Identification of the key odor-active compounds responsible for varietal smoky aroma in wines made from the East Asian species

A smoky aroma was found in wines made from East Asian species that had not been treated with oak products or exposed to smoke. In this study, a combined method of sensory analysis and quantitation of aroma compounds was used to identify the chemical basis of this smoky aroma. Syringol, eugenol, 4-ethylguaiacol, and 4-ethylphenol were confirmed as the key odor-active compounds contributing to the varietal smoky notes in wines of East Asian species. The concentrations of these compounds showed significant variation between grape species. The highest levels of syringol were found in Vitis amurensis wines, with an average of 178.8 μg/L. The average concentration of eugenol in V. davidii wines was 101.5 μg/L, about 10 times higher than in other species. 4-Ethylphenol and 4-ethylguaiacol were both abundant in the wines of the East Asian species. The results of the sensory interaction between the four compounds showed a complete addition effect for eugenol, a partial addition effect for syringol, and a hyper-addition effect for 4-ethylguaiacol and 4-ethylphenol on the smoky attribute.

Systematic revision of Hydnum species in Japan

Hydnum (Hydnaceae, Basidiomycota) exhibits endemic species diversity in East Asia; however, few comprehensive systematic studies have been conducted to date. Here, we performed morphological, ecological, phylogenetic, and biological evaluations of the taxonomy of Hydnum species in Japan. In total, 186 Japanese Hydnum specimens were used for morphological observations. Phylogenetic trees were constructed using sequence data of nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) region and a portion of translation elongation factor 1-α (tef1). Intra- and interspecific mating tests using 78 monokaryotic strains of 13 species did not conflict with species delimitation inferred from their ITS and tef1 phylogenetic relationships. This study provides detailed morphological descriptions of 15 rigorously identified species from Japan, nine of which are described as new: H. alboluteum, H. albopallidum, H. pinicola, H. itachiharitake, H. minospororufescens, H. orientalbidum, H. subberkeleyanum, H. tomaense, and H. tottoriense. Three species documented in this work are new to Japan: H. boreorepandum, H. mulsicolor, and H. umbilicatum. The remaining three species (H. cremeoalbum, H. minus, and H. repando-orientale), previously reported from Japan, are redescribed using data from newly collected materials. We also transferred two old species (Hericium fimbrillatum and Sarcodon nauseofoetidus) from East Asian Hydnum into other genera.