Effects Of Resistant Corn Starch And High Pressure Processing On The Thermal Gelling Properties Of Myosin

Myosin (M) is the main gelling protein during the gelation process of meat, which determines the gel properties of meat products. Basing on good processing characteristics and the dietary fiber function of resistant corn starch (RCS), and the application of high pressure processing (HPP) for the development of low-fat meat products, the effects of RCS on the properties of chicken breast myosin gel and HPP on the properties of M-RCS gel were investigated. The mechanism of heat-induced gelation was explored with detecting the molecular properties, physicochemical properties and microstructure of the M-RCS system. The results showed as follow:(1) RCS (0.1-0.6%, w/w) could significantly increase the water holding-capacity (WHC) and gel strength of M gels (P<0.05).(2) RCS could significantly increase the turbidity and reactive sulfhydryl groups of M-RCS, could decrease the surface hydrophobicity (P＜0.05), increase the a-helix content, decrease β-folding content (P<0.05), and could improve the thermal denaturation peak temperature Tpeak2 of the myosin, while reducing the phase-transition enthalpy △H2 value (P<0.05). Moreover, RCS could enhance the thermal induced gel abilities of M, increase the storage modulus G’ value and reduce the relaxation time T22 and T23 of water proton (P<0.05), and weakened the water mobility in M-RCS gels. RCS also induced a crosslinking, homogenous and three-dimensional gel network structure. These resulted in high WHC value and gel strength.(3) HPP (100-400MPa) could significantly increase WHC of M-RCS gels while decreasing the gel strength (P<0.05).(4) HPP could promote the unfolding of protein and molecular aggregation in the M-RCS, and lead to its turbidity, active sulphur content and surface hydrophobicity increased (P＜0.05); a-helix content decreased, the content of β-angle increased (P<0.05). HPP could decrease the thermal denaturation peak temperature Tpedt(P＜0.05), lower thermal stability of the M-RCS system, weaken the thermal induced gel abilities of M-RCS, and decrease the storage modulus G’value. Meanwhile, the relaxation time T2 of water proton of the M-RCS system reduced (P<0.05), which enhance the entrapping water ability of M-RCS. Moreover, HPP eventually lead to M-RCS system form a high degree of aggregation, soft tissue, large hollow and uniform gel network structure, and increase the WHC value and decrease gelstrength of the M-RCS system.(5) These results will provide a theoretical basis for the development of functional meat products with low-fat and high dietary fiber.