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 ³

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

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

³ Department of Chemistry, College of Education for Pure Science. University of Mosul, Iraq.

10.22067/ifstrj.2026.97581.1549

Abstract

Enzymatic browning processes negatively impact many food products, such as fresh juices, particularly their sensory properties and nutritional value, ultimately leading consumers to reject the affected products. Natural antioxidants have been used to reduce this phenomenon, preserving these products and preventing their quality deterioration. This research investigates the antioxidant and enzyme inhibitory activities of eggplant peel ethanolic (EEPE) and aqueous (AEPE) extracts, as well as their capacity for scavenging DPPH radicals and inhibition of browning enzymes 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 at 4°C, more than AEPE. Purified mango pulp PPO was of approximately 54 kDa molecular weight and was effectively extracted 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 response reflects the potential of eggplant peel, agricultural waste, as a natural substance for food preservation due to its antioxidant and anti-browning activities.

Keywords

Eggplant peel extract

antioxidant activity

Polyphenol oxidase

enzymatic browning

mango juice

Subjects

• Food Chemistry

---