Wheat Germ Lipoxygenase: Its Effect on Dough Rheology, Microstructure, and Bread Making Quality

Abstract

Extracted lipoxygenase from defatted wheat germ of commercial bread wheat along with raw and defatted germ were used to study their effect on rheological characteristics of wheat flour dough and bread making quality. The addition of 500 U and 1000 U of lipoxygenase increased the water absorption from 59.5 to 62.3 and 66.7%, respectively. The dough stability increased to 10.5 min, whereas mixing tolerance index values marginally decreased, and the addition of raw or defatted germ did not affect the mixing profile of the wheat flour dough. Breads with lipoxygenase were softer with a lower firmness value of 546 g when compared to the control (594 g) and had brighter crumb as seen in the reduction in ΔE values from 22.34 (control) to 19.04. The addition of gluten along with the lipoxygenase showed a synergistic effect. The specific volume of breads increased to 3.95 cc/g and the firmness values decreased to 538 g. Scanning electron micrographs at different stages of bread processing have shown improvement in the gluten network.

Keywords:

• Wheat germ
• Lipoxygenase (LOX)
• Farinograph characteristics
• Alveograph characteristics
• Bread
• SEM

ACKNOWLEDGMENTS

The authors are thankful to Mr. Anbalagan, CIFS, CFTRI, Mysore, for his help in carrying out scanning electron microscopy.