The following became clear after the comparison of potatoes both cooked with pressure pan and steamer.
Cooking condition of pressure pan to attain the core of potatoes (150g) to the same hardness as that cooked with steamer was 5 min. for heating until steam leak and continuously heating for 3 min, and further intact holding for 5 min.
Although the hardness of potato core became almost the same, the exterior of potato with pressure pan became overtender.
Mushed potato made from the potato cooked with pressure pan was more sticky and harder than that with steamer. In the case of mushed potato with pressure pan, tissue were partially destructed and the amount of gelatinized starch which flowed out from tissue and the amount of soluble pectin were greater than the case of that with steamer.
When cooking time was prolonged for 2 min, those tendency became more clearly.
Both the consumption of gas and time required for cooking, in case of pressure pan, decreased by apporoximately one-half in quantity of those of those of steamer.

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This study was carried out to know whether recommended temperature-Time course until boiling of cooked rice is for the sake of the uniform gelatinization of rice starch or for the water absorption of rice grain.
First, homogenized rice, instead of rice grain, was employed to avoid the influence of the rice tissues, and the period necessary to attain the boiling point was setted to 5,10,20 and 40 min., respectively, from the initial temperature of 30°C, and as the results no differences were confirmed between these samples.
Second, the texture of cooked rice, which was cooked under the usual cooking conditions except the cooking times, was compared. When cooked under slow temperature increase, like as the case of over 20 min, for the boiling, the longer the cooking time is, the less homogeneity in the texture and the difference of water absorption between the top and the bottom in a pot was significant. On the other hand, in the case of shorter cooking time, like as 5 min, to attain the boiling point, it seemed to be too short to get enough water content necessary to gelatinize the starch at the center of the rice grain.
From these results, as the cooking method of rice, to adjust the temperature increase so as to attain to boiling point after 10 min. cooking seemed to be not based on the matter of the gelatinization of starch but on the point to obtain the uniform water absorption in the pot.

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