ATR spectroscopy and chemometrics for rapid identification of superior, engineered β-fructofuranosidases. Kim M. Trollope, Heinrich Volschenk, Johann F.
Analytical and Bioanalytical Chemistry
Electronic Supplementary Material
Direct, simultaneous quantification of fructooligosaccharides by FT-MIR ATR spectroscopy and chemometrics for rapid identification of superior, engineered β-fructofuranosidases
Kim M. Trollope, Heinrich Volschenk, Johann F. Gӧrgens, Rasmus Bro, Hélène H. Nieuwoudt
1
Fig. S1 Stacked tacked pure component powder FT-MIR FT MIR ATR spectra for fructose, glucose, sucrose, 11 kestose and nystose. Spectra were collected from 4000 to 550 cm−1. The ATR diamond exhibits broad bands in the 2700–1800 2700 cm-1 regions due to carbon bond absorption while hydrogen and nitrogen content is responsible for bands at 3100 cm-1 and 1500–1000 1500 cm-1, respectively [1] [1] Li-Chan Chan E, Chalmers JM, Griffiths P (2010) Applications of vibrational spectroscopy in food science: Volumes I and II: Analysis of food, drink and related materials. John Wiley & Sons, Chichester, UK
Table S1 Sample statistics of datasets used in PLS modelling Glucose
Fructose
Sucrose
1-Kestose estose
Nystose
Number of samples*
112 (8)
151 (5)
180 (9)
159 (8)
129 (7)
Number of batches
4
4
8
9
7
Concentration range (g/L)
53.0 .0 – 104.5
2.6 – 88.0
4.1 – 204.1
0 - 77.66
1.0 – 43.0
Mean (g/L) + SD
80.1 + 13.3
16.3 + 13.6
81.8 + 60.7
25.9 + 18.4
11.5 + 9.8
*Number of spiked samples is indicated in brackets SD Standard deviation
2
Table S2 Results of applying interval selection in PLS modelling for glucose, fructose, sucrose, 1-kestose and nystose Validation statistics Sugar
Model
Calibration statistics
Fructose
Sucrose
1-Kestose
Nystose
50% data split
Percentage improvement in avg RMSEP
Variable selection
Number of latent variables
R2
RMSEC (g/L)
RMSECV (g/L)
RMSEP (g/L)
RMSEP (g/L)
%
None
5
0.854
4.6
5.2
5.5 + 0.2
6.1
0.00
a
forward iPLS
5
0.840
4.7
5.3
6.2 + 1.0
6.9
-13.2
b
reverse iPLS
6
0.829
4.8
5.5
7.3 + 1.1
6.6
-34.4
None
6
0.940
3.0
3.3
3.9 + 0.1
3.7
0.00
c
forward iPLS
8
0.973
2.0
2.3
2.2 + 0.4
2.8
44.0
d
reverse iPLS
6
0.940
3.1
3.3
3.2 + 0.4
4.3
17.5
None
6
0.944
13.8
14.4
13.6 + 0.9
15.3
0.00
e
forward iPLS
7
0.974
9.1
9.7
10.0 + 0.3
10.6
26.0
f
reverse iPLS
6
0.945
13.4
14.2
14.4 + 0.3
15.2
-6.4
None
6
0.819
7.2
7.8
8.4 + 0.8
7.8
0.0
g
forward iPLS
5
0.864
6.1
6.8
6.9 + 0.5
8.5
18.2
h
reverse iPLS
7
0.869
5.6
6.7
6.4 + 0.4
7.5
23.5
None
4
0.911
2.6
2.9
2.9 + 0.4
2.8
0.00
i
forward iPLS
4
0.940
2.2
2.4
2.6 + 0.4
2.2
11.6
j
reverse iPLS
6
0.945
2.0
2.3
2.7 + 0.3
2.7
7.8
Wavenumbers used (cm-1) Glucose
70% data split Average + SD
3996.461 901.135
3996.461 901.135
3996.461 901.135
3996.461 901.135
3996.461 901.135
Number samples –
–
–
–
–
112
151
180
159
129
of
SD Standard deviation (n = 3) R2 Coefficient of determination