Stabilization of blackberry extract by interaction with bovine sodium caseinate in the presence of tara gum

Abstract BACKGROUND The antioxidant capacity of anthocyanins (AC) rapidly degrades during storage, highlighting the need for their stabilization. The conformational properties and high proline content of sodium caseinate (NaCAS), combined with the formation of NaCAS microgels in the presence of tara gum (TG) and acid gelation, suggest its potential as an effective stabilizing or encapsulating agent of AC. RESULTS Spectrofluorimetric results suggest the formation of a complex between NaCAS and AC. Fourier transform infrared spectroscopy demonstrated that the presence of TG and blackberry extract (BEX) modifies the NaCAS spectra in the analyzed range. These results validated the presence of hydrogen bonding and hydrophobic interactions between NaCAS and AC. The impact of the AC–NaCAS complex on the stability of the antioxidant capacity was assessed. After 43 days of storage, the lyophilized complex with an optimal BEX concentration retained 70% of its iron‐reducing power. Additionally, the results indicate that, at the tested concentrations of BEX, the radical scavenging capacity of NaCAS is minimally affected. CONCLUSION The present study demonstrates that the bioactive properties of the aqueous extract of blackberry are effectively stabilized through the formation of complexes with NaCAS in the presence of TG. Both AC and TG interact with NaCAS, but in different ways. The antioxidant capacity of these mixtures, demonstrated through both reducing power and free radical capture, is preserved to a high degree after storage. © 2025 Society of Chemical Industry.