A comparison of dried shiitake mushroom in log cultivation and mycelial cultivation from different geographical origins using stable carbon and nitrogen isotope analysis

We determined carbon and nitrogen isotopic compositions (δ¹³C and δ¹⁵N) of dried shiitake mushroom (Lentinula edodes) samples from Japan, China, South Korea and Brazil in order to discriminate their geographical origins. In log cultivation, the δ¹³C values of Japanese dried shiitake samples were lower than those of Chinese samples, depending on the δ¹³C values of log and their growth conditions. In mycelial cultivation, the δ¹³C and δ¹⁵N values of Japanese dried shiitake samples were higher than those of Chinese samples. By using the δ¹³C and δ¹⁵N values, 87.4% of Japanese dried shiitake samples (n = 95) and 87.9% of Chinese dried shiitake samples (n = 66) in log cultivation, 90.0% of the Japanese dried shiitake samples (n = 50) and 93.9% of Chinese dried shiitake samples (n = 114) in mycelial cultivation, were correctly classified according to the production site. These results suggested that the δ¹³C and δ¹⁵N values will be potentially useful for tracing their geographical origin of dried shiitake samples. (author)