Abstract:

This study investigated and compared meat color, thawing loss, cooking loss, and shear force of beef subjected
to normal freezing and quick freezing. The microstructure of frozen beef was also studied by HE staining, scanning electron
microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the H value of bovine tendon
muscle subjected to quick freezing-thawing process rose by only 0.9%, compared to as high as 9.4% for the normally
frozen and thawed sample, suggesting a significant difference between both freezing methods (P < 0.05). Thawing loss of
beef tendon muscle subjected to normal freezing was significantly higher than that of the sample subjected to fast freezing
(P < 0.01). At the same time, cooking loss of beef tendon muscle subjected to normal freezing was also significantly higher
than that of the samples subjected to fast freezing (P < 0.05). In addition, shear force of beef tendon muscle subjected to normal
freezing was lower but not significantly than that of the quick-frozen and control groups. Electron microscopy results showed
that normal freezing could result in noticeably bigger intermuscular gap and larger intermyofibrillar space in thawed beef when
compared with fast freezing, and it also destroyed the cross-sectional area of muscle fibers. On the other hand, fast freezing could
protect the bright color of beef and improve its eating quality. In addition, fast freezing could greatly reduce the size of ice crystals
in meat, protect the microstructure of meat, and optimize the taste of meat.

Key words: fast freezing, beef, quality, structure