Rheological, Thermal, Structural, and Chemical Changes during Oxidation of Gum Arabic by Ozone

ABSTRACT

Gum Arabic (GA) samples with 6% (w/v) concentration in water were ozonated for 5, 30, and 60 min, corresponding to 0.0030, 0.0125, and 0.0140 g consumed ozone/L, respectively. Ozonation steadily reduced the viscosity, flow, and consistency index of GA suspensions significantly (P < 0.05). Although no apparent changes were observed in the general chemical structure of GA samples, an increase in the absorbance of -OH bends was detected by FTIR analysis. DSC peak temperatures (292.0 ± 0.1 to 281.0 ± 0.9 °C) and pH values of samples (4.84 ± 0.13 to 2.90 ± 0.09) were decreased upon ozonation. Small but statistically significant differences (P < 0.05) were obtained for water solubility and water absorption index of samples after ozonation. Phenolic compounds and radical scavenging activities in GA were increased significantly (P < 0.05) by ozonation. Ozonation, which is an environmental-friendly unit operation, would offer valuable contributions to relevant industries with improved properties of GA.

KEYWORDS:

• Antioxidant activity
• Chemical structure
• FTIR
• Green oxidant
• Gum Arabic
• Rheology

Acknowledgments

Financial support by the Scientific and Technological Research Council of Turkey (TUBITAK), 1002 Project No: 217O192, is greatly appreciated. We also thank Prof. Dr. Mehmet Kahraman and Assist. Prof. Dr. Dilek Büyükbeşe, both from Gaziantep University (Turkey), for their support during our research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01919512.2022.2106185

Additional information

Funding

This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK).