Development of highly water-dispersible complexes between coenzyme Q₁₀ and protein hydrolysates

The water-solubility of coenzyme Q₁₀ (CoQ₁₀) is extremely low because of its hydrophobicity, which results in low bioavailability. In this study, peptide mixtures derived from different proteins (casein, albumin, gelatin, lysozyme, zein and hemoglobin) were prepared and used as dispersants ofCoQ₁₀. Most peptide mixtures, except for that derived from lysozyme, enhanced the water-dispersibility of CoQ₁₀ by forming complexes with CoQ₁₀. In particular, the apparent solubility of CoQ₁₀complexed with the casein hydrolysate (Pep_cas) was the highest. Pep_cas was fractionated by ammonium sulfate precipitation and ultrafiltration to find the most effective peptides for enhancing water-dispersibility of CoQ₁₀. The peptide fraction that had a relatively hydrophobic nature and peptides of higher-than-average molecular weights (Pep_casA) was found to be the most effective. Results from differential thermal analysis and powder X-ray diffraction revealed that the complex between CoQ₁₀ and Pep_casA in the solid state was amorphous. In solution, the complex is a hydrocolloid with particle sizes of 154-279 nm.