Optimization of extraction time and amplitude in the ultrasound-assisted extraction method for total phenolic content and antioxidant activity of cocoa pod husk extract
Nur Hidayat (a*), Suprayogi (b), Sri Suhartini (c), Indah Fitriana Subekti (d), Arlis Erliana Savitri (e), Amanna Ilma Rizqina (f), Devin Edna Dhana (g)

Faculty of Agricultural Technology Department of Agroindustrial Technology, Universitas Brawijaya, Jl. Veteran, Malang, ZIP 65145, Indonesia
*nhidayat[at]ub.ac.id

Abstract

Cocoa pod husk is an agricultural waste with potential as a natural antioxidant source due to its polyphenol content. This study aimed to optimize amplitude and extraction time in Ultrasound-Assisted Extraction (UAE) for maximizing total phenolic content and antioxidant activity of cocoa pod husk extract. The study employed the Response Surface Methodology (RSM) with two factors, namely amplitude (60%, 70%, and 80%) and extraction time (30, 45, and 60 minutes), resulting in 9 experiments plus 5 center points. Dried cocoa pod husk was ground, sieved to a uniform particle size, and extracted using 52% (v/v) ethanol-water with a sample to solvent ratio according to UAE standards. Total phenolics were determined by Folin-Ciocalteu and antioxidant activity by DPPH assay. Amplitude and extraction time significantly influenced both responses. The highest phenolic content (15.14 mg GAE/g) occurred at 80% amplitude and 60 minutes, while the best antioxidant activity (IC&#8325-&#8320- 76.39 ppm) occurred at 60% amplitude and 60 minutes. RSM optimization predicted optimum conditions at 60% amplitude and 38.01 min, producing 13.72 mg GAE/g phenolics, 82.75 ppm antioxidant activity, and 0.729 desirability. UAE optimization has the potential to produce high-quality cocoa pod husk extract for applications in the food and pharmaceutical industries.

Keywords: Cocoa pod husk- Ultrasound Assisted Extraction- Response Surface Methodology- Total phenolic content- Antioxidant activity

Topic: Agricultural and bioprocess engineering