Study on non-equilibrium freezing within a bio tissue and stable form of ice-crystal for long-term freezing preservation of foods

2015 Fiscal Year Final Research Report

• Project/Area Number: 25660093
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Food science
• Research Institution: Hokkaido University
• Principal Investigator: YAMADA Masahiko 北海道大学, 工学(系)研究科(研究院), 准教授 (70230480)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 生体組織 / 食品 / 凍結保存 / 低温変性 / 蛋白質 / 脂質 / 相変化

Outline of Final Research Achievements

As a basic research for the long-term preservation of bio-tissue and foods under low-temperature condition, observation of ice-crystals which form in a bio-tissue and molecular simulation of the system of proteins and water have been carried out. By both the observations and molecular simulations, irreversible change of the structure of proteins and water were confirmed to happen. From the results of molecular simulations, at -50℃, a molecule of Collagen II increased its length by 7%, while that of Myosin II decreased its length by 1% comparing to the condition at 37℃. The simulation results of Collagen and water system showed that the water molecule in freezing condition intruded in the protein structure. While for the case of Myosin, molecular structure of protein tended to fold in the middle part of the structure. This tendency implies the possibility of destruction of bio tissue such as human mussels during freezing preservation.

Free Research Field

伝熱工学