Abstract: In order to explore the optimal ultra high pressure (UHP) treatment for enhancing the effect of flaxseed gum in improving myofibrillar protein gel properties, myofibrillar protein gels with flaxseed gum treated under different pressure conditions (0.1–400 MPa, 10 min) were evaluated for rheological properties, water distribution as analyzed by low-field nuclear magnetic resonance (NMR), intermolecular forces and microstructure. The influence of UHP on the effect of flaxseed gum on the water-holding capacity (WHC) and strength of myofibrillar protein gel was elucidated. The results showed that upon exposure to pressure ranging between 0.1 and 100 MPa, flaxseed gum significantly increased the WHC, and decreased the storage modulus (G’), loss modulus (G’’) and gel strength (P < 0.05); at a pressure of up to 200 MPa, flaxseed gum further enhanced the WHC and increased G’, G’’ and the peak area of bound water of myofibrillar protein gel, promoting the formation of a compact cross-linked gel network structure and consequently increasing the gel strength (P < 0.05); the effect of flaxseed gum on the WHC and gel strength was mitigated with increasing pressure from 300 to 400 MPa. Hydrophobicity and reactive sulfhydryl group content increased significantly in both the control and treatment groups with increasing pressure from 0.1 to 400 MPa (P < 0.05) and were not affected by the presence or absence of flaxseed gum. In conclusion, flaxseed gum can improve the gel properties of myofibrillar protein to the maximum extent at 200 MPa, and this pressure is optimal for improved gel properties of myofibrillar protein with flaxseed gum.

Key words: myofibrillar protein, ultra high pressure, flaxseed gum, gel properties, mechanism