A DSC study on the effects of various maltodextrins and sucrose on protein changes in frozen-stored minced blue whiting muscle

Abstract

A DSC heat denaturation study on the effects of various maltodextrins and sucrose on protein changes in minced blue whiting muscle during frozen storage at −10 and −20 °C was carried out. All maltodextrins slowed down the decreases in the denaturation enthalpies (ΔHd) ascribed to myosin and actin, making evident a noticeable effectiveness against protein denaturation, especially at −20 °C. Sucrose was as effective as maltodextrins at −20 °C, but was the least effective treatment at −10 °C. Significant correlations between both ΔHds and either protein solubility or formaldehyde production were found at each storage temperature. A low protein sensitivity to the small amounts of formaldehyde produced during the first weeks of storage and errors associated with the determination of enthalpies led to poorer correlations at −20 °C. Maximum denaturation temperatures (Tmax) correlated with protein solubility only at −20 °C. No clear relationship between either Tmax and the effectiveness of cryostabilisation was found, as Tmax also depends on the effectiveness of the treatments against the thermal denaturation of proteins.