Potential geo-discriminative tools to trace the origins of the dried slices of shiitake (Lentinula edodes) using stable isotope ratios and OPLS-DA

•δ13C, δ15N, δ18O, and δ34S varied significantly with country of origin (P < 0.05).•Externally validated test provided an excellent predictability (Q2cum = 0.881).•δ18O and δ15N were the best indicators for shiitake origin discrimination.•The probability of wrong classification of geographical origin was the below 1.2%.