Table 1. Face centered design for optimization of senior-friendly gelatin gels formulated with pork skin gelatin, κ-carrageenan, and calcium chloride
| Sample number | Experimental factor |
| Code value | Real value (%, w/v) |
| X1 | X2 | X3 | Gelatin | Carrageenan | Calcium chloride |
| 1 | –1 | –1 | –1 | 6.60 | 2.50 | 0.235 |
| 2 | 1 | –1 | –1 | 33.00 | 2.50 | 0.235 |
| 3 | –1 | 1 | –1 | 6.60 | 6.25 | 0.235 |
| 4 | 1 | 1 | –1 | 33.00 | 6.25 | 0.235 |
| 5 | –1 | –1 | 1 | 6.60 | 2.50 | 2.351 |
| 6 | 1 | –1 | 1 | 33.00 | 2.50 | 2.351 |
| 7 | –1 | 1 | 1 | 6.60 | 6.25 | 2.351 |
| 8 | 1 | 1 | 1 | 33.00 | 6.25 | 2.351 |
| 9 | –1 | 0 | 0 | 6.60 | 4.375 | 1.293 |
| 10 | 1 | 0 | 0 | 33.00 | 4.375 | 1.293 |
| 11 | 0 | –1 | 0 | 19.80 | 2.50 | 1.293 |
| 12 | 0 | 1 | 0 | 19.80 | 6.25 | 1.293 |
| 13 | 0 | 0 | –1 | 19.80 | 4.375 | 0.235 |
| 14 | 0 | 0 | 1 | 19.80 | 4.375 | 2.351 |
| 15 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |
| 16 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |
| 17 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |
| 18 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |
| 19 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |
| 20 | 0 | 0 | 0 | 19.80 | 4.375 | 1.293 |