*3.6. Correlation Analysis*

In order to shed light on the potential antibacterial components in spice extracts, the correlations among antibacterial activity on *S. aureus* (indicated by the DIZ values), antioxidant activity (indicated by the FRAP and TEAC values), and TPC were analyzed. As shown in Table 5, a strong positive correlation was found between TPC and FRAP/TEAC values (*r* > 0.9, *p* < 0.01), suggesting that polyphenols mainly contributed to the antioxidant activity of spice extracts. However, regarding the relationship between DIZ values and FRAP/TEAC values, a significant but weak positive correlation (*r* < 0.5, *p* < 0.01) was observed, indicating that antioxidant activity of spice extracts was only slightly related to their antibacterial capacity. Besides, DIZ values were also found to be weakly correlated with TPC (*r* = 0.541 and 0.568, *p* < 0.01), suggesting that polyphenols were only partly responsible for the antibacterial activity of spice extracts on *S. aureus*, and some other substances should exist in spice extracts to contribute to their overall antibacterial activity.

**Table 5.** Correlation analysis among antibacterial activity, antioxidant activity, and total phenolic content.


Pearson correlation analysis was performed to analyze the relationships among the means of parameters. *p* < 0.01 was defined as statistical significance.
