Extensive screening for herbal extracts with potent antioxidant properties

Area of Science:

• Natural Product Chemistry
• Food Science
• Biochemistry

Background:

• Oxidative stress is implicated in various health issues and food spoilage.
• Natural antioxidants from herbs offer a promising alternative to synthetic additives.
• Screening for potent and stable antioxidant compounds is crucial for food applications.

Purpose of the Study:

• To identify herbal extracts with significant superoxide radical (O(2) (•-)) and hydroxyl radical ((•)OH) scavenging activities.
• To evaluate the heat resistance of these potent antioxidant herbal extracts.
• To provide insights for selecting effective antioxidants for food applications.

Main Methods:

• Large-scale screening of approximately 1000 ethanol herbal extracts using electron spin resonance (ESR)-spin trapping for O(2) (•-) scavenging.
• Further evaluation of selected extracts for (•)OH scavenging using ESR and Fenton reaction.
• Assessment of heat resistance of extracts under thermal stress.

Main Results:

• Four edible herbal extracts (Punica granatum peel, Syzygium aromaticum bud, Mangifera indica kernel, Phyllanthus emblica fruit) demonstrated potent O(2) (•-) scavenging.
• All four selected extracts also effectively scavenged (•)OH.
• Extracts from P. granatum (peel), M. indica (kernel), and P. emblica (fruit) exhibited significant heat resistance.

Conclusions:

• Selected herbal extracts possess potent antioxidant properties against O(2) (•-) and (•)OH.
• Pomegranate peel, mango kernel, and Phyllanthus emblica fruit extracts are heat-stable antioxidants suitable for food processing.
• These findings support the use of specific herbal extracts as natural food antioxidants.