QSBR Study of Bitter Taste of Peptides: Application of GA-PLS in Combination with MLR, SVM, and ANN Approaches

Table 2

Details of the observed-predicted (using MLR, SVM, and ANN methods) bitterness and corresponding errors (IPD).

Peptide sequence	Observed	MLR	IPD	SVM	IPD	ANN	IPD
Training data set
R	1.60	1.20	25.1	1.81	13.4	1.90	18.5
F	1.70	1.86	9.3	1.83	7.5	1.86	9.5
P	1.90	1.87	1.6	2.36	24.3	2.16	13.5
L	1.70	1.82	6.9	1.82	7.3	1.86	9.4
V	1.70	1.62	5.0	1.61	5.3	1.68	1.1
GR	1.00	2.00	100.1	2.31	130.7	2.06	106.0
RR	2.11	2.38	12.9	2.69	27.4	2.84	34.7
PP	2.34	2.05	12.4	2.35	0.2	2.26	3.3
KP	2.52	2.39	5.0	3.28	30.1	3.20	26.8
PR	2.52	1.97	21.7	3.26	29.3	3.22	27.9
RF	2.60	2.68	3.0	2.81	8.1	2.76	6.0
RP	3.10	2.34	24.5	3.05	1.5	3.03	2.1
LI	2.40	2.07	13.8	2.12	11.5	2.01	16.4
KF	2.04	2.46	20.8	1.83	10.5	1.84	10.0
VF	2.52	2.46	2.5	2.32	8.0	2.36	6.3
VY	2.52	2.44	3.1	2.74	8.8	2.77	9.9
YG	2.52	2.37	6.1	2.48	1.7	2.39	5.3
YY	2.63	2.82	7.2	2.47	6.0	2.47	6.0
FI	2.83	2.62	7.6	2.32	18.0	2.06	27.2
IF	2.83	2.54	10.2	3.58	26.6	3.52	24.4
YF	3.10	2.70	12.9	3.31	6.8	3.29	6.2
VA	1.16	1.63	40.9	1.55	33.9	1.49	28.6
VG	1.19	1.34	12.9	1.56	30.8	1.36	14.3
PA	1.32	1.62	22.5	1.59	20.5	1.55	17.2
IE	1.37	2.13	55.5	2.30	68.2	2.12	54.7
IQ	1.49	1.91	28.3	1.97	32.5	1.93	29.7
IS	1.49	1.80	20.7	1.67	12.4	1.80	20.7
IT	1.49	2.11	41.3	2.08	39.6	2.03	36.2
SL	1.49	1.99	33.7	2.14	43.8	1.92	28.7
WE	1.56	2.63	68.6	2.70	73.0	2.65	69.6
IK	1.65	2.40	45.5	2.42	46.5	2.33	41.3
IA	1.68	1.77	5.5	1.64	2.3	1.66	1.1
AL	1.70	1.52	10.9	1.78	4.7	1.77	3.8
VV	1.71	1.59	6.9	1.70	0.5	1.63	4.8
LA	1.72	1.84	6.9	1.72	0.1	1.76	2.3
PY	1.80	2.09	15.9	1.93	7.3	2.02	12.1
GW	1.89	2.18	15.5	2.00	5.7	2.15	13.9
PL	2.22	1.98	10.9	2.21	0.2	1.95	12.0
PI	2.33	1.85	20.5	2.10	9.9	1.92	17.6
IP	2.40	2.06	14.1	2.25	6.3	2.03	15.3
YL	2.40	2.52	5.2	2.61	8.9	2.55	6.1
LY	2.46	2.79	13.4	2.89	17.3	2.76	12.2
IW	3.05	2.84	6.9	2.86	6.3	2.76	9.5
FY	3.13	2.80	10.4	2.90	7.5	2.84	9.2
LW	3.40	2.63	22.6	2.80	17.8	2.86	16.0
IV	1.90	1.80	5.3	2.31	21.5	2.06	8.2
FV	2.23	2.55	14.4	2.29	2.8	2.06	7.4
VE	2.23	1.99	10.6	2.57	15.4	2.46	10.3
YP	1.70	2.51	47.8	1.72	1.0	1.57	7.9
PK	2.23	2.06	7.8	2.27	1.7	2.10	5.9
LD	2.23	2.19	1.7	2.26	1.3	2.09	6.2
AD	2.23	2.15	3.7	2.22	0.5	2.00	10.5
LE	2.52	2.15	14.6	2.33	7.5	2.13	15.5
GE	2.83	2.13	24.8	2.63	7.2	2.58	8.8
VL	2.11	2.04	3.2	2.47	16.9	2.37	12.4
GP	1.79	2.28	27.3	2.09	16.7	1.94	8.6
FG	2.00	2.24	12.1	2.25	12.5	2.26	12.8
PF	2.14	2.28	6.4	2.34	9.3	2.29	6.9
GF	2.36	2.25	4.5	2.30	2.5	2.24	5.2
GY	2.15	2.14	0.4	2.12	1.5	2.17	0.8
LF	2.82	2.52	10.5	2.70	4.2	2.55	9.4
FL	2.85	2.58	9.4	2.64	7.4	2.57	9.7
GL	1.64	1.80	9.6	1.70	4.0	1.75	6.6
LG	1.71	1.70	0.7	1.58	7.7	1.70	0.6
IG	2.01	1.71	15.1	1.69	16.0	1.70	15.6
GI	2.17	1.91	12.1	1.82	16.3	1.84	15.4
LL	2.47	2.21	10.5	2.33	5.6	2.08	16.0
II	2.54	2.05	19.1	2.24	11.9	2.05	19.1
IL	2.54	2.12	16.6	2.29	9.9	2.08	18.2
RGP	1.90	2.51	31.8	1.66	12.4	1.83	3.9
FGG	2.34	2.27	3.2	2.10	10.3	2.09	10.9
GFG	2.52	2.35	6.7	2.25	10.9	2.10	16.5
PPP	2.70	2.39	11.6	2.62	3.1	2.42	10.3
GLL	2.83	2.37	16.4	2.33	17.6	2.07	26.7
RPG	3.10	2.71	12.7	2.46	20.5	2.37	23.5
LGG	1.00	1.68	67.6	1.75	75.0	1.67	67.1
GGL	2.00	1.99	0.4	2.00	0.2	1.92	4.1
LGL	2.30	2.38	3.3	2.43	5.8	2.34	1.7
LLG	2.30	2.35	2.1	2.39	4.0	2.31	0.3
PIP	2.85	2.37	16.7	3.71	30.1	3.51	23.2
LLL	2.92	2.70	7.5	3.06	4.8	2.94	0.9
GYG	1.70	1.72	1.3	2.63	54.5	2.42	42.2
GVV	2.34	2.05	12.4	2.98	27.3	3.07	31.3
VVV	2.34	2.38	1.8	1.76	24.9	1.64	29.8
PPF	2.63	2.48	5.7	3.38	28.4	3.38	28.5
YGG	2.63	2.60	1.3	2.67	1.6	2.46	6.3
RPF	2.83	3.28	15.9	2.55	9.8	2.44	13.8
FGF	2.92	2.85	2.4	3.24	11.1	3.29	12.5
DLL	3.10	3.18	2.6	2.63	15.2	2.67	13.7
GFF	3.23	3.04	5.9	3.14	2.8	3.08	4.7
FPF	3.40	3.31	2.8	3.38	0.6	3.25	4.4
GYY	3.40	3.02	11.2	3.15	7.4	3.06	9.9
PFP	3.40	2.88	15.3	2.74	19.5	2.58	24.2
YYY	3.70	3.45	6.8	3.73	0.7	3.57	3.5
GGV	1.48	1.93	30.2	1.75	18.4	1.79	21.0
PGG	2.34	1.69	27.6	2.02	13.6	2.00	14.6
GGF	2.83	2.42	14.4	2.39	15.4	2.36	16.8
GGP	2.04	1.95	4.4	2.60	27.3	2.51	23.1
PPG	2.04	2.22	8.6	2.35	15.4	2.16	5.7
FFG	2.65	2.93	10.5	3.06	15.5	2.99	12.8
ELL	3.40	2.91	14.5	2.73	19.7	2.82	17.0
FFF	3.70	3.44	7.1	4.28	15.7	3.94	6.4
EGG	2.83	2.06	27.2	2.71	4.2	2.61	7.9
YGY	3.10	2.84	8.5	2.87	7.4	2.79	10.0
YPF	3.52	3.03	13.9	3.18	9.6	3.04	13.7
GGLG	1.60	1.92	19.8	1.55	3.3	1.34	16.2
FGFG	3.52	2.94	16.4	3.55	1.0	3.56	1.2
GPFF	3.80	3.21	15.6	3.19	16.0	3.15	17.0
RPGF	3.80	3.39	10.9	3.41	10.2	3.36	11.6
FGGF	3.92	3.08	21.5	3.32	15.3	3.2	18.3
RPFF	4.40	3.82	13.2	4.42	0.4	4.24	3.6
GLGG	1.70	1.84	8.2	1.70	0.2	1.74	2.3
LGGG	1.90	1.98	4.1	2.26	18.9	1.92	0.8
PFPP	2.34	3.14	34.3	2.39	1.9	2.41	2.8
GPPF	2.52	2.88	14.2	2.56	1.7	2.47	1.9
RRPP	2.7	3.14	16.4	3.00	11.2	3.11	15.3
VYPF	3.52	3.46	1.6	2.97	15.7	3.05	13.5
PFIV	3.52	3.12	11.5	3.28	6.9	3.33	5.5
FFPR	4.00	3.87	3.2	3.79	5.2	3.87	3.3
FFPP	2.52	3.27	29.6	2.51	0.3	2.43	3.5
FFPE	2.76	3.56	28.8	3.49	26.3	3.55	28.6
GGFF	2.85	3.48	22.0	2.39	16.1	2.34	18.1
FFPG	2.90	3.38	16.6	3.37	16.3	3.35	15.6
LLLL	3.23	3.35	3.7	3.18	1.6	3.23	0.0
FFGG	2.52	3.20	27.0	2.41	4.4	2.31	8.2
RRPFF	4.70	4.15	11.7	4.69	0.3	4.63	1.4
GGGLG	1.90	2.28	19.9	2.34	23.1	2.08	9.4
GLGGG	1.90	2.15	12.9	1.77	7.0	1.69	10.8
LGGGG	1.90	2.16	13.6	2.51	32.3	2.49	31.1
GGVVV	2.11	2.84	34.6	2.21	4.7	2.02	4.5
FFPGG	2.83	3.58	26.6	3.18	12.4	3.18	12.2
PGPIP	3.11	3.25	4.6	3.26	4.8	3.19	2.6
RGPPF	2.63	3.45	31.2	2.95	12.2	2.89	9.8
PPFIV	2.92	3.30	12.9	2.64	9.6	2.69	7.9
RPGFF	3.51	3.82	8.8	3.98	13.4	3.86	9.9
RPGGFF	4.04	3.95	2.3	4.28	5.8	4.06	0.6
PFPGPI	3.36	3.63	8.1	3.65	8.7	3.56	6.0
RPFFGG	3.92	4.11	4.7	4.22	7.6	4.07	3.9
RGPPGF	3.52	3.31	5.9	3.55	0.9	3.43	2.6
RGPPFI	4.60	3.60	21.7	3.47	24.7	3.52	23.4
RGPFIV	4.30	3.84	10.7	3.83	10.9	3.76	12.6
RGGFIV	3.10	3.35	8.0	3.02	2.6	2.89	6.7
RGPPFF	4.23	4.04	4.6	4.13	2.4	3.98	5.9
RRPPGF	4.40	3.73	15.3	4.79	9.0	4.75	7.9
RRPPFF	5.15	4.13	19.9	5.08	1.4	5.40	4.9
GPPFIV	2.92	3.40	16.6	3.28	12.4	3.20	9.5
GGFFGG	3.70	4.02	8.8	3.72	0.4	3.55	4.0
KPPFIV	3.82	3.56	6.8	3.42	10.4	3.51	8.2
GGRPFF	4.04	4.07	0.6	3.98	1.5	3.83	5.1
PVLGPV	3.30	3.25	1.6	3.26	1.2	3.21	2.8
FPPFIV	3.52	3.66	4.0	4.18	18.8	4.09	16.3
RGPPGGV	2.48	3.07	23.9	2.93	18.2	2.96	19.2
RGPPGFF	4.40	3.97	9.7	4.04	8.3	3.93	10.7
RGPPFFF	5.00	4.45	11.1	4.62	7.6	4.47	10.6
VIIPFPG	3.60	4.08	13.3	3.49	3.1	3.5	2.8
VIFPPGR	4.10	4.33	5.5	3.87	5.6	3.83	6.6
RGPPGIG	2.78	3.49	25.5	3.41	22.7	3.43	23.5
RGPPGGF	3.08	3.25	5.4	3.17	3.0	3.10	0.8
YPFPGPI	3.80	4.09	7.7	4.21	10.7	4.05	6.6
RPPPFFF	4.70	4.73	0.6	4.41	6.2	4.22	10.2
VIPFPGR	4.15	4.13	0.5	4.38	5.6	4.23	1.9
PFPGPIP	3.60	3.54	1.6	4.00	11.2	3.98	10.7
RGPPGFG	3.68	3.56	3.1	3.47	5.7	3.49	5.2
RGPFPIV	3.95	3.85	2.5	3.92	0.7	3.88	1.9
RPFFRPFF	5.00	5.11	2.2	4.96	0.9	5.03	0.6
RGPKPIIV	4.08	3.87	5.0	4.21	3.2	3.83	6.3
VYPFPPGI	3.82	4.23	10.7	4.21	10.1	4.15	8.7
RGPEPIIV	4.51	3.87	14.2	4.12	8.7	3.80	15.8
RGPPGGFF	4.11	3.37	18.0	3.28	20.1	3.28	20.3
GGRPFFGG	4.40	4.30	2.3	3.92	10.8	3.81	13.3
RGPPGGGFF	3.95	4.05	2.6	4.24	7.4	4.09	3.5
GGRGPPFIV	4.10	3.95	3.6	4.35	6.1	4.30	4.9
RGPPFIVGG	4.31	4.06	5.7	4.04	6.3	4.01	7.1
FFRPFFRPFF	5.15	5.49	6.7	4.21	18.2	4.06	21.1
PVRGPFPIIV	5.40	4.16	22.9	4.82	10.8	4.18	22.6
VYPFPPGINH	4.30	4.48	4.3	4.51	4.9	4.38	2.0
VYPFPPGIGG	3.52	4.20	19.2	3.08	12.4	3.00	14.9
VYPFGGGINH	3.64	3.96	8.7	4.01	10.1	3.88	6.6
RPFFRPFFRPFF	5.00	5.44	8.9	5.04	0.8	5.22	4.4
RGPPFIVRGPPFIV	4.40	4.92	11.8	3.87	12.0	3.75	14.8
PVLGPVRGPFPIIV	4.83	4.36	9.7	5.11	5.9	4.48	7.2
Test data set
RG	2.11	1.97	6.4	2.29	8.4	2.01	4.6
AV	1.16	1.71	47.6	1.59	37.4	1.58	36.3
ID	1.37	2.07	51.4	2.07	51.2	1.97	43.9
VD	1.90	1.94	2.2	2.36	24.5	2.15	13.4
LV	2.23	1.89	15.1	1.75	21.6	1.82	18.4
VI	2.23	1.90	14.7	1.99	10.9	1.96	12.1
FP	2.77	2.54	8.3	2.65	4.3	2.46	11.1
FF	3.01	2.75	8.6	2.89	4.0	2.82	6.5
AF	1.81	2.41	33.4	2.55	40.7	2.39	31.8
PGR	1.60	2.65	65.4	2.60	62.3	2.65	65.9
RRR	2.40	3.55	48.0	3.52	46.8	3.55	47.8
FIV	2.83	2.77	2.1	2.68	5.2	2.71	4.2
GGY	2.83	2.44	13.8	2.55	9.7	2.45	13.5
GRP	3.10	2.64	14.8	2.54	18.1	2.64	15.0
YYG	3.20	3.10	3.2	3.17	0.9	3.11	2.9
KPF	3.40	3.18	6.4	3.14	7.6	3.11	8.5
GLG	2.00	1.58	21.3	1.57	21.5	1.69	15.7
GPG	1.70	2.09	23.2	2.11	24.0	2.01	18.1
KPK	2.52	2.97	17.7	2.82	11.8	3.02	19.9
VYP	2.52	2.97	17.7	2.87	13.9	2.90	15.0
GGGL	2.34	2.26	3.2	2.39	2.1	2.10	10.0
RPFG	3.41	3.47	1.8	3.37	1.1	3.34	1.9
RGFF	3.80	3.69	3.0	3.95	4.0	3.83	0.7
GGLGG	1.90	2.29	20.6	1.93	1.7	1.92	0.9
GGGGL	2.65	2.21	16.6	2.40	9.5	2.17	17.9
PGPGPG	2.60	3.10	19.2	3.14	20.6	3.09	19.0
PFPIIV	3.90	3.43	12.0	3.55	9.0	3.40	12.7
VIFPPG	2.68	3.80	41.8	3.71	38.4	3.66	36.6
RGPPFIV	4.30	3.86	10.3	3.75	12.7	3.78	12.1
VYPFPPG	3.52	4.06	15.4	4.09	16.1	3.95	12.2
RGPFPIIV	5.40	4.14	23.3	4.40	18.5	4.14	23.4
RGPGPIIV	4.81	3.84	20.3	4.26	11.5	3.88	19.2
RRPPPFFF	5.70	4.78	16.2	4.76	16.5	4.69	17.6
VIIPFPGR	3.85	4.54	18.0	4.47	16.1	4.51	17.1
VYPFPPIGNH	4.30	4.46	3.7	4.48	4.1	4.38	1.8
GGRGPPFIVGG	4.40	4.21	4.3	4.21	4.4	4.11	6.6
Validation data set
IN	1.49	2.11	41.9	2.12	42.4	2.01	34.8
WW	3.60	2.99	16.9	3.18	11.7	3.05	15.3
GV	1.74	2.22	27.8	2.19	25.8	2.08	19.8
FPK	2.52	3.10	22.9	2.94	16.7	3.14	24.7
FPP	2.34	2.65	13.3	2.56	9.6	2.62	12.1
PGP	2.04	2.56	25.4	2.57	26.0	2.41	18.0
VIF	2.89	2.78	3.8	2.79	3.6	2.82	2.3
RPPFIV	4.10	3.74	8.7	3.61	12.0	3.65	11.0
RGPPFGG	3.23	3.37	4.5	3.23	0.1	3.34	3.3
RGPPFIIV	4.30	4.12	4.1	4.20	2.4	3.99	7.2