Table 3. Antioxidant enzymes activity of duck and chicken breast exposed with gaseous ozone during refrigerated storage.

Item	Treatment	Storage (day)
		0	1	2	3	4
Catalase activity (U/g)	Duck+Ozone	93.35±6.1aA	87.40±5.1aB	73.61±1.3aC	65.36±8.1bD	58.82±5.6bE
	Duck	93.35±6.1aA	89.56±7.5aA	78.19±8.3aB	75.82 ±1.3aB	68.15±10.3aC
	Chicken+Ozone	55.89±8.7bA	46.70±4.7bB	44.12±5.3bBC	40.17±1.3cC	30.38±5.6cD
	Chicken	55.89±8.7bA	49.19±3.4bB	48.31±5.6bB	42.19±4.3cC	30.96±5.1cC
Glutathione peroxidase activity (U/g)	Duck+Ozone	0.28±0.06aA	0.21±0.06bAB	0.19±0.01aB	0.16±0.01aBC	0.12±0.07bC
	Duck	0.28±0.06aA	0.27±0.09aA	0.23±0.05aAB	0.20±0.05aB	0.18±0.03aB
	Chicken+Ozone	0.26±0.10aA	0.21±0.05bA	0.21±0.06aA	0.18±0.06aA	0.13±0.02bB
	Chicken	0.26±0.10aA	0.25±0.09abA	0.22±0.01aAB	0.20±0.04aB	0.15±0.06abB

Mean values±standard deviation.

^a-dMeans in the same column followed by different superscript letters in lower-case are significantly different (p<0.05).

^A-EMeans in the same row followed by different superscript letters in upper-case are significantly different (p<0.05).