The overall lipid oxidation was drastically accelerated as storage
progressed due to the denatured structure of the pork muscles
through cooking treatment and aerobic storage. The initial TBA value
of the control (CON) was 1.60 mg MDA/kg sample and increased
to 4.81 mg MDA/kg sample after 12 days storage.
Samples treated with different concentrations of CHI had no significant
difference (p > 0.05) which reached the value about 4.08 mg
MDA/kg sample, indicating a weaker antioxidation. GOG10 and
GOG5, respectively reduced the final TBA value by 34.7% and
25.2% than the CON sample and high concentration of GOG had
better effect, which showed stronger antioxidation than CHI.
Stewed-pork treated with high concenrtation of ginger, onion,
garlic–chitosan solution (Mix1) had the lowest TBA value
(2.24 mg MDA/kg sample) at the end of storage. This may be due
to strong antioxidant activity of spice extracts and synergistic
effect with chitosan. These results were consistent with studies
done by Kim et al. (2010), who reported fresh semimembranosus
pork marinated with garlic or onion juice improved meat quality
and extended the shelf life to 7 days. Hettiarachchy, Glenn,
Gnanasambandam, and Johnson (1996) reported the synergistic
effectiveness of synthetic and natural antioxidants in controlling
lipid oxidation in meat products and obtained the similar results.