and hazard index (HI) calculations for different age groups of the population were also carried out, based on the AFM₁ content of milk samples and on available food consumption data in Serbia. AFM₁ was detected in 69.9% (984/1408) of raw milk samples in 2015 versus 84.9% (3094/3646) in 2016, while in heat-processed milk, AFM₁ was detected in 77.8% (364/468) in 2015 versus 98.5% (753/765) in 2016. On the basis of the obtained results, 450 (9%) of raw and 14 (1.1%) of heat-processed milk samples were contaminated with AFM₁ levels above the maximum permitted level in Serbia (0.25 μg kg^?1). However, a large percentage of raw and heat processed milk in Serbia (30.1% and 17.3%, respectively) was contaminated with AFM₁ levels above the maximum permitted level regulated in the European Union (0.05 μg kg^?1). Therefore, in order to protect consumer health, it is extremely important to further control the level of aflatoxins in milk, and this should be considered as a high priority for risk management actions.     

Determination of acrylamide in food using a UPLC–MS/MS method: results of the official control and dietary exposure assessment in Cyprus

ABSTRACT

The determination of acrylamide in potato products, bakery products and coffee, and the human dietary exposure is reported. The method reported is based on a single extraction step with water, followed by the clean-up of the extract using solid phase extraction columns and finally, the determination of acrylamide using UPLC–MS/MS. The MS/MS detection was carried out using an ESI interface in positive ion mode. Internal calibration was used for the quantification of acrylamide, because of the suppression/enhancement matrix effects due to the complex nature of the samples. The method performance characteristics were determined after spiking blank samples. The mean recoveries in spiked coffee samples, potato chips, breakfast cereals and crispbread ranged from 93% to 99%, with RSDs lower than 5% for both repeatability and reproducibility conditions. The estimated limits of detection and quantification of the method were 10 and 32 μg kg^?1, respectively. The method was used for monitoring acrylamide in 406 samples. Acrylamide amounts ranged from <32 to 2450 μg kg^?1. A total of 360 samples (89%) were contaminated with acrylamide, but only 14% of the samples exceeded the benchmark levels of the EU legislation. Foods with the highest mean acrylamide amounts were potato crisps (642 μg kg^?1), French fries (383 μg kg^?1) and biscuits (353 μg kg^?1). The mean and 95th percentile acrylamide exposures of adolescents in Cyprus were 0.8 and 1.8 μg kg^?1 body weight per day, respectively. The estimated levels of dietary exposure to acrylamide are not of concern with respect to neurotoxicity. However, the margins of exposure (MOEs) indicate a concern for carcinogenicity. Potato fried products (45%), fine bakery ware (21%) and potato chips (14%) contributed the most to overall acrylamide exposure.     

Liking for foods high in salt and fat is associated with a lower diet quality but liking for foods high in sugar is not – Results from the PREDISE study

The research aimed at examining how liking for foods high in salt and fat and for foods high in sugar are associated with overall diet quality and how these associations differ according to individual characteristics (i.e., sex, age, education, income, nutrition knowledge, and energy reporting status) in French-speaking adults from the Province of Quebec, Canada. As part of the web-based cross-sectional PREDISE study, 1096 men and women completed online questionnaires. The Food Liking Questionnaire assessed reported liking for a variety of salty foods (high in salt and fat) and sweet foods (high in sugar and either high-fat or low-fat) on a scale from 1 to 9. The Canadian Healthy Eating Index (C-HEI) was computed based on data collected using 24-hour food recalls. Women (vs. men) reported lower liking for salty foods (5.97 ± 1.34 vs. 6.58 ± 1.16, p < 0.0001) and for sweet foods (5.52 ± 1.36 vs. 5.71 ± 1.25, p = 0.015). Multiple linear regressions showed that liking for sweet foods was not associated with C-HEI (B = −0.10, p = 0.78). Given a significant sex interaction in the association between liking for salty foods and C-HEI (p interaction = 0.0218), subsequent analyses were stratified by sex. Multiple linear regressions supported that liking for salty foods was more strongly inversely associated with C-HEI in men (B = −3.37, p < 0.0001) than women (B = −1.46, p = 0.0035). In conclusion, a strong liking for salty foods may interfere with healthy eating, especially in men. Building on these results, future studies should investigate the potential of interventions designed to improve the healthiness of food habits in individuals with strong liking for these foods.     

Microprobe techniques for speciation analysis and geochemical characterization of mine environments: the mercury district of Almadén in Spain

Metallurgic calcines with very high mercury and methylmercury content from the Almadén mining district were analyzed by synchrotron-based microprobe techniques. Information about mercury speciation was obtained by micro-EXAFS (microscopic extended X-ray absorption fine structure) spectroscopy, whereas elemental associations were evaluated by micro-XRF (microscopic X-ray fluorescence analysis) mapping. Complementary characterization methodologies, including X-ray diffraction (XRD), inductively coupled plasma-optical spectroscopy (ICP-OES), as well as a sequential extraction scheme (SES), were used to predict the potential availability of mercury. Analysis of total metal content revealed extremely high concentrations of mercury and iron (between 7 and 35 and 65-70 g kg(-1), respectively) and high zinc concentrations (2.2-2.5 g kg(-1)), whereas other metals such as copper, nickel, and lead were found at low concentration levels (30-300 mg kg(-1)). Micro-EXAFS results indicate that cinnabar (HgS(red)) is one of the main species within the studied mercury-rich particles (5-89% of total mercury content), together with more soluble mercury compounds such as Hg3(SO4)02 (schuetteite) and HgO (5-55% of total mercury content). Additionally, element-specific micro-XRF maps of selected mercury-rich particles in the studied samples revealed an evident correlation among Hg-Pb-Ni (and S), indicating a possible geochemical linkage of these elements. Correlations were also found among Fe-Mn and Hg, which have been attributed to sorption of mercury onto oxyhydroxides of Fe and Mn. This finding was supported by results from a sequential extraction scheme, where a significant     

A comparative study of physicochemical and conformational properties in three vicilins from Phaseolus legumes: Implications for the structure–function relationship

The polypeptide constituents, physicochemical and conformational properties of three vicilins from kidney, red and mung beans, fractionated using combined acid extraction and ion-exchange chromatographic techniques, were characterized and compared. The tested physicochemical and conformational properties included amino acid composition, surface charge and hydrophobicity, protein solubility (PS; as a function of pH), emulsifying activity index (EAI) and emulsion stability index (ESI), as well as secondary, tertiary and/or quaternary conformations. The amino acid composition (especially relative acidic/basic charged amino acid ratio, and the percentage of polar uncharged amino acids) was an intrinsic physicochemical parameter that largely determined other physicochemical and conformational properties. The PS and EAI (and ESI) of these vicilins at various pH values were associated with each other, and both were closely related to their surface charge and/or hydrophobicity. Far-UV CD spectral analyses indicated that these vicilins exhibited similar secondary structure compositions at pH deviating from the isoelectric point (about pH 4.5). However, their tertiary and/or quaternary conformations, as determined by differential scanning calorimetry, intrinsic fluorescence and near-UV CD spectroscopy, remarkably varied. At pH 7.0 or 9.0, there were close relationships between the EAI and the flexibility in quaternary conformation, and between the ESI and the flexibility in tertiary conformation. This is the first observation to elucidate the importance of tertiary and/or quaternary conformations for the emulsifying properties of legume vicilins. Additionally, an underlying mechanism of the emulsification process for the vicilins (trimeric form) with excellent emulsifying properties was proposed.     

Granulomorphometry: a suitable tool for identifying hydrophobic and disulfide bonds in β-lactoglobulin aggregates. Application to the study of β-lactoglobulin aggregation mechanism between 70 and 95°C

This work deals with the investigation of β-lactoglobulin (β-LG) aggregation by granulomorphometry. In the first part of this study, we showed that the binding interactions involved in aggregate structure could be identified by their appearance in granulomorphometric pictures. The reliability of this analytical approach was demonstrated by comparing the appearance of β-LG aggregates in the presence and absence of a thiol-blocking agent (N-ethylmaleimide). The translucency of the aggregates was associated with hydrophobic interactions and their opacity was associated with disulfide bonds. We state, based on the morphology of the aggregates, along with the color of protein aggregates and insoluble materials, that hydrophobic interactions had a better water-holding capacity than disulfide bonds. Additionally, our results suggest that disulfide and hydrophobic bonds compete for β-LG aggregate shaping. In the second part of this work, interesting features of granulomorphometry useful for identifying aggregate binding interactions were highlighted to clarify the effect of temperature on the aggregation mechanisms occurring in a β-LG concentrate with a moderate calcium content (6.6mmol·L(-1)). Heat treatment experiments were performed between 70 and 95°C, and granulomorphometric measurements (aggregate size, aggregate number, and gray level of the picture) were conducted at different sampling times up to 4h. Results, which were interpreted in light of calculated β-LG denaturation levels, revealed that the aggregation mechanism could be split into 2 steps. Initially, β-LG denatured quickly, leading to fast β-LG aggregation by disulfide bonds. The denaturation rate then declined, which drastically slowed the disulfide aggregation mechanism. From that point on, a second aggregation path became preponderant. It consisted of the agglomeration of small aggregates by hydrophobic interactions and resulted in the formation of large aggregates containing both interaction types. This second aggregation mechanism was clearly favored at high temperatures because it was not detected in our experiments at temperatures below 85°C.     

Short communication: Genetic parameters for milk protein composition predicted using mid-infrared spectroscopy in the French Montbéliarde,Normande, and Holstein dairy cattle breeds

Genetic parameters for the major milk proteins were estimated in the 3 main French dairy cattle breeds (i.e. Montbéliarde, Normande, and Holstein) as part of the PhénoFinlait program. The 6 major milk protein contents as well as the total protein content (PC) were estimated from mid-infrared spectrometry on 133,592 test-day milk samples from 20,434 cows in first lactation. Lactation means, expressed as a percentage of milk (protein contents) or of protein (protein fractions), were analyzed with an animal mixed model including fixed environmental effects (herd, year × month of calving, and spectrometer) and a random genetic effect. Genetic parameter estimates were very consistent across breeds. Heritability estimates (h²) were generally higher for protein fractions than for protein contents. They were moderate to high for α_S1-casein, α_S2-casein, β-casein, κ-casein, and α-lactalbumin (0.25 < h² < 0.72). In each breed, β-lactoglobulin was the most heritable trait (0.61 < h² < 0.86). Genetic correlations (r_g) varied depending on how the percentage was expressed. The PC was strongly positively correlated with protein contents but almost genetically independent from protein fractions. Protein fractions were generally in opposition, except between κ-casein and α-lactalbumin (0.39 < r_g < 0.46) and κ-casein and α_S2-casein (0.36 < r_g < 0.49). Between protein contents, r_g estimates were positive, with highest values found between caseins (0.83 < r_g < 0.98). In the 3 breeds, β-lactoglobulin was negatively correlated with caseins (?0.75 < r_g < ?0.08), in particular with κ-casein (?0.75 < r_g < ?0.55). These results, obtained from a large panel of cows of the 3 main French dairy cattle breeds, show that routinely collected mid-infrared spectra could be used to modify milk protein composition by selection.