Food Science: Professor Luo Ruiming, Ningxia University, et al.: Effects of ATPase activity changes on microstructure and water retention during post-slaughter ripening of Tan mutton

Tan sheep are high-quality characteristic breeds distributed in Shaanxi, Gansu and Ningxia, and are loved by consumers because of their delicious meat and rich nutrition
.
At present, excessive juice loss during post-slaughter ripening is still one of the main problems affecting the appearance, nutritional value and economic value of
Tan lamb.
Therefore, it is of great significance
to study the formation of drip loss during post-slaughter ripening to guide the production and processing of Tan mutton.

Ji Chen, Luo Ruiming* and others from the College of Agronomy of Ningxia University selected the longitis dorsal muscle of Tan sheep as the research object, matured for 8 days, and determined the response of water retention of Tan lamb to the change of ATPases activity by measuring ATPase activity, Caspase-3 viability, microstructure and quality index changes, in order to provide a theoretical basis
for guiding the production and processing of Tan mutton.

1.
Changes in pH value and drip loss rate during the ripening process of Tan lamb after slaughter

It can be seen from Fig.
1 that the drip loss rate of the longest muscle of the back of the sheep during post-slaughter maturation showed a trend of first increasing and then decreasing with the extension of maturity time (P<0.
05), and reached a maximum value (7.
57%)<b10> at 2 days of maturity.
The higher the drip loss rate, the worse the water retention of meat, indicating that the water retention of Tan lamb was poor when ripening for 2 days, and with the extension of the ripening time, the water content that could be lost in the meat was generally reduced, so the drip loss rate also decreased
.

It can be seen from Figure 2 that the pH value of beach lamb decreased significantly (P<0.
05) after 0~2 days of maturity, and decreased to the lowest (5.
55) when ripening 2 days, and the change was not significant (P>0.
05) after 2~4 days, and increased significantly to 5.
63 (P<0.
05)<b10> after 4 days.
Previous studies have shown that the muscle pH of livestock can be reduced to 5.
4~6.
3 in the early stage of post-slaughter maturity, and the results of this study are in line with this rule
.
During post-slaughter maturation, the rate and degree of muscle pH decline significantly affect the activity of metabolic enzymes, which has an important impact
on meat color, tenderness, water retention and the formation of flavor precursors.

2.
Changes in the microstructure of the longest muscles and degradation of myofibrillar protein during post-slaughter maturation