Abstract: In the paper, pomegranate (Punica granatum L.) pomace was used as the research object and its pectin was extracted by ultrasonic assisted electrolysis water method. The extraction process of pomegranate pectin extracted by ultrasonic assisted electrolysis was optimized, and its composition and structural characteristics were analyzed. According to single factor experiment, the optimal extraction conditions of pomegranate pomace pectin were obtained by Box-Benhnken design optimization: ultrasonic power 100 W, pH 1.7, extraction temperature 60 ℃, extraction time 33 min and material to liquid ratio was 1:18 g/mL, and the pectin extraction yield of pomegranate pomace reached 14.95%. Compared with the ordinary ultrapure water (UP water) extraction process, the extraction yield is increased 2.2%, and the pectin extracted by electrolysis water (EWP) has a lower molecular weight (7.294×106 g/mol) and higher galacturonic acid content (70.29%), together with FTIR and NMR, indicates that EWP has a higher degree of esterification (64.38%). It can be seen that the ultrasonic assisted electrolysis water extraction method is an efficient and environmentally friendly method. The experimental research provides technical support for improving the added value of pomegranate fruit products and realizing the efficient and comprehensive utilization of by-products.

Key words: pomegranate pomace, pectin, electrolysis water, ultrasound