Mycotoxin contamination and co-occurrence of aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEA), ochratoxin A (OTA) and fumonisin B1 (FB1) in animal feed are frequently observed and can impact animal health also at low doses. The addition of binders to contaminated diets is considered a most promising dietary approach to reduce toxic effects of mycotoxins. In the EU, the use of these substances as technological feed additives has been officially approved and a variety of products are on the market claiming multi-toxin binding capacities. The efficacy of binders in sequestering different mycotoxins has been poorly addressed. The aim of this study was the screening of commercial products and agricultural by-products for preparing a nutritional composition intended to reduce bioavailability of a large range of mycotoxins. 52 commercial products from 26 industrial partners, including minerals, yeast-based products and blend of components, and 37 agricultural by-products were tested. Preliminary adsorption tests allowed to select 4 commercial products and 4 agricultural by-products as effective in sequestering simultaneously AFB1, ZEA, OTA and FB1. All products failed in binding DON, but activated carbon. Batch adsorption experiments were performed at different pHs with selected binders to determine adsorption parameters (capacity, affinity, chemisorption index), and kinetic and thermodynamic parameters. Mineralogical analysis (XRD) showed that 3 out of the 4 commercial products selected as best multi-toxin adsorbents (designated by the supplying companies as minerals) were organoclays. All these products showed lower maximum adsorption capacity and chemisorption index than a mineral product containing carbon. The latter was found to be the most effective, adsorbing simultaneously up to 34 mg AFB1, 184 mg ZEA, 256 mg OTA and 332 mg FB1 per gram of product. Most commercial additives, but two organoclays and one yeast cell wall product, were found to be non-toxic in 2 bioassays. Interestingly, some micronized vegetable dried materials were successful in adsorbing mycotoxins. Contact time curves showed that the simultaneous adsorption of AFB1, ZEA, OTA and FB1 by these materials is rapid, reaching the adsorption equilibrium within 10 min. Toxin adsorption was improved when the sizes of agricultural materials in the form of micro-particles were less than 500 µm. Medium pH did not affect toxin adsorption. Based on Langmuir equilibrium isotherms, selected products sequestered simultaneously up to 3.0 mg AFB1, 3.2 mg ZEA, 2.4 mg OTA and 0.1 mg FB1 per gram of product. Single and multi-component adsorption isotherms showed that AFB1, ZEA and FB1 adsorptions is not influenced by the simultaneous presence of different toxins. Thermodynamic parameters suggested that hydrophobic interaction could be associated to AFB1 and ZEA adsorption, while electrostatic interaction could be responsible for OTA and FB1 binding. In conclusion, this study shows that most commercial products, regardless of their composition, are ineffective towards the large range of mycotoxins that can be found in feed. Some commercial products can be even highly toxic in toxicity bioassays. Selected agricultural by-products or mixtures of them can be good candidates for being used as multi-mycotoxin binders.
Multi-mycotoxin adsorbing materials: efficacy assessment of commercial products and development of new feed additives to reduce mycotoxin contamination.
Avantaggiato G;Greco D;Damascelli A;Visconti A
2013
Abstract
Mycotoxin contamination and co-occurrence of aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEA), ochratoxin A (OTA) and fumonisin B1 (FB1) in animal feed are frequently observed and can impact animal health also at low doses. The addition of binders to contaminated diets is considered a most promising dietary approach to reduce toxic effects of mycotoxins. In the EU, the use of these substances as technological feed additives has been officially approved and a variety of products are on the market claiming multi-toxin binding capacities. The efficacy of binders in sequestering different mycotoxins has been poorly addressed. The aim of this study was the screening of commercial products and agricultural by-products for preparing a nutritional composition intended to reduce bioavailability of a large range of mycotoxins. 52 commercial products from 26 industrial partners, including minerals, yeast-based products and blend of components, and 37 agricultural by-products were tested. Preliminary adsorption tests allowed to select 4 commercial products and 4 agricultural by-products as effective in sequestering simultaneously AFB1, ZEA, OTA and FB1. All products failed in binding DON, but activated carbon. Batch adsorption experiments were performed at different pHs with selected binders to determine adsorption parameters (capacity, affinity, chemisorption index), and kinetic and thermodynamic parameters. Mineralogical analysis (XRD) showed that 3 out of the 4 commercial products selected as best multi-toxin adsorbents (designated by the supplying companies as minerals) were organoclays. All these products showed lower maximum adsorption capacity and chemisorption index than a mineral product containing carbon. The latter was found to be the most effective, adsorbing simultaneously up to 34 mg AFB1, 184 mg ZEA, 256 mg OTA and 332 mg FB1 per gram of product. Most commercial additives, but two organoclays and one yeast cell wall product, were found to be non-toxic in 2 bioassays. Interestingly, some micronized vegetable dried materials were successful in adsorbing mycotoxins. Contact time curves showed that the simultaneous adsorption of AFB1, ZEA, OTA and FB1 by these materials is rapid, reaching the adsorption equilibrium within 10 min. Toxin adsorption was improved when the sizes of agricultural materials in the form of micro-particles were less than 500 µm. Medium pH did not affect toxin adsorption. Based on Langmuir equilibrium isotherms, selected products sequestered simultaneously up to 3.0 mg AFB1, 3.2 mg ZEA, 2.4 mg OTA and 0.1 mg FB1 per gram of product. Single and multi-component adsorption isotherms showed that AFB1, ZEA and FB1 adsorptions is not influenced by the simultaneous presence of different toxins. Thermodynamic parameters suggested that hydrophobic interaction could be associated to AFB1 and ZEA adsorption, while electrostatic interaction could be responsible for OTA and FB1 binding. In conclusion, this study shows that most commercial products, regardless of their composition, are ineffective towards the large range of mycotoxins that can be found in feed. Some commercial products can be even highly toxic in toxicity bioassays. Selected agricultural by-products or mixtures of them can be good candidates for being used as multi-mycotoxin binders.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
