A common peak eluted around 6.5 mL was detected in high intensity with the MALLS detector, which coincided with high RI intensity. Thus, a high molar weight component was present in a high concentration, and could be assigned to pectic polysaccharide. An intense RI peak eluted around 8.5 mL (Fig. 4c), coincided with that with a minimal light scattering intensity, possibly due to the co-extracted high concentration of low molecular weight polymer together with the dragon fruit pectin which was absent in apple and citrus pectins. The co-eluted low molecular weight polymer with the predominant pectic polysaccharides could be the free neutral polysaccharides or pectin side chains (Kravtchenko, Berth,
Voragen, & Pilnik, 1992). A common peak eluted around 9.5 mL could be attributed to the contaminant protein that is usually present in minor amount in pectin. The root mean square radius of dragon fruit peel pectin was not significantly different from that of the commercial pectins.