For the first time all over the world, the European Union with the Regulation (EC) No 386/2009 regulates the position of additives intended for the control of mycotoxins in feed. According to this regulatory status, a new functional group in the category of technological feed additives was opened and substances that suppress or reduce mycotoxin absorption, promote the excretion of mycotoxins or modify their mode of action, were recognized. Substances (e.g., clay and other minerals, micro-organisms, yeast cell walls,...) that are mixed into feed in order to adsorb mycotoxins in the digestive tract of animals can be included in this new functional group. So far, the contribution of mycotoxin adsorbents to the safety of the feed chain in the EU has not yet been fully exploited. No official method is available to correctly define their capacity and affinity in adsorbing mycotoxins. The aim of this work is to develop a simple in vitro test to be further validated and used at European level as a standard for characterization of the new feed additives in adsorbing mycotoxins. Two mycotoxins (aflatoxin B1 and zearalenone) were individually mixed with adsorbent materials at 37°C, at different pHs (3, 5 or 7), to study the adsorption process. The assayed materials were an activated carbon and 16 commercial products including mineral or organic products and blend of components. Adsorption isotherms obtained from the experimental data were fitted to multiple isotherm equations (i.e., Langmuir and Freundlich equations). The Prediction Residual Error Sum of Squares (PRESS), the sum of squares of residual (SSres), and the correlation coefficients between theoretical and experimental values (r) were used to assess the goodness of the fits and the reliability of the adsorbing parameters (capacity and affinity) derived from the equations. The Langmuir and Freundlich equations were found as appropriate models to study zearalenone and aflatoxin B1 adsorption, respectively. These data support the hypothesis that mycotoxins assayed herein are adsorbed with different mechanisms onto adsorbent materials. How the in vitro characterization of adsorbent materials in binding mycotoxins can be predictive of their efficacy in reducing mycotoxin bioavailability in vivo is still unknown and has to be discussed taking into account further studies. At this regard, previous experiments (independent from the above tests) performed in our laboratory using both in vivo tests and a physiologically relevant in vitro model simulating the gastrointestinal tract of animals will be reviewed.
Assessment of the efficacy of a new category of Feed Additives in reducing mycotoxin contamination
Avantaggiato G;Visconti A
2009
Abstract
For the first time all over the world, the European Union with the Regulation (EC) No 386/2009 regulates the position of additives intended for the control of mycotoxins in feed. According to this regulatory status, a new functional group in the category of technological feed additives was opened and substances that suppress or reduce mycotoxin absorption, promote the excretion of mycotoxins or modify their mode of action, were recognized. Substances (e.g., clay and other minerals, micro-organisms, yeast cell walls,...) that are mixed into feed in order to adsorb mycotoxins in the digestive tract of animals can be included in this new functional group. So far, the contribution of mycotoxin adsorbents to the safety of the feed chain in the EU has not yet been fully exploited. No official method is available to correctly define their capacity and affinity in adsorbing mycotoxins. The aim of this work is to develop a simple in vitro test to be further validated and used at European level as a standard for characterization of the new feed additives in adsorbing mycotoxins. Two mycotoxins (aflatoxin B1 and zearalenone) were individually mixed with adsorbent materials at 37°C, at different pHs (3, 5 or 7), to study the adsorption process. The assayed materials were an activated carbon and 16 commercial products including mineral or organic products and blend of components. Adsorption isotherms obtained from the experimental data were fitted to multiple isotherm equations (i.e., Langmuir and Freundlich equations). The Prediction Residual Error Sum of Squares (PRESS), the sum of squares of residual (SSres), and the correlation coefficients between theoretical and experimental values (r) were used to assess the goodness of the fits and the reliability of the adsorbing parameters (capacity and affinity) derived from the equations. The Langmuir and Freundlich equations were found as appropriate models to study zearalenone and aflatoxin B1 adsorption, respectively. These data support the hypothesis that mycotoxins assayed herein are adsorbed with different mechanisms onto adsorbent materials. How the in vitro characterization of adsorbent materials in binding mycotoxins can be predictive of their efficacy in reducing mycotoxin bioavailability in vivo is still unknown and has to be discussed taking into account further studies. At this regard, previous experiments (independent from the above tests) performed in our laboratory using both in vivo tests and a physiologically relevant in vitro model simulating the gastrointestinal tract of animals will be reviewed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
