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

Table 3

Effects of pH on the enzymatic hydrolysis of regenerated silk fibroin using FoodPro and Alcalase at 60 °C.

Enzyme		FoodPro		Alcalase
pH	Time (h)	Residual protein (%)	Amino acids (mg/L)	Residual protein (%)	Amino acids (mg/L)
6.5	0	100.0 ± 0.92^c	27 ± 0.7^i	100.0 ± 2.55^c	27 ± 0.7^f
	3	84.9 ± 0.88^b	1,857 ± 10.0^h	86.4 ± 2.38^b	1,826 ± 42.8^e
	5	83.4 ± 4.87^b	2,058 ± 13.2^g	87.2 ± 2.53^b	1,895 ± 2.4^d
7.0	0	100.0 ± 0.49^c	27 ± 0.7^i	100.0 ± 1.62^c	27 ± 0.7^f
	3	80.6 ± 5.74^ab	2,223 ± 2.4^f	81.3 ± 0.69^a	2,072 ± 16.4^c
	5	80.7 ± 2.30^ab	2,254 ± 19.0^e	82.0 ± 2.45^a	2,156 ± 55.7^c
8.0	0	100.0 ± 1.92^c	27 ± 0.7^i	100.0 ± 1.83^c	27 ± 0.7^f
	3	79.7 ± 1.55^ab	2,355 ± 10.0^d	79.2 ± 2.59^a	2,300 ± 50.8^b
	5	77.4 ± 0.20^a	2,515 ± 25.5^a	79.0 ± 1.83^a	2,435 ± 6.4^a
9.0	0	100.0 ± 1.51^c	27 ± 0.7^i	100.0 ± 3.18^c	27 ± 0.7^f
	3	79.4 ± 4.45^ab	2,372 ± 14.0^c	79.5 ± 0.85^a	2,291 ± 148^b
	5	76.2 ± 1.50^a	2,442 ± 32.7^b	80.2 ± 1.24^a	2,397 ± 29.1^a

a–i: means in the same column followed by different letters differ significantly ().