Table 5. Linear regression analysis on the acid value and peroxide value of oils within deep-fat fryer according to deep-fat frying number and fried food

Content	Edible oils	Linear regression analysis	r2	Quality limit	Exceed the standard times
Acid value	Soybean	y=0.0571x+0.3891	r2=0.9480	2.5	37
	Lard	y=0.0542x+0.7535	r2=0.9719		32
	Canola	y=0.045x–0.1214	r2=0.9389		58
	Palm	y=0.0159x+1.123	r2=0.9723		87
Peroxide value	Soybean	y=0.6961x+0.9068	r2=0.9376	50	69
	Lard	y=0.6502x+5.8745	r2=0.9403		68
	Canola	y=0.7099x–4.9274	r2=0.9329		77
	Palm	y=0.0991x+5.4001	r2=0.9059		450