Table 2. Free amino acid contents (mg/100g dry weight) of dried sweet potato strips supplemented with different concentration of soybean pulp

	0%	1%	3%	5%
Threonine	7.15±0.11^a	11.96±0.50^b	14.04±0.84^c	14.07±0.25^c
Tyrosine	2.30±0.04^a	2.01±0.19^b	1.90±0.11^b	2.48±0.14^a
Arginine	1.12±0.14^a	2.47±0.15^b	3.61±0.28^c	4.39±0.06^d
Alanine	54.67±1.12^a	43.80±2.69^b	51.45±2.11^a	54.40±0.80^a
Proline	5.64±1.38	4.86±1.43	5.32±1.16	5.74±1.71
Lysine	N.D.^a	0.46±0.02^b	0.66±0.10^c	0.63±0.02^c
Histidine	0.49±0.05^a	0.72±0.07^b	0.94±0.08^c	0.89±0.03^c
Isoleucine	1.85±0.05^a	1.66±0.10^b	1.97±0.07^a	1.98±0.07^a
Leucine	2.75±0.09^a	2.74±0.17^a	3.23±0.13^b	3.30±0.09^b
Methionine	N.D.^a	0.64±0.03^b	0.74±0.04^c	0.76±0.03^c
Phenylalanine	12.45±0.12^a	14.08±0.79^b	16.42±0.60^c	16.50±0.36^c
Tryptophan	1.42±0.09^a	1.77±0.16^b	2.33±0.13^c	2.71±0.12^d
Valine	3.82±0.13^a	3.07±0.20^b	3.67±0.14^a	3.66±0.15^a
Glutamic acid	48.20±2.23^a	58.56±3.30^b	70.70±1.61^c	73.54±0.99^c
Aspartic acid	33.18±2.49^a	16.74±1.80^b	18.53±0.78^bc	20.26±1.22^c
Serine	14.07±0.65^a	9.54±0.52^b	11.34±0.44^c	11.55±0.38^c
Glycine	1.56±0.09^a	1.32±0.06^b	1.62±0.08^ac	1.73±0.03^c

Different letters indicate significant differences from the 0% control group (p<0.05). 0%: dried sweet potato strips without soybean pulp; 1%: dried sweet potato strips supplemented with 1% soybean pulp; 3%: dried sweet potato strips supplemented with 3% soybean pulp; 5%: dried sweet potato strips supplemented with 5% soybean pulp.