Abstract:

The active protein films prepared with different concentrations of rosemary and soy protein isolate were used for
color protection and preservation of fresh pork in high-oxygen modified atmosphere. Changes in CIE a* value, metmyoglobin,
thiobarbituric acid reactive substances (TBARS) value, protein carbonyl and hardness value of fresh pork were determined.
The results showed that direct treatment with rosemary at 0.05 g/100 mL effectively inhibited lipid oxidation and discolouration
in the later period of storage in high oxygen atmosphere packaging. Protein films incorporated with different concentrations
of rosemary showed different antioxidant effects on pork. Pure protein film and the film with rosemary at a concentration of
0.025 g/100 mL were unable to inhibit discoloration of pork, but they delayed lipid and protein oxidation to a certain extent.
The films with rosemary concentration at 0.1 and 0.2 g/100 mL effectively delayed the decline of a* value and the formation of
metmyoglobin and TBARS value, and its protection on meat color was better than that observed with direct addition of rosemary,
but these two groups failed to inhibit the formation of protein carbonyl. While the film with 0.05 g of rosemary /100 mL exerted
better protection than that of direct addition of rosemary on color, lipids, proteins and other parameters of fresh pork, it basically
maintained the hardness value of meat during storage. These results indicate that protein film incorporated with rosemary increased
the antioxidant activity of rosemary on pork in high oxygen atmosphere packaging.

Key words: rosemary, soy protein isolate, high-oxygen modified atmosphere, antioxidation, pork