Comparative analysis of taste compounds in shiitake mushrooms processed by hot-air drying and freeze drying

ABSTRACT

Shiitake mushrooms were processed by hot-air drying (HD) and freeze-drying (FD) to investigate the taste compounds. The total free amino acids in HD samples treated at 60°C was the highest as compared to the other three dried samples. Although cysteine was not detected in fresh shiitake mushroom (FSM), it was released during the drying process and its content increased with the temperature increase from 50°C to 70°C. The content of total organic acids was the highest in the HD sample treated at 60°C (56579.6 µg/g DW). Based on the obtained moisture contents, all compounds were calculated to their contents in respective FSMs, the content of Glu, citric acid, and succinic acid increased during drying as temperature increase from 50°C to 70°C. It indicated that new taste compounds were produced during the HD process. The content of total nucleotides was the highest in HD samples treated at 50°C, and the lowest in FD sample. The HD samples treated at 70°C showed the highest equivalent umami concentrations (EUC) (25.2 g MSG/100 g), followed by at 60°C (19.7 g MSG/100 g), 50°C (14.7 g MSG/100 g) and FD samples (12.0 g MSG/100 g). Our results indicated that different drying treatments led to different physiochemical properties and nutritional contents in Shiitake mushrooms.

KEYWORDS:

• Shiitake mushroom
• hot-air drying
• freeze drying
• free amino acid
• organic acid
• nucleotide
• taste compounds

Additional information

Funding

This work was supported by the the National Key R&D Program of China [2016YFD0400705]; the National Natural Science Foundation of China [31401604].