The Effect of Sodium Chloride with Varying Concentration on Characteristics and Rheology of Extracted Gluten from Wheat Flour

Abstract

Gluten is a vegetable protein with the potential to be developed into functional food because of its high protein content. Gluten is viscoelastic which gives chewiness characteristics. In Indonesia, gluten is still imported and limited to processing food or to substitute for animal protein. This study aims to determine the effect of NaCl addition on the characteristics and rheology of extracted gluten. Addition of NaCl to the dough, 1%, 2% and 3%, respectively. The results showed that the extracted gluten had a protein content of 83.23-86.93%, moisture content of 1.17-1.54%, ash content of 0.13-0.16%, and fat content of 0.28-0.89%. These results are in accordance with the Codex International Standard. This showed that the gluten contained in wheat flour is good as a commodity in the food industry. Increasing the NaCl amount would also increase the tensile strength and the % elongation of gluten produced in the range of 88.71-201.90 gf/mm 2 and 7.10-14.51%, respectively. It showed that this addition affects the empirical rheological quality of the dough, strengthening the gluten network so that the extracted gluten from wheat flour in addition to food fortification can also be used for non-food purposes. The FT-IR spectrum showed the presence of bands, including β-sheet (1612 and 1633 cm-1) in the intermolecular and intramolecular structures of gluten, α-helix (1658-1650 cm-1), and β-turn (1668 cm-1) linked to the glutamine side chain. These contribute to the secondary structure of the gluten protein. The presence of β-sheet and β-turn in the FT-IR spectrum of gluten indicates that the gluten contained in wheat flour is more elastic and stable. The gluten in this study has functional groups in the same wavenumber range as the functional groups from the literature. The addition of NaCl to the dough did not have a significant effect on the absorption bands on the gluten spectra.