The use of 2D NMR to study b-cyclodextrin complexation and debittering of amino acids and peptides

Abstract

This work fully demonstrated the formation of amino acids complexes with b-cyclodextrin (b-CD) by the method of nuclear magnetic resonance with the rotating frame Overhauser effect spectroscopy (ROESY) and diffusion ordered spectroscopy (DOSY) techniques. The tested amino acids display the following decreasing order of affinity for b-CD: tryptophane > tyrosine > phenylalanine > proline > histidine > isoleucine. The influence of complexation on taste perception was determined with a trained panel to qualify taste alterations of single amino acids and quantify the debittering of soy protein hydrolysate by b-CD complexation. The results showed that b-CD complexation is effective for modifying single amino acids taste perception and debittering soy protein hydrolysate. Bitterness sensation of the latter is reduced by 90% when 5% b-CD was added, thus b-CD is recommended as a prospective additive for masking bitter taste of new functional food products.