Carrageenans in meat systems
Dennis G. Olson
Meat model systems were used to evaluate the interactions between meat proteins and carrageenans and the nature of the forces involved in such as interactions. Experiments conducted with salt-soluble meat proteins (SSMP) and carrageenan (CGN) mixtures indicated that the force needed to compress muscle protein and CGN gels varied with the type of CGN used. Addition of [kappa]- and \iota-CGN increased the gel strength of SSMP gels, however, this effect was significantly greater when [kappa]-CGN was used. The force needed to compress [kappa]-CGN and SSMP gels independently did not add up to the total force required to compress combined SSMP/[kappa]-CGN, suggesting that an interaction between these two polymers may have occurred. [lambda]-CGN affected negatively the gelation of SSMP. All CGN were effective in increasing water holding capacity. SDS-PAGE of samples treated with various destabilizing agents did not indicate the presence of an interaction. Cryo-Scanning electron microscopy studies of SSMP, [kappa]-CGN and SSMP/[kappa]-CGN gels suggested that improvement of water holding capacity and texture of combined SSMP/[kappa]-CGN gels may be due to physical reorganization of the molecules rather than to a molecular interaction between SSMP and [kappa]-CGN;Differential scanning calorimetry studies showed no evidence of protein-polysaccharide interaction. Changes in transition temperatures of myosin and actin were observed upon addition of salt, however, no major shifts in denaturation temperatures of meat proteins were detected when up to 2% CGN was used;The effect of salt type, pH, phosphates and carrageenans on the freeze/thaw stability of cooked-pork sausages was also evaluated. Sodium tripolyphosphate (STPP) decreased thaw drip and increased hardness of all treatments regardless of the type of salt of CGN. KCl did not affect the texture of control samples in the presence of STPP, but decreased the functionality of [kappa]- and \iota-CGN. Meat pH significantly (P < 0.05) increased the hardness and decreased the thaw drip of all CGN treatment, except for [lambda]-CGN which remained unchanged. [kappa]- and \iota-CGN were effective in improving the stability of sausages prepared with low pH meats.