Improvement of quality of Ginkgo biloba seeds powder by solid-state fermentation with Eurotium cristatum for developing high-value ginkgo seeds products

In this study, we investigated the feasibility of Ginkgo biloba seeds powder by solid-state fermentation with Eurotium cristatum for developing high-value ginkgo seeds products. The optimum fermentation medium was consisted of 10 g of 40-mesh ginkgo seeds powder loaded in 100 mL Erlenmeyer flask with 50% (w/w) of water content, 4% (w/w) of MgSO₄ and 5% (w/w) of KH₂PO₄ addition. The optimum fermentation conditions were pH 5.0, 2 × 10⁸ CFU/g of inoculum size, 3 mL of sterilized water supplemented every two days during the four days of fermentation. Through fermentation, the spore number of E. cristatum was improved by about 36 times with the production of lovastatin reaching (54.10±0.16) µg/g. The antioxidant activity of fermented ginkgo seeds powder also got obvious enhancement, which could help eliminate excess free radicals produced by normal metabolism. The content of free amino acids increased by 82.32%. Except that the sugar was consumed in some degree, the other nutritional and functional components were well preserved while the content of detrimental ginkgolic acids was reduced by 44.97%. In addition, fermented ginkgo seeds powder possessed better digestibility and showed pleasant orange-like smelling. In conclusion, the quality of ginkgo seeds powder was remarkably improved through solid-state fermentation by using E. cristatum, which could be a promising way for functional applications of ginkgo seeds.