Research Article

Application of Food-Grade Proteolytic Enzyme for the Hydrolysis of Regenerated Silk Fibroin from Bombyx mori

Table 4

Selection of the second proteolytic enzyme to enhance the efficiency of enzymatic hydrolysis of FoodPro-treated silk fibroin.

Enzyme treatmentStageReaction conditionResidual protein (%)Amino acids (mg/L)
Time (h)Temperature (°C)pH

Silk fibroin060100.0 ± 1.54c17 ± 0.7j
1st step: FoodPro (FP)13608.070.6 ± 3.81b2,040 ± 23.7i
2nd stepFP ⟶ Alcalase2+3608.065.5 ± 5.67b2,611 ± 22.0d
FP ⟶ Alphalase2+3607.065.6 ± 6.83b2,505 ± 28.7e
FP ⟶ Bromelain2+3507.068.7 ± 9.73b2,455 ± 16.2fg
FP ⟶ Collupulin2+3606.068.5 ± 8.32b2,227 ± 4.7h
FP ⟶ Flavourzyme2+3507.055.1 ± 2.91a4,519 ± 42.1a
FP ⟶ Neutrase2+3507.065.4 ± 8.68b2,453 ± 16.2fg
FP ⟶ Pomod 1922+3505.067.1 ± 7.39b2,689 ± 54.7c
FP ⟶ Promod 2782+3607.067.7 ± 7.61b2,438 ± 35.7g
FP ⟶ Promod 2792+3605.065.0 ± 7.38b2,746 ± 18.7b
FP ⟶ Protamex2+3507.066.6 ± 6.11b2,453 ± 25.7f

+3: additional reaction time. a–j: means in the same column followed by different letters differ significantly (p < 0.05).