Ettore Coni

The Assessment of Reference Values for Elements in Human Biological Tissues and Fluids: A Systematic Review

Abstract A survey is presented of the rationale of and the operative procedures for the assessment of reference values of minor and trace elements in human blood (whether entire, plasma, or serum), urine, milk, hair, kidneys, liver, and lungs. Literature sources available on this subject matter have been scanned over the past 30 years and reference values have been critically and selectively reported. The need for further harmonization of strategies and better comparability of experimental data is emphasized.

Protective effect of oleuropein, an olive oil biophenol, on low density lipoprotein oxidizability in rabbits

On the basis of the results obtained with pilot studies conducted in vitro on human low density lipoprotein (LDL) and on cell cultures (Caco-2), which had indicated the ability of certain molecules present in olive oil to inhibit prooxidative processes, an in vivo study was made of laboratory rabbits fed special diets. Three different diets were prepared: a standard diet for rabbits (diet A), a standard diet for rabbits modified by the addition of 10% (w/w) extra virgin olive oil (diet B), a modified standard diet for rabbits (diet C) differing from diet B only in the addition of 7 mg kg−1 of oleuropein. A series of biochemical parameters was therefore identified, both in the rabbit plasma and the related isolated LDL, before and after Cu-induced oxidation. The following, in particular, were selected: (i) biophenols, vitamins E and C, uric acid, and total, free, and ester cholesterol in the plasma; (ii) proteins, triglycerides, phospholipids, and total, free, and ester cholesterol in the native LDL (for the latter, the dimensions were also measured); (iii) lipid hydroperoxides, aldehydes, conjugated dienes, and relative electrophoretic mobility (REM) in the oxidized LDL (ox-LDL). In an attempt to summarize the results obtained, it can be said that this investigation has not only verified the antioxidant efficacy of extra virgin olive oil biophenols and, in particular, of oleuropein, but has also revealed a series of thus far unknown effects of the latter on the plasmatic lipid situation. In fact, the addition of oleuropein in diet C increased the ability of LDL to resist oxidation (less conjugated diene formation) and, at the same time, reduced the plasmatic levels of total, free, and ester cholesterol (−15, −12, and −17%, respectively), giving rise to a redistribution of the lipidic components of LDL (greater phospholipid and cholesterol amounts) with an indirect effect on their dimesions (bigger by about 12%).

Minor and trace element content in sheep and goat milk and dairy products

Abstract The concentration ranges of certain health-related elements in milk and cheese are closely dependent upon animal species and feeding, time of year of sample collection, environmental conditions and manufacturing processes. The present study deals with the assessment of selected trace elements such as AI, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Pt, Sr and Zn in sheep and goat milk as well as in typical cheese, and concludes a series of studies previously carried out on cows milk and related products. Samples of milk, curd and cheese following salting and after ripening for 1, 4 and 8 weeks were analysed. Quantitative determinations were performed mainly by inductively coupled plasma atomic emission spectrometry. The results obtained show considerable differences among the trace element contents of sheep and goat milk and related products. Furthermore, significant differences were also found when comparing the present data on sheep and goat milk with those previously obtained for cows milk. This sheds further light on the influence of animal species, feeding characteristics and environmental conditions on the distribution of trace elements in dairy products.

Preliminary evaluation of the factors influencing the trace element content of milk and dairy products

Abstract As part of an overall monitoring programme launched by the Istituto Superiore di Sanita (Italian National Institute of Health) within the framework of the RAISA (Advanced Researches for the Innovation of Agricultural Systems) project supported by the National Research Council, an investigation was undertaken with the following goals: (i) assessment of the content of selected trace elements such as Al, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Pt, Sr and Zn in raw cows milk and cheese; (ii) identification of possible correlations between animal feeding, year period of sample collection, environmental conditions and levels of elements in raw cows milk; and (iii) evaluation of the influence of the manufacturing process on the concentration ranges of certain health-related elements in milk products. Quantitative determinations were carried out mainly by inductively coupled plasma atomic emission spectrometry. The results obtained show considerable differences among the levels of trace elements in raw milk samples collected during different periods of the same year. Furthermore, differences occur also among the trace element contents of raw milk and related products. All this provides evidence that animal feeding, year period of sample collection, environmental conditions and manufacturing processes all play a key role in the distribution of trace elements.

Effects of dietary virgin olive oil phenols on low density lipoprotein oxidation in hyperlipidemic patients.

The aim of this study was to assess the effects of the dietary intake of extra virgin olive oil on the oxidative susceptibility of low density lipoproteins (LDL) isolated from the plasma of hyperlipidemic patients. Ten patients with combined hyperlipidemia (mean plasma cholesterol 281 mg/dL, triglycerides 283 mg/dL) consumed a low-fat, low-cholesterol diet, with olive oil (20 g/d) as the only added fat, with no drug or vitamin supplementation for 6 wk. Then they were asked to replace the olive oil they usually consumed with extra virgin olive oil for 4 wk. LDL were isolated at the beginning, and after the 4 wk of dietary treatment. LDL susceptibility to CuSO4-mediated oxidation was evaluated by measuring the extent of lipid peroxidation. We also determined fatty acid composition and vitamin E in plasma and LDL and plasma phenolic content. Extra virgin olive oil intake did not affect fatty acid composition of LDL but significantly reduced the copper-induced formation of LDL hydroperoxides and lipoperoxidation end products as well as the depletion of LDL linoleic and arachidonic acid. A significant increase in the lag phase of conjugated diene formation was observed after dietary treatment. These differences are statistically correlated with the increase in plasma phenolic content observed at the end of the treatment with extra virgin olive oil; they are not correlated with LDL fatty acid composition or vitamin E content, which both remained unmodified after the added fat change. This report suggests that the daily intake of extra virgin olive oil in hyperlipidemic patients could reduce the susceptibility of LDL to oxidation, not only because of its high monounsaturated fatty acid content but probably also because of the antioxidative activity of its phenolic compounds.

Bioaccumulation Potential of Dietary Arsenic, Cadmium, Lead, Mercury, and Selenium in Organs and Tissues of Rainbow Trout (Oncorhyncus mykiss) as a Function of Fish Growth

The distribution and potential bioaccumulation of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss Walbaum, 1792), a major aquaculture species, was studied in relation to fish growth over a period of >3 years. Fish were reared under normal farming conditions, that is, fed a standard fish food and exposed to negligible levels of waterborne trace elements. The age-related variations in the content of each trace element in gills, kidney, liver, muscle, and skin were studied through nonparametric regression analysis. A buildup of all elements in all tissues and organs was observed, but due to dilution with growth, the concentrations did not increase, except in a few cases such as cadmium and mercury in liver and kidney. In muscle tissue, the concentrations of mercury, lead, and selenium did not alter significantly with growth, whereas cadmium increased but remained at exceedingly low levels. The concentration of arsenic in muscle tissue peaked at 14 months and then decreased in adult specimens. Arsenic speciation by high-performance liquid chromatography--inductively coupled plasma mass spectrometry revealed that arsenic in muscle was almost exclusively present in the form of nontoxic arsenobetaine. Application of a mercury mass balance model gave predicted concentrations in agreement with measured ones and showed that in farmed rainbow trout the ratio of mercury concentrations in feed and in fish is about 1:1. Therefore, rainbow trout does not approach the limits established for human consumption even when reared with feed at the maximum permitted levels. These findings highlight the low bioaccumulation potential of toxic trace elements such as cadmium, lead, and mercury in rainbow trout following dietary exposure. On the other hand, selenium concentrations in muscle (about 0.2 microg g (-1) of fresh weight) show that rainbow trout may be a good source of this essential element.

Detection of animal fats in butter by differential scanning calorimetry: A pilot study

Because of its high price, butter has always been the object of adulteration by addition of less expensive vegetable or animal fats. Although a number of methods have been proposed for the detection of butterfat adulteration, none has found widespread use. For this reason, a study was conduced to assess the use of differential scanning calorimetry (DSC) for detecting the presence of added animal fat, i.e., chicken fat, in butter. The results obtained show that DSC is an efficient method for characterizing pure animal fats as well as their mixtures. Furthermore, the accuracy with which data are obtained, in combination with the sensitivity of DSC to subtle changes in chemical composition of the sample, makes DSC an attractive possibility for development as a quality control procedure.

A methodological approach to the assessment of trace elements in milk and dairy products

Abstract A detailed protocol was applied to the study and quantification of Al, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Pt, Sr and Zn in raw cows milk and dairy products. The investigation was prompted by the paucity of data available on minor and trace elements in such matrices, despite their importance in nutrition or in food contamination. As a part of an overall monitoring programme, a study was thus undertaken with the following goals: (i) actual measurement of the concentration of the aforesaid elements in milk and related products; (ii) identification of possible correlations between animal feeding, time of year of sample collection, environmental condition and levels of elements in raw cows milk; and (iii) evaluation of the influence of the manufacturing process on the concentration ranges of certain health-related elements in milk products. Quantitative determinations were carried out by means of inductively-coupled plasma atomic emission spectrometry (ICP-AES). The results obtained show considerable differences among the levels of trace elements in raw milk and those in derived products. This provides evidence of the fact that manufacturing processes play a key role in the distribution of trace elements.

Analytical approach to obtaining reference values for minor and trace elements in human milk

An investigation was undertaken in order to assess reference values for various minor and trace elements in human milk of urban and rural population groups, sub-divided in their turn into smokers and non-smokers. Eligibility criteria were defined and strictly adhered to. An over-all strategy was worked out to guarantee reliability and representativity of experimental data, in particular by minimising all possible sources of chemical contamination or loss. The study was carried out mainly by means of inductively coupled plasma atomic emission spectrometry given its inherent multi-elemental nature. For a total of 59 subjects the following median values were obtained (µg g–1): Al, 0.161; Ba, 0.026; Cd, 0.002; Cd, 0.019; Cu, 0.387; Fe, 0.661; Li, 0.004; Mg, 29.41; Mn, 0.006; Ni, 0.032; Pb, 0.014; and Zn, 3.29. Possible correlations with specific living conditions of subjects were also attempted.

Identification of chemical species of some trace and minor elements in mature breast milk

The chemical speciation of trace elements of environmental, toxicological, clinical and nutritional interest was undertaken in breast milk, with the goal of ascertaining the chemical forms of Ba, Bi, Cd, Cu, Li, Mg, Mn, Mo, Pb, Sr, Tl and Zn. At the same time, the analytical potential of size-exclusion chromatography (SEC) coupled with quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) for the purpose of chemical speciation was further explored. Breast mature milk from 30 mothers living in Turin (Italy) and its surroundings was analyzed. Total element concentrations obtained in this study were similar to those reported for human milk in other countries. As regards speciation data, these pointed to the presence in human milk of specific ligands, such as enzymes and citrates, with strong affinity for some elements, presumably increasing the bioavailability of the elements themselves. The experimental approach and the analytical method developed in this study appear adequate for the purpose and can therefore be exploited for similar investigations.