High methoxyl pectin grafted onto gallic acid by one- and two-pot redox-pair procedures

Cortés-Avendaño P.; Quispe-Roque J.; Macavilca E.A.; Condezo-Hoyos L. · Food Chemistry (2024) · DOI: 10.1016/j.foodchem.2024.139865

Resumen

The aim of this research was to graft gallic acid (GA) onto high methoxyl pectin (HMP) through the redox-pair of ascorbic acid (Aa) and hydrogen peroxide (H2O2) with one- and two-pot procedures. The effectiveness of the both procedures and the chemical, physical and antioxidant properties of the obtained HMP-GA were evaluated. HMP-GAone-pot (23.3 ± 0.21 mg GA Equivalent (GAE)/g) and HMP-GAtwo-pot (32.3 ± 0.52 mg GAE/g) were best obtained at H2O2/Aa molar ratio-HMP/GA weight ratio of 9.0–0.5 and 16.0–0.5, respectively. The UV–Vis and FT-IR spectra and along with their derivative and thermal gravimetric analyses, revealed differences between HMP-GAone-pot and HMP-GAtwo-pot. The latter exhibited a greater antioxidant capacity than the former in single electron transfer (ET), hydrogen atom transfer (HAT), and ET-HAT mixed assays. The chemical differences can be attributed to side reactions that may have interfered with the grafting reaction. Consequently, HMP-GA, possessing unique antioxidant and prebiotic properties, can be synthesized through redox-pair procedures.

Instituciones: Universidad Nacional Agraria La Molina; Universidad Nacional José Faustino Sánchez Carrión