Influence of biopolymers on the solubility of branched-chain amino acids and stability of their solutions

- Microfluidization increased the initial solubility of branched-chain amino acids.
- Stabilizer increased the saturation concentration of branched-chain amino acids.
- Stabilizer type was a main factor to affect the stability of amino acid solutions.
- Amino acid:stabilizer ratio did not affect the BCAA solubility.
- The solution stability was not affected by amino acid:stabilizer ratio.

This study confirmed the possibility of biopolymer-type stabilizers to increase the saturation concentration of branched-chain amino acids by preventing their crystallization/precipitation. Although microfluidization increased the initial solubility, it failed to increase the saturation concentration of the branched-chain amino acids. The saturation concentration of the branched-chain amino acids increased from 3.81% to 4.42% and 4.85% after the incorporation of food hydrocolloids and proteins, respectively. However, the branched-chain amino acids:stabilizer ratio did not affect the solubility. In the case of food hydrocolloid-based solutions, crystal formation and growth of branched-chain amino acids occurred during storage, resulting in the precipitation of branched-chain amino acid crystals. However, food proteins effectively increased the stability of the solubilized branched-chain amino acids. The improved solubility and stability of the solubilized branched-chain amino acids could be attributed to interactions between the functional groups (carboxyl, amine, sulfate, aliphatic, aromatic, etc.) of the stabilizer and the branched-chain amino acid molecules.