| Models | Equations | References |
| Newton | X* = exp(−kt) | Ayensu (1997) |
| Page | X* = exp(−ktn) | Ayensu (1997) |
| Henderson et Pabis | X* = a × exp(−kt) | Westerman et al., (1973) |
| Midilli | X* = a × exp(−ktn) + b × t | Midilli et al., (2002) |