## 3 Results and Discussion
### Pressing Time  
The pressing time was noted in all STDs. The predicted center point STDs 9, 10, and 11 (restriction die: 0.6 cm, temperature: 60 \({}^{\circ}\)C, and sieve size > 1.4 mm) showed a pressing time of 37.00 min, whereas the actual values were observed as 42.00, 35.00, and 39.00 min, respectively. Other center point STDs 20, 21, and 22 (restriction die: 0.6 cm, temperature: 60 \({}^{\circ}\)C, and sieve size < 1.4 mm) showed a predicted pressing time of 90.34 min, but the actual values were found to be 96.00, 92.00, and 89.00 min, respectively (Table 2).  
Analysis of variance of the 2 FI model for the pressing time showed that the model was significant (\(p\) < 0.0001) with adjusted R\({}^{2}\) (0.9861), predicted R\({}^{2}\) (0.9779), and non-significant lack of fit (\(p\) = 0.6063) values (Table 3). The results indicated that the 2 FI model equation was acceptable for predicting the pressing time to produce CSO. The CCD-generated 2 FI equation for pressing time (min) was as follows (Equations (12) and (13)):  
\[\text{Time (min)}=42.8613-15.6022\text{A}+0.0356\text{B}+0.0378\text{AB}\text{ (For sieve size > 1.4 mm)} \tag{12}\]  
\[\text{Time (min)}=105.7059+17.0728\text{A}-0.4494\text{B}+0.0378\text{AB}\text{ (For sieve size < 1.4 mm)} \tag{13}\]  
The pressing time influenced the rubber seed oil yield, which increased with pressing time [38]. Pressing time is one factor that affects the yield and quality of the oil. When we used sieve level 1, the pressing time did not alter, whereas sieve level 2 showed significant fluctuations in the pressing time (Figure 5).  
The maximum recovery of sesame oil was achieved with a restriction die size of 10 mm, seed moisture content of 8.03%, and pressing speed of 20 rpm using the screw-pressing method [39]. In our study, when the pressing time increased (100 min), the TPC (5.18 \(\upmu\)g GAE/g of oil) decreased (Tables 2 and 3). The results indicated that if the cocoa seed was exposed to heat for a long time, even at a low temperature, the TPC content would be affected. Sieve size plays a critical role in pressing time. At the same temperature (40 \({}^{\circ}\)C) and restriction die size (0.8 cm), different sieve sizes had a dramatic effect on the pressing time (level 1: 35 min, level 2: 100 min) (Table 2).  
The ANOVA analysis suggested that temperature and sieve size had a significant (\(p\) = 0.0044) impact on CSO yield. The temperature (\(p\) = 0.0036), sieve size (\(p\) < 0.0001), restriction die and sieve size (\(p\) = 0.0079), and temperature and sieve size (\(p\) = 0.0004) significantly influenced the pressing time.  
Figure 4: Response surface plot showing the effect of temperature and restriction die size on total phenolic content of CSO. (**a**) Sieve size: >1.4 mm, (**b**) Sieve size: <1.4 mm.  
The restriction die (\(p\) = 0.0055), temperature (\(p\) = 0.0248), sieve size (\(p\) = 0.0346), temperature and sieve size (\(p\) = 0.0065), and temperature\({}^{2}\) (\(p\) = 0.0023) significantly influenced the acid value.  
The restriction die (\(p\) = 0.001), temperature (\(p\) = 0.0425), and the restriction die and temperature\({}^{2}\) (\(p\) = 0.0026) significantly influenced the peroxide value.  
The temperature (\(p\) = 0.0001), sieve size (\(p\) = 0.0078), restriction die and temperature (\(p\) = 0.0363), restriction die and sieve size (\(p\) = 0.0428), and the restriction die\({}^{2}\) and sieve size (\(p\) = 0.007) significantly influenced the total phenolic content for CSO extraction (Table 4).