Effect of processing time, temperature and alkali concentration on yield extraction, structure and gelling properties of corn fiber arabinoxylans

• Longer alkali extraction time and higher temperature increased arabinoxylan yields.
• Alkali molarity did not affect arabinoxylans yield and phenolics extracted for 8 h.
• Phenolic concentration in arabinoxylans correlated negatively with yield extraction.
• Ester-linked ferulic acid in arabinoxylans correlated positively with gel strength.
• Experimental and simulated arabinoxylan extraction had agreement in parameter data.

The effect of time (2, 8 h), temperature (40, 60 °C) and NaOH concentration (0.25, 0.50 M) on yield extraction, hydroxycinnamic acid (HCA) concentration and gelling properties of corn fiber arabinoxylans (CFAX) were evaluated. The yield of arabinoxylans (AX) was higher at 8 h and 60 °C whereas alkali concentration did not influence this value. A negative correlation existed between AX yield and ester-linked HCA (r = −0.7). Stronger CFAX gels were formed at higher ester-linked ferulic acid concentrations (e-FA). Prediction equations and a range of desirable values of AX yield, e-FA and complex viscosity (η*) were generated to select alkaline conditions. The selected conditions (6 h, 0.3 M NaOH, 60 °C) had the third highest AX yield (36.6%) whereas in in terms of e-FA and gel strength it had the fourth position (0.59 μg e-FA/mg AX dry basis (db), η* 185 Pa s).

Figure optionsDownload as PowerPoint slide