High pressure processing accelarated the release of RG-I pectic polysaccharides from citrus peel.

High pressure processing (HPP) has become a promising strategy for extracting bioactive constituents. In this study, the impact of HPP treatment at various pH values (2.0, 8.0, and 12.0) on the macromolecular, structural, antioxidant capacity, rheological characteristics and gel properties of citrus pectic polysaccharide was investigated. The results showed that pressure and pH significantly affected the yield and Rhamnogalacturonan I (RG-I) characterizations. The yields of high pressure extraction at pH 12 (28.13 %-33.95 %) were significantly higher than the yields at pH 2 (14.85 %-16.11 %) and pH 8 (8.75 %-9.65 %). The yield of HPP (500 MPa/10 min) assisted alkali extraction is more than 2 times of that of HPP assisted acid extraction. The RG-I structure ratio of HPP-alkali extraction pectic polysaccharide (74.51 %) was significantly higher than that of traditional pectin (41.83 %). The results showed that HPP assisted alkali is a potential pectic polysaccharide extraction technology.