Characterization and Assessment of Effects of Drying Temperature on Edible Mushrooms with HS-GC–MS

A recent study aimed to analyze the effect of temperature on volatile organic compounds (VOCs) and nutrient composition of the Boletus bainiugan, a species of mushroom native to the Henan, Sichuan, and Yunnan provinces in Central and Southwestern China (1), in order to enable the characterization of chemical composition and rapid assessment of the mushroom’s nutrient content and provide a reference for the study of the effect of temperature on their nutrient and aroma components. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS) was used for the identification of the VOCs. A paper based on this research was published in Current Research in Food Science (2).

Rich in proteins, polysaccharides, fibers, and other nutrients, mushrooms have become one of the favorite ingredients in cuisines worldwide (3). In addition, they also contribute to good health with mushroom polysaccharides, phenolics, terpenoids, and other bioactive components (4). While wild edible mushrooms are more popular, unfortunately fewer wild edible mushrooms are available, as fresh mushrooms are highly perishable food items and tend to lose their quality immediately after harvest (5). Wild mushrooms are also affected by climate, and the yield is seasonally dependent. Extending the shelf life of mushrooms is therefore an essential challenge, with drying being one of the most widely used methods in doing so.

According to the researchers, 86 Boletus bainiugan were divided into five groups, and dried at different temperatures. HS-SPME-GC–MS identified 51 and 69 VOCs in the Phlebopus portentosus and Cantharellus yunnanensis genuses, respectively, and revealed that 65 °C retained a high level of volatile constituent substances. Variability was noted in volatile substances at different drying temperatures, with 21 differential metabolites screened for by orthogonal partial least squares discriminant analysis (OPLS-DA). At the same time, the nutrient composition of Boletus bainiugan at different drying temperatures was determined and found to be lower at 55 °C and 65 °C, with the presence of differences in the chemical composition of the samples at different temperatures characterized by Fourier transform infrared (FT-IR) and Fourier transform near-infrared (FT-NIR) spectroscopy. The chemometrics model effectively identified differences in the chemical composition for, and predicted protein, polysaccharide, crude fiber, and fat content of, Boletus bainiugan at different temperatures (2).

The researchers concluded that 65 °C was most favorable for the retention of VOCs, and the contents of total protein, fat, polysaccharide, and fiber were highly correlated with the FT-IR spectra. It was also pointed out that there are other factors which affect the nutritional quality of Boletus bainiugan, including its origin, species, preservation conditions, and storage age, and these factors should be taken into account simultaneously in future studies.

A variety of dried mushrooms. © attitudevisual - stock.adobe.com

References

1. Boletus bainiugan. Wikipedia. (accessed 2024-09-05).

2. Zheng, C.; Li, J.; Liu, H.; Wang, Y. Effect of Drying Temperature on Composition of Edible Mushrooms: Characterization and Assessment via HS-GC-MS and IR Spectral Based Volatile Profiling and Chemometrics. Curr. Res Food Sci. 2024, 11 (9), 100819. DOI: 10.1016/j.crfs.2024.100819

3. Zheng, C.; Li, J.; Liu, H.; Wang, Y. Review of Postharvest Processing of Edible Wild-Grown Mushrooms. Food Res. Int.2023, 173, 113223. DOI: 10.1016/j.foodres.2023.113223

4. Kushairi, N.; Tarmizi, N. A. K. A.; Phan, C. W.; Macreadie, I.; Sabaratnam, V.; Naidu, M.; David, P. Modulation of Neuroinflammatory Pathways by Medicinal Mushrooms, with Particular Relevance to Alzheimer's disease. Trends Food Sci. Technol.2020, 104 (2), 153-162. DOI: 10.1016/j.tifs.2020.07.029

5. Zhang, K.; Pu, Y.-Y.; Sun. D.-W. Recent Advances in Quality Preservation of Postharvest Mushrooms (Agaricus bisporus): A Review. Trends Food Sci. Technol. 2018, 72-82. DOI: 10.1016/j.tifs.2018.05.012