Effects of inulin with different polymerization degrees on the structural and gelation properties of potato protein
Qiongling Chen, Xiaowen Wang, Yu Wang, Tianqi Guo, Peihan Guan, Jinyu Hou, Zhenjia Chen
Abstract
This study investigated the effect of inulin with different polymerization degrees (DP), including L-inulin (DP 2–6), M-inulin (DP 10–23) and H-inulin (DP 23–46), on the structural and gelation properties of potato protein isolate (PPI). Results revealed that textural properties (hardness, cohesiveness, springiness and chewiness) and water-holding capacity (WHC) of PPI-inulin composite gels were positively correlated with the inulin DP and addition content at 0–1.5% (w/v), but deteriorated at 2% due to phase separation. The addition of 1.5% H-inulin showed the most significant increment effects on the WHC (18.65%) and hardness (2.84 N) of PPI gel. Furthermore, M-/H-inulin were more effective in increasing the whiteness and surface hydrophobicity, as well as in strengthening hydrogen bonds and hydrophobic interactions than L-inulin. Fourier transform infrared spectroscopy analysis and microstructural observation indicated that inulin with higher DP promoted more generation of β-sheet structures, and leading to the formation of stronger and finer network structures.