Wild Strawberry-like Flavor Produced by the Fungus Wolfiporia cocos - Identification of Character Impact Compounds by Aroma Dilution Analysis after Dynamic Headspace Extraction

Brown-rot fungi are particularly suitable for the sustainable and cost-efficient biotechnological production of natural flavors. In this study, Wolfiporia cocos was employed for the fermentation of European black currant pomace supplemented with aspartate in surface cultures to produce a flavor reminiscent of wild strawberries. Aroma dilution analysis (ADA) by means of dynamic headspace extraction was developed as a suitable technique for solid samples. The character impact compounds were quantified by stable isotope dilution analysis and standard addition and validated by recombination experiments. (R)-Linalool (1879 mg kg-1, ADA 211), methyl anthranilate (2206 mg kg-1, 210), 2-aminobenzaldehyde (771 mg kg-1, 25), and geraniol (138 mg kg-1, 25) were identified as key aroma compounds. Recombination experiments demonstrated that the combination of the four analyzed compounds was responsible for the odor impression reminiscent of wild strawberries.