Effects of pressurized cooking on the relationship between the chemical compositions and texture changes of lotus root (Nelumbo nucifera Gaertn.)

The texture of lotus root is hard and crispy, and the root can maintain its appearance and mouth feel after cooking at 100 degrees C for over 60 min. This study tried to elucidate relationships between pressurized cooking treatments (at 100 degrees C for 1, 3, 5, 10, 20, 30, 60 min and at 110 degrees C, 121 degrees C and 132 degrees C for 1, 3, 5, 10, 20, 30 min, respectively) and changes in its chemical composition and texture. Results showed that the contents of hemi-cellulose and cellulose of lotus root decreased with increasing pressurized cooking temperature/duration during heat treatment while lignin content remained almost the same. The NDF contents decreased more than did the ADF contents. Relative hardness of lotus root decreased with increasing pressurized cooking temperature/duration while solid loss increased (P < 0.05). These results could be used as references for the lotus root industry, as well as an academic basis for future development. (c) 2007 Elsevier Ltd. All rights reserved.