Microwave assisted extraction and characterization of pectin from grapefruit peel

In this study, pectin was obtained from dried grapefruit peels by microwave assisted extraction, and the properties of pectin were compared to pectin obtained by conventional extraction. Both extraction methods were optimized for pectin yield with response surface method and Box-Behnken design was used. In addition, the obtained pectins were used in the production of apricot marmalade, and their physicochemical and sensory properties were investigated. Optimum extraction conditions for the conventional extraction at 80oC were determined as 30 ml/g of the liquid solid ratio, 3 h and pH 1; for microwave assisted extraction were determined as 30 ml/g, 90 s and pH 1. The yields for both pectin were found to be 35.95% and 21.88%, respectively. It was determined that the pectins obtained by both methods had high degree of esterification. FT-IR analysis was performed for both pectins. Pectin obtained by microwave assisted extraction was compared with pectin obtained by the conventional method and their structures were found to be similar to each others. It was found that marmalade produced with pectin obtained by microwave assisted extraction had better sensory properties than that with produced with pectin obtained by conventional extraction.