Pectin extraction and characterization from kidney bean hulls using hot acid and ultrasonic assisted extraction methods

Abstract

In order to evaluate kidney bean husks, extraction of pectin from this waste was carried out under hot acid and ultrasonic assisted extraction methods. Dilute solutions of different organic and inorganic acids were used as extraction solutions, and their effects on the yields and properties of the extracted pectins were investigated by making changes in extraction conditions including temperature and time. Increasing extraction temperature, longer extraction time and decreasing the pH of the medium increased the pectin yields for both methods. Pectin yields were higher when inorganic acids were used as extraction media under ultrasonic assisted extraction method. All extracted pectins are in the class of high ester pectin. The FTIR spectra of the extracted pectins and commercial pectin were very similar to each other and gave similar vibration bands.