Geographical Identification for Shiitake (Lentinula edodes) using Korean and Chinese Medium-based Bag Cultivation

A shiitake (Lentinus edodes) mushroom has been used for centuries owing to its unique and pleasant flavor in several East Asia. It was cultivated with the wood logs or the mediumbased bag method, but because of the limited supply of hardwood, the specific cultivation conditions, and the long time required, the bag method is now widely used to supply the market with high-quality. A shiitake using the Chinese inoculated medium in Korea is consistently increased, and a geographical origin labeling is becoming an issue for consumers and farmers. Therefore, this study aimed to examine stable isotope ratios features of shiitake using Korean medium, Chinese inoculated-medium, and also compared these with the shiitake directly imported from China. While a discrimination model for geographical identification appeared a classification accuracy of 93.5% for both original and cross-validated sample sets when the shiitake using Chinese inoculated medium was considered as China origin, if considered as Korea origin, the accuracy was decreased to ~80%. Hence, this study suggests the shiitake using the Chinese inoculated medium in Korea would be labeled as “China origin”, and the current origin labeling method depending on duration of medium preparation, inoculation, and cultivation in a specific country was not suitable. Our findings contribute to accurate geographical identification of shiitake mushrooms in Korea, and may extend potential applications in international mushroom markets.