Effect of Bacillus natto solid-state fermentation on the functional constituents and properties of Ginkgo seeds

In the present investigation, fibrinolytic Ginkgo seeds were produced by solid-state fermentation (SSF) with Bacillus natto strains, and some parameters of the fermentation processes were investigated. Under optimal fermentation conditions, the fibrinolytic activity of Ginkgo seeds reached 3,682 ± 43 IU/g with the fermentation parameters of relative humidity 80%, initial water content 73%, fermentation temperature 38°C, inoculation volume 18%, and fermentation time 38 hr, respectively. The fermented Ginkgo seeds possessed a superior potential for the production of Nattokinase. What's more, the fermented Ginkgo seeds possessed higher total flavonoid and lower ginkgolic acids contents, which could enhance bioactivity and guarantee food safety. Sensory evaluations indicated that Ginkgo seeds produced by SSF could also be consumed as a kind of popular food. PRACTICAL APPLICATIONS: Fermented food is popular in countries. It can not only improve the sensory properties of the products, reduce undesirable constituents, and make nutrients easily absorbable, but also improve the nutritional properties. Ginkgo biloba L is one of the oldest species that has existed on earth for more than 200 million years. However, the application of Ginkgo seeds has been limited because of the ginkgolic acids. In a previous study, immobilized Bacillus natto acted upon Ginkgo seeds to enhance the bioactivity and safety of fermented Ginkgo seeds. However, separating the fermented Ginkgo seeds from the liquid needs a large amount of energy. The solid-state fermentation of Ginkgo seeds is a good choice to produce functional Ginkgo seed products.