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

BACKGROUND: 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. RESULTS: 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. CONCLUSIONS: 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.

Effect of different drying methods on product quality, bioactive and toxic components of Ginkgo biloba L. seed.

BACKGROUND: Ginkgo biloba seeds are used as a functional food across Asia. However, the presence of toxic compounds has limited their application. In this study, freeze drying, infrared drying, hot-air drying and pulsed-vacuum drying were used to dry G. biloba seeds. A comprehensive analysis was performed on their product quality, antioxidant activities, bioactive and toxic components. RESULTS: Results showed that the drying methods had a significant influence on product quality with freeze drying being superior due to the minimal microstructural damage, followed by infrared drying and pulsed-vacuum drying. Infrared-dried product possessed the strongest antioxidant activities and higher bioactive compound content than hot-air-dried and pulsed-vacuum-dried product. Toxic compounds in fresh G. biloba seeds (ginkgotoxin, ginkgolic acid and cyanide) were reduced markedly by drying. Ginkgotoxin was reduced fourfold, and the contents of acrylamide, ginkgolic acid and cyanide in dried G. biloba seeds were reduced to the scope of safety. Amongst the four drying methods, infrared drying had the shortest drying time, and its product showed higher quality and bioactive compound content, and stronger antioxidant activities. CONCLUSIONS: These findings will offer salient information for selecting a drying method during the processing of ginkgo seeds. Infrared drying could be considered as a multiple-effect drying method in the processing of ginkgo seeds. © 2020 Society of Chemical Industry.

Preparation of Starch-Hard Carbon Spherules from Ginkgo Seeds and Their Phenol-Adsorption Characteristics.

Carbon spherules from ginkgo seed starch were prepared through stabilization and carbonization processes. The ginkgo seed starch was first stabilized at 195 °C for 18 h, then carbonized at 500 °C for 2 h under an N2 atmosphere. The characterization results confirmed that carbon spherules were in the size range of 10-20 µm. Experimental data were also evaluated to find out the kinetic characteristics of phenols on the carbon spherules during the adsorption process. Adsorption processes for phenol, p-nitrophenol and p-chlorophenol were found to follow the pseudo-first order kinetic model with R² values of 0.995, 0.997 and 0.998, while the rate constants k1 = 0.014, 0.009 and 0.011 min-1 showed that the adsorption is mainly controlled by adsorbate diffusion. The equilibrium data were analyzed with the Langmuir, Freundlich and Temkin-Pyzhev models and the best fit was observed with the Freundlich isotherm, suggesting the physical adsorption of phenols. From the thermodynamic functions, ∆G, ∆H, and ∆S were calculated, which showed that adsorption is more favorable at low temperature and is an exothermic process, and the adsorption of p-nitrophenol and p-chlorophenol were more advantageous than that of phenol.

Review of Ginkgo biloba-induced toxicity, from experimental studies to human case reports.

Ginkgo biloba seeds and leaves have been used as a traditional herbal remedy for thousands of years, and its leaf extract has been consumed as a botanical dietary supplement for decades. Ginkgo biloba extract is a complex mixture with numerous components, including flavonol glycosides and terpene lactones, and is one of the most widely sold botanical dietary supplements worldwide. Concerns about potential health risks for the general population have been raised because of the widespread human exposure to Ginkgo biloba and its potential toxic and carcinogenic activities in rodents. The National Toxicology Program conducted 2-year gavage studies on one Ginkgo biloba leaf extract and concluded that there was clear evidence of carcinogenic activity of this extract in mice based on an increased incidence of hepatocellular carcinoma and hepatoblastoma. Recently, Ginkgo biloba leaf extract has been classified as a possible human carcinogen (Group 2B) by the International Agency for Research on Cancer. This review presents updated information on the toxicological effects from experimental studies both in vitro and in vivo to human case reports (caused by ginkgo seeds or leaves), and also summarizes the negative results from relatively large clinical trials.

Preparation of ZIF-8 and Its Application in Determination of Pyridoxine and Pyridoxal in Ginkgo Seeds by Ultra-Performance Liquid Chromatography.

A new rapid and accurate method was developed for simultaneous determination of pyridoxine and pyridoxal in ginkgo seeds, using ultra-performance liquid chromatography (UPLC) equipped with a fluorescence detector. Diluted hydrochloric acid solution was used as the extracting solvent. For the pretreatment of extracts, a zeolitic imidazolate framework material (ZIF-8) was prepared and characterized. An ODS-BP column (4.6 mm × 250 mm × 5 µm) was used for separation. The conditions of sample extraction, cleaning and separation were optimized. The linear correlation coefficient (R2) of the analyte was better than 0.9999, indicating good linearity. The limits of detection (LODs) of pyridoxal and pyridoxine were 0.0065 mg/kg and 0.0057 mg/kg, respectively, and limits of quantitation (LOQs) were 0.022 mg/kg and 0.019 mg/kg, respectively. The recovery of the two substances ranged from 86.2% to 110.4%, and the relative standard deviation (n = 6) was less than 7.5%. The method was applied to determine the contents of pyridoxine and pyridoxal in actual ginkgo seed samples with satisfactory results.

Evaluation of proximate composition, flavonoids, and antioxidant capacity of ginkgo seeds fermented with different rice wine starters.

Ginkgo seeds are distinguished as source of highly promising food and traditional Chinese herbal for thousands of years. It is well known for the significant curative effects on some diseases, such as cough and asthma. The current work aimed to study the proximate composition, phytochemical content, and antioxidant capacity of ginkgo seeds fermented by 17 varieties of rice wine starters. Solid state fermentation was used to improve the nutrition of ginkgo seeds. Correlation analysis showed that there was a significant correlation between the flavonoids, approximate composition, and antioxidant activity in fermented ginkgo seeds. Through principal component analysis (PCA), Yp rice wine starter was found as the most suitable for ginkgo seeds fermentation. After fermentation of Yp rice wine starter, the content of quercetin increased by 188.1%, the content of reducing sugars and peptides increased by 16 and 24 times, respectively, and the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radicals increased from 4.69 to 12.43 mg TE/g. The solid-state fermentation of ginkgo seeds could be efficiently applied to food industrial production, and fermentation significantly increased the antioxidant activity and flavonoid content of ginkgo seeds, as well as improved their nutrition. PRACTICAL APPLICATION: Traditionally, rice wine starter was used for brewing wine, only some folk use rice wine starter for food production. In this paper, ginkgo seeds are selected for fermentation, which not only solves the problem of ginkgo seeds surplus, but also provides a reliable technical route for industry. It provides reference for the application of rice wine starter in food in the future.

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.

Two new phenolic glycosides isolated from Ginkgo seeds.

Two new phenolic glycosides, 7S, 8R-urolignoside-9'-O-ß-D-glucoside (1) and scrophenoside G (2), were isolated and identified from the seeds of Ginkgo biloba L., a famous traditional medicine and functional food around the world. Their structures were elucidated by spectroscopic methods (1D and 2D NMR, HR-ESI-MS, and CD), and the comparisons of spectroscopic data with the reported values in the literature.

Qualitative and Quantitative Analysis of Carbohydrate Modification on Glycoproteins from Seeds of Ginkgo biloba.

Recent progress in the relationship between carbohydrate cross-reactive determinants (CCDs) and allergic response highlights the importance of carbohydrate moieties in the innate immune system. Previous research pointed out that the protein allergen in Ginkgo biloba seeds is glycosylated, and the oligosaccharides conjugated to these proteins might also contribute to the allergy. The aim of this study was to analyze carbohydrate moieties, especially N-linked glycans, of glycoproteins from Ginkgo seeds originating from different places for detailed structures, to enable further research on the role played by N-glycans in Ginkgo-caused allergy. Results of monosaccharide composition and immunoblotting assays indicated the existence of N-glycans. Detailed structural elucidation of the N-glycans was further carried out by means of hydrophilic interaction ultraperformance liquid chromatography (HILIC-UPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In total, 14 out of 16 structures detected by UPLC were confirmed by MALDI-TOF-MS and tandem mass spectrometry, among which complex-type N-glycans bearing Lewis A determinants and high-mannose-type N-glycans were identified from Ginkgo seeds for the first time. Precise quantification of N-glycans was performed by use of an external standard, and both the absolute amount of each N-glycan and the percentage of different types of N-glycan showed significant diversity among the samples without any pattern of geographic variation.