Loquat Flowers Exceed Leaves: A Less Explored Phenolic Source with Functional Potential

Area of Science:

• Plant biochemistry
• Food science
• Pharmacognosy

Background:

• Loquat (Eriobotrya japonica) by-products are underutilized.
• Growing interest in plant bioactives and sustainable food systems.
• Need to explore phenolic composition and bioactivities of loquat leaves and flowers.

Purpose of the Study:

• Compare phenolic profiles of loquat leaves and flowers.
• Evaluate and compare in vitro bioactivities (antioxidant, antidiabetic).
• Support valorisation of loquat by-products as functional ingredients.

Main Methods:

• Extraction and quantification of polyphenolic fractions (extractable and non-extractable).
• HPLC-ESI-QTOF-MS for phenolic profiling.
• In vitro assays: FRAP, ABTS, glucose dialysis retardation index, α-glucosidase inhibition.

Main Results:

• Flowers had higher total polyphenols than leaves.
• Distinct phenolic profiles between flowers and leaves, with flowers richer in phenolic acids and specific compounds.
• Flower extracts showed higher antioxidant activity and potent α-glucosidase inhibition, exceeding acarbose.
• Leaf extracts demonstrated a modest glucose diffusion delay, but lacked significant α-glucosidase inhibition.

Conclusions:

• Loquat flowers are a promising source of bioactive polyphenols.
• Valorisation of loquat by-products, especially flowers, is supported for functional food and health applications.
• Findings contribute to sustainable utilization of agricultural by-products.