Evaluation of Some Functional Properties of Extracted Pectin from Pomegranate Peel by Microwave Method

Pectin is a complex mixture of polysaccharides in the cell wall of plants. The aim of this study was to evaluate the efficiency of pectin extraction from pomegranate peel using microwaves and to investigate some of its functional properties.

Some functional properties of pectin extracted from pomegranate peel including degree of esterification, galacturonic acid content, emulsifying properties, emulsion stability, water and oil storage capacity, antioxidant capacity and infrared spectrum behavior were investigated after optimization of extraction procedure. Extraction of pectin from pomegranate peel as an abundant and available source were performed for the first time by microwave at 120 °C in a certain ratio of solid to liquid under different pH conditions (1.5, 2.25 and 0.3), irradiating times (60, 120 and 180 seconds) and at three energy levels (300, 500 and 700 watts).

Pectin extraction efficiency under optimal conditions (power 700 watts, time 120 seconds and pH of 1.5) was 20.42%. The degree of esterification of pectin was 33.24%, galacturonic acid content was 75.35% and its emulsifying activity was 56.4% and the emulsion obtained at 4 °C was more stable than the resulting emulsion at 24 °C. The storage capacity of water and oil per gram of extracted pectin was 3.86 and 2.13 gr, respectively.

The application of pectin extracted from pomegranate peel by microwave method has a good efficiency and due to its good functional properties can pave the way for its use in some food formulations.