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 degrees C was carried out. All maltodextrins slowed down the decreases in the denaturation enthalpies (deltaHd) ascribed to myosin and actin, making evident a noticeable effectiveness against protein denaturation, especially at -20 degrees C. Sucrose was as effective as maltodextrins at -20 degrees C, but was the least effective treatment at -10 degrees C. Significant correlations between both deltaHds 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 degrees C. Maximum denaturation temperatures (Tmax) correlated with protein solubility only at -20 degrees 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.