Nanocompounds of iron and zinc: their potential in nutrition

Abstract

Recent studies suggest nanostructured oxides and phosphates of Fe and atomically mixed Fe/Zn may be useful for nutritional applications. These compounds may have several advantages over existing fortificants, such as ferrous sulfate (FeSO(4)), NaFeEDTA and electrolytic iron. Because of their very low solubility and formation of soft agglomerates of micron size at neutral pH as well as their light native color, they tend to be less reactive in difficult-to-fortify foods and thus have superior sensory performance. At gastric pH the soft agglomerates break up and the Fe compounds rapidly and completely dissolve due to their very high surface area. This results in in vitro solubility and in vivo bioavailability comparable to FeSO(4). Doping with Mg and/or Ca may increase solubility and improve sensory characteristics by lightening color. Feeding the nanostructured compounds at 150-400 µg Fe day(-1) for 15 days to weanling rats in two studies did not induce measurable histological or biochemical adverse effects. No significant Fe was detected in the submucosa of the gastrointestinal tract or lymphatic tissues, suggesting that the nanosized Fe is absorbed through usual non-heme Fe absorption pathways. Thus, these novel compounds show promise as food fortificants or supplements.

Is nano safe in foods? Establishing the factors impacting the gastrointestinal fate and toxicity of organic and inorganic food-grade nanoparticles

“…Iron oxide (Fe 2 O 3 ) nanoparticles may be utilized in foods as colorants or sources of bioavailable iron. [47][48][49][50] The range of applications of iron oxide as a food colorant in the United States are highly limited, i.e., up to 0.1 wt% in sausages as part of casings. 51 It was estimated that the mean intake of iron oxide from consumers of these products was around 450 μg/ day.…”

Nanomaterials for products and application in agriculture, feed and food

“…The solubility and the bioavailability of poorly acid-soluble iron compounds can be improved by decreasing their primary particle size and thereby increasing their specific surface area. Nanostructured iron containing compounds may prove useful for iron fortification of certain foods (Zimmermann & Hilty, 2011).…”

The role of the food matrix and gastrointestinal tract in the assessment of biological properties of ingested engineered nanomaterials (iENMs): State of the science and knowledge gaps

“…Organic engineered nanomaterials (ENMs) are often intentionally added to foods or beverages to encapsulate vitamins, nutraceuticals, flavors, colors, or antimicrobials (Livney, 2015; McClements et al , 2015; Shin et al , 2015; Yao et al , 2015b). Inorganic ENMs are intentionally added to foods for numerous reasons: TiO 2 is added to provide opacity and brightness (Weir et al , 2012); SiO 2 nanoparticles are added to modify food texture and powder flow characteristics (Dekkers et al , 2011; Peters et al , 2012); iron oxides (Fe 2 O 3 or Fe 3 O 4 ) are added to provide bioavailable iron for nutritional purposes (Raspopov et al , 2011; Zimmermann and Hilty, 2011) or as colorants; and, Ag nanoparticles are added as antimicrobial agents (Hajipour et al , 2012). …”