Underlying mechanisms and combined effects of transglutaminase and κ-carrageenan on the quality profiles and in vitro digestibility of frankfurters

Abstract

As a typical emulsified meat product, frankfurters have been widely consumed all over the world mainly due to their unique flavor, desired oral sensation, and higher nutritional values. The present study aimed to investigate the combined effects of different concentrations (0, 0.1, 0.3, and 0.5%, w/w) of transglutaminase (TG) and κ-carrageenan (KC, 0.2%, w/w) on the quality profiles and in vitro digestibility of frankfurters. The results showed that the combination of TG and KC significantly reduced the cooking loss and significantly promoted the emulsion stability of frankfurters (P < 0.05). Meanwhile, compared with frankfurters containing TG or KC alone, the simultaneous incorporation of 0.3% TG and 0.2% KC had the best optimal promoting effect on the textural properties of frankfurters, as well as the formation of denser and finer meat protein gel matrix. Moreover, hydrogen bonds and disulfide bonds were the main molecular forces of the frankfurters in the presence of TG and KC. In addition, the combination of TG and KC resulted in lower in vitro protein digestibility of frankfurters than those with TG or KC alone (P < 0.05), which was mainly because TG-induced cross-linking promoted the formation of ordered conformation of meat protein and subsequently enhanced the physical entanglement between KC and meat protein. In short, our results provided some vital information for the simultaneous incorporation of TG and KC in the processing of emulsified meat products.