Inhibition of Enzymatic Browning in Mango Juice Using Antioxidant-Rich Eggplant Peel Extracts: A Kinetic and Preservation Study

Articles in Press

Document Type : Research Article-en

Authors

May G. Ameen Aldabbagh ¹

Oday H. Ali AL-Jammaas ²

Rana T. Ibrahim Altaee ¹

Omar Y. Al-abbasy ¹

¹ Department of Chemistry, College of Education for Pure Science, University of Mosul, Iraq

² Department of Food Science, College of Agriculture and Forestry, University of Mosul, Iraq

https://doi.org/10.22067/ifstrj.2026.97581.1549

Abstract

Enzymatic browning processes negatively influence many food products, such as fresh juices, particularly their sensory properties and nutritional value, ultimately leading consumers to reject such products. Natural antioxidants have been used to reduce this phenomenon, preserving these products and preventing quality deterioration. This research investigates the antioxidant and enzyme inhibitory activities of eggplant peel ethanolic (EEPE) and aqueous (AEPE) extracts, by scavenging DPPH radicals method in mango juice (MJ) during cold storage. EEPE had greater DPPH radical scavenging capacity (0.66 mg/g) than AEPE (0.52 mg/g), although both extracts were weaker than vitamin C (0.73 mg/g). Enzymatic browning assays revealed that EEPE suppressed PPO and POD activities in mango juice (MJ), contributing to decreased browning intensity and better preservation of phenolic content after 15 days storage at 4°C, more than AEPE. Purified mango pulp PPO was of approximately 54 kDa molecular weight and was effectively extracted and purified using ammonium sulfate precipitation, dialysis, and CM-Cellulose ion exchange chromatography with a purification fold value of 15.07. Kinetic studies revealed that EEPE acted like a competitive inhibitor of PPO, while AEPE exhibited non-competitive inhibition. This finding reflects the potential of eggplant peel,as an agricultural waste, is a potent natural substance to be used in food preservation due to its antioxidant and anti-browning activities.

Keywords

Antioxidant activity

Eggplant peel extract

Enzymatic browning

Food preservation

Mango juice

Peroxidase

Polyphenol oxidase

Subjects

• Food Chemistry

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Authors retain the copyright. This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)

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