The multiple quadratic regression equation fitting the relationship between the four factors and PCs content is as follows: 9 According to Table 9 , the model is highly significant ( p ≤ 0.001), indicating high credibility.
In contrast, the lactose, citrate, and sodium benzoate treatment groups demonstrated a decreasing trend in DPPH radical scavenging capacity (Fig. 5 A, B and C) ( p < 0.05).
Results and analysis of effects of food ingredients on DPPH radical scavenging ability Compared to their respective control groups, the DPPH radical scavenging capacity of crude PCs extract in the glucose, sucrose, ascorbic acid, and sodium bisulfite treatment groups exhibited an increasing trend with rising concentrations ( p < 0.05).