Identification and effect of ethyl galactoside on the properties and baking quality of dough

One of the reaction products of lactose and lactase in the presence of ethanol was isolated and identified as ethyl galactoside (EG) using gas-liquid chromatography, fast atom bombardment-mass spectrometry and H-1 and C-13 Nuclear Magnetic Resonance Spectroscopies. Dough and bread qualities were studied by adding three different levels of EG (0.033, 0.067 and 0.134 mmol per kg of wheat flour) to the bread ingredients. Addition of 0.067 mmol EG per kg of wheat flour indicated significantly large loaf volume of the bread, and retarded the firmness of bread during storage when compared to, the control. The small level of EG significantly improved the bread qualities as compared with lactose or a combination of lactose and lactase. And also, the wheat flour dough containing EG (0.067 mmol) significantly reduced the modulus of elasticity and viscosity coefficient. The addition of EG (0.067 mmol) to the bread ingredients slightly tended to lower the gelatinisation temperature of starch. The scanning electron microscopic observations indicated that the gluten portion of dough containing EG was developed well, and this caused the large loaf volume and good appearance from cross view of bread. (C) 2003 Elsevier Science Ltd. All rights reserved.