The Extraction of Pectin by Microwave Heating

Abstract

In order to shorten the extraction time as well as to get high quality pectin, extraction of pectin by microwave (Mw) heating (2450MHz, 1030W) was investigated. In the pectin xtracted with 0.05N hydrochloric acid from the pulp of Satsuma mandarin (Citrus unshiu MARC.) and apple fruit (Malvs pumila MILLER var domestica SCHNEIDER), the extraction time by Mw heating was considerably shortened as compared with the ordinary method by water bath at 85°C. Further, the content of pectin extracted by Mw heating was higher than that of pectin extracted by water bath. Pectin was extracted by Mw heating for five minutes a time and the extraction was repeated three times. As the basis of total extracted pectin, about 60-75% of pectin at the first time and 20-25% at the second time were extracted. Galacturonic acid content, degree of esterification, relative viscosity of pectin prepared from the pulp of citrus and apple fruit were both decreased according to the increase of extraction time.