Microwave Assisted Extraction: A Technological Alternative for Valorization of Orange Peel for Pectin Extraction

Abstract

Pectin, a component of the plant cells, exists in the primary cell wall along with the middle lamella of plant tissues and is found mostly in citrus fruit peels. Peels of orange is an important source of pectin which is utilized as an emulsifying, gelling and thickening agent in varied food products. Currently, extraction of pectin is done through hot water at low pH for hours which is a time-consuming process. However, microwave extraction has verified to boost the pectin yield in lesser time. This study highlights the ability of microwave assistance in extraction of pectin from orange peels. Extraction of pectin was done with the varied combinations of microwave power (160, 320, and 480 W), microwave time (1, 2 and 3 min) and pH of citric acid solution (pH: 1, 1.5, 2). To analyze the outcome of microwave power, microwave time and pH on pectin yield, Box Behnken design of Response Surface Methodology was used. The optimized conditions, as per desired function test, determined for the peak pectin yield as 24.00% were; microwave power of 478 W, microwave time of 2.2 min and pH of 1.05. The validation test conducted on pectin extraction was found in acceptance with the optimized conditions.