Detoxification of the Fumonisin Mycotoxins in Maize: An Enzymatic Approach

oleh: Johanna Alberts, Gerd Schatzmayr, Wulf-Dieter Moll, Ibtisaam Davids, John Rheeder, Hester-Mari Burger, Gordon Shephard, Wentzel Gelderblom

Format: Article
Diterbitkan: MDPI AG 2019-09-01

Deskripsi

Enzymatic detoxification has become a promising approach for control of mycotoxins postharvest in grains through modification of chemical structures determining their toxicity. In the present study fumonisin esterase FumD (EC 3.1.1.87) (FUM<i>zyme</i><sup>&#174;</sup>; BIOMIN, Tulln, Austria), hydrolysing fumonisin (FB) mycotoxins by de-esterification, was utilised to develop an enzymatic reduction method in a maize kernel enzyme incubation mixture. Efficacy of the FumD FB reduction method in &#8220;low&#8221; and &#8220;high&#8221; FB contaminated home-grown maize was compared by monitoring FB<sub>1</sub> hydrolysis to the hydrolysed FB<sub>1</sub> (HFB<sub>1</sub>) product utilising a validated LC-MS/MS analytical method. The method was further evaluated in terms of enzyme activity and treatment duration by assessing enzyme kinetic parameters and the relative distribution of HFB<sub>1</sub> between maize kernels and the residual aqueous environment. FumD treatments resulted in significant reduction (&#8805;80%) in &#8220;low&#8221; (&#8805;1000 U/L, <i>p</i> &lt; 0.05) and &#8220;high&#8221; (100 U/L, <i>p</i> &lt; 0.05; &#8805;1000 U/L, <i>p</i> &lt; 0.0001) FB contaminated maize after 1 h respectively, with an approximate 1:1 &#181;mol conversion ratio of FB<sub>1</sub> into the formation of HFB<sub>1</sub>. Enzyme kinetic parameters indicated that, depending on the activity of FumD utilised, a significantly (<i>p</i> &lt; 0.05) higher FB<sub>1</sub> conversion rate was noticed in &#8220;high&#8221; FB contaminated maize. The FumD FB reduction method in maize could find application in commercial maize-based practices as well as in communities utilising home-grown maize as a main dietary staple and known to be exposed above the tolerable daily intake levels.