Physical chemistry of water and micro-structure to determine the water activity of food

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02944
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Hiroshi Nakagawa 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 物質科学研究センター, 研究主幹 (20379598)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 構造食品科学 / 水分活性 / 中性子散乱 / 熱分析 / 水和 / ナノ構造 / 澱粉の糊化・老化 / 蛋白質ゲル

Outline of Final Research Achievements

Gelatinization of starch was analyzed by quasi-elastic neutron scattering, and changes in starch molecular motility corresponding to the DSC endothermic peak were detected, suggesting that molecular motility increases by gelatinization. We also found that starch molecular motility is suppressed with retrogradation. A new simultaneous measurement system employing attenuated total reflection sampling method of infrared spectroscopy was developed and applied to the analysis of food materials. As a result, structural changes associated with retrogradation of starch were captured by small-angle neutron scattering and FT-IR. The analysis of the structure-property relationship of food products by combining various spectroscopic measurements, thermal analysis, and other experimental techniques based on neutron scattering is effective for analyzing the microstructure of food products and the relationship between water and microstructure in food products.

Free Research Field

食品科学

Academic Significance and Societal Importance of the Research Achievements

水分活性は食品の保存性や品質を評価する実用的な指標であり、その有効性は広く認められており、食品加工などの現場で既に利活用されている。一方、水分活性は食品の分子構造にも影響を受けるが、ナノスケール動的挙動で特徴付けられる食品構造物性(分子構造とその運動性)が食品の水和状態にどのように影響を与えるかは未解明な点が多い。本研究で解明した食品のミクロ構造と水和状態の関係性などは、食品の物性や品質をミクロな視点から理解するために重要な情報となる。