Natural Clays as Potential Amino Acids Carriers for Animal Nutrition Application

Abstract

This study has the main purpose of testing natural carriers as more sustainable alternatives to polymeric coating. New clay-based hybrid organic–inorganic materials have been prepared. An innovative procedure for the intercalation of the bioactive molecule is proposed. The synthesis process implies the use of mild operating conditions and does not require the use of organic reactants or solvents. Moreover, the use of natural carriers, and milder environmentally friendly process conditions, fulfill the requirement of a mostly safe, greener production. The capture and the release properties of the final material mainly depend on the carrier morphology. Large zeolite content in the mineral clays can favor the capture of very large methionine loadings, but due to the trapping mechanism, typical of these structures, zeolites prevent a satisfactory release in mild condition and physiological condition. The Freundlich adsorption model has been found to be able to predict the capture behavior. Once the proper carrier is selected, the preparation procedure guarantees the protection of the amino acid in the right form. Neither the structure of the inorganic matrix nor the amino acid structure was changed in the preparation process. Methionine was detected in its zwitterionic form, showing the main IR bands only slightly affected by the interaction. Further studies on methionine bioaccessibility and intestinal absorption from methionine–Adsorbene (MET–ADS) are required to optimize the application of natural clay in in-field animal nutrition.