. 2019 Dec 13;5:100075. doi: 10.1016/j.fochx.2019.100075

Table 2.

Gluten microstructure changes (secondary structure, gluten extractability, and SH and SS groups) induced by KHCO₃ or NaHCO₃.

Sample	Secondary structure^*					Gluten extractability			Concentration of SH and SS groups
Sample	Extended chains (%)	β-Sheet (%)	Random coil (%)	α-helix (%)	β-turn (%)	Gliadin (μg/mg)	Glutenin (μg/mg)	Gliadin to Glutenin	Total SH (nmoles/mg)	Free SH (nmoles/mg)	SS (nmoles/mg)
C1	4.74 ± 0.47^a	19.48 ± 0.90^b	27.16 ± 2.10^a	14.30 ± 1.04^a	14.60 ± 1.02^a	234.19 ± 21.15^a	119.86 ± 7.74^a	1.96 ± 0.14^a	7.18 ± 0.52^a	0.83 ± 0.11^a	3.17 ± 0.26^a
K1	4.64 ± 0.53^a	21.19 ± 0.05^ab	18.17 ± 0.72^ab	24.55 ± 2.52^a	20.49 ± 2.99^a	230.80 ± 26.40^a	130.50 ± 12.92^a	1.78 ± 0.21^ab	7.13 ± 0.32^a	0.92 ± 0.04^ab	3.10 ± 0.14^a
K2	5.18 ± 0.62^a	24.08 ± 1.13^a	16.33 ± 1.36^b	19.94 ± 3.84^a	18.26 ± 6.85^a	201.83 ± 6.11^a	133.56 ± 6.41^a	1.51 ± 0.03^b	7.38 ± 0.30^a	1.00 ± 0.15^ab	3.19 ± 0.10^a
K3	4.68 ± 0.70^a	23.59 ± 0.42^a	13.43 ± 2.88^b	18.12 ± 2.43^a	17.09 ± 1.46^a	216.37 ± 19.61^a	115.73 ± 6.05^a	1.87 ± 0.08^ab	8.26 ± 0.85^a	0.92 ± 0.06^ab	3.67 ± 0.42^a
K4	3.12 ± 0.92^a	18.09 ± 0.53^b	17.82 ± 4.11^ab	24.20 ± 0.22^a	12.50 ± 4.28^a	197.66 ± 26.19^a	131.58 ± 11.03^a	1.50 ± 0.08^b	8.30 ± 0.85^a	1.02 ± 0.02^b	3.54 ± 0.22^a
S1	4.57 ± 0.82^a	20.46 ± 0.23^ab	22.04 ± 0.83^ab	20.11 ± 2.09^a	18.01 ± 1.12^a	216.34 ± 18.35^a	132.56 ± 14.43^a	1.64 ± 0.05^ab	7.62 ± 0.04^a	0.89 ± 0.04^ab	3.37 ± 0.03^a

^ab

Means with different superscripts within the same column are significantly different at p < 0.05.

Gluten secondary structures deconvolved from amide bands: I. Full assignment is given as extended chains (1600–1615 cm⁻¹), β-Sheet (1624–1640, 1681 cm⁻¹), random coil (1640–1650 cm⁻¹), α-helix (1650–1660 cm⁻¹), β-turn (1660–1670, 1694 cm⁻¹). See Table 1 for sample identification.