Magnesium in food

Distribution of magnesium in food classes is summarized in Table I. 

Oxalic acid and its soluble salts are poisonous to humans and animals, whereas insoluble salts of calcium and magnesium oxalate are not. Oxalates ingested by humans may be precipitated by calcium as an insoluble complex, which then is excreted in feces [21, 22, 23]. In both cases reported by Chien et al [21], patients ingested sour carambola juice on an empty stomach so that the protective effect of calcium and magnesium in food was not present. The dehydration state may have contributed to the development of carambola- associated acute nephropathy. The authors do not report any concomitant neurological signs or symptoms [21]. 

Pennington JATand Young B (1990) Sodium, potassium, calcium, phosphorus and magnesium in foods from the United States Total Diet Study. J Food Comp Anal 3 145-165. 

Magnesium. In the adult human, 50—70% of the magnesium is in the bones associated with calcium and phosphoms. The rest is widely distributed in the soft tissues and body duids. Most of the nonbone Mg ", like K", is located in the intracellular duid where it is the most abundant divalent cation. Magnesium ion is efftcientiy retained by the kidney when the plasma concentration of Mg fads in this respect it resembles Na". The functions of Na", K", Mg ", and Ca " are interrelated so that a deficiencv of Mg " affects the metaboHsm of the other three ions (26). Foods rich in magnesium are listed in Table 9. 

Bohn, T. et al., Chlorophyll-bound magnesium in commonly consumed vegetables and fruits relevance to magnesium nutrition, J. Food Sci., 69, S347, 2004. 

Mineral deficiencies are not uncommon and can have quite a variety of causes—e. g., an unbalanced diet, resorption disturbances, and diseases. Calcium deficiency can lead to rickets, osteoporosis, and other disturbances. Chloride deficiency is observed as a result of severe Cr losses due to vomiting. Due to the low content of iodine in food in many regions of central Europe, iodine deficiency is widespread there and can lead to goiter. Magnesium deficiency can be caused by digestive disorders or an unbalanced diet—e.g., in alcoholism. Trace element deficiencies often result in a disturbed blood picture—i. e., forms of anemia. 

Cieslik, E., Sikora, E. (1998). Correlation between the levels of nitrates and nitrites and the contents of potassium, calcium and magnesium in potato tubers. Food Chem., 63(4), 525-528. 

Chlorophyll. Chemically pure chlorophyll is difficult to prepare, since it occurs mixed with other colored substances such as carotenoids. Commercially it is solvent extracted from the dried leaves of various plants such as broccoli or spinach. Chlorophyll is water-iosoluble. It has none of the characteristics of a dye in that it has no aflinity for the usual libers such as cotton or wool. Chlorophyll is properly classified as a pigment tCI Natural Green 3 Cl 75810), As such. It finds use lor coloring soaps, waxes, inks. fats, or nils. Chlorophyll is an ester composed of an acidic pint, chlorophyllin, esterilied by an aliphatic alcohol known as phylol. Hydrolysis of chlorophyll using sodium hydroxide produces the moderately water-soluble sodium salts of chlorophyllin. phytol. and methanol. The magnesium in chlorophyllin may be replaced by copper. The sodium copper chlorophyllin salt is heat-stable, and is ideal for coloring foods where heat is involved, such as in canning. 

TABLE 1. DISTRIBUTION OF MAGNESIUM IN VARIOUS FOOD GROUPS... 

Ministry of Agriculture, Fisheries and Food (1973) The Analysis of Agricultural Materials - Magnesium in Plant Material, Method 45, Technical Bulletin RB 427, HMSO, London, UK. 

Anticaking agents include carbonates, phosphates, silicates, and fatty acid salts of calcium and magnesium. Levels of anticaking agents in food products are determined by manufacturing, based on good practices. 

---