Submerged fermentation of Ginkgo biloba seed powder using Eurotium cristatum for the development of ginkgo seeds fermented products.

Abstract

Ginkgo biloba seeds are well known for the significant curative effects on relieving cough and asthma. However, the development of products from ginkgo seeds still falls behind at present, resulting in a great waste of ginkgo seeds' resource. In this work, submerged fermentation of ginkgo seed powder using Eurotium cristatum was studied to investigate its feasibility as a new processing method. To promote the growth of E. cristatum, the optimum fermentation medium was 80.0 g L-1 of ginkgo seed powder with addition of 5.0 g L-1 calcium chloride (CaCl2 ), 4.0 g L-1 magnesium sulfate (MgSO4 ), 1.25 g L-1 zinc sulfate (ZnSO4 ) and 0.65 g L-1 iron(II) sulfate (FeSO4 ). The optimum fermentation conditions were pH 5.8 ± 0.1, inoculum size 5.1 × 106 CFU mL-1 , liquid medium volume 100 mL in 250-mL Erlenmeyer flask and fermentation 4 days. Through fermentation, the production of lovastatin in fermentation broth could reach up to 32.97 ± 0.17 μg mL-1 and the total antioxidant capacity was improved by more than two-fold. In addition, 40.15% of the ginkgotoxin in ginkgo seed powder was degraded while the entire degradation of ginkgolic acids was obtained. Moreover, fermented ginkgo seed powder suspension presented pleasant fragrances, and the activities of amylase and protease were enhanced to 11.30 ± 0.10 U mL-1 and 23.01 ± 0.20 U mL-1 , respectively. Submerged fermentation using E. cristatum could significantly enhance the functional value and safety of ginkgo seed powder, and had great potential to become a novel processing method for the development of ginkgo seeds fermented products. © 2020 Society of Chemical Industry.