In vitro model for the evaluation of toxicity and antinutritional effects of sulphites.

The food preservatives, sulphur dioxide and its salts, are known to present some toxic, mutagenic and antinutritional effects; in fact they interact with a number of nutrients, e.g. some vitamins, notably thiamine (Th) and folic acid (FA). The effect of different concentrations of sodium bisulphite in cell culture media has been studied in vitro on a human cell line, HEp-2, deriving from a carcinoma of the larynx. Moreover, the sulphites have been tested with different levels of Th and FA with the aim of elucidating how much the cellular response depended on either the anti-nutritional effect or the toxicity of sulphites. Cell growth has been taken as an index of cytotoxicity and measured both as total protein content and as colony-forming ability. With no Th and FA in the culture medium, a clear decrease of cell growth was observed either with or without addition of sodium bisulphite. A dose-dependent reduction of protein content was detected in cells treated with 10, 50, 100, 200, 250 or 500 microM sodium bisulphite. Moreover, when the cells were treated with 10 or 100 microM of this compound, the colony-forming ability was reduced both in number and colony size. As far as the interaction of the two vitamins with sodium bisulphite is concerned, when these nutrients were present in the medium at 0.5, 1.0, 1.5, 2.0 or 2.5 mg/l, a similar growth profile, determined from their concentration, was observed in treated and control cells, the growth levels being affected by the sodium bisulphite contents. At higher levels of Th and FA, the growth index was still increasing only in treated cells, this phenomenon being particularly evident in cultures treated with 200 microM sodium bisulphite. The colony-forming ability was reduced in controls but still increased in treated cells at the highest concentration of vitamins.

[Chemical and nutritional evaluation of commercial bakery products for children (author's transl)]. / Studi sul valore nutritivo di alcuni prodotti da forno destinati prevalentemente all'infanzia

Various bakery products, differing in either composition or processing, all widely consumed in Italy by school children, have been studied. Protein, lipid, reducing and total sugars, amino acid and available lysine contents have been determined, as well as biological parameters have been calculated to verify hypotheses about growth factors. The products examined have low protein biological value and the proteins are considerably demaged by technological processing. Lysine, always the limiting amino-acid in these proteins, is shown to be unavailable in percentages varying from 20 to 60% of the total lysine. Upon describing growth as a function of protein content, the correlation improves considerably. Furthermore, when this variable, protein content, is associated with the corrected chemical score in a linear model, the correlation reaches even higher values.