Page 250 - Natural Antioxidants, Applications in Foods of Animal Origin

Methods and Their Applications for Measuring 229
VetBooks.ir meat color and flavor) of these products. High oxygen (80%) modified

atmosphere packaging (HOX MAPackaging) was developed to maintain the
freshness by maintaining levels of oxygenated myoglobin pigments during
lengthy distribution and storage at retailers.

6.2.5 ANALYSIS OF OXIDATION OF RAW MEAT PIGMENTS

HOX MAPackaing provides an oxygen rich headspace to maintain high
levels of oxymyoglobin (the pigment responsible for the bright pink or red
color of ground meat and sausages). The data in the Figure 6.19 show how
headspace gases in HOX MAPackaged ground beef change during storage.
The biochemically active meat absorbs oxygen from the headspace to convert
myoblobin (a purple meat pigment) to oxymyoglobin (oxygenation) and also
promotes lipid oxidation. As oxygen is depleted in the headspace, meat color
decreases as oxymyoglobin levels decrease and lipid oxidation increases.
Photographs 6.2(a), 2(b), and 2(c) of HOX MAPackaged ground turkey
(70% ground skinless thigh meat, 30% breast trimmings) show the change in
color during storage in a cooler (Pettersen et al., 2004). From left to right the
HOX MAPackaged ground turkey becomes progressively more oxidized, raw
meat color becomes progressively less appealing (i.e., lower colorimetric a*
values). At some point, the deterioration of color would result in discounting
the price of the meat product to the consumer or discarding the product.

PHOTOGRAPHS 6.2(a), (b), and (c), left to right. For minimally processed HOX
MAPackaged products, raw meat color and lipid oxidation are inversely related. As meat
color degrades to brown, lipid oxidation (as measured by TBARS) increases. Photographs
and colorimetry data from internal study.

Photographs 6.3(a) and 3(b) of 80% lean HOX MAPackaged ground
beef show color degradation over time. Colorimetry data (colorimetric a*)
are higher in beef than that of turkey due to the increased inherent concentra-
tion of oxymyoglobin in 80% lean beef compared to that of ground turkey
with 30% breast muscle trimmings.