Figure 1.

Protocols for the experiments: (a) The cooling experiment. (1) t_ext (extraction time) to remove samples from the heater at 65±2°C and pH 1.6 (1.5 h was the time chosen). (2) Δt_cool (cooling time at 25±2°C and pH 1.6) for different times up to 28 days, and (3) t_repl (replacement time) to replace the cooler samples into 65±2°C and pH 1.6. For graph (i), the standard kinetic curve () was obtained by fitting Eq. (2) to averaged data from twelve different runs. The values of the parameters from the model fit using Eq. (2) were: t_lag = 3.47 h, t₅₀ = 4 h, k_app = 3.76 h^-1 (R²=0.983). For graph (ii), we used averaged data for the standard kinetic experiment (◆) and for cooled and re-heated samples (). (b) The seeding experiment. (1) Left figure: t_{ext,olig/fiber} (extraction time for oligomer or fiber) is the time at which samples are removed from a run at 65±2°C and pH 1.6, and (2) Right figure: sigmoidal curves with and without seeds. Averaged data were used for the standard kinetic experiment (◆) and for a seeded run (). Model fits using Eq. (2) ().