Mechanisms of inulin addition affecting the properties of chicken myofibrillar protein gel

Abstract

This paper studied the effects of inulin addition (0–20 mg mL −1 ) on the properties of chicken myofibrillar protein (MP) heat-induced gel. The molecular forces to maintain the gel structure, gelling formation process and gel microstructure were studied to explore the influencing mechanism of inulin on gel properties of MP. The results showed that the springiness and hardness of MP-inulin gel significantly increased when inulin was added at 5–20 mg mL −1 , while the water holding capacity (WHC) significantly enhanced at 5–10 mg mL −1 inulin addition ( P < 0.05). The most appropriate inulin addition to improve the properties of MP mixed gel was 10 mg mL −1 . The addition of 20 mg mL −1 inulin decreased the cooking loss of mixed gel. Inulin promoted the exposure of more hydrophobic groups and the formation of disulfide bonds. Inulin addition significantly decreased the I850/I830 in Raman spectrometry, indicating an increase in the formation of hydrogen bonds with MP molecules. However, inulin had little effect on electrostatic interaction between MP molecules. During the heating process, the highest storage modulus (G′) value was observed in MP samples added with 15 mg·mL −1 inulin at gel forming and strengthening stage. The denaturation enthalpy (ΔH) value of myosin decreased when inulin exceeded 10 mg mL −1 . The microstructure showed that MP composite gel with 10 mg mL −1 inulin had a dense and well-aggregated network structure. These results indicated that inulin addition could make MP denaturation easier during heating, strengthen the molecular forces of MP and the gel network structure, thus improving the MP gel properties. • Inulin addition improved the gel properties and microstructure of myofibrillar protein. • Inulin strengthened the molecular forces of myofibrillar protein in gels. • Inulin addition made myofibrillar protein more prone to thermal denaturation. • Mechanisms of inulin addition affecting properties of myofibrillar protein gel was revealed.