Zn In Milk Research Articles

Effect of Dietary Energy Level during Late Gestation on Mineral Contents in Colostrum, Milk, and Plasma of Lactating Jennies.

This study investigated the effects of dietary energy levels during late gestation on mineral content in the plasma, colostrum, and milk of jennies postpartum. Twenty-four pregnant multiparous DeZhou jennies, aged 6.0 ± 0.1 years, with a body weight of 292 ± 33 kg, an average parity number of 2.7 ± 0.1, and similar expected dates of confinement (74 ± 4 days), were randomly allocated to three groups and fed three diets: high energy (12.54 MJ/kg, HE), medium energy (12.03 MJ/kg, ME), and low energy (11.39 MJ/kg, LE). Blood samples were collected from the jugular vein of each jenny at time points of 0 h, 24 h, 48 h, 5 d, 7 d, and 14 d after parturition. Additionally, milk samples were collected through manual milking, and an analysis of the mineral content was conducted. The results showed that compared with HE, both ME and LE significantly increased the levels of calcium (Ca), phosphorus (P), zinc (Zn), selenium (Se), molybdenum (Mo), and cobalt (Co) in the plasma and Ca, P, magnesium (Mg), copper (Cu), manganese (Mn), Zn, selenium (Se), molybdenum (Mo), and Co in the milk of jennies postpartum (p < 0.05); ME also increased the levels of potassium (K), iron (Fe), and Mn in plasma and K and Fe in milk (p < 0.05). The levels of Ca, K, Mg, P, Fe, Cu, Mn, Co, Se, Zn, and Mo in plasma and milk gradually decreased with increasing postpartum time. Their contents were the highest at 0 h postpartum, rapidly decreased after 24 h postpartum, and declined to the lowest on day 14 postpartum. The interaction between dietary energy level and postpartum time showed that although the concentrations of the minerals Ca, P, K, Mg, Fe, Cu, Mn, Zn, Co, Se, and Mo decreased in jennies' plasma and milk in the treatment groups with different energy levels as postpartum time increased, the pattern of change was also influenced by dietary energy level. The influence of dietary energy level in late gestation on the mineral content of milk and plasma during the postpartum colostrum phase was higher than that during the milk phase. In conclusion, this study demonstrated that, under the current experimental conditions, the mineral content of the colostrum, milk, and plasma of jennies after parturition was dependent on the dietary energy level during late gestation.

Effectiveness of energy dispersive X-ray fluorescence for the quantification of mineral elements in skim milk and whey powders

Milk and whey are subjected to quick deterioration due to bacterial growth. Turning them into powder allows for extended shelf life, easier storage, and more effective transport. Monitoring mineral elements in dairy powders is crucial for both technological and nutritional implications. Current analysis of minerals in food matrices is time consuming and requires high costs and labor. In this view, energy dispersive x-ray fluorescence (ED-XRF) may represent a potential alternative technique to rapidly determine mineral content of food matrices. The present study aimed to investigate the effectiveness of ED-XRF technique for the prediction of Na, Mg, P, S, K, Ca, Cu, and Zn in skim milk and whey powders. Reference analysis for mineral concentration in dairy powders was inductively coupled plasma optical emission spectrometry. The accuracy of ED-XRF for the prediction of mineral elements was assessed on all available samples (global calibration set; n = 23), and after splitting the whole data in a training set (n = 16) and a testing set (n = 7), comprising 70% and 30% of the available samples, respectively. The accuracy of prediction was moderate to low for Na and Mg, whereas robust predictions were obtained for P, S, K, Ca, Cu, and Zn, with coefficients of determination in global calibration from 0.88 to 0.99, and ratios performance to deviation in testing from 2.14 to 24.74. Results suggest that ED-XRF can be considered for accurate prediction of main mineral elements in dairy powders.

The Nutritional Value of Plant Drink against Bovine Milk—Analysis of the Total Concentrations and the Bio-Accessible Fraction of Elements in Cow Milk and Plant-Based Beverages

Four types of non-dairy (plant) drinks—almond, oat, rice, and soy—as well as cow milk with varying fat contents (1.5%, 2.0%, and 3.2%), were examined and compared in terms of the total concentrations of Al, As, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Mn, Ni, P, Pb, Sb, Se, Sr, and Zn using inductively coupled optical emission spectrometry (ICP OES). Additionally, in vitro gastrointestinal digestion was used to determine the bio-accessible fraction of selected elements, evaluating the nutritional value and risk assessment involved with the consumption of these beverages. A significant difference in the mineral profile was observed depending on the type of plant drink, with the highest content of elements noted in the soy drink and the lowest in the rice drink. Except for Ca and P, the soy drink appears to be a much better source of essential nutrients, including Cu, Fe, and Mn, than cow’s milk. A similar Ca content in plant beverages can be obtained only by adding calcium salt at the stage of its production. Interestingly, by using the multivariate data analysis, the average content of the selected elements (Cu, K, Na, P, and Zn) can be used both to differentiate dairy and non-dairy milk samples according to their type and to distinguish plant drinks from milk of animal origin. The bio-accessibility of essential elements (Ca, Cu, Fe, Mg, Mn, P, Zn) in cow milk was within 8.37–98.2% and increased with an increase in its fat content. Accordingly, by drinking 1 L of this milk daily, it is possible to contribute to the recommended dietary intakes of Ca, P, Cu, Mg, and Zn between 5.6–68%. Although the bio-accessibility of elements in the rice drink was the highest (9.0–90.8%), the soy drink seems to be the best source of nutrients in bioavailable forms; its consumption (1 L/day) covers the requirements of Cu, Mn, Mg, Ca, P, and Zn in 7.0–67%. Unfortunately, both groups of beverages are not important sources of Fe (plant drink) and Mn or Fe (cow milk) in the human diet. On the other hand, potentially toxic elements (Al, B, Ba) were found in them in a relatively inert form.

105 Awardee Talk: Timing of Dietary Zinc Supplementation During Gestation did not Affect Trace Element Concentrations in Sows and Their Piglets

Abstract Gestating sows (n = 267) were used to determine if timing of high dietary zinc supplementation in a commercial setting would reduce pre-weaning mortality of pigs and influence maternal and piglet copper (Cu), iron (Fe), and zinc (Zn) concentrations. Sows from three consecutive weekly farrowing groups were assigned randomly within parity to one of three dietary treatments consisting of: 1) Control: a corn-soybean meal diet containing 125 ppm supplemental Zn supplied by zinc hydroxychloride; 2) Breed-to-Farrow (B-to-F): as Control + 141 ppm supplemental Zn as ZnSO4 (266 ppm total supplemental Zn) fed from 5 days after breeding to farrowing; and 3) Day 110-to-Farrow (D110-to-F): as the Control diet fed from breeding to farrowing + 2,715 ppm supplemental Zn as ZnSO4 (2,840 ppm total supplemental Zn) starting on day 110 of gestation until farrowing. A subset of ten sows per treatment (n = 30; average parity = 3) were selected to assess Cu, Fe, and Zn concentrations of serum, colostrum, and milk. Sera were isolated from blood collections at allotment and the day before respective farrowing date of each sow. Colostrum was collected the day of farrowing and milk on day 2 of lactation. At farrowing, two average and two low birth weight pigs from each sow (n = 122) were selected for collections of serum and tail samples at days 1 and 2 of age, respectively. The statistical model included fixed effects of treatment, farrowing group, and the random effect of their interaction. The piglet model was similar but included the random term of pig nested within sow. There were no differences in concentrations of Cu, Fe, and Zn in sow serum, milk, or colostrum attributable to dietary treatment. Piglet serum concentrations of Cu, Fe, and Zn were unaffected by feeding gestating sows high levels of supplemental zinc at any time (Table). Low birth weight pigs born to sows fed the Control diet tended (P = 0.082) to have increased concentrations of Cu in tails compared with pigs born to sows fed high zinc. In conclusion, timing of dietary zinc supplementation to gestating sows had minimal influence on concentrations of important trace elements in sows and their offspring.

CONCENTRATIONS OF CHEMICAL ELEMENTS IN SHEEP MILK FROM THREE FARMS IN SLOVAKIA FROM AREAS WITH DIFFERENT ENVIRONMENTAL BURDEN

Milk is considered as a basic food, highly nutritious, and recommended for everyday consumption during the whole human life. However, due to environmental pollution, milk is not just a source of essential minerals, but potentially can contain heavy metals and trace elements as well which can threaten human health. The study aimed to determine the occurrence of 22 elements: Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, Zn in raw sheep milk collected from areas with different environmental burden in Slovakia. Samples were collected from three farms, one from Orava region (potentially undisturbed area) and two from Spiš region (slightly and heavily disturbed area) during the period of lactation. Analysis of the elements was performed using an inductively coupled plasma-optical emission spectrometry with axial plasma configuration and with auto-sampler SPS-3. Statistical significant differences (P &lt; 0.05) were found in concentrations of following elements: Al, As, Ba, Ca, K, Li, Sr, and Zn. Calcium, potassium, sodium, and magnesium were most represented in samples from all monitored farms. The highest element variation was found in sheep milk samples from the heavily disturbed area. This fact confirmed the quality of monitored areas according to environmental regionalization by The Ministry of the Slovak Republic and the Slovak Environmental Agency. Heavy metals found in the heavily disturbed area do not represent any concerns according to European legislation, except lead, for which the mean concentration represents 0.02 mg/kg. This value was set by EC Regulation no. 1881/2006 and Codex Alimentarius as the level of the permitted limit of concentration of Pb in milk.

English

Camel milk has numerous nutraceutical and therapeutical properties due to camel s desert habitat and grazing habits on wild vegetation. However limited literature was available about the milk composition of camel breeds of south Punjab in Pakistan. The current study aims to depict variations in nutritional aspects of milk among camel breeds of South Punjab Pakistan. The various parameters of milk i.e. physicochemical analysis fatty acids composition protein contents amino acid profiling and mineral concentrations were evaluated and characterized to provide fundamental knowledge to researchers interested in working in its medicinal role. Minerals i.e. Na K Zn and Pb in camel milk were found in considerable concentrations such as 405.94?0.02 204.16?0.10 2.45? 0.02 and 0.25?0.02 ppm accordingly. During physicochemical analysis pH and protein were present in higher amounts. Casein of camel breeds contains higher amounts of amino acids i.e. Leucine (0.25?0.039 %) Lysine (0.12?0.019 %) Aspartic acid (0.18?0.017 %) and Glutamic acid (0.56?0.087 %). Fatty acids were present in significant concentrations in all camel breeds i.e. Butyric acid (0.760?0.012 g/100g) Lauric acid (0.770?0.120 g/100g) Myristic acid (12.420?1.163 g/100g) and Linoleic acid (2.390?0.112 g/100g). Camel milk is less prone to allergies and can be used in dairy-based food products infant milk formulas and medicinal industries.

Determination of Heavy Metals in Cocoa Products Consumed in Nairobi County Kenya

Cocoa is an important cash crop obtained from the beans of the Theobroma cacao tree belonging to the family Malvaceae. Its products are rich in several classes of phenolic compounds such as Flavanols, procyanidins, and anthocyanins. These compounds are attributed to copious health benefits. In addition to the bioactive compounds, cocoa contains heavy metals whose origin and levels depend on natural and anthropogenic activities. Beyond permissible limits, these metals are linked to deleterious damage to several systems in the human body. This study aims to determine the concentration of some heavy metals in Cocoa products and compare the levels with the permissible exposure limits stipulated by international health agencies. This was achieved by wet digestion of the strategically sampled cocoa products and their analysis using the atomic absorption spectrometry technique. The average concentration of Lead (Pb), Copper (Cu), Zinc (Zn), and Manganese (Mn) in cocoa powder was 0.154±0.021, 0.270±0.037, 0.794±0.063, and 0.334±0.015 respectively. The average concentration of Pb, Cu, Zn, and Mn in cocoa butter was 0.329±0.008, 0.028±0.038, 0.116±0.075, and 0.124±0.008 respectively. The average concentration of Pb, Cu, Zn, and Mn in chocolate milk was 0.463±0.003, 0.042±0.066, 0.296±0.015, and 0.162±0.010 respectively. Cadmium levels were below the detection limit in all the samples. The results obtained in all the samples were within the WHO and KEBS permissible levels in food products.

Association of Zn and Cu Levels in Cord Blood and Maternal Milk with Pregnancy Outcomes among the Slovenian Population.

Trace elements, including zinc (Zn) and copper (Cu), are known to play important roles in human health. The present study aimed to assess the levels of Zn and Cu in cord blood and maternal milk and to analyze their association with maternal and infant characteristics and pregnancy outcomes in a Slovenian study population of mothers and their neonates recruited within the PHIME prospective cohort study. The study included 324 mothers, but the data on Zn and Cu levels in both cord blood and maternal milk was available for 243 mothers. Questionnaires were used to assess the socio-demographic and health status of the mothers, their lifestyle habits (including detailed nutritional habits), and their residential and occupational histories. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure Zn and Cu levels in cord blood and maternal milk. Low Zn levels in cord blood were associated with lower gestational age and birth weight and were correlated with an increased probability of the birth of small for gestational age (SGA) infants. Maternal smoking influenced the Cu levels in both cord blood and maternal milk. Cord blood Cu levels were higher and Cu levels in maternal milk were lower in smoking compared to non-smoking mothers. Most importantly, a decreased Zn/Cu ratio in cord blood was associated with lower gestational age and lower birth weight. This indicates the overall positive effects of Zn and negative effects of Cu on pregnancy outcomes.

Macro Minerals and Trace Elements in Milk of Dairy Buffaloes and Cows Reared in Mediterranean Areas

Aim of this study was to evaluate the differences in Ca, P, K, Na, Mg, Zn, Fe, Cu, Mn, Se, Mo, Co, Li, B, Ti, Rb, and Sr concentrations in milk from buffaloes and cows reared in the same farm in Mediterranean areas and fed diets including the same ingredients. Individual milk samples were obtained from 32 Mediterranean buffaloes and 29 Italian Friesian cows and samples of milk, dietary ingredients and drinking water were analyzed for the investigated chemical elements by inductively coupled plasma-mass spectrometry. Data about milk element concentrations were processed by one-way analysis of variance. Buffalo milk contains higher concentrations of Ca, P, Mg, Zn, Fe, Cu, B, Ti, and Sr, and lower concentrations of K, Na, Mo, Li, and Rb compared to cow milk, whereas milk from both species contains similar concentrations of Mn, Se, and Co. The concentrations of the investigated elements in the diet were similar for both species and the differences observed between buffalo and cow milk were not dependent on environmental factors.

Distribution of selected trace elements in the major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Zn, Cu, Mn, Se, Mo, Co, Li, B, Ti, Cr, Rb, Sr, Cd, and Pb in donkey milk and their distribution in major milk fractions (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were provided by 16 clinically healthy lactating donkeys. Subsequent centrifugation, ultracentrifugation, and ultrafiltration were carried out to remove fat, casein, and whey proteins to obtain skim milk, a supernatant whey fraction, and the aqueous phase of milk, respectively. Concentrations of the elements were measured in whole milk and fractions by inductively coupled plasma-mass spectrometry, and the concentrations associated with fat, casein, and whey proteins were then calculated. The effect of removal of fat, casein, and whey proteins was determined by repeated-measures ANOVA. The fat fraction of donkey milk carried a small (∼4.5% to 13.5%) but significant proportion of Mo, Co, Ti, Cr, and Sr. The casein fraction in donkey milk carried almost all milk Zn, a majority of Cu and Mn, and most of Mo, Ti, and Sr. Relevant proportions, between 20% and 36%, of Se, Co, and Cr were also associated with caseins. The majority of Se, Co, Li, B, Cr, and Rb, and relevant proportions of Mn, Mo, Ti, and Sr were found in soluble form (ultracentrifuged samples) and distributed between whey proteins and the aqueous phase of milk (ultrafiltered samples). Whey proteins in donkey milk carried the majority of milk Se and Co. All Li and B was present in the aqueous phase of milk, which also contained most Rb and Cr, and 17% to 42% of Mn, Se, Mo, Co, Ti, and Sr.

Breast-Milk Rubidium and Other Trace Elements are Associated with Neurocognitive Development in Infants at Age of 8 Months

BackgroundTrace elements may affect neurodevelopment. There is a lack of data on breast-milk rubidium (Rb) in relation to neurodevelopment in infants. The associations of copper (Cu), zinc (Zn) and strontium (Sr) with neurodevelopment in infants remain uncertain. ObjectivesWe sought to evaluate the associations of breast-milk Rb (primary exposure), Cu, Zn, and Sr with neurodevelopment in infants at age 8 months. MethodsThe study cohort included 117 breastfed infants. Breast-milk samples were collected at 42 days and 8 months postpartum. Breast-milk Rb, Zn, Cu, and Sr were measured by inductively coupled plasma mass spectrometer. Neurodevelopment was assessed at age 8 months. The primary outcomes were attention and working memory scores, as evaluated by the A-not-B task. Other outcomes included the Mental Development Index (MDI) and Psychomotor Development Index (PDI) as evaluated by the Bayley Scale of Infant Development III. Generalized linear models and restricted cubic spline regression were used to assess the associations between trace elements and neurodevelopment indices. Bonferroni correction was conducted on all data presented. ResultsA nonlinear association was observed between breast-milk Rb at 42 days and infant’s attention at age 8 months (nonlinearity P = 0.037). Positive associations were observed with infant MDI scores and breast-milk Rb at 42 days (β = 4.46; P = 0.06) and 8 months (β = 3.79; P = 0.009) postpartum. Breast-milk Zn at 42 days was positively associated with infant’s attention (β = 0.31; P = 0.039). Sr at 42 days was positively correlated with attention (β = 0.18; P = 0.043) and MDI scores (β = 2.18; P = 0.015) at 8 months. Inverted U-shape associations were observed for breast-milk Cu at 42 days with infant attention and PDI scores. All associations were not significant after correction for multiple tests. ConclusionsOur data suggest that Rb, Zn, Cu, and Sr in breast milk at certain concentrations are associated with neurodevelopment in breastfed infants. Further studies are warranted to validate the findings.

Nitric acid and hydrogen peroxide in the digestion of milk and cheeses for the detection of heavy metals

The content of arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb) and zinc (Zn) in milk and cheeses was determined, comparing the use of nitric acid and a mixture of nitric acid and hydrogen peroxide (HNO3 + H2O2) in acid digestion. The milk was collected from storage tanks in localities of Huejotzingo and cheeses in Santa Ana Xalmimilulco, Huejotzingo, Puebla. Digestion was carried out in a CEM MarsX microwave. The determination was in an ICP OES. As it showed (p &lt;0.01) when using HNO3 (0.13 mg kg-1) with respect to the mixture. The Cd, Zn and Pb showed (p &lt;0.01), with the use of the mixture with respect to HNO3. The content of Cd, As, Cu and Cr in the cheese there was difference (p &lt;0.01) when using HNO3 compared to the mixture. This shows that there is specificity for metal detection, with HNO3 being the most efficient

Extraction Induced by Emulsion Breaking for Ca, Cu, Fe, Mn, Ni, and Zn Determination in Chocolate by Flame Atomic Absorption Spectrometry.

Chocolate is a rich source of essential and non-essential elements. A new liquid-liquid extraction (LLE) approach, extraction induced by emulsion breaking (EIEB), is proposed in which the analyzed elements are transferred from the organic phase to the aqueous phase before measurement by flame atomic absorption spectrometry (FAAS). To compare EIEB to microwave digestion (MWD) for extraction of elements from chocolate prior to FAAS. EIEB parameters were varied to optimize the procedure. EIEB-FAAS was then compared to MWD-FAAS for the analysis of Ca, Cu, Fe, Mn, Ni, and Zn in milk and dark chocolate samples. A certified reference material (NIST 2384, baking chocolate) was analyzed to determine the recoveries of Ca, Cu, Fe, Mn, and Zn by the two methods. The optimized EIEB extraction method involves dilution of tempered chocolate with toluene, ultrasonic emulsification with acidified Triton X-114, breaking the emulsion by heating, and centrifugation to produce two well-defined phases. Analysis of dark and milk chocolate samples showed similar repeatability by EIEB-FAAS (RSDr 0.3 to 6.6% in dark and 0.5 to 8.7% in milk) and MWD-FAAS (RSDr 0.5 to 5.4% in dark and 0.7 to 10.2% in milk), with no significant difference detected between the methods for analysis of Ca, Cu, Fe, Mn, Ni, and Zn based on Student's t-test. Analysis of NIST 2384 baking chocolate certified reference material for Ca, Cu, Fe, Mn, and Zn demonstrated recoveries of 98.6 to 99.5% for EIEB-FAAS compared to 95.8 to 98.6% for MWD-FAAS. EIEB-FAAS was shown to provide high recovery and excellent repeatability for accurate determination of Ca, Cu, Fe, Mn, Ni, and Zn from dark and milk chocolates. The EIEB-FAAS method is simpler and requires fewer reagents compared to other sample preparation methods and allows the calibration to be carried out using aqueous calibration solutions.

ANALYSIS OF CONCENTRATIONS OF RISK AND TOXIC ELEMENTS IN SHEEP MILK FROM AREA OF SLOVAKIA WITH POTENTIALLY UNDISTURBED ENVIRONMENT

Concentration of toxic metals in milk, especially in industrial regions, may serve as a direct bioindicator of the quality of milk, which is an important food in human diet. The aim of this study was to find actual contamination of selected area of Slovakia and to determine the effect of lactation stages on the concentration of risk and toxic elements in sheep´s milk of Tsigai breed. Monitoring of environment was performed by sampling of soil, feed, and milk samples from 400 ewes. Selected elements in feed and milk were detected using the AAS-HG, AES-ICP, AAS-ETA, AAS-AMA, and AAS-F and in soil samples by ICP-OES. Concentrations of toxic elements (As, Hg, Pb, Ni) were found in the soil samples, which corresponded to MRL, and their content was not reflected in the samples of feed and milk of sheep and were below the LOQ. The effect of lactation stage was statistically significant only in case of Ca (P&lt;0.05), where a significant increase in concentration of this element was found throughout the lactation period. A statistically significant increase of concentrations of Se, Mg, Zn and Fe (P&lt;0.05) in sheep milk was recorded only in the late stage of lactation. Pearson´s correlation analysis showed a several very strong and positive correlation relationships in individual lactation stages of sheep. The very low concentrations, below LOQ of selected toxic elements in milk confirmed, that level of contamination of the selected area of Slovakia is very low, and milk from this area of Slovakia is in good hygienic quality and it is safety for direct consumption or for further processing.

A Survey of the Vitamin and Mineral Content in Milk from Yaks Raised at Different Altitudes.

In this study, the content of vitamins and of toxic and beneficial (macro- and micro-) minerals in milk from yaks raised at different altitudes (3,215, 4,340, and 5,410 m) was investigated. For comparison, the components in cow's milk were also measured. At higher altitudes, a significant (P < 0.05) increase in vitamin A and vitamin E was observed in the yak's milk, whereas the opposite was observed for vitamin B1 and vitamin B2. No significant statistical difference in vitamin C, Ca, P, Na, K, and Mg concentrations was observed in milk from yaks raised at different altitudes. The concentrations of Zn in milk from yaks raised at different altitudes showed no statistical difference, whereas the Mn and Fe concentrations in milk from yaks raised at 3,215 m were lower than those raised at higher altitudes. The concentrations of Pb and Cd in yak's milk did not exceed the maximum permissible concentrations (Codex Alimentarius Commission), whereas their concentrations were higher in milk from yaks raised at 3,215 m than at higher altitudes. These findings indicated that the contents of vitamins and minerals in yak milk varied in different altitudes.

Public health implications of heavy metals in foods and drinking water in Ethiopia (2016 to 2020): systematic review

BackgroundBesides their benefits, heavy metals are toxic, persistent, and hazardous to human health, even at their lower concentrations. Consumption of unsafe concentrations of food contaminated with heavy metals may lead to the disruption of numerous biological and biochemical processes in the human body. In developing country including Ethiopia, where untreated or partially treated wastewater is used for agricultural purposes, the problems related to the consumption foods contaminated with heavy metals may poses highest risk to human health. Therefore, this review was aimed to determine the public health implications of heavy metals in foods and drinking water in Ethiopia.MethodsThe articles published from 2016 to 2020 were identified through systematic searches of electronic databases that include MEDLINE/PubMed, EMBASE, CINAH, Google Scholar, WHO, and FAO Libraries. The data was extracted using a predetermined data extraction form using Microsoft Excel, 2016. The methodological quality of the included studies was assessed using mixed methods appraisal tool (MMAT) version 2018 and Joanna Briggs Institute Critical Appraisal tools to determine the relevance of the studies. Finally, the results were evaluated based on the FAO/WHO guidelines for foods and drinking water.ResultsA total of 1019 articles published from 2016 to 2020 were searched from various electronic databases and by manual searching on Google. Following the initial screening, 317 articles were retrieved for evaluation and 49 articles were assessed for eligibility, of which 21 studies were included in the systematic review. The mean concentration of Cr, Cd, Pb, As, Hg, Zn, Cu, Ni, Co, Fe and Mn in fruits and vegetables ranged from 2.068–4.29, 0.86–1.37, 1.90–4.70, 1.01–3.56, 3.43–4.23, 19.18–98.15, 4.39–9.42, 1.037–5.27, 0.19–1.0, 199.5–370.4, 0.26–869 mg/kg, respectively. The mean concentration Cr, Cd, Pb, As, Zn, and Fe in meat and milk ranged from 1.032–2.72, 0.233–0.72, 1.32–3.15, 0.79–2.96, 78.37–467.7, and 505.61–3549.9 mg/kg, respectively. The mean concentration of Cr, Cd, Pb, Zn, and Cu in drinking water ranged 0.0089–0.054, 0.02–0.0237, 0.005–0.369, 0.625–2.137, and 0.176–1.176 ml/L, respectively. The mean concentration of Cr, Cd, Pb, Zn, Cu, Ni, Co, Fe, and Mn in other edible cereals ranged from 0.973–2.165, 0.424–0.55, 0.65–1.70, 70.51–81.58, 14.123–15.98, 1.89–13.8, 1.06–1.59, 67.866–110.3, and 13.686–15.4 mg/kg, respectively.ConclusionThis systematic review identified heavy metals in foods and drinking water and determined their public health implications. The results of this finding imply that the majority of the studies reported high concentrations of toxic heavy metals in foods and drinking water that are hazardous to human health. Therefore, effective food safety and risk-based food quality assessment are essential to protect the public health.

Quantification of zinc concentrations in serum, milk and faeces of dairy cattle as a measure of effective zinc supplementation for management of facial eczema

Aims: To investigate the relationship between Zn concentrations in serum and those in milk or faeces, and to assess the ability of the Zn concentrations in milk, serum and faeces to predict intake of ZnO in dairy cattle. Method Seventy cows from one commercial farm in the Waikato region of New Zealand received one of seven dose rates (0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 g/100 kg bodyweight (BW)) of ZnO given by oral drench, every morning, for 7 consecutive days. Every afternoon, milk and blood samples were collected from all cows. Free-catch faecal samples were collected during the afternoon milking on 3 days throughout the trial. Linear mixed models were used to assess the relationship between the concentration of Zn in serum and that in milk, and in faeces, respectively, and the relationship between dose rate of ZnO and concentrations of Zn in serum, faeces and milk, respectively. Receiver operating characteristic curve analysis was used to determine the ability of the Zn concentration in serum, milk and faeces to predict that a cow had been treated with a dose of ZnO ≥2.5 g/100 kg, the industry-recommended dose rate needed to protect against facial eczema. Results: A 1-µmol/L increase in Zn concentration in milk was associated with a 0.14 (95% CI=0.11–0.17) µmol/L increase in Zn concentration in serum. Zn concentration in faeces was scaled by its SD; a 1 SD increase was associated with a 1.83 (95% CI=0.54–3.12) µmol/L increase in zinc concentration in serum. Zn concentrations in serum and faeces increased with increasing dose rates of ZnO. No differences in Zn concentrations in milk were noted between animals dosed with 1.5–3.5 g ZnO/100 kg BW, inclusive. At the optimal threshold for Zn concentration in serum, 22 µmol/L, the sensitivity was 0.76 (95% CI=0.69–0.82) and specificity 0.85 (95% CI=0.80–0.89). For the concentration of Zn in faeces, the optimal threshold was defined as 17.36 mmol/kg, with a corresponding sensitivity of 0.84 (95% CI=0.84–0.85) and specificity of 0.85 (95% CI=0.73–0.94). At the optimal threshold for the Zn concentration in milk (76.6 µmol/L), the sensitivity was lower than the other two sample types at 0.59 (95% CI=0.52–0.67), but with a similar specificity of 0.84 (95% CI=0.79–0.88). Conclusions and clinical relevance: The concentration of Zn in milk shows promise as an initial screening test to identify dairy farms that do not provide adequate zinc to provide protection against FE.

An observational study on the relationship between zinc concentrations in bulk tank milk and in serum and farmer-reported zinc supplementation of dairy cattle for facial eczema prophylaxis

ABSTRACT Aims To describe the concentration of Zn in bulk tank milk (BTM) in a sample of New Zealand dairy farms, investigate the association between the method of Zn administration for facial eczema prophylaxis and Zn concentrations in BTM and investigate the relationship between the concentration of Zn in serum and that in BTM. Methods Multiple BTM samples (n = 3,330) collected during milk pick-up by the milk tanker driver were stored and tested for 121 farms, in Northland (n = 50), Waikato (n = 51) and Southland (n = 20) from February to May 2017. Enrolled farms provided retrospective information on the type of Zn supplementation (if any) used for the prevention of facial eczema and the timeframe over which supplementation occurred. In addition, the concentration of Zn in serum was measured in blood samples collected from ≥15 cattle per farm for 22 farms from Northland (n = 11) and Waikato (n = 11), and compared against the concentrations of Zn in BTM on the day of blood sampling. A linear mixed model was used to model log Zn concentrations in BTM using method of Zn supplementation, region, milk fat and protein percentage, volume of milk, and frequency of milk pick-up as risk factors. A mixed logistic regression model was used to assess the relationship between Zn concentrations in BTM and the presence of cows with a concentration of Zn in serum of ≥20 µmol/L. Results The median Zn concentration in BTM was 67.9 (min 38.9, max 146.6) µmol/L. The median range of Zn concentrations for repeated samples of BTM within farm was 22.6 µmol/L. In comparison to farms that did not use any form of Zn supplementation, farms that supplemented Zn through a slow-release capsule, oral drench, in feed or a combination of in-feed and water were associated with increased concentrations of Zn in BTM (p < 0.001). There was no difference in Zn concentrations in BTM between farms that administered Zn through the water only and farms that did not administer Zn (p = 0.22). Every 15.3 μmol/L increase in Zn concentration in BTM was associated with 2.2 times (95% CI=1.7–2.9) the odds of a cow having Zn concentration in serum ≥20 μmol/L. Conclusion and clinical relevance Zn concentration in BTM is highly variable between farms, days and Zn administration method. Zn concentration in BTM content has modest potential as a way to signal whether a herd has achieved the high Zn status considered to be protective against FE.

Estimated Absorbed Zinc Intake Is Low in Breastfed 6–11.9 Month Old Infants: Data From the Feeding Infants and Toddlers (FITS) Study, 2016

ObjectivesTo calculate daily absorbed zinc (Zn) intakes, evaluate and rank dietary Zn sources, and assess the percentage of 6–11.9 month old breastfed, mixed fed, and formula fed infants at risk for inadequate absorbed Zn based on their intake and dietary Zn sources. MethodsFITS is a cross-sectional dietary survey of children aged 0–47.9 months in the U.S. For this analysis, Zn absorption factors utilized in the Dietary Reference Intake (DRI) methodology (50% for human milk, 30% for all other sources) were applied to all food sources of Zn in the 24 hour dietary recall for 6–11.9 month old infants (n = 902). The estimated amount of Zn in human milk (0.83μg/ml) and the absorbed Zn requirement for 6–12 month old infants (836μg/day) were based on DRI methodology. Dietary Zn sources were ranked according to contribution to total calculated absorbed Zn. Differences in calculated mean absorbed Zn intakes and the percentage of infants falling below the daily absorbed zinc requirement among breastfed (n = 296), mixed fed (n = 102), and formula fed infants (n = 448) were assessed by unpaired t-tests. ResultsAmong 6–8.9 month old breastfed infants, the mean absorbed Zn (0.58 μg/day) and percentage of infants falling below the daily dietary intake requirement (90.9%) were significantly different than mixed fed, (1.32μg/day and 14.5% below) or formula fed infants (2.17μg/day and 0.1% below, p < 0.0001 for all comparisons). Among 9–11.9 month old infants, the mean absorbed Zn intakes and percentage of infants falling below the daily requirement improved, but remained significantly different across all feeding types (1.00 μg/day and 33.4% of infants below in breastfed, 1.33μg/day and 13.8% below in mixed fed, 2.41μg/day and 0.0% below in formula fed, p < 0.0001 for all comparisons except difference in means for breastfed vs. mixed fed p = 0.0011). The primary sources of calculated absorbed Zn were human milk or infant formula followed by infant cereal and then meat. ConclusionsUsing established factors to account for bioavailability of dietary Zn sources, the majority of breastfed older infants are at risk for inadequate Zn intake, especially during the initial time of introduction of solid foods. Focusing on high Zn containing intake, including meat and fortified cereals may be important to assure adequate Zn intake. Funding SourcesNestlé Research, Switzerland and Nestlé Nutrition, Arlington, VA.

The Effects of a Zinc-Methionine Supplementation in High Producing Dairy Cows

<span style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">The objective of this study was to examine the effects of a Zn-methionine complex in diet on milk yield, milk component yields, SCC, and milk Zn concentration of Holstein cows around peak lactation. After matching for parity and days in milk (DIM), 12 lactating Holstein cows (67 ± 2.5 DIM; 1385 ± 43 kg BW) were assigned to one of two dietary treatments: 1) control (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">CTL</b>, n = 6), a TMR diet with 74 mg/kg added Zn in the form of zinc sulfate, n = 6) or 2) CTL supplemented with Zn-methionine complex (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Zn-Met</b>, n =6) providing additional 20 mg of Zn/kg (512 mg/head/d). Dry matter intake (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">DMI</b>) was lower by 0.8 kg/d for Zn-Met than CTL throughout the study (<i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> =0.05). Milk yield of Zn-Met decreased compared to CTL (40 vs 42 kg/d, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.01) during the first 35 d but had similar milk yield during the last 35 d of the study. Milk protein and fat percentages, and fat yield were not different between treatments. Milk protein yield was similar between treatments during the first 35 d but tended to increase for Zn-Met (1.41 vs. 1.33 kg/d, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i>= 0.10) during rest of the study. Cows receiving Zn-methionine complex tended to have lower SCC (126 vs 328 ×10<sup style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">3</sup> cells/mL, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.07) and greater concentration of Zn (4.48 vs 4.06 ppm, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.05) in milk throughout the study.&nbsp; Overall, the present Zn-methionine complex tended to improve milk protein yield and SCC more prominently as feeding progressed. However, it decreased DMI suggesting a negative impact on palatability of the diet.</span>