Structure and Water Relations of Melanoidins Investigated by Thermal, Rheological, and Microscopic Analysis

Figures & data

Scheme 1 Flow diagram of the WSM, LMW and HMW preparation.

Figure 1 Adsorption isotherm and T_g curve of WSM. Lines: isotherms resulting from GAB (determination coefficient R = 0.993) and BET (R = 0.992) equations fitting. Dots are experimental points.

Table 1 GAB and BET parameters of WSM

Equations	m0 (gwater × gdry matter ^−1)	CG; CBET	k
GAB	0.0832	0.7278	0.937
BET	0.0485	1.6994

Figure 2 DSC traces of dry and hydrated (aw 0.86) WSM and LMW samples. Arrows show T_g, T′_g and T′_m.

Figure 3 DSC traces of dry HMW. Arrow indicates the thermal degradation endothermic peak; (a: first scan; b: second scan).

Figure 4 DSC traces of HMW solution (27% w/w). Arrow indicates T′_m.

Figure 5 Images from optical microscope of WSM hydrated at different water activities. Magnification: 25.

Figure 6 G′, G′′, complex viscosity (η∗) and phase angle of WSM, LMW and HMW fractions in the frequency range of 0.1–10 Hz.

Figure 7 Cox-Merz superimposition of steady shear viscosity (η) and complex viscosity (η∗) of WSM and LMW and HMW fractions.

Figure 8 Reduced viscosity of WSM dissolved in water as function of concentration. Inner rectangle: reduced viscosity of WSM dissolved in NaCl 0.05 M.

Table 2 Intrinsic viscosity, K′ and critical concentrations of LMW, HMW fractions, and WSM

Sample	[η] (dL·g^−1)	K′	C∗ (g·dL^−1)
LMW	0.021	1.23	47.6
HMW	0.023	2.29	43.5
WSM	0.025	0,33	40.0