Digestibility and Physicochemical Characteristics of Blood Sausages Made with Korean Traditional Fermented Food

This study evaluated the quality characteristics of blood sausages where salt (NaCl) was replaced with traditional Korean fermented foods. Five types of traditional fermented materials were used as salt substitutes: Doenjang (T1), Gochujang (T2), Cheonggukjang (T3), Magjang (T4), and Kimchi (T5). The salinity of each traditional fermented food material was measured, and amounts equivalent to 1.5% salt were added. Blood sausages containing these fermented foods had higher protein content and pH compared to the control (p<0.05). Protein digestibility was also improved by the addition of fermented foods (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the protein distribution in T3 had a higher amount of low-molecular-weight proteins in the 25-50 kDa range compared to the other treatments. The hardness, gumminess, and chewiness were the highest in the control and lowest in T3 (p<0.05). Springiness and cohesiveness did not show significant differences among the treatments. The amino acid composition showed no difference in total content (p>0.05). However, Glu and Ser levels were significantly higher in sausages supplemented with traditional fermented food than in the control (p<0.05). Apparent viscosity and storage modulus (G') of blood sausages with Korean traditional fermented foods were lower than those of the control. Loss modulus (G") and tan δ tended to be lower in all treatments compared to the control, except for T4. Therefore, traditional Korean fermented foods are effective at tenderizing the physical properties and improving the protein digestibility of blood sausages.