Mljekarstvo (Sep 2012)
Removal of aflatoxin M1 from artificially contaminated yoghurt by using of new synthesized dehydroacetic acid analogues
Abstract
Dehydroacetic acid (DHA) and its new synthesized analogues, 4-hydroxy-3-(p-toluoyl)-6-(ptolyl)-2H-pyrane-2-one (DHT) and 5-Bromo-4-hydroxy-3-(p-toluoyl)-6-(p-tolyl)-2H-pyrane-2-one (BrDHT) were tested for removal of aflatoxin M1 (AFM1) from artificially contaminated yoghurt with known concentrations of this toxin to determine the possible use of these chemicals as a means of controlling AFM1 accumulation. Yoghurt from cow’s milk was artificially contaminated with AFM1 at levels of 0.01 to 0.5 μg/L. Yoghurts were stored at 4 °C and 7 °C, respectively, for up to 28 days. Analysis of AFM1 in yoghurt was carried out using two dimensional thin-layer chromatography (TLC) - visual estimation. The limit of detection was 0.15 ng/L. The recoveries of AFM1 from the samples spiked at levels of 10, 50, 100, and 500 ng/L were between 80.6 and 107.8 %, respectively. Concentrations of DHA and DHT of 0.01 and 0.03 μmol/L had non or little effect on AFM1 content in experimentally contaminated yoghurt, whereas concentrations higher than 0.05 μmol/L, partially inhibited AFM1 content. The percentage loss of the initial AFM1 amount in yoghurt was estimated by about 15 and 25 %, and 22 to 45 % by the end of storage, respectively. In experiments with 0.01 and 0.05 μmol/L of BrDHT or higher, the concentration of AFM1 was reduced after 28 days by 20 to 95 % or completely, respectively, depending on the time and temperature of deposit. Detection of toxicity of investigated analogues was evaluated by using the brine shrimp (Artemia salina) larvae as a screening system for the determination of their sensitivity to some chemicals
