Aluminium coffee percolators as a source of dietary aluminium

Utensílios para alimentos e implicações nutricionais

Há grande variedade de materiais empregados na confecção de utensílios para os alimentos: barro, ferro, vidro, cerâmica, inox, pedra, alumínio e outros. Cerca de 43% de panelas vendidas atualmente nos Estados Unidos são de aço inoxidável. Outra parcela da população utiliza utensílios de alumínio. Este artigo visa especular a contribuição nutricional de utensílios usados na preparação de alimentos e feitos de três diferentes materiais (alumínio, ferro e aço inoxidável), através de revisão de literatura científica.

Contribution of aluminum from packaging materials and cooking utensils to the daily aluminum intake

Migration of aluminum (Al) from packaging materials and cooking utensils into foods and beverages was determined at intervals during cooking or during storage by graphite furnace atomic absorption spectroscopy. High amounts of Al migrated into acidic products such as mashed tomatoes during normal processing in normal, non-coated Al pans. After 60 min cooking an Al content of 10-15 mg/kg was measured in tomato sauce. Surprisingly, the Al concentration was also increased up to 2.6 mg/L after boiling tap water for 15 min in Al pans. Storage of Coca-Cola in internally lacquered Al cans resulted in Al levels below 0.25 mg/L. In contrast, non-coated Al camping bottles containing lime blossom tea acidified with lemon juice released up to 7 mg Al/L within 5 days. The Al concentration in coffee was lower than that of the tap water used in its preparation, even if prepared in Al heaters. In Switzerland, where most pans nowadays are made of stainless steel or teflon-coated Al, the average contribution for the use of Al utensils to the daily Al intake of 2-5 mg from the diet is estimated to be less than 0.1 mg.

Aluminum and chronic renal failure: sources, absorption, transport, and toxicity

In normal subjects the gastrointestinal tract is a relatively impermeable barrier to aluminum with a low fractional absorption rate for this metal ion. Aluminum absorbed from the gastrointestinal tract is normally excreted by the kidneys; in the presence of impaired renal function aluminum is retained and accumulates in body tissues. Aluminum-containing medications are given, by mouth, to patients with chronic renal failure as phosphate-binding agents for the therapeutic control of hyperphosphatemia. Patients with chronic renal failure are also exposed to aluminum in domestic tap-water supplies used either for drinking or, in those on dialysis treatment, in the preparation of their dialysate. In patients with end-stage chronic renal failure, particularly in those on treatment by hemodialysis, the accumulation of aluminum in bone, brain, and other tissues is associated with toxic sequelae. An increased brain content of aluminum appears to be the major etiological factor in the development of a neurological syndrome called either "dialysis encephalopathy" or "dialysis dementia"; an increased bone content causes a specific form of osteomalacia. An excess of aluminum also appears to be an etiological factor in a microcytic, hypochromic anemia that occurs in some patients with chronic renal failure on long-term treatment with hemodialysis. The various mechanisms involved in the toxic phenomena associated with the accumulation of aluminum in body tissues have not been clearly defined but are the subject of extensive investigations.

Aluminium content of foods and diets

Literature data on the aluminium content of individual foods have been compiled, summarized and presented by food groups. The contribution of aluminium from food preparation and cooking utensils and from food additives is discussed. Literature data on the daily intake of aluminium are summarized, and the contribution of food groups to daily aluminium intake is estimated. The major sources of dietary aluminium include several with aluminium additives (grain products, processed cheese and salt) and several that are naturally high in aluminium (tea, herbs and spices). The aluminium that may migrate from aluminium utensils is probably not a major or consistent source of this element. Daily intakes of aluminium, as reported prior to 1980, were 18-36 mg per day. More recent data, which are probably more accurate, indicate intakes of 9 mg per day for teenage and adult females and 12-14 mg per day for teenage and adult males.

New aspects on the chemistry of tea and coffee. III

The previous review for 1983/1984 is now continued with references to recent publications (1984/1985) and as before covers the chemistry and technology of tea (leaf, green and black) and coffee (raw, roasted and instant soluble), with particular reference to composition and changes during manufacture, extraction and storage. The effects of composition on the quality of the beverage, with mention of particular physiological properties, are included (210 references).