Trace elements and their distribution in protein fractions of camel milk in comparison to other commonly consumed milks

Abstract

Studies on camels' milk, whether with respect to concentration or bioavailability of trace elements from this milk, are limited and warrant further investigation. The object of this study was to analyse the concentration and distribution of zinc, copper, selenium, manganese and iron in camel milk compared to those in human milk, cows' milk and infant formula under similar experimental conditions. Camels' milk and cows' milk were collected from local farms, human milk samples were obtained from healthy donors in Kuwait and infant formula was purchased locally. Milk fractionation was performed by ultra-centrifugation and gel-column chromatography. The concentration of trace elements was analysed by atomic absorption spectrometry and that of protein was determined spectrophotometrically. The concentration of manganese and iron in camels' milk was remarkably higher (7–20-fold and 4–10-fold, respectively) than in human milk, cows' milk and infant formula. The zinc content of camels' milk was higher than that of human milk but slightly lower than in cows' milk and infant formula. The concentration of copper in camels' milk was similar to that of cows' milk but lower than in human milk and infant formula. The selenium content of camels' milk was comparable to those of other types of milk. Approximately 50–80% of zinc, copper and manganese in camels' milk were associated with the casein fraction, similar to that of cows' milk. The majority of selenium and iron in camels' milk was in association with the low molecular weight fraction. It is recommended that camels' milk be considered as a potential source of manganese, selenium and iron, perhaps not only for infants, but also for other groups suspected of mild deficiency of these elements. Further investigations are required to confirm this proposal.

Response of lactic acid bacteria to milk fortification with dietary zinc salts

“…As far as the average Zn 2þ content of bovine milk is concerned, values in this study are comparable with those reported in the literature (Al-Awadi & Srikumar, 2001;Lante, Lomolino, Cagnin, & Spettoli, 2006). By contrast, the unfortified batches of Squacquerone and Caciotta were characterized by a slightly higher average Zn 2þ content than those previously reported (Gambelli, Belloni, Ingrao, Pizzoferrato, & Santaroni, 1999;Lante et al, 2006).…”

“…In this investigation, the fortification method proved to significantly affect both the cheese composition (total solids, protein, fat and salt) and zinc recovery. In cows' milk, zinc is principally chelated by caseins (Al-Awadi & Srikumar, 2001;Drago & Valencia, 2002) and this explains its abundant retention in the curd during milk coagulation (Al-Awadi & Srikumar, 2001;Brulé & Fauquant, 1982;Cichoscki, Valduga, Valduga, Tornadijo, & Fresno, 2002;de la Fuente, Fontecha, & Juárez, 1996;Drago & Valencia, 2002;Gulbas & Saldamli, 2005). Desired levels of Zn 2þ (>10 mg kg À1 ), not exceeding the critical limits (Maret & Sandstead, 2006), were found in the zinc-fortified cheese batches.…”

“…A further property that makes milk-based products like yoghurt and cheese the logical choice for zinc fortification is their low pH (Rosado, 2003). In cows' milk, zinc is mainly bound to caseins, while only minor quantities of this mineral are associated with the whey and fat fractions (Al-Awadi & Srikumar, 2001;de la Fuente, Olano, & Juarez, 1997;Sandström, Keen, & Lönnerdal, 1983). More specifically, in casein micelles, two thirds of the zinc is bound to colloidal calcium phosphate and one-third bound to phosphorylated serine and threonine residues (Singh, Flynn, & Fox, 1989).…”

Effect of Selenium Supplementation on Blood Status and Milk, Urine, and Fecal Excretion in Pregnant and Lactating Camel

“…One reference only was available on selenium content of camel milk [29], and the reported value (13.9±2.4 ng/mL) was quite lower than in our study, but the authors did not mention the lactation stage. In dairy cow, the milk Se concentration varied from 19.4 to 53.7 ng/mL with Se dietary selenium between 0.15 and 0.40 ppm [21].…”

Mineral and nutritional analysis of Polish infant formulas

“…The nutritive value of goat milk has also been established (Aganga et al, 2002;Coni et al, 1996;Elmastas et al, 2005;Park, 2000;Rodrígez Rodrígez et al, 1999b), and the quality of sheep milk was investigated by Aganga et al (2002), Coni et al (1996), and Elmastas et al (2005). Mare milk has been analyzed by Grace et al (1999), Marconi and Panfili (1998), and Pelizzola et al (2006), and the chemical composition of camel milk has been determined (Al-Awadi and Srikumar, 2001;Dell'Orto et al, 2000;Zhang et al, 2005). In addition to the mineral composition of whole milk, the distribution of elements in different kinds of milk (such as raw milk, ultra-heat treated (UHT) milk, skim milk, calcium-fortified milk, milk with omega-3 fatty acids) and milk fractions, such as curds and milk whey, has been investigated (Cava-Montesinos et al, 2005;Rivero Martino et al, 2001;Zubeir et al, 2005).…”