市販の代表的な澱粉である馬鈴薯澱粉と異種澱粉であるコーンスターチなどを混合し, 粘性, ゲル特性を調べた結果, 次のことがわかった.
1) 4%澱粉濃度のアミログラム特性値は, 粘度上昇開始温度では, コーンスターチの混合比が増すに従いS字型に増加し, 最高粘度および30℃冷却粘度では, コーンスターチの増加に伴いほぼ比例して減少した.
2) 15%澱粉濃度のゲル強度では, コーンスターチが馬鈴薯澱粉に10-50%の範囲で混合されると, ゲル強度は対照馬鈴薯澱粉より10-20%高くなった.
3) 顕微鏡観察では, ゲル強度上昇効果のみられた混合澱粉のうち, 糊化開始温度の高いコーンスターチ粒は膨潤が遅れていた. 一方, 上昇効果のみられなかった混合系では, 両澱粉の糊化, 膨潤は並行して進んでいた.
4) ゲル強度上昇効果を示した混合澱粉の低温保存によるゲル強度の変化は, 85℃加熱処理では馬鈴薯澱粉に, また120℃加熱処理ではコーンスターチに近似した変化を示した.
以上のことから, 馬鈴薯澱粉とコーンスターチの混合系におけるゲル強度上昇効果は, 糊化, 膨潤の遅れたコーンスターチが充填材として機能し, ゲルを補強すると推定される. この特性は, 水産および畜肉ねり製品のゲル補強に応用できる.

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昭和57年産水稲うるち米34点について, 官能検査による食味評価を行い, それと同時に理化学的性質を測定して, 食味評価 (総合評価) を目的変数とし, 理化学的性質21項目を説明変数に選び, 多重回帰分析を行った.
その結果, 精米のタンパク質 (乾物), 精米粉のアミログラフ特性のうち, 最高粘度, 最低粘度, ブレークダウン, 精米の炊飯特性のうち, 炊飯液のヨード呈色度の5項目の測定値から, 食味をある程度推定できる判定式を作ることができた.
また, 昭和58年産水稲うるち米18点を用いて, 食味の判定式の妥当性を検討した.

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ジャガイモ澱粉について, 温水処理後の試料および未処理試料のそれぞれにつき, 広い昇温速度範囲 (0.05-8Kmin^-1) でDSC分析を行い, それらの糊化挙動を比較検討した. その結果, 糊化温度の昇温速度依存性は温水処理試料のほうが未処理試料に比べて大きいこと, また, 糊化開始温度および糊化ピーク温度は温水処理によって高温側に移ることが認められた. さらに, 温水処理試料の糊化熱 (吸熱量) として, 未処理試料の値 (4.3±0.17cal g^-1) より大きな値 (4.7±0.17cal g^-1) が得られた. これらのことは, 温水処理により澱粉粒内の分子配列が変化し (アニーリング), 澱粉粒の構造は熱力学的により安定な, そしてより均一な構造に変化することを示唆するものである.

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This review deals with two kinds of physical modifications of starch which have been socalled “warm water treatment” and “heat-moisture treatment.”
A temperature-composition diagram illustrating the gelatinization and the melt of starch granules has been constructed from the DSC data that show two kinds of endothermic transitions for the starch-water system. The diagram obtained corresponds to that of the crystalline polymerpoor solvent (diluent) system. Thermal phase transitions of the starch-water system have been discussed using the diagram.
The effect of warm water treatment on starch granules has been studied: This treatment causes the sharpening and the rise of the gelatinization temperature range, and the reduction of the swelling power and the solubility. The structural changes in granules during the treatment have been interpreted in terms of the annealing of semicrystallites of starch molecules. In fact, photomicrographs presented in the paper well shows the annealing process of starch granules with increasing temperature. It was concluded that this treatment brings about increases in homogeneity of both individuals and populations of starch granules through the process of annealing of starch crystallites.
Heat-moisture treatment brings about changes in the physical properties of starch through the process of the “melting” of starch granules. In the case of potato starch, the “B” pattern of X-ray diffraction is changed to “A” or “C” pattern, involving increases in heterogeneity of granular structure. The gelatinization properties of potato starches treated at various moisture levels and temperatures were examined and the relationships between the treatment conditions and the gelatinization properties have been clarified. From the results, it was concluded that heat-moisture treatment brings about irreversible disordering of granular structures with increasing of associative forces among starch molecules in granules.
Degradation of the physically modified starches with amylases and mineral acids were also studied. Susceptibility of heat-moisture treated potato starches to amylases was much larger than that of untreated one, but not in the case of corn starch. Microscopic observations by SEM showed that the degradation of the treated potato starch with glucoamylase from R. niveus and α-amylase (liquefying type) from B. subtilis (BLA) proceeded in the different mode each other. Differences in the action mode of BLA on the digestion of corn and the treated potato starch were also shown. In contrast to the heat-moisture treated potato starch, the warm water treated potato starch showed less susceptibility to amylases than the untreated one did. Some scanning electron micrographs of acid-modified potato starch granules were also presented.
In conclusion, the possibilities of the utilization of the physically modified starches were described.

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The basic concept and outline of the subsite theory were described, which correlates quantitatively the subsite structure (the arrangement of subsite affinities) to the action pattern of amylases in a unified manner. The subsite structures of several exo- and endo-amylases and an α-glucosidase were shown in histograms, from which the binding modes of linear substrates and glucose can be predicted.
The theory is effectively utilized as follows: 1) Interpretation of the substrate specificity of the amylase. 2) Calculation of the change in product distribution in the course of hydrolytic reaction catalyzed by the amylase. 3) Characterization of the nature of subsites by spectroscopic methods and chemical modification. 4) Prediction of change in action pattern by chemical modification. 5) Detailed analysis of mechanisms of amylase-catalyzed reactions by fast reaction techniques.
Several actual examples of application of the theory to amylases, including glucoamylase, Taka-amylase A and bacterial liquefying α-amylase, were described.

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