# Magnetic Properties of Commercial Cornflakes
## 1 Introduction  
Since the last century, food has been fortified to combat global malnutrition. Iron, zinc, and vitamins are the primary elements added to processed foods, which are primarily composed of carbohydrates. Iron is the most essential element in preventing anemias or related diseases caused by a deficit in daily intake or intestinal malabsorption [1, 2]. Flour and flour-derived foods, as well as cereals, are fortified to ensure an efficient absorption of essential nutrients when these are lacking in the traditional diet [3].  
The most popular cereals, eaten mainly for breakfast in millions of households, are made from toasted rice, oats, wheat, or maize. The type and concentration of iron added to foods depend on the manufacturer's criteria and the health legislation of each country [4].  
Iron may be added in a water-soluble form (ferrous sulfate, gluconate, lactate, or ferric citrate), in a dilute acid-soluble form (ferrous fumarate, succinate), in an insoluble form (different ferric phosphates), or as protected iron compounds (Fe-ethylenediaminetetraacetic acid) [5].  
On the other hand, using iron oxides like magnetite, maghemite, or hematite as fortification elements is not entirely standardized. Some side effects have been observed because of their nanometric sizes, which are related to an accumulative effect in the organism and cytotoxic properties [6]. In contrast, several authors have emphasized the feasibility of using iron oxides, such as magnetite, as a fortification complement, for example, in wheat biscuits [7; 8; 9] or yogurt fortified with maghemite [10]. Other important applications related to the food industry include antimicrobial activity, the production of artificial enzymes, and food preservation [11].  
Frequently, it is difficult to identify the type of fortifying iron added to the foods. Also, when it is indicated, the oxidation state of iron may be confusing because it depends on how it was obtained. Thus, metallic iron could be described as elemental, electrolytic, or reduced iron [5]. Other iron-containing food additives are colorants. In particular, the pigment E172 contains three different chemical compounds: yellow Fe\({}_{2}\)O\({}_{3}\)(H\({}_{2}\)O), red Fe\({}_{2}\)O\({}_{3}\), and black Fe\({}_{3}\)O\({}_{4}\)[12; 13]. From the perspectives of physical chemistry and biochemistry, the toxicological properties of these colorants have been widely discussed [14; 15]. Consequently, the European Food Safety Authority (EFSA) considered the maximum recommended concentrations of E172 for coloring foods, indicating a no observable adverse effect level (NOAEI) of 1 g/kg*d for microsized iron oxides. In contrast, nanosized iron oxides at this concentration exhibited severe toxic symptoms in rats [16].  
On the other hand, in 2020, [PERSON] et al. analyzed the iron content of a popular brand of cornflakes in the United Kingdom [17]. Using high-precision spectroscopy, the crystal structure was found to correspond to body-centered cubic (BCC) metallic iron (also known as alpha iron), with no detectable traces of iron oxide.  
This work aims to determine the magnetic properties of the most popular cereal on the American continent [18] and investigate the presence of oxidized iron. We have observed a lack of information in the nutritional information table displayed for many foods, specifically the omission of specifying the type of iron included.