Extract of Phenolics From Pomegranate Peels

Abstract

The effects of different solvents, temperature conditions, solvent-solid ratios and particle sizes on solid-solvent extraction of the total phenolics, proanthocyanidins and flavonoids herein also referred to as antioxidant from pomegran- ate marc peel (PMP) was studied. Water, methanol, ethanol, acetone, and ethyl acetate extraction efficiencies at extraction times of 0.17 to 10 min, extraction temperatures of 25 to 95°C, ratios of solvent/solid of 5:1 to 50:1 and particle sizes of 10 to 40 mesh were evaluated. At 40 °C, solvent/solid ratio of 15:1, extraction time of 240 min and particle size of 40 mesh, methanol gave the highest extract yield of the total phenolics (8.26%), followed by water (5.90%), ethanol (1.55%), acetone (0.37%), and ethyl acetate (0.18%), respectively. However, at an extraction temperature of 95°C, the total phe- nolics extract yield with water was 11.15% for particle size of 40 mesh, solvent/solid ratio of 15:1, and extraction time of 2 min. Despite the lowest extract yield at extraction temperature of 40 °C, solvent/solid ratio of 15:1, extraction time of 240 min and particle size of 40 mesh, ethyl acetate extraction gave the highest content of the total phenolics (20.24%), proanthocyanidins (2.65%) and flavonoids (3.92%) in the extract. The DPPH antioxidant activity of extracts had a linear relationship with the total phenolics content in the extracts (R 2 =0.9779). This study revealed that water extraction, which has the economic and safety merits, can be used as an environmentally friendly method for producing antioxidants from the PMP.