extremely significantp < 0.01
The experimental variables were associated with the following formula: Yields = 4.68 + 0.23 A + 0.12 B + 0.63 C − 0.025 AB − 0.15 AC − 0.13 BC − 0.18 A 2 − 0.47 B 2 − 1.33 C 2 The variance analysis demonstrated that coefficients A , B , C , AC , BC , A 2 , B 2 , and C 2 were extremely significant ( p < 0.01), whereas the interaction effects of AB showed no significant difference on cCPP yields, which indicates that the variables A , B , C , AC , BC , A 2 , B 2 , and C 2 could significantly influence the extraction yields of cCPPs.