The effect of the addition of soybeans on the softening of carrots during cooking

It has been observed in our daily life that the addition of soybeans to cooking solution promotes the softening of vegetables during cooking. In order to investigate the effect of addition of soybeans during cooking on the softening of vegetables, experiments were conducted, how to change the texture of carrots by the addition of soybean cooking solution or its fractions (drawing parts) during cooking. Centrifugal separation and ion exchange treatment of the soybean cooking solution were carried out. The effects of the addition of the soybean cooking solution and its fractions on the softening of carrot during cooking were investigated with regard to the properties of firmness and cohesiveness of texture. It was found that a large quantity of potassium was contained in the soybean cooking solution. Potassium salt promoted the softening of carrot during cooking. Potassium salt decreased the firmness of the carrots during cooking, but decreased little the cohesiveness. While the supernatant of the soybean cooking solution and the deanion fraction of it decreased both the firmness and the cohesiveness of carrots during cooking. Furthermore, it was suggested that there were some promoting factors besides potassium ion for the softening of the carrots during cooking in the supernatant of the soybean cooking solution, and that there were also some preventing factors for the softening of carrots in the decation fraction. (Received Aug. 5, 2003 ; Accepted Dec. 17, 2003)