摘要：Two thermal analysis techniques – Differential scanning calorimetry (DSC) and Differential thermal analysis (DTA), – were used to study the cryoprotective effects of polydextrose on chicken surimi. The samples of chicken surimi were mixed with: (a) different mass fractions of polydextrose ( w = 2–10%), (b) κ-carrageenan ( w = 0.5%) and different mass fractions of polydextrose ( w = 2–10%), and (c) NaCl ( w = 2%) and different mass fractions of polydextrose ( w = 2–10%). Chicken surimi was produced following a modified procedure of Dawson et al . (1988) on a broiler (Sasso, 12 weeks, and 1.73 kg live wt.), that was quickly frozen and stored for 3 months at –25°C. Initial freezing point (Ti), thermal transition temperature (Tp), and denaturation enthalpy (Δ H ) were evaluated. The greatest effects of the cryoscopic depression of the initial freezing point Ti were exhibited by the samples of chicken surimi with added 2% NaCl and 10% polydextrose. Differential scanning calorimetry (DSC) revealed a shift in the thermal transition temperature of myosin and actin to a higher temperature as the mass fraction of polydextrose increased. Since the denaturation enthalpy is directly related to the amount of native proteins, higher values of Δ H indicate higher cryoprotective effects of polydextrose.
