Optimization of Keratin Hydrolysate Extraction from Tannery Sheep Hair Waste

Table 1

The Box-Behnken experimental design of KH extraction.

Variables	Low (−)	Middle (0)	High (+)
Temperature (°C)	65	80	95
The concentration of NaOH (N)	0.5	0.75	1.0
Time (hr.)	1.50	2.50	3.50