Destruction of aflatoxins B1 and G 1 in bread making.

The effect of processing steps as well preservatives used in French bread making namely propionic acid and/or potassium sorbate (0.2%) on the destruction of aflatoxins B1 and G1 was studied.Mixing and baking processes showed marked destruction of aflatoxins B1 and G1; being 71.2% and 52.5% for aflatoxin B1 after mixing and baking steps, while reaching 73.9% and 54.5% for aflatoxin G1. Fermentation step caused additional 15.3% and 15.0% destruction of aflatoxins B1 and G1.On the other hand, aflatoxin B1 destruction was 79.2% and 50.7% when propionic acid was used and 75.3 and 56.7% in the presence of potassium sorbate and after mixing and baking steps respectively.Concerning aflatoxins G1 it was found that mixing and baking steps showed destruction of 81.9% and 53.4% in the presence of propionic acid and 75.1 and 49.4% in the presence of potassium sorbate in this respective order.Generally, it can be concluded that using propionic acid as preservative appeared to be more effective on the destruction of aflatoxins B1 and G1 than potassium sorbate in French bread making.

Fate of aflatoxins B1 and G 1 residues during biscuit processing.

Effect of biscuit processing on the destruction of aflatoxins B1 and G1 with and/or without some commonly leavening agents used namely sodium bicarbonate, ammonium bicarbonate and sodium bisulfite and sodium chloride.It was found that mixing step reduced the concentration of aflatoxins B1 and G1 by 80.7% and 82.7%, while the effect of baking step being 28.9% and 21.5%. The effect of mixing was found to be more pronounced than that baking step.The highest destruction effect on aflatoxin B1 was observed by adding a mixture composed of sodium and ammonium bicarbonate and sodium bisulfite followed by sodium chloride, sodium bisulfite, ammonium bicarbonate and/or sodium bicarbonate alone, where the reduction values of toxin after mixing were 93.4,91.9,91.7, 88.8 and 86.6% respectively, while the baking effect ranged 17.2 to 34.5% in the presence of different leaving agents added.Concerning aflatoxin G1; the highest destructive effect of toxin was adsorbed by adding a mixture of sodium and ammonium bicarbonate and sodium bisulfite followed by sodium bisulfite, sodium chloride, ammonium bicarbonate and/or sodium bicarbonate alone since the destruction values of such toxin after mixing were 96.2%, 92.8%, 92.6%, 89.0% and 87.7% respectively, while the baking effect ranged 20.9 to 34.5% in all leavening agents added.