Abstract
Food is an essential in our daily life so that its quality, safety and nutrient are critical issues about which people really care. Japanese Agriculture Standard Law (JAS law) draws up the regulations and laws to protect consumers from harmful and false food. The implements of these regulations, to some extent, are based on some reliable, precise analytical protocols, which have traceability for food safety and quality. Tea is the most popular beverage in the world after water. In Japan, annual consumption of tea is around 120000t (H23). Thus, tea is a very favorable food to Japanese, who want safe and high-quality tea. As we know, tea's flavors and tastes quite depend on its origins, cultivars and plucking seasons. Therefore, I am trying to develop a methodology to identify the origins (cultivars and geographical origins) and plucking seasons of tea including their mixture through five variables (δ13Ccaffeine, δ13Cbulk, δ15Ncaffeine, δ15Nbulk values and caffeine concentration). An analytical protocol was developed for measuring δ13C values of caffeine from tealeaves (Wu et al., 2012). In this meeting, the application of this protocol for δ15N values measurement is presented. The preliminary results indicated that there was feasible to determine two variables (δ13Ccaffeine and δ15Ncaffeine) by the protocol. Meanwhile, they have a correlation for discriminating origins of tealeaves.
