Abstract #M182

# M182
Assessment of the capacity of certain mycotoxin binders to adsorb amino acids.
A. Kihal1, M. Rodriguez-Prado1, C. Godoy1, C. Cristofol1, S. Calsamiglia*1, 1Universitat Autonoma de Barcelona, Bellaterra, Spain.

The objective of the study was to evaluate the capacity of 6 mycotoxin binders to adsorb 4 different essential amino acids. The experiment was conducted in in vitro conditions to simulate a post ruminal digestion model in 2 phases: first phase to simulate the gastric digestion with pepsin, malic acid, citric acid, acetic acid and lactic acid at pH 3; and a second phase to simulate intestinal digestion with bile salts and pancreatin extract at pH 6.5. The experimental design was a factorial 6 × 4 with main factors being mycotoxin binders (bentonite, clinoptiolite, sepiolite, montmorillonite, active carbon and yeast cell walls) and amino acids (lysine, methionine, threonine and tryptophan). Amino acids were incubated separately (Study 1) and together (Study 2) with each mycotoxin binder. The average adsorption in Study 1 was high (49%), with the highest adsorption for clinoptiolite (56%) and the lowest for sepiolite (44%). For the adsorption of amino acids, tryptophan (63%) was adsorbed the highest and lysine (36%) the lowest. Adsorption of threonine was different among mycotoxin binders being lowest for active carbon (20%), and for tryptophan being lowest in montmorillonite (40%), and highest in clinoptiolite (78%) and active carbon (77%). In Study 2, the average adsorption was lower than in Study 1 (19%), suggesting that there was competition for the adsorption surface. Adsorption was highest for the yeast cell wall (22%) and lowest for clinoptiolite (4%). For the adsorption of amino acids, threonine (22%) was the highest and methionine (16%) the lowest. Adsorption of tryptophan was different among mycotoxin binders being lowest for clinoptiolite (0%), bentonite (2%) and sepiolite (10%), and highest for yeast cell wall (49%). For methionine, adsorption was lowest for clinoptiolite (5%) and highest for montmorillonite (25%). Mycotoxin binders have a high degree of adsorption of amino acids, which may limit their bioavailability. Results also suggest that the adsorption is competitive among amino acids.

Key Words: mycotoxin binders, amino acid