Phenolic compounds with antioxidant activity from strawberry leaves: a study on microwave-assisted extraction...

Area of Science:

• Agricultural Chemistry
• Food Science
• Phytochemistry

Background:

• Strawberry leaves are a rich source of bioactive compounds, including polyphenols.
• Polyphenols possess significant antioxidant properties, making them valuable for health and industry.
• Efficient extraction methods are crucial for maximizing the recovery of these valuable compounds.

Purpose of the Study:

• To optimize microwave-assisted extraction (MAE) for polyphenols from strawberry leaves.
• To evaluate the impact of key extraction parameters on polyphenol yield and antioxidant activity.
• To identify the major antioxidant polyphenols present in the extracts.

Main Methods:

• Response surface methodology (RSM) using Box-Behnken design (BBD) was employed for optimization.
• Four factors were investigated: extraction time, microwave power, ethanol concentration, and liquid-solid ratio.
• Total phenolic content (TPC) and antioxidant capacity (DPPH, FRAP assays) were measured.

Main Results:

• Optimized MAE conditions: 40s, 300W, 51.1% ethanol, 61.6 mL/g.
• Achieved TPC of 89.21 mg GAE/g, DPPH inhibition of 79.80%, and FRAP of 34.62 mM FE/g.
• Model prediction accuracy showed less than 5% absolute error.
• HPLC analysis identified sinapic acid and rutin as major antioxidant compounds.

Conclusions:

• MAE is a highly efficient technique for extracting polyphenols from strawberry leaves.
• The optimized method provides high yields of compounds with significant antioxidant capacity.
• This study highlights the potential of strawberry leaves as a sustainable source of valuable antioxidants.