Prebiotics and the Bioavailability of Minerals and Trace Elements

Promising evidence exists for a stimulatory influence of prebiotic carbohydrates (non-digestible oligosaccharides (NDO) and lactulose) on the bioavailability of minerals and trace elements, although most information is available from rat experiments. Because the number of human studies is limited, additional research is needed, especially studies that focus on the long-term effects of prebiotics on bone metabolism. The hypothesized mechanisms suggest that prebiotics that result in a strong pH reduction, a pronounced osmotic effect, a stimulation of the exchange of protons, an increased level of butyrate and calbindin, and an enlarged surface area in the colon may be promising candidates for increasing the absorption of minerals and trace elements. Because the place of colonic fermentation seems to be of influence in these mechanisms, the use of mixtures of different types of prebiotics is of special interest. Probiotics are involved in most prebiotic-related mechanisms, possibly mediated in part by the production of polyamines. Therefore, the combined use of pre- and probiotics may yield promising results. More detailed information on the present state-of-the-art concerning the effects of prebiotics on the bioavailability of minerals and trace elements in different life stages, discussed by study design and its underlying mechanisms, can be found in this review.     

Prebiotics and the Bioavailability of Minerals and Trace Elements

Abstract

Promising evidence exists for a stimulatory influence of prebiotic carbohydrates (non‐digestible oligosaccharides (NDO) and lactulose) on the bioavailability of minerals and trace elements, although most information is available from rat experiments. Because the number of human studies is limited, additional research is needed, especially studies that focus on the long‐term effects of prebiotics on bone metabolism. The hypothesized mechanisms suggest that prebiotics that result in a strong pH reduction, a pronounced osmotic effect, a stimulation of the exchange of protons, an increased level of butyrate and calbindin, and an enlarged surface area in the colon may be promising candidates for increasing the absorption of minerals and trace elements. Because the place of colonic fermentation seems to be of influence in these mechanisms, the use of mixtures of different types of prebiotics is of special interest. Probiotics are involved in most prebiotic‐related mechanisms, possibly mediated in part by the production of polyamines. Therefore, the combined use of pre‐ and probiotics may yield promising results. More detailed information on the present state‐of‐the‐art concerning the effects of prebiotics on the bioavailability of minerals and trace elements in different life stages, discussed by study design and its underlying mechanisms, can be found in this review.     

Essential and trace elements content of commercial infant foods in the UK

There is a paucity of data in respect of the nutritional quality of complementary foods for infants and young children aged between 6 and 12 months. The primary objective of this study was to examine nutritive values of such complementary infant food on the UK market in order to ascertain their suitability relative to dietary guidelines for the 6–9 months age group. Quantitative analyses were conducted on eight different products representing four popular brands (meat and vegetable based) currently on sale in the UK. Eight major mineral and trace elements, namely: calcium, copper, magnesium, iron, zinc, potassium, sodium and selenium were measured by ICP–OES and ICP–MS. The results of these studies were referenced to the Recommended Nutrient Intake (RNI) values for 6–9 months old children, and a menu of entire daily intake of minerals and trace elements was composed taking into consideration the nutrient and energy intake from milk consumption. Based on these comparisons, all the food samples studied in this work contained less essential minerals than expected from the RNI values except for potassium in meat and vegetable based recipes. These results suggest that commercial complementary infant foods on the UK market may not contain the minimum levels of minerals required for the labelling declaration of micronutrient content (Commission Directive 2006/125/EC). This provides opportunities and scope for product optimisation to improve their nutritive value.     

Trace element deficiencies and fertility in ruminants: a review.

Various minerals (copper, cobalt, selenium, manganese, iodine, zinc, and iron) can influence reproductive performance of ruminants. Reproductive failure may be induced by deficiencies of single or combined trace elements and by imbalances. This review is focused on maladjustments of trace elements leading to impaired breeding performance. Opinion is diverse as to the existence of various reproductive disturbances from either a severe copper depletion or a marginal dietary copper deficiency. Field experience suggests that administration of cobalt to ruminants on cobalt-deficient diets improves their impaired breeding performance. Selenium infertility in ewes is more prevalent in some areas and in some seasons, but the actual cause of this malady and the continuing role of additional factors are unknown. Manganese is necessary for normal fertility in ruminants, and feeding low-manganese rations depresses conception rates. Lack of iodine impairs thyroid activity and also ovarian function. Reproductive failure in the female and in spermatogenesis are manifestations of zinc deficiency. Despite forages rich in iron, low availability in certain instances could affect adversely ruminant reproduction. Knowledge of biochemical dysfunctions from trace element deficiencies is essential to determine the role which trace elements play in fertility of ruminant animals.     

硒的生理学功能及富硒强化食品的研究进展

硒是人体必需的微量元素之一,本文综述了元素硒对人体的重要生理功能、硒缺乏症与硒中毒、硒的推荐摄入量及富硒食品的开发现状,并指出了膳食硒的研究方向。     

Physicochemical Properties,Minerals, Trace Elements,and Heavy Metals in Honey of Different Origins: A Comprehensive Review

Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.     

Effect of casein phosphopeptides on bioavailability of the alimentary minerals

Caseinophosphopeptides (CPPs) are phosphorylated casein-derived peptides which possess the ability to bind and solubilise minerals, such as Ca2+. The high bioavailability of Ca2+ fram milk and dairy products has been attributed to the production of CPPs which are produced following digestion of casein by the action of gastrointestinal proteinases. CPPs, which appear to be resistant to extensive proteolytic degradation, accumulate in the distal small intestine where they are purported to play a role in enhancing the passive absorption of Ca2+ and other trace elements. A recent human feeding tral reported improved Ca2+ and Zn2+ absorption following CPPs incorporation into food. This review summarises the production, characterization and potential applications of CPPs.     

Mineral and trace element concentrations in cultivars of tomatoes

The concentrations of minerals (P, Na, K, Ca and Mg) and trace elements (Fe, Cu, Zn and Mn) were determined in 167 tomato samples belonging to five cultivars (Dorothy, Boludo, Dunkan, Dominique and Thomas) produced on the island of Tenerife. The contribution to the intake of minerals and trace elements was in general low, with special emphasis on the contributions of K and Mg. The cultivar, cultivation method, period of sampling and region of production in the island influenced the concentrations of minerals and trace elements of the tomatoes. Trace elements seemed more influenced by the cultivar than the minerals, and the cultivation method affected mineral contents more than trace element contents. The period of sampling had an important influence on the mineral and trace elements. Many correlations were observed between the minerals and trace elements studied. Applying discriminant analysis, the tomato samples tended to be classified according to the cultivation method, period of sampling and region of cultivation.     

Invited review: formation of keratins in the bovine claw: roles of hormones, minerals, and vitamins in functional claw integrity

Keratins are the characteristic structural proteins of the highly cornified epidermis of the skin, feathers, and hoof. Keratin proteins provide the structural basis for the unique properties of the biomaterial horn and its protective function against a wide range of environmental factors. Hoof horn is produced through a complex process of differentiation (keratinization) of epidermal cells. Formation and biochemical binding of keratin proteins and synthesis and exocytosis of intercellular cementing substance (ICS) are the hallmarks of keratinization. It is finalized by the programmed death of the living epidermal cells, i.e., cornification, that turns the living epidermal cells into dead horn cells. The latter become connected by the intercellular cementing substance. The functional integrity of hoof horn essentially depends on a proper differentiation, i.e., keratinization of hoof epidermal cells. Keratinization of hoof epidermis is controlled and modulated by a variety of bioactive molecules and hormones. This process is dependent on an appropriate supply of nutrients, including vitamins, minerals, and trace elements. Regulation and control of differentiation and nutrient flow to the epidermal cells play a central role in determining the quality and, consequently, the functional integrity of hoof horn. Decreasing nutrient supply to keratinizing epidermal cells leads to horn production of inferior quality and increased susceptibility to chemical, physical, or microbial damage from the environment. A growing body of evidence suggests that hormones, vitamins, minerals, and trace elements play critical roles in the normal development of claw horn and correct keratin formation.     

乌龙茶中的微量元素及其检测技术研究进展

乌龙茶不仅具有保健功效,还具有一定的药理功能,这与其含有丰富的生化成分与微量元素有着十分重要的关系。近年来,微量元素与人体健康的关系成为了人们关注的热点之一。本文综述了微量元素对于人体健康的影响,乌龙茶干茶和茶汤中微量元素含量的研究概况及其对人体健康的影响,以及原子吸收光谱、电感耦合等离子体质谱法、电感耦合等离子体原子发射光谱法3种测定乌龙茶中微量元素的方法。通过比较,3种方法都有各自的优点和缺陷,在选择测定乌龙茶中微量元素含量的方法时,最好多种方法结合使用,以提高测定效率及测定的精确度。通过对乌龙茶中微量元素含量及测定方法的综述,以期为研究乌龙茶中微量元素含量的方法提供参考,为建立更加合适的茶叶中微量元素营养价值评价体系提供参考。     

Effect of cooking time on the quality, minerals and vitamins of spaghetti produced from two Italian durum wheat varieties

Spaghetti was made from two Italian durum wheat varieties and cooked for 10, 15 and 20 min. Percentages of water absorption and cooking loss were determined. Measurable amounts of soluble nitrogen, starch, minerals and vitamins were found in the water used for cooking.
Minerals and vitamins were determined in cooked spaghetti. The percentage reduction of metals increased with increasing cooking time, but trace elements decreased after 10 min of cooking and then became stable at the longer times. It is preferable to cook spaghetti for 15 min.     

Mineral and trace element content of various vegetarian foodstuffs available in Belgium

 Atomic absorption spectrometry was used to determine mineral (Na, K, Ca and Mg) and trace element content (Zn, Fe, Cu and Si) of various vegetarian foodstuffs in Belgium. Thirty-five commercially available products were analysed after a wet-acid destruction in a closed-vessel destruction bomb. Various important sources of the minerals and trace elements were identified. Since data for vegetarian foods in Belgium are non-existent, the concentration values are compared with the scarce literature data and particularly with levels found in the same products available in The Netherlands. Received: 2 June 1998 / Revised version: 5 October 1998     

NaFeEDTA的络合作用对体内营养素吸收代谢的影响

介绍了铁营养强化剂NaFeEDTA的化学结构和理化特性,以及它在体内吸收代谢的途径和产物。综述了国内外对NaFeEDTA是否影响体内金属离子吸收代谢的研究进展,分析了NaFeEDTA的络合作用是否影响体内营养物质的吸收代谢,并从多个层面上指出发生该负面影响发生的可能性很小,可见在现有研究水平下NaFeEDTA是一种安全有效的铁营养强化剂。     

NaFeEDTA的络合作用对体内营养素吸收代谢的影响

本文介绍了铁营养强化剂NaFeEDTA的化学结构和理化特性，以及它在体内吸收代谢的途径和产物，综述了国内外对NaFeEDTA是否影响体内金属离子吸收代谢的研究进展，分析了NaFeEDTA的络合作用是否影响体内营养物质的吸收代谢，并从多个层面上指出发生该负面影响的可能性很小，可见在现有研究水平下NaFeEDTA是一种安全有效的铁营养强化剂。     

Minerals in whey and whey fractions

Liquid and dried acid and sweet wheys and the concentrates and permeates obtained from ultrafiltration of whey were analyzed for major and trace minerals. Calcium, magnesium, sodium, and potassium were determined by atomic absorption and phosphorus by a colorimetric method. Zinc, iron, copper, and manganese were determined by flameless atomic absorption. The composition of all wheys and their fractions differed in nutritionally important minerals. Calcium was three times as great and zinc twenty times as great in acid whey as in sweet whey.     

Effect of source of trace minerals in either forage- or by-product–based diets fed to dairy cows: 2. Apparent absorption and retention of minerals

Eighteen multiparous cows were used in a split-plot replicated Latin square with two 28-d periods to evaluate the effects of source of supplemental Cu, Zn, and Mn (sulfates or hydroxy) on apparent absorption of minerals when fed in either a forage- or by-product–based diet. The by-product diets were formulated to have greater concentrations of NDF and lesser concentrations of starch, and specific ingredients were chosen because they were good sources of soluble fiber and β-glucans, which bind trace minerals in nonruminants. We hypothesized that hydroxy trace minerals would interact less with digesta and have greater apparent absorption compared with sulfate minerals, and the difference in apparent absorption would be greater for the by-product diet compared with the forage-based diet. During the 56-d experiment, cows remained on the same fiber treatment but source of supplemental trace mineral was different for each 28-d period; thus, all cows were exposed to both mineral treatments. During each period cows were fed no supplemental Cu, Zn, or Mn for 16 d, followed by 12 d of feeding supplemental minerals from either sulfate or hydroxy sources. Supplemental minerals for each of the mineral sources fed provided approximately 10, 35, and 32 mg/kg of supplemental Cu, Zn, and Mn, respectively, for both fiber treatments. Total Cu, Zn, and Mn dietary concentrations, respectively, were approximately 19, 65, and 70 mg/kg for the forage diets and 21, 85, and 79 for the by-product diets. Treatment had no effect on dry matter intake (24.2 kg/d) or milk production (34.9 kg/d). Cows consuming the by-product diets had greater Zn (1,863 vs. 1,453 mg/d) and Mn (1,790 vs. 1,588 mg/d) intake compared with cows fed forage diets, but apparent Zn absorption was similar between treatments. Manganese apparent absorption was greater for the by-product diets compared with the forage diets (16 vs. 11%). A fiber by mineral interaction was observed for Cu apparent absorption, as cows fed hydroxy minerals with forage diets had greater apparent absorption compared with cows fed sulfate minerals; however, the opposite was observed with the by-product diets. Source of supplemental trace minerals and type of fiber in diets affected availability of Cu and Mn and should be considered in ration formulation.     

Dietary factors affecting trace element bioavailability from human milk, cow's milk and infant formulas

Bioavailability of trace elements is affected by the type of diet in which they are presented. In general, absorption of the elements iron, zinc, copper, manganese and selenium appears to be higher from human milk than from cow's milk or cow's milk formula while absorption from soy formula appears to be lower than from milk-based products. The effects of individual components such as protein source, carbohydrate, phytate, organic acids and other cations on absorption need to be assessed and the integrated effects of individual dietary components need to be assessed in the intact diet. While ideally absorptive studies should be performed in human infants, there is a need for developing useful and valid models for assessing trace element bioavailability. Increased knowledge about trace element absorption from different infant diets and the factors involved will lead to a better understanding of trace element requirements of infants. This will help in the suggestion of ways to improve means of supplementation.     

RESEARCH NOTE: A COMPARISON OF THE CHEMICAL COMPOSITION OF ZANDER (SANDER LUCIOPERCA) LIVING IN DIFFERENT LAKES OF TURKEY

In the present work, the proximate compositions, minerals and trace element contents of zander ( Sander lucioperca ) caught from two lakes (Beyşehir Lake and Seyhan Dam Lake) of Turkey were compared. There were significant differences between moisture and lipid contents, although there were no statistically significant differences between crude protein and ash contents. The mineral and trace elements determined were Na, K, Ca, P, Mg, Zn, Cu, Fe, Pb and Se. Although Na and Fe contents of zanders in two different lakes were different from each other ( P <  0.01), we found no statistically significant differences in terms of Mg, Ca, P, Cu, Pb, Se, Zn contents ( P >  0.01). Among the minerals analyzed, K was the highest followed by P, Ca, Na and Mg. The most abundant trace elements were Zn, Fe, Cu, Se followed by Pb, and these elements were below the limits proposed by Turkish Food Codes for human consumption in the meat of zander.

PRACTICAL APPLICATIONS

This present study includes information about the nutritional value of zander, which lives in the fresh water lakes of our country and of which people are fond and is being exported. The comparison of the proximate, mineral and trace element contents of the same species which are caught in two different lakes has been made. In the scope of human nutrition, in accordance with the minerals which have got much importance, it involves useful information about what the position of this fish is, and whether it contains any risk due to trace elements. Furthermore, concerning this subject, it will also light the way for studies to be made in the future.     

乳酸菌富集微量元素Se、Cr、Zn的初步研究

研究了乳酸菌对硒、铬、锌通过生物转化将无机态微量元素富集转化为细胞内的有机态微量元素。结果表明:适当提高培养基中硒、铬、锌的浓度,有利于乳酸菌的生长和微量元素有机态的富集转化,但是当它们浓度超出一定范围时,则抑制乳酸菌的生长。这3种元素中,乳酸菌对锌的富集转化能力最强,铬次之,而对硒的富集转化能力最弱。     

Mineral and trace element concentrations of dairy products from goats’ milk produced in Tenerife (Canary Islands)

The concentrations of the minerals, Na, K, Ca and Mg, and the trace elements, Fe, Cu, Zn and Se, were determined in 400 samples of goats’ dairy products (100 raw milk, 100 whey, 100 fresh and 100 semi-hard cheeses) produced in the island of Tenerife. All the minerals and trace elements analysed presented significant differences in the concentration between the dairy products analysed. The season of production had a greater influence on the mineral and trace element concentration than the region of production and the amount of fibre in the goats’ diet. An almost complete differentiation of the samples according to the type of dairy product was observed applying a stepwise discriminant analysis.