Functional Protein Components in Lean Finely Textured Tissue from Beef and Pork

Abstract

High ionic strength soluble (HIS) proteins, low ionic strength soluble (LIS) proteins, and insoluble (IN) proteins from lean finely textured tissue (LFTT) which was derived from beef and pork trimmings, were evaluated. The IN protein fraction was the major component in LFTT, followed by the LIS protein fraction. The HIS protein fraction from LFTT was present in the smallest quantity. Gels from LFTT had a soft texture and low water retention due to the low level of HIS proteins. SDS-PAGE showed that the major proteins in the LFTT HIS fraction were myosin and actin, but they were present in much smaller quantities than in muscle meats.

Frankfurters with Lean Finely Textured Tissue as Affected by Ingredients

“…LFTB and LFTP responded somewhat differently to changes in salt, suggesting a different performance by proteins from the two LFTT (He and Sebranek, 1996). Batters made from LFTP produced a more stable mixture, especially relative to fat binding than those made with LFTB.…”

“…It was not clear what caused this difference. However, a comparison of the two LFTT products has shown that LFTB contained a smaller quantity of high ionic strength soluble (HIS) proteins than LFTP (He and Sebranek, 1996). The greater effect of -carrageenan on gel strength of LFTB protein extracts may reflect more interactions between -carrageenan molecules in the absence of HIS protein interactions.…”

“…Use of LFTP resulted in no difference for firmness or cohesiveness. LFTT had a different protein solubility profile as compared with regular muscle meat with less solubilized high ionic strength proteins (He and Sebranek, 1996). Protein gelation of myofibrillar protein (high ionic strength soluble) determines the development of a desirable structure of meat product (Asghar et al, 1985).…”

“…Substituting LFTB for muscle meat in frankfurters resulted in less soluble myofibrillar protein; therefore, less protein interactions probably occurred, resulting in softer texture of the frankfurters. Likewise, the greater amount of low ionic strength soluble proteins from LFTT (He and Sebranek, 1996) may have softening effects on texture (Nuckles and Smith, 1991). The LFTB had a greater collagen content as well, which may soften the texture of these products (Ladwig et al, 1989a).…”

“…These materials are high in protein and low in fat, and may serve as an economical lean substitute. However, the functionality of LFTB and LFTP has been shown to be less than for lean beef or pork (He and Sebranek, 1996). Many nonmeat ingredients such as salt, phosphates, carrageenans, and isolated soy protein (ISP) are used to maintain or improve functionality and stability of processed meats.…”