The correlation between the pressure sensitivity of biological molecules and the diversity in their constituent units reveals that membrane lipids play important roles in the environmental adaptation of organisms. Bilayer membranes formed by typical membrane lipids, i.e., phospholipids, undergo phase transitions in response to changes in various external environmental factors and thereby change their membrane states. Therefore, the environmental adaptation of phospholipid bilayer membranes can be thermodynamically characterized by constructing phase diagrams with respect to bilayer phase transitions. Numerous kinds of phospholipids are found in biomembranes, and this variety is due to structural variations in each of the five functional groups (what we call “modules”) of which a single phospholipid molecule consists. By selecting a standard lipid and systematically comparing its phase diagram with those of other phospholipids whose molecular structures have been modified, it is possible to elucidate how each phospholipid bilayer adapts to its environment. In this review, we describe the temperature-pressure phase diagrams of the bilayer membranes of various phospholipids which are created by introducing various structural modifications (i.e., hydrophobic chains, chain linkage types, and polar head groups) to the standard lipid molecule in a systematic manner to discuss the the environmental adaptation of phospholipid bilayers under high pressure.

Subcritical and supercritical water is a solvent that greatly expands the potential of water as a reaction solvent using high temperature and high pressure. A variety of reactions and reaction processes related to green chemistry can be realized by utilizing characteristics such as fast reactions, unique solvent properties, and tunability of solvent properties according to temperature and pressure. This paper describes the chemical reactions occurring in subcritical and supercritical water and how they relate to solvent properties. The paper also introduces applications in organic reactions such as organic synthesis, chemical conversion of biomass, and plastic degradation, as well as in the synthesis of metal oxide nanoparticles. Furthermore, the paper discusses reaction processes that utilize changes in solvent properties.

High hydrostatic pressure (HHP) processing of foods was first commercialized as a nonthermal pasteurization technology of high quality products. Although its development in Japan has progressed only slowly, countries in Europe and North America have actively adopted this emerging technology. HHP food processing is now widely applied not only for the pasteurization of meat products, juices, and various pastes, but also for shucking lobsters and shellfish. The installation of HHP processing equipment has expanded steadily, and contract processing services have also grown in parallel. This paper reviews HHP food processing from its basic and application aspects.