*2.2.8. Statistical analysis*

*2.2.5. Gel preparation*

1.5 hoursof cooking and 24 hoursof hydrolysis

104 Wastewater Treatment Engineering

Maize waste water Nejayote 1

**Scheme 1.** Nixtamalization conditions and arabinoxylans extraction (AX1, AX2).

*2.2.6. Rheological test*

*2.2.7. Microstructure*

duplicate.

AX1 and AX2 solutions at 10% (w/v) were prepared in 0.1 M sodium acetate buffer pH 5.5. Laccase (1.675 nkat per mg polysaccharide) was used as a cross-linking agent. AX1 and AX2 gels were allowed to develop for 4 hours at 25°C. The measurements were performed in

**Characterizationof AX1 and AX2 Rheological and structural characteristics**

**of AX1 and AX2 gels**

Maize waste water Nejayote 2

**Nixtamalization**

0.5 hoursof cooking and 4 hoursof hydrolysis

AX1 AX2

**Extractionof AX1 and AX2**

Small amplitude oscillatory shear was used to follow the gelation process of AX1 and AX2 solutions at 10% (w/v). Solutions were mixed with laccase (1.675 nkat per mg AX) and immediately placed on the parallel plate geometry (4.0 cm in diameter) of a strain controlled rheometer (Discovery HR-3 rheometer; TA Instruments, New Castle, DE, US). Exposed edges were covered with silicone oil to prevent evaporation. The dynamic rheological parameters used to evaluate the gel network were the storage modulus (G'), loss modulus (G"), crossover point (G'>G"), and tan delta (tan δ, G"/G'). AX1 and AX2 gelation were monitored at 0.25 Hz and 5% strain. At the end of the network formation a frequency sweep (0.01–10 Hz) was carried

AX1 and AX2 gels at 10% (w/v) were frozen in liquid nitrogen and lyophilized at −37°C/0.133 mbar overnight in a Freezone 6 freeze drier (Labconco, Kansas, MO). The microstructure of

out. Rheological measurements were performed in duplicate [4].

FA content was made in triplicates and the coefficients of variation were lower than 5%. Small deformation measurements were made in duplicates and the coefficients of variation were lower than 5%. All results are expressed as mean values.
