Abstract
Calcium, phosphorus, and iron content in Tsuruna (a vegetable) were determined. Calcium and phosphorus content were high in May and June, when calcium was above 90mg% and phosphorus was approximately 60mg%. Iron was approximately 3mg% regardless of sampling time.
The solubility of calcium, phosphorus and iron contained in Tsuruna was investigated by soaking and boiling in water. Also, the cooking losses of those minerals were investigated by boiling and soaking Tsuruna in water to get rid of the harshness. Moreover, the Tsuruna prepared as above was soaked In 0.5% HCl (HCl concentratian in gastric juice) at 37°C (bodily temperature) for two hours (staying time of food taken in the stomach) and the amounts of calcium, phosphorus and iron dissolved were determined to estimate the utilization of those minerals by the body.
The greater part of the calcium of Tsuruna was insoluble, and the cooking loss and the amount of calcium dissolved in HCl were small. The greater part of the phosphorus and iron of Tsuruna was soluble. Their cooking losses were so large that the amounts of those minerals dissolved in HCl were small.
Tsuruna was also compared with spinach and Kyôna in regard to the matter described above.
