Abstract: In order to optimize the ultrasound-assisted extraction of pectin from potato pulp left after starch extraction, five key factors affecting pectin yield including ultrasound power, extraction temperature and pH, the length of extraction time and solid-to-liquid ratio were investigated by one-factor-at-a-time experimental design, and a mathematical model representing the relationship between the function and the five variables was constructed using quadratic regression orthogonal rotation combination design, and the effects of pairwise cross-interactions among the above factors on pectin yield were evaluated by response surface analysis (RSM). The optimal process for the extraction of pectin from potato pulp was determined to be the extraction of the raw material at 80 ℃ for 47.6 min with a 21-fold volume of water under the assistance of ultrasound treatment at 300 W.  Under these optimal conditions, the yield of potato pectin reached up to 15.76%. Furthermore, the obtained product was analyzed for its physico-chemical parameters, and all the analytical results met the requirements of the national and industrial standards.

Key words: potato pulp, ultrasonic extraction, pectin, optimization, composition analysis