Optimization of Extraction Parameters for Phenolics Recovery from Avocado Peels Using Ultrasound and Microwave...

Area of Science:

• Food Chemistry
• Green Chemistry
• Biotechnology

Background:

• Avocado peels (Persea americana) represent a significant waste stream (~20% of fruit weight).
• These peels are rich in valuable bioactive compounds with high revalorization potential.
• Valorizing avocado waste can contribute to a more sustainable agri-food sector.

Purpose of the Study:

• To optimize phenolic compound extraction from avocado peels using ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE).
• To compare the efficiency of UAE and MAE in extracting total antioxidant capacity (TAC) and total phenolic compounds (TPC).
• To identify optimal extraction parameters for maximizing phenolic recovery.

Main Methods:

• Central Composite Design (CCD) was employed to optimize extraction parameters.
• Variables studied included ethanol (EtOH) concentration, temperature, and time for both UAE and MAE.
• Phenolic content and antioxidant capacity were quantified; individual phenolics were analyzed using HPLC/MS.

Main Results:

• Ethanol concentration emerged as the most critical factor influencing phenolic extraction.
• Optimal conditions were identified as 94.55% EtOH with moderate temperatures and short extraction times.
• UAE showed superior performance, extracting 15% more procyanidins under milder conditions (45 °C for 5 min) compared to MAE (67 °C for 12 min).

Conclusions:

• Both UAE and MAE are effective technologies for extracting antioxidants from avocado peels.
• UAE offers a more efficient and potentially greener alternative due to lower temperature and time requirements.
• The findings support the sustainable valorization of avocado processing byproducts.