To evaluate the relationship between muscle fiber characteristics and the quality of frozen/thawed pork meat, four different muscles, M.longissimus thoracis et lumborum (LTL), M. psoas major (PM), M.semimembranosus (SM), and M. semitendinosus (ST), were analyzed from twenty carcasses. Meat color values (lightness, redness, yellowness, chroma, and hue) changed due to freezing/thawing in LTL, which showed larger IIAX, IIX, and IIXB fibers than found in SM (P < 0.05). SM and ST showed a significant decrease in purge loss and an increase in shear force caused by freezing/thawing (P < 0.05).
Fig: Representative stained cross-sections (A) and relative cross-sectional area (B) of pork skeletal muscles. LTL, M. longissimus thoracis et lumborum; PM, M. psoas major; SM, M. semimembranosus; ST, M. semitendinosus; nc, not considered. The merged images were obtained by incubation with BA-F8 (anti-myosin heavy chain (MHC) slow), SC-71 (anti-MHC 2a and 2x), BF-35 (anti-MHC slow and 2a), and BF-F3 (anti-MHC 2b). Bar = 100 µm. Different letters (a–d) on the bar in (B) indicate significant differences between muscle fiber types within the same muscle at P < 0.05.
Compared with LTL, SM contains more type IIXB muscle fibers and ST had larger muscle fibers I and IIA (P < 0.05). PM was the most stable of all muscles, since only its yellowness and chroma were affected by freezing/thawing (P < 0.05). These results suggest that pork muscle fiber characteristics of individual cuts must be considered to avoid quality deterioration during frozen storage.
Cheng, H., Song, S. & Kim, GD. Frozen/thawed meat quality associated with muscle fiber characteristics of porcine longissimus thoracis et lumborum, psoas major, semimembranosus, andsemitendinosus muscles. Sci Rep 11, 13354 (2021). https://doi.org/10.1038/s41598-021-92908-3