Table 1. Characterization of edible silk fibroin coating thickness as a function of dip coating steps and of relative beta-sheet content as a function of exposure time to water annealing.

Number of dip coating processes (x) in silk fibroin suspension [Dx]	Thickness [μDm]
D1	27 ±D 8
D2	32 ±D 7
D4	35 ±D 8
Exposure time to water annealing post-processing [hours]	Silk fibroin coating crystallinity [relative content of beta-sheet structures, %]
0	23 ±D 2
1	36 ±D 3
6	48 ±D 4
12	58 ±D 5

No statistically significant difference was found in the coating thickness for increasing number of dip coating steps. The relative beta sheet content of silk fibroin coating was calculated with a previously reported methodology based on the quantification of the relative beta sheets structures in the Amide III absorbance peak collected with ATR-FTIR spectroscopic analysis.