Table 4. Polynomial equations of Opuntia hymifusa stem by enzyme hydrolysis condition

Response1)	The second order polynomial	R2	Significance
Total yield	Y = 39.544286 + 3.025357X1 + 0.258512X2 + 1.558214X12 - 0.315000X1X2 - 0.174196X22	0.9073	0.0342
TDF content	Y = 79.125714 - 17.270357X1 - 16.466012X2 - 0.263214X12 + 5.040000X1X2 + 0.887946X22	0.9801	0.0017
SDF content	Y = 78.492857 - 18.548095X1 - 16.600714X2 - 0.162857X12 + 5.375000X1X2 + 0.861786X22	0.9751	0.0026
IDF content	Y = 4.030000 + 1.087500X1 - 1.793750X2 - 0.032500X12 - 0.340000X1X2 + 0.293125X22	0.8886	0.0483

X₁, enzyme concentration; X₂, reaction time.
TDF, total dietary fiber; SDF, water-soluble dietary fiber; IDF, water-insoluble dietary fiber.