北海道もち米の6地域4カ年における搗き餅の硬化性と糊化特性を調査した。それらの最小値最大値の差異および変動係数は，年次間が地域間に比べ大きく，年次間と地域間との比の大きさおよび特性間の相関係数から，同比の小さい順にⅠ群の最高粘度とブレークダウン，Ⅱ群の最低粘度，最終粘度およびコンシステンシー，Ⅲ群の糊化開始温度，最高粘度到達温度，最高粘度到達時間および硬化性に分けられた。年次間ではこれら3群の糊化特性の中で，Ⅱ群とⅢ群において硬化性と正の相関関係が認められ，Ⅲ群で最も明確であった。また，出穂後40日間の日平均積算気温（登熟気温）が高いほどⅡ群，Ⅲ群および硬化性が高くなり，その関係はⅢ群と硬化性で最も明確であった。一方，地域間ではこれらの関係が概して明確ではなかった。さらに，精米蛋白質含有率が高いほど，Ⅰ群とⅡ群では年次間と地域間とも，Ⅲ群では年次間のみで，特性値が低くなった。また，炊飯米の物理特性で，平年並みの登熟気温年産と高温の登熟気温年産を比べると，平年登熟年産は柔らかいが粘りが弱く食味が劣るものの，5 ℃ 24时間貯蔵より硬くなりにくく柔らかさが持続した。一方，高温登熟年産は粘りが強く5 ℃ 24时間貯蔵により硬くなり，粘りもやや低下した。また，高蛋白ほど，両年産とも粘りが弱く食味が低下する傾向にあり，良食味もち米生産のため低蛋白米生産技術が重要であった。
Hardening speed of pounded rice-cake and gelatinization property of glutinous rice were investigated in six areas of Hokkaido during four years. The range of the yearly variations (differences between the two extreme values and coefficients of variation) was larger than that of regional variations. Using the ratio of yearly to regional variations and values of correlation coefficient among those properties, in ascending order of ratio, the properties were classified as: Group 1: maximum viscosity and break down; Group 2: minimum viscosity, final viscosity and consistency; Group 3: gelatinization initiation temperature, temperature at which maximum viscosity was shown, time in which maximum viscosity was shown and hardening speed of pounded rice-cake. Among years, for gelatinization property, a positive relationship was seen for properties in Group 2 and Group 3 with hardening speed of pounded rice-cake, and the clearest positive relationship was seen for properties in Group 3. Moreover, the higher the cumulative daily mean temperature during 40 days after heading (grain-filling temperature), the higher the values in Groups 2 and 3 and hardening speed of pounded rice-cake; and, the clearest positive relationship was seen for properties in Group 3 and hardening speed of pounded rice-cake. However, the relationship with the area was not clear. Moreover, the higher the protein content; the lower the values in Group 1 and Group 2 among years and among areas, and the lower the values in Group 3 among years only. In addition, physical properties of cooked rice produced in the normal grain-filling temperature year (NGFTY) were compared with those in the high grain-filling temperature year (HGFTY). The cooked rice produced in NGFTY was softer and less sticky, namely the eating quality was lower. However, it was less stiffened and was kept soft by storage at 5 ℃ for 24 hours after cooking. On the other hand, cooked rice in HGFTY was stickier, and became hard and less sticky with storage at 5 ℃ for 24 hours. Moreover, the higher the protein content, the lower the stickiness, namely the eating quality was lower in both NGFTY and HGFTY. Therefore, the cultivation technique to obtain low protein content rice was considered important to obtain glutinous rice with good eating quality.