“Raw food” diet: the effect of maximal temperature (46 ± 1 °C) on aflatoxin B1 and oxalate content in food

“Raw food” diets are controversially accepted, but have been fashionable for a while and this trend seems to continue in the near future. Since the “raw food” diets are based on fruits, vegetables, nuts, seeds, sprouted grains and beans, higher daily intakes of this kind of food present a risk of higher intake of aflatoxins and oxalates, which consequently poses a health risk. The effect of the maximal temperature allowed at processing (46 ± 1 °C) has not yet been studied on aflatoxins and oxalates. In our study, their presence was determined by employing high pressure liquid chromatography with UV detection at the wavelength of 365 nm and 210 nm, respectively. A regression analysis was used to examine the changing of the content of oxalic acid and aflatoxin B1 over time. The content of “naturally” present aflatoxin B1 in selected dried fruits remained the same during 3 h of experiment at 46 ± 1 °C. On the contrary, the oxalate content in vegetables with low oxalic acid (tomatoes and chicory) decreased, whereas the temperature (46 ± 1 °C) had no effect on oxalic acid in spinach (higher oxalic content) and in pure solutions of oxalic acid in deionized water.