Effects of different mechanical processes on the structural and powdery properties of insoluble undenatured type II collagen

•Insoluble undenatured type II collagen (IUC-II) was gained by non-enzymatic method.•The structural and powdery properties were regulated by three mechanical processes.•Wet medium milling was most effective in improving powdery properties of IUC-II.•Low-acyl gellan gum (LAGG) could protect the triple helix structure of IUC-II.•LAGG further improved powdery properties but hindered the digestion of IUC-II.