Evaluation of the activity of natural phenolic antioxidants, extracted from industrial coffee residues, on the stability of poly(1,4‐butylene succinate) formulations

• Published in: Journal of applied polymer science 2023-06, Vol.140 (21), p.n/a
• Main Authors: Bianchi, Stefano, Marchese, Paola, Vannini, Micaela, Sisti, Laura, Tassoni, Annalisa, Ferri, Maura, Mallegni, Norma, Cinelli, Patrizia, Celli, Annamaria
• Format: Article
• Language: English
• Subjects: ABTS assay; Activation energy; Antioxidants; biodegradable polymer; Biopolymers; Coffee; Degradation; Formulations; kinetic methods; Materials science; natural antioxidant; Phenols; Polymers; Residues; Scavenging; thermal oxidization
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.53878

In this work, the evaluation of the antioxidant activity of natural phenolic compounds is performed and compared to that of a conventional antioxidative agent. Phenolic molecules, extracted from industrial processing coffee residues, are added to a matrix of poly(1,4‐butylene succinate) (PBS). The apparent activation energy (Ea) of the thermo‐oxidative degradation is calculated by employing different methods like Kissinger‐Akahira‐Sunose, Flynn‐Wall‐Ozawa and Friedman. The results are compared with the antioxidant activity evaluation obtained through the ABTS radical scavenging assay. From the average activation energies, it is observed that the addition of the natural antioxidants led to an increase in the activation energy of the degradation process as a function of the phenolic compound content. This trend is confirmed by the results of the ABTS assay. Hence, this study proves that the active molecules extracted from agri‐food waste could be employed to improve the antioxidant capacity of the biopolymer, even if the composition of the extract must be evaluated in order to mitigate the effects of other components. The antioxidant activity of natural phenolic molecules added to a bio‐polymer is evaluated through thermogravimetric analysis: the apparent activation energy (Ea) of the thermo‐oxidative degradation is calculated. The addition of phenolic compounds to the poly(1,4‐butylene succinate) led to an increase in the activation energy as the active molecules content increased. This analysis demonstrates the acquired antioxidant capacity of the formulated biopolymer.