Many of odor active compounds have various odor characteristics and unique chemical structures. Some of them have chirality based on chiral centers in their structure. Among them, there are different odor characteristics and odor thresholds between its enantiomers. Therefore, it is very important for flavor science to clarify the relationship between the absolute stereochemistry and the odor property. Two significant techniques are known for approaching to the study for chiral compounds; supercritical fluid chromatography (SFC) and vibrational circular dichroism (VCD). The former is one of optical resolution technique for racemic compounds using CO₂ supercritical fluid. The latter is a recently developed technique for determination of absolute stereochemistry of organic compounds coupled with density functional theory (DFT) theoretical calculation. In this review, these two powerful tools for the investigation of chiral odor active compounds are introduced.

It is well known chiral stationary phases (CSPs) based on polysaccharide derivatives show extremely higher chiral recognition ability for a wide range of racemic compounds. Nowadays, most of people who determine optical purity of their compounds have adopted chromatographic method using polysaccharide derivatives type columns, so called, “chiral columns”. Although chiral columns based on polysaccharide derivatives are the most powerful tool for chiral separation, there have been a few chiral compounds which cannot be separated on chiral columns yet. And it has been believed that the representatives of such difficult compounds to be separated are triglycerides. But recently interesting articles have been reported about a direct chiral separation of triglyceride compounds. Here we would like to look over the chiral separation using CSPs for HPLC and introduce the current situation about polysaccharide derivatives CSPs.

Phytochemicals with anti-oxidant activities present in fruits and vegetables such as vitamin C, vitamin E, carotenoids and flavonoids. They are considered to contribute to the protective effect against oxidative stress by scavenging reactive oxygen species (ROS). Evaluation of dietary antioxidants effect, it is important to study the overall effect from all antioxidants in the diet. Validated method is necessary for measuring the total antioxidant capacity of food. Hydrophilic and lipophilic oxygen radical absorbance capacity (H-, and L-ORAC) and singlet oxygen absorption capacity (SOAC) are methods for evaluating antioxidant capacities of hydrophilic and lipophilic compounds. We improved the original method for ORAC and SOAC determination, and evaluated the precision by interlaboratory studies.