Removing aflatoxin M1 from milk with native lactic acid bacteria, centrifugation, and filtration

  • Željka Kuharić Andrija Štampar Teaching Institute for Public Health, Zagreb
  • Željko Jakopović University of Zagreb, Faculty of Food Technology and Biotechnology, Zagreb
  • Iva Čanak University of Zagreb, Faculty of Food Technology and Biotechnology, Zagreb
  • Jadranka Frece University of Zagreb, Faculty of Food Technology and Biotechnology, Zagreb
  • Jasna Bošnir Andrija Štampar Teaching Institute for Public Health, Zagreb
  • Željka Pavlek Andrija Štampar Teaching Institute for Public Health, Zagreb
  • Martina Ivešić Andrija Štampar Teaching Institute for Public Health, Zagreb
  • Ksenija Markov University of Zagreb, Faculty of Food Technology and Biotechnology, Zagreb
Keywords: HPLC, lactic acid bacteria, L. plantarum KM, secondary fungal metabolites, viable and heat-treated cells

Abstract

In order to minimise human exposure to aflatoxin M1 (AFM1) the levels of this highly carcinogenic mycotoxin in milk, heat-treated milk, and other dairy products have been limited to <0.05 µg kg-1. However, its removal from dairy products presents a challenge for dairy producers, as commercial additives change organoleptic properties, and filtration alone yields poor results. The aim of this study was to find a strain of lactic acid bacteria (LAB) from milk or dairy products that most effectively binds AFM1 and to see whether heat treatment of the selected LAB affects the binding efficiency. We also wanted to investigate whether centrifugation can improve filtering of the obtained AFM1-LAB complexes from milk. To do that, we isolated and identified 10 native LAB species/strains, incubated their viable or heat-treated cells (108 CFU mL-1) in milk spiked with 0.5 µg L-1 of AFM1 at 4 °C for 0, 2, 4, and 24 h, and quantified the amount of unbound AFM1 with HPLC. AFM1 binding efficiency ranged from 21 to 92 % for viable cells and from 26 to 94 % for the heat-treated ones. Since both viable and heat-treated Lactobacillus plantarum KM showed the best results, we used it for the next step in AFM1 removal from milk. Heat treatment in combination with filtration and centrifugation yielded removal as high as 96 %.

Published
2018-12-03
How to Cite
1.
Kuharić Željka, Jakopović Željko, Čanak I, Frece J, Bošnir J, Pavlek Željka, Ivešić M, Markov K. Removing aflatoxin M1 from milk with native lactic acid bacteria, centrifugation, and filtration. AIHT [Internet]. 3Dec.2018 [cited 24May2019];69(4). Available from: https://arhiv.imi.hr/index.php/arhiv/article/view/983
Section
Original article