Effect of extrusion temperature and material moisture on the damaged starch content of brown rice flour and noodle quality

The brown rice flour was extruded at different extrusion temperature and material moisture,and the extrusion modified brown rice flour was then mixed with wheat flour(1∶1,w/w) to make noodles. The effects of extrusion temperature and material moisture on the damaged starch and noodle quality were systematically studied,and the correlation between damaged starch content of brown rice flour and noodle quality was analyzed. The results showed that the damaged starch content of brown rice flour was significantly reduced with the increase of the material moisture,and the UCDc was to the minimum value of 14.9 at the material moisture content of 25%. As the extrusion temperature increased,the damaged starch content decreased and then increased,and the UCDc data got to the lowest value of 14.9 at 120 ℃. Correlation analysis showed that,the cooking loss of brown rice noodles significantly increased with the increase of damaged starch content,however,firmness,hardness and chewiness decreased and the overall quality of noodles declined. When the extrusion temperature and material moisture were 120 ℃ and 25% respectively,the UCDc value of damaged starch content got to 14.9,and the brown rice noodle quality was relatively good at this condition.