Contributions of non-volatile and volatile compounds to the umami taste and overall flavour of shiitake mushroom extracts and their application as flavour enhancers in cooked minced meat

Aqueous extracts of dried shiitake mushrooms (Lentinus edodes) were prepared as taste and flavour enhancers for meat formulations. Effects of time and temperature on the chemical and sensory properties of the extracts were examined. Extracts prepared at 70 °C had significantly higher concentrations (p < 0.001) of the savoury tasting 50-ribonucleotides than those prepared at 22 °C but increasing the extraction time from 30 to 360 min only increased their recovery slightly (p = 0.053). In contrast, higher temperature extracts had considerably smaller concentrations of the major volatile compounds, such as lenthionine, 1-octen-3-ol, 1,3-dithiethane and dimethyl disulfide, because of loss through volatilisation. A sensory discrimination test showed that the lower temperature extract was perceived to have less umami taste than the higher temperature extract (p = 0.048). Incorporating the 70 °C shiitake extract into minced meat formulations led to significantly higher levels of savoury tasting 50-ribonucleotides in the cooked meat but no significant difference in umami perception.