Shiitake Research Citations

Storage temperature significantly influences the levels of health-promoting compounds in shiitake mushrooms. Compared to mushrooms stored at lower temperatures (1°C and 3°C), those stored at 5°C exhibited a higher level of total phenolics in their pileus after 2 weeks of storage; however, storage at 5°C also increased the deterioration of the fruiting body. In mushrooms stored at all temperatures, the eritadenine content in the pilei tended to increase up to 2 weeks of storage. In contrast, the ergothioneine content in the pileus decreased during storage, with a significantly lower level detected in mushrooms stored at 5°C for 4 weeks.

The study suggests that storage at lower temperatures (1°C and 3°C) may be better for preserving certain bioactive compounds. While storage at 5°C increased total phenolics after 2 weeks, it also increased mushroom deterioration and significantly decreased ergothioneine content after 4 weeks. The mechanisms underlying the accumulation of phenolics and eritadenine may be related to mushroom deterioration during storage. The findings indicate that the levels of health-promoting compounds in shiitake mushrooms are influenced by storage temperature, suggesting the potential to control adjustments of specific bioactive compounds by regulating storage conditions.

Blue light increases the ergothioneine contents and antioxidative activities in shiitake mushrooms. In this study, blue light increased the ergothioneine content, with the ergothioneine content of L808 cultivar (about 2.8 mg/g) being higher than that of Sanbackhyang cultivar (about 1.2 mg/g). Additionally, fruiting body production (yield) on the medium irradiated with blue light increased in both cultivars. These results suggest that blue light is effective in shortening the cultivation period and increasing ergothioneine contents during shiitake cultivation.

Blue light exposure provides multiple benefits for shiitake cultivation. Fruiting body production (yield) increased in both cultivars tested (L808, 555 ± 60 g/3 kg medium; Sanbackhyang, 1090 ± 106 g/3 kg medium). Additionally, blue light increased the ergothioneine contents and antioxidative activities. Since the cultivation period of shiitake is approximately 120-150 days, which is longer than that of other edible mushrooms, blue light can help shorten the cultivation period while simultaneously increasing the health-promoting ergothioneine content.

The L808 cultivar produces significantly more ergothioneine under blue light conditions compared to the Sanbackhyang cultivar. The ergothioneine content of L808 was about 2.8 mg/g, which is more than double that of Sanbackhyang (about 1.2 mg/g). This suggests that cultivar selection is an important factor when aiming to maximize ergothioneine content in shiitake mushrooms, especially when combined with blue light exposure during cultivation.

The stem (stipe) of shiitake mushrooms contains more beta-glucans than the cap (pileus). This study found that beta-glucan content ranged from 20% to 44% in the cap, but was higher at 30% to 56% in the stem. Beta-glucans are the healthy compounds in shiitake that may help with cancer, high blood pressure, and high cholesterol, so eating the whole mushroom including the stem gives you more of these beneficial compounds.

Substrate composition significantly affects both shiitake yield and nutritional value. The study found that mixing oak and eucalyptus sawdusts improved shiitake yield and nutritional value compared to using oak sawdust alone. Mushrooms obtained in the EUC-OS-WB (eucalyptus-oak-wheat bran) mixture recorded the highest protein and crude fiber contents (15.1% and 5.4% respectively). There was also an improvement in mushroom protein, crude fibers, and vitamin C contents, and a decrease in carbohydrate contents on most substrates compared to control. The mixture containing oak and eucalyptus sawdust has good potential to improve shiitake yield and nutritional value.

The substrate EUC-OS-WB: 400-400-200 (eucalyptus-oak-wheat bran) had the highest biological efficiency (74.1%) compared to all treatments and produced mushrooms with the highest protein and crude fiber contents (15.1% and 5.4% respectively). This mixture containing oak and eucalyptus sawdust could be an appropriate alternate for producing shiitake mushrooms with improved nutritional value compared to using oak sawdust alone, demonstrating that substrate composition directly influences the nutritional profile of the harvested mushrooms.