Soaking test with physiological salt and bile solutions was carried out for polylactic acid (PLA), polycaprolacton (PCL), polyglycolic acid (PGA) and their copolymers. Biodegradability was evaluated by measuring mechanical properties and molecular weight of these polymers as a function of soaking time. In homopolymers, PGA degraded very quickly, but other two polymers kept the mechanical strength for more than 100 days. In the copolymer composed of lactic acid and glycolic acid, the degradation rate varied with mole ratio. Generally the degradation rate of copolymers was found to be rapid as compared with hompolymers. The polymers that are useful in the field of bio-science can be prepared from the copolymers of biodegradable components by changing the monomer ratio.
The luminescent value of green tea leaves is different by the different processing methods : that of brown rice tea (genmaicha) is the highest because of the luminescence of brown rice, and followed, in order, by boiled tea (sencha) and roasted tea (hojicha). It was also revealed that the higher the measurement temperature, more the luminescent value increases.