The main active constituents and detoxification process of Ginkgo biloba seeds and their potential use in functional health foods

Sequential fermentation of Ginkgo biloba seeds by Bacillus subtilis natto and Lactobacillus plantarum enhanced nutrition, flavor and lipid-lowering activity

BACKGROUND

Ginkgo biloba seeds (GBS) are rich in flavonoids, proteins and reducing sugar, and have been consumed as food and medicinal nuts for thousands of years. However, the presence of ginkgotoxins and their poor palatability limit people's consumption of them.

RESULTS

This study used solid-state fermentation with Bacillus subtilis natto and Lactobacillus plantarum to enhance the safety and benefits of GBS. Optimized fermentation conditions increased the content of beneficial components like total flavonoids, soluble protein and reducing sugar while eliminating unpleasant odors (isoamyl aldehyde and hexanal) and reducing the toxin 4'-O-methylpyridoxine by 91.17%. Fermentation of GBS powder can significantly enhance its anti-inflammatory and antioxidant activities in vitro (P < 0.001). Furthermore, it exhibits a dose-dependent effect within a certain concentration range. Mixed fermentation (FBnLp) was evaluated for its effects on obesity and metabolic syndrome in mice fed a high-fat diet. FBnLp significantly reduced body and liver weight gain, prevented dyslipidemia and decreased inflammatory and oxidative stress compared to unfermented GBS. Histological analysis showed that FBnLp improved liver health by reducing fat accumulation and preventing non-alcoholic fatty liver disease. Meanwhile, it was found that feeding FBnLp increased the expression of CPT-1α, which regulates energy expenditure and fat breakdown, and downregulated the expression of SREBP-1c, FAS and ACC, which regulate fat synthesis.

CONCLUSION

This research provides new insights and technological support for the application and development of FBnLp as a functional product, addressing key issues in its use and industry growth. © 2024 Society of Chemical Industry.

Structural characterization of a α-d-glucan from Ginkgo biloba seeds and its protective effects on non-alcoholic fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD) poses a great global challenge to public health, yet it holds promise for amelioration through plant-derived polysaccharide. Ginkgo biloba seeds have long been used as medicine and food, which has potential benefits for various chronic diseases. However, the protective role of Ginkgo biloba seed polysaccharide against NAFLD remains unclear. In this study, we isolated and purified polysaccharide (GBSP-2) from Ginkgo biloba seeds. GBSP-2 is composed of α-d-glucopyranose residues, which are interconnected with α-d-glucopyranose units linked by (1→4) bonds, (1→4,6) bonds and (1→3,4) bonds, the ratio distribution is 15:1:1. By studying a mouse model, we investigated the effect of GBSP-2 (100 or 200 mg/kg) on high-fat-diet-induced NAFLD. We demonstrated that GBSP-2 significantly alleviated NAFLD, as evidenced by reduced hepatic steatosis, decreased inflammation, improved oxidative stress and ameliorative glucolipid metabolic disorders. Furthermore, GBSP-2 mitigated gut microbiota disturbance of NAFLD mice and markedly increased the abundance of Akkermansia, Romboutsia, Lactobacillus and Bacteroides. Mechanistically, GBSP-2 could activate AMPK/ACC signaling pathway to inhibit lipid synthesis by generating 3,4-dihydroxyphenylpropionic acid (DHPPA). Overall, these findings suggest that GBSP-2 plays a multi-channel and multi-target role in improving NAFLD through the gut-liver axis.

Screening of Solvent Systems for Countercurrent Chromatography Separation of Polar Constituents from Ginkgo biloba L. Seeds

The separation of large polar constituents presents a substantial challenge in natural product research when employing column chromatography techniques, as the process is both complex and time-consuming. In this study, an acetonitrile/tetrahydrofuran/di-(2-ethylhexyl) phosphoric acid/aqueous saturated sodium chloride solvent system was developed and utilized for the countercurrent chromatography of polar constituents from Ginkgo biloba L. seeds. Five polar constituents were effectively isolated using an acetonitrile/tetrahydrofuran/di-(2-ethylhexyl) phosphoric acid/aqueous saturated sodium chloride (2:2:0.8:3, v/v) solvent system using a two-step countercurrent chromatography method. In the initial countercurrent chromatography process, three constituents were successfully purified from the methanol extract: compound 1, compound 4, and compound 5. Compounds 2 and 3, co-eluted from the column, were further subjected to three inner-recycling chromatographic procedures. At last, five constituents were purified and identified, including 4'-O-methylpyridoxine (1); two indole alkaloid N-glucosides, ginkgoside B (2) and ginkgoside A (3); 2-(4-hydroxybenzyl) malic acid (4); and coniferyl alcohol (5). The results demonstrated that the acetonitrile/tetrahydrofuran/di-(2-ethylhexyl) phosphoric acid/aqueous saturated sodium chloride solvent system serves as a feasible system for the efficient countercurrent chromatography separation of polar components.

Hyaluronic acid promotes heat-induced gelation of ginkgo seed proteins

This study aimed to investigate how varying concentrations (0.01-0.5 %, w/v) and molecular weights (50, 500, 1500 kDa) of hyaluronic acid (HA) affect the physicochemical properties of heat-induced ginkgo seed protein isolate (GSPI)-HA composite gel. Incorporating HA increased viscosity (up to 14 times) and charge (up to 23 %) of GSPI-HA aggregates, while reducing particle size (up to 31 %) and improving gel texture, particularly with high molecular weight HA. However, high concentrations (0.5 %, w/v) of HA weakened gel texture. Non-covalent bonds primarily drive the formation of a continuous gel network between HA and GSPI, resulting in small pores and enhanced hydration properties. With increasing HA molecular weight, non-covalent interactions between GSPI and HA increased, leading to improved gel thermal stability. Overall, the study suggests that manipulating the molecular weight and concentration of HA can enhance the gelling properties of GSPI, leading to the development of a diverse array of GSPI-HA composite gels with varied properties.

Optimization of α-L-arabinofuranosidase CcABF on clarification and beneficial active substances in fermented ginkgo kernel juice by artificial neural network and genetic algorithm

This study aimed at using α-L-arabinofuranosidase CcABF to improve the clarity and active substances in fermented ginkgo kernel juice by artificial neural network (ANN) modeling and genetic algorithm (GA) optimization. A credible three-layer feedforward ANN model was established to predict the optimal parameters for CcABF clarification. The experiments proved the highest transmittance of 89.40% for fermented ginkgo kernel juice with this understanding, which exhibited a 25.56% increase over the unclarified group. With the clarification of CcABF, the antioxidant capacity in juice was enhanced with the increase of total phenolic and flavone contents, and the maximum DPPH and hydroxyl radical scavenging rates were increased by 89.71% and 26.65%, respectively. The contents of toxic ginkgolic acids declined markedly, while the active ingredients of ginkgetin and ginkgolide B showed a modest increase. Moreover, changes in free amino acids and volatile compounds improved the nutritive value and flavor of clarified fermented ginkgo kernel juice.

Comprehensive Exploration of the Neuroprotective Mechanisms of Ginkgo biloba Leaves in Treating Neurological Disorders

Neurological disorders (NDs) are diseases that seriously affect the health of individuals worldwide, potentially leading to a significant reduction in the quality of life for patients and their families. Herbal medicines have been widely used in the treatment of NDs due to their multi-target and multi-pathway features. Ginkgo biloba leaves (GBLs), one of the most popular herbal medicines in the world, have been demonstrated to present therapeutic effects on NDs. However, the pharmacological mechanisms of GBLs in the treatment of neurological disorders have not been systematically summarized. This study aimed to summarize the molecular mechanism of GBLs in treating NDs from the cell models, animal models, and clinical trials of studies. Four databases, i.e., PubMed, Google Scholar, CNKI, and Web of Science were searched using the following keywords: "Ginkgo biloba", "Ginkgo biloba extract", "Ginkgo biloba leaves", "Ginkgo biloba leaves extract", "Neurological disorders", "Neurological diseases", and "Neurodegenerative diseases". All items meeting the inclusion criteria on the treatment of NDs with GBLs were extracted and summarized. Additionally, PRISMA 2020 was performed to independently evaluate the screening methods. Out of 1385 records in the database, 52 were screened in relation to the function of GBLs in the treatment of NDs; of these 52 records, 39 were preclinical trials and 13 were clinical studies. Analysis of pharmacological studies revealed that GBLs can improve memory, cognition, behavior, and psychopathology of NDs and that the most frequently associated GBLs are depression, followed by Alzheimer's disease, stroke, Huntington's disease, and Parkinson's disease. Additionally, the clinical studies of depression, AD, and stroke are the most common, and most of the remaining ND data are available from in vitro or in vivo animal studies. Moreover, the possible mechanisms of GBLs in treating NDs are mainly through free radical scavenging, anti-oxidant activity, anti-inflammatory response, mitochondrial protection, neurotransmitter regulation, and antagonism of PAF. This is the first paper to systematically and comprehensively investigate the pharmacological effects and neuroprotective mechanisms of GBLs in the treatment of NDs thus far. All findings contribute to a better understanding of the efficacy and complexity of GBLs in treating NDs, which is of great significance for the further clinical application of this herbal medicine.

Could protein phosphatase 2A and glycogen synthase kinase-3 beta be targeted by natural compounds to ameliorate Alzheimer's pathologies?

Alzheimer's disease (AD) is a progressive neurological disorder that impairs memory and cognitive abilities, primarily in the elderly. The burden of AD extends beyond patients, impacting families and caregivers due to the patients' reliance on assistance for daily tasks. The main features of the pathogenesis of AD are beta-amyloid plaques and neurofibrillary tangles (NFTs), that strongly correlate with oxidative stress and inflammation. NFTs result from misfolded and hyperphosphorylated tau proteins. Various studies have focused on tau phosphorylation, indicating protein phosphatase 2A (PP2A) as the primary tau phosphatase and glycogen synthase kinase-3 beta (GSK-3β) as the leading tau kinase. Experimental evidence suggests that inhibition of PP2A and increased GSK-3β activity contribute to neuroinflammation, oxidative stress, and cognitive impairment. Hence, targeting PP2A and GSK-3β with pharmacological approaches shows promise in treating AD. The use of natural compounds in the drug development for AD have been extensively studied for their antioxidant, anti-inflammatory, anti-cholinesterase, and neuroprotective properties, demonstrating therapeutic advantages in neurological diseases. Alongside the development of PP2A activator and GSK-3β inhibitor drugs, natural compounds are likely to have neuroprotective effects by increasing PP2A activity and decreasing GSK-3β levels. Therefore, based on the preclinical and clinical studies, the potential of PP2A and GSK-3β as therapeutic targets of natural compounds are highlighted in this review.

L-Theanine Improves the Gelation of Ginkgo Seed Proteins at Different pH Levels

L-theanine (L-Th), a non-protein amino acid naturally found in teas and certain plant leaves, has garnered considerable attention due to its health benefits and potential to modify proteins such as ginkgo seed proteins, which have poor gelling properties, thereby expanding their applications in the food industry. The objective of this study was to investigate the impact of varying concentrations of L-Th (0.0%, 0.5%, 1.0%, and 2.0%) on the gelling properties of ginkgo seed protein isolate (GSPI) at various pH levels (5.0, 6.0, and 7.0). The GSPI gels exhibited the highest strength at a pH of 5.0 (132.1 ± 5.6 g), followed by a pH of 6.0 (95.9 ± 3.9 g), while a weak gel was formed at a pH of 7.0 (29.5 ± 0.2 g). The incorporation of L-Th increased the hardness (58.5-231.6%) and springiness (3.0-9.5%) of the GSPI gels at a pH of 7.0 in a concentration-dependent manner. However, L-Th did not enhance the gel strength or water holding capacity at a pH of 5.0. The rheological characteristics of the GSPI sols were found to be closely related to the textural properties of L-Th-incorporated gels. To understand the underlying mechanism of L-Th's effects, the physicochemical properties of the sols were analyzed. Specifically, L-Th promoted GSPI solubilization (up to 7.3%), reduced their hydrophobicity (up to 16.2%), reduced the particle size (up to 40.9%), and increased the ζ potential (up to 21%) of the sols. Overall, our findings suggest that L-Th holds promise as a functional ingredient for improving gel products.

Morphological Characteristics, Ultrastructure, and Chemical Constituents of the Endotesta in Ginkgo (Ginkgo biloba L.)

Ginkgo biloba L. is a tree species of significant economic and ecological importance. Prior studies of the Ginkgo biloba seed coat have predominantly focused on the sarcotesta and sclerotesta, with less attention paid to the endotesta. In this study, the development and formation of Ginkgo endotesta were examined using light microscopy and transmission electron microscopy. The structural properties of the mature endotesta were analyzed using micro-CT imaging and scanning electron microscopy. The results indicate that the endotesta possess a membranous structure primarily originating from the inner bead peridium, a segment of bead core tissue, and the macrospore membrane. The endotesta from the middle constriction line to the chalazal end comprises a single layer with a greyish-white papery structure. In contrast, the endotesta was divided into two inner and two outer layers, from the middle constriction line to the micropylar end. The outer endosperm adheres closely to the sclerotesta, while the inner endosperm adheres to the seed kernel. The surface of the endotesta was irregularly raised, with thicker wax at the chalazal end, whereas the micropylar end demonstrated similar characteristics with thinner wax and tumor layers. The endotesta contained 17 amino acids, 18 fatty acids, 10 trace elements, and 7 vitamins. Overall, its nutritional value was relatively well balanced.

Isolation, virtual screening, action mechanisms, chelation with zinc ions, and stability of ACE-inhibitory peptides from ginkgo seed globulin

Ginkgo seed has potential applications in the prevention and treatment of hypertension, but its application in food is limited. Thus, ginkgo seed globulin was hydrolyzed using dual enzymes (Alcalase and thermolysin). After gel column separation, reverse-phase high-performance liquid chromatographic purification, and ESI-MS/MS analysis, five oligopeptides containing fewer than 12 amino acid residues were obtained. Among them, the heptapeptide Glu-Ala-Ser-Pro-Lys-Pro-Val (EASPKPV) offered relatively high capacities to inhibit ACE (IC50: 87.66 μmol L-1) and bind with zinc ions (5.35 ± 0.32 mg g-1). Moreover, EASPKPV showed competitive inhibitory kinetics against ACE. Fourier-transform infrared spectroscopy analysis evidenced that the amino group and carboxyl group of EASPKPV could both provide binding sites for zinc ions. EASPKPV can restrain ACE in the following ways: (i) competitively linking with five key residues (Gln281, Ala354, Glu376, Lys511, and Tyr523) in the S1 and S2 pockets of ACE by short hydrogen bonds; (ii) binding to thirteen active residues of ACE via hydrophobic interactions; and (iii) binding with residue His383 or the zinc ion of zinc tetrahedral coordination. Additionally, simulated gastrointestinal digestion did not show any remarkable efficacy on the capacities of EASPKPV to restrain ACE and bind with zinc ions. These results indicate that ginkgo peptides may be used for antihypertension.

Distinction of Male and Female Trees of Ginkgo biloba Using LAMP

Ginkgo biloba is utilized as food, medicine, wood, and street trees among other things. The objective of this study was to develop a loop-mediated isothermal amplification (LAMP) assay for gender distinction of G. biloba. Male-specific SCAR gene can be utilized to identify G. biloba gender using LAMP. The optimized LAMP conditions, temperature 60 °C, 2-mM MgSO4, and [F3/B3]:[FIP/BIP] primer ratio of 1:4 were selected as final conditions. The G. biloba SCAR LAMP displayed a sensitivity of 10 ng when amplified by concentration under the optimum conditions. Additionally, it demonstrated a particular response in male with SYBR Green I in LAMP analysis that can be a more powerful tool for field and scale-up applications. Our work represents a first attempt to identify G. biloba gender using LAMP and offers an efficient and reliable tool for roadside landscaping.

Overview and Recent Progress on the Biosynthesis and Regulation of Flavonoids in Ginkgo biloba L

Flavonoids and their derivatives play important roles in plants, such as exerting protective activity against biotic and abiotic stresses, functioning in visual signaling to attract pollinators, and regulating phytohormone activity. They are also important secondary metabolites that are beneficial to humans. Ginkgo biloba L. is a well-known relict plant considered to be a "living fossil". Flavonoids present in ginkgo leaves have antioxidant and anti-aging capacities and show good therapeutic effects on a variety of neurological diseases. To date, studies on flavonoids have mainly focused on their extraction, pharmacological effects, and component analysis and on the expression levels of the key genes involved. However, a systematic review summarizing the biosynthesis and regulatory mechanisms of ginkgo flavonoids is still lacking. Thus, this review was conducted to comprehensively introduce the biological characteristics, value, and utilization status of ginkgo; summarize the effects, biosynthetic pathways, and transcriptional regulation of flavonoids; and finally, discuss the factors (ecological factors, hormones, etc.) that regulate the biosynthesis of flavonoids in ginkgo. This review will provide a reference basis for future research on the biosynthesis and efficient utilization of flavonoids in ginkgo.

Identification and Expression of the MADS-box Gene Family in Different Versions of the Ginkgo biloba Genome

MADS-box transcription factors play important roles in many organisms. These transcription factors are involved in processes such as the formation of the flower organ structure and the seed development of plants. Ginkgo biloba has two genome versions (version 2019 and version 2021), and there is no analysis or comparison of the MADS-box gene family in these two genomes. In this study, 26 and 20 MADS-box genes were identified from the two genomes of Ginkgo, of which 12 pairs of genes reached more than 80% similarity. According to our phylogenetic analysis results, we divided these genes into type I (Mα and Mγ subfamilies) and type II (MIKC and Mδ subfamilies) members. We found that both sets of genomes lacked the Mβ gene, while the MIKC gene was the most numerous. Further analysis of the gene structure showed that the MIKC genes in the two genomes had extralong introns (≥20 kb); these introns had different splicing patterns, and their expression might be more abundant. The gene expression analysis proved that GbMADS genes were expressed to varying degrees in eight Ginkgo biological tissues. Type II GbMADS genes not only were found to be related to female flower bud differentiation and development but also are important in seed development. Therefore, MADS-box genes may play important roles in the development of Ginkgo reproductive organs, which may suggest a genetic role in sexual differentiation. This study further contributes to the research on MADS-box genes and provides new insights into sex determination in Ginkgo.

Molecular Characterization and Genetic Diversity of Ginkgo (Ginkgo biloba L.) Based on Insertions and Deletions (InDel) Markers

As a "living fossil", ginkgo (Ginkgo biloba L.) has significant ornamental, medicinal, and timber value. However, the breeding improvement of ginkgo was limited by the lack of enough excellent germplasms and suitable molecular markers. Here, we characterized numerous polymorphic insertion/deletion (InDel) markers using RAD-seq in 12 different ginkgo cultivars. The total of 279,534 InDels identified were unequally distributed across 12 chromosomes in the ginkgo genome. Of these, 52.56% (146,919) and 47.44% (132,615) were attributed to insertions and deletions, respectively. After random selection and validation, 26 pairs of polymorphic primers were used for molecular diversity analysis in 87 ginkgo cultivars and clones. The average values of observed heterozygosity and polymorphism information were 0.625 and 0.517, respectively. The results of population structure analyses were similar to those of neighbor-joining and principal component analyses, which divided all germplasms into two distinct groups. Moreover, 11 ginkgo core collections accounted for approximately 12.64% of the total ginkgo germplasms obtained, representing well the allelic diversity of all original germplasms. Therefore, these InDels can be used for germplasm management and genetic diversity analyses in ginkgo and the core collections will be used effectively for ginkgo genetic improvement.

Alkali-Induced Phenolic Acid Oxidation Enhanced Gelation of Ginkgo Seed Protein

The effect of alkali-induced oxidation of three phenolic acids, namely gallic acid, epigallocatechin gallate, and tannic acid, on the structure and gelation of ginkgo seed protein isolate (GSPI) was investigated. A mixture of 12% (w/v) GSPI and different concentrations of alkali-treated phenolic acids (0, 0.06, 0.24, and 0.48% w/w) were heated at 90 °C, pH 6.0, for 30 min to form composite gels. The phenolic treatment decreased the hydrophobicity of the GSPI sol while enhancing their rheological properties. Despite a reduced protein solubility, water holding capacity, stiffness, and viscoelasticity of the gels were improved by the treatments. Among them, the modification effect of 0.24% (w/v) EGCG was the most prominent. Through the analysis of microstructure and composition, it was found to be due to the covalent addition, disulfide bond formation, etc., between the quinone derivatives of phenolic acids and the side chains of nucleophilic amino acids. Phenolic acid modification of GSPI may be a potential ingredient strategy in its processing.

Inhibitory effect of Ginkgo biloba seeds peptides on methylglyoxal-induced glycations

The aim of this study was to investigate the antiglycation activity and mechanism of two identified peptides, Valine-Valine-Phenylalanine-Proline-Glycine-Cysteine-Proline-Glutamic acid (VVFPGCPE) and Serine-Valine-Aspartic acid-Aspartic acid-Proline-Arginine-Threonine-Lysine (SVDDPRTL), from Ginkgo biloba seeds protein hydrolysates. Both VVFPGCPE and SVDDPRTL were efficient in bovine serum albumin (BSA)-methylglyoxal (MGO) model to inhibit BSA glycation, while VVFPGCPE showed higher antiglycation activity than SVDDPRTL. In antioxidant assays, VVFPGCPE scavenged more hydroxyl and super anion radicals, and chelated more Fe²⁺. Moreover, VVFPGCPE was more efficient in alleviating glycoxidation since it retained higher content of tryptophan and reduced dityrosine and kynurenine generation. Compared with SVDDPRTL, VVFPGCPE showed better performance in inhibiting protein aggregation and amyloid-like fibrillation formation. Therefore, VVFPGCPE was selected for further mechanism study. The circular dichroism analysis suggested VVFPGCPE could preserve α-helix structure and stabilize protein structure. The MGO trapping assay indicated VVFPGCPE (5 mg/mL) could capture 66.25% MGO within 24 h, and the mass spectrometry revealed VVFPGCPE could trap MGO by forming VVFPGCPE-mono-MGO adducts. Besides, molecular simulations suggested VVFPGCPE could interact with key glycation residues, arginine and lysine residues, of BSA mainly through van der Waals and hydrogen bonds. This study might supply a theoretical basis for the development of VVFPGCPE as an effective antiglycation agent.

Site-Directed Mutation of Salicylate Decarboxylase Gene and Mechanism of Ginkgo Acid Decarboxylation

Ginkgo seed is an important Chinese medicine and food resource in China, but the toxicity of ginkgo acid in it limits its application. Previous studies have found that salicylic acid decarboxylase (Sdc) has a decarboxylation degradation effect on ginkgo acid. In order to improve the decarboxylation ability of Sdc to Ginkgo acid, 11 residues of the Sdc around the substrate (salicylic acid) were determined as mutation targets according to the analysis of crystal structure of Sdc (PDB ID:6JQX), from Trichosporon moniliiforme WU-0401, and a total of 30 single point mutant enzymes and one compound mutant enzyme were obtained. With Ginkgo acid C15:1 as the substrate, it was found from activity assay that Sdc-Y64T and Sdc-P191A had higher decarboxylation activity, which increased by 105.18% and 116.74% compared with that of wild type Sdc, respectively. The optimal pH for Sdc Y64T and Sdc-P191A to decarboxylate Ginkgo acid C15:1 was 5.5, which is the same as the wild type Sdc. The optimal temperature of Sdc-P191A was 50 °C, which was consistent with that of the wild type Sdc, but the optimal temperature of the mutant Sdc-Y64T was 40 °C, which was 10 °C lower than that of wild type Sdc.

Isolation and purification of 12 flavonoid glycosides from Ginkgo biloba extract using sephadex LH-20 and preparative high-performance liquid chromatography

An efficient and rapid preparative method for the separation and purification of flavonoid glycosides from the Ginkgo biloba extract (GBE) was developed by sephadex LH-20 and preparative high-performance liquid chromatography (HPLC). 40 g GBE of 24% flavonoids were loaded onto the sephadex LH-20 column and five fractions (1.15, 2.57, 1.32, 4.45, and 3.31 g) at flavonoid content of 72.3, 54.2, 63.5, 51.2, and 59.2% were produced. Ultimately, 12 flavonoid glycosides that are at least purities of 97.7% were obtained from 100 mg of each fraction by preparative HPLC. The fraction A, B, and D each contained two flavonoids, yielded 35, 30, 23, 20, 25, and 25 mg, respectively. The fraction C and E each contained three flavonoids, produced 20, 13, 15, 18, 15, and 20 mg, respectively. The chemical structures of the purified compounds were identified by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI/MS).

Time-Series-Dependent Global Data Filtering Strategy for Mining and Profiling of Xenobiotic Metabolites in a Dynamic Complex Matrix: Application to Biotransformation of Flavonoids in the Extract of Ginkgo biloba by Gut Microbiota

Efficient characterization of xenobiotic metabolites and their dynamics in a changing complex matrix remains difficult. Herein, we proposed a time-series-dependent global data filtering strategy for the rapid and comprehensive characterization of xenobiotic metabolites and their dynamic variation based on metabolome data. A set of data preprocessing methods was used to screen potential xenobiotic metabolites, considering the differences between the treated and control groups and the fluctuations over time. To further identify metabolites of the target, an in-house accurate mass database was constructed by potential metabolic pathways and applied. Taking the extract of Ginkgo biloba (EGB) co-incubated with gut microbiota as an example, 107 compounds were identified as flavonoid-derived metabolites (including 67 original from EGB and 40 new) from 7468 ions. Their temporal metabolic profiles and regularities were also investigated. This study provided a systematic and feasible method to elucidate and profile xenobiotic metabolism.

Potentialities of Ginkgo extract on toxicants, toxins, and radiation: a critical review

Exposure to toxins is a severe threat to human health and life in today's developing and industrialized world. Therefore, identifying a protective chemical could be valuable and fascinating in this case. The purpose of this article was to bring together thorough review of studies on Ginkgo biloba to aid in the creation of ways for delivering its phytoconstituents to treat toxicants and radiation. This review gathered and evaluated studies on the defensive impact of Ginkgo biloba extract (GBE) against toxicities caused by toxic chemical agents (such as lead, cadmium, and aluminum), natural toxins (for example, lipopolysaccharide-induced toxicity and damage, gossypol, latadenes, and lotaustralin), and radiation (for example, gamma, ultra-violet, and radio-frequency radiation). According to this review, GBE has a considerable therapeutic effect by influencing specific pathophysiological targets. Furthermore, GBE has antioxidant, anti-inflammatory, anti-apoptotic, and antigenotoxicity properties against various toxicities. These are due to flavone glycosides (primarily isorhamnetin, kaempferol, and quercetin) and terpene trilactones (ginkgolides A, B, C, and bilobalide) that aid GBEs' neutralizing effect against radiation and toxins by acting independently or synergistically. This will serve as a reference for the functional food, cosmetic, and pharmaceutical industries worldwide.

A critical review of current technologies used to reduce ginkgotoxin, ginkgotoxin-5'-glucoside, ginkgolic acid, allergic glycoprotein, and cyanide in Ginkgo biloba L. seed

The Ginkgo biloba has astonished scholars globally with enormous bioactives, with sales exceeding $10 billion since 2017. The Ginkgo biloba seed (GBS) is an essential part of culinary culture. Nevertheless, toxins in fresh Ginkgo biloba seed (GBS) have limited GBSs' daily consumption. Ginkgotoxin and ginkgotoxin-5-glucoside cause poisoning, tonic-clonic convulsions, and neurotoxic effects. Ginkgolic acid causes cytotoxicity and allergies. Allergic glycoprotein in GBS causes nausea, seizures, dyspnea, mydriasis, vomiting, and bellyache. The amygdalin-derived hydrocyanic acid cause dizziness, vomiting, cramping, and sleeping disorders. Food products are frequently exposed to various processing techniques to increase food safety and functionality. As a result, this review focused on the technologies that have been used to minimize toxins in GBS. In addition, a comparison of these techniques was made based on their benefits, drawbacks, feasibility, pharmacological activities, and future direction or opportunities to improve current ones were provided.

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.

Genome-Wide Identification of the Ginkgo (Ginkgo biloba L.) LBD Transcription Factor Gene and Characterization of Its Expression

Lateral organ boundaries domain (LBD) proteins are plant-specific transcription factors involved in various transcriptional regulation processes. We identified a total of 37 GbLBD genes in ginkgo, and based on gene structure and phylogenetic analysis, the GbLBD gene family was classified into class I (33, with the largest number of Id genes (16)) and class II (4). The ginkgo LBD gene was also analyzed regarding its chromosomal distributions, gene duplications, promoters, and introns/exons. In addition, gene expression profiling and real-time quantitative PCR analysis showed that the expression of 14 GbLBD genes differed in six different tissues and three developmental stages. The GbLBD gene of class II were highly expressed relative to the class I gene in all tissues and developmental stages, while class Id gene were generally at low levels or were not expressed, especially in seed developmental stages. The expression pattern analysis of cold/drought treatment and IAA/ABA hormone treatment showed that abiotic stress treatment could significantly induce the expression of GbLBD gene, of which class II genes played a key role in stress treatment. Our study provides a solid foundation for further evolutionary and functional analysis of the ginkgo LBD gene family.

Chemical Characterization and Potential Mechanism of the Anti-Asthmatic Activity of a Subfraction from Schisandra chinensis Fruit Extract

Schisandra chinensis fruit is a widely edible and medicinal resource, whose extract had a good inhibitory effect on airway inflammation in asthmatic mice. However, the main active components remain unknown. In this work, we found that PET2, a subfraction of its ethanolic extract petroleum ether, displayed significant anti-inflammatory effects in interleukin (IL)-4/tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells. Meanwhile, in the ovalbumin (OVA)-induced allergic asthma mice model, PET2 (200 and 400 mg/kg) had significant effects on attenuating airway inflammatory cell infiltration and reducing serum Th2-related cytokines. Further studies led to the isolation and identification of 14 compounds, guided by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based rapid characterization of chemical constituents. Combining network pharmacology analysis and in vitro experiments, we found that six compounds from PET2 had good anti-inflammatory properties. The potential mechanism may be involved in Fc epsilon RI, T cell receptor, and Jak-STAT signaling pathways. This study clarified the anti-inflammatory properties of the main active fraction and active compounds of S. chinensis fruit and provided a theoretical basis for its anti-asthma scientific utilization.

Ginkgolides and Huperzine A for complementary treatment of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual deterioration of cognitive function, memory, and inability to perform daily, social, or occupational activities. Its etiology is associated with the accumulation of β-amyloid peptides, phosphorylated tau protein, and neuroinflammatory and oxidative processes in the brain. Currently, there is no successful pharmacological treatment for AD. The few approved drugs are mainly aimed at treating the symptoms; however, due to the increasing discovery of etiopathological factors, there are great efforts to find new multifunctional molecules to slow down the course of this neurodegenerative disease. The commercial Ginkgo biloba formulation EGb 761® and Huperzine A, an alkaloid present in the plant Huperzia serrata, have shown in clinical trials to possess cholinergic and neuroprotective activities, including improvement in cognition, activities of daily living, and neuropsychiatric symptoms in AD patients. The purpose of this review is to expose the positive results of intervention with EGb 761® and Huperzine in patients with mild to moderate AD in the last 10 years, highlighting the pharmacological functions that justify their use in AD therapy.

Circumstantial Insights into the Potential of Traditional Chinese Medicinal Plants as a Therapeutic Approach in Rheumatoid Arthritis

The advanced era has invited a plethora of chronic and autoimmune infirmities unmistakably dominated by rheumatoid arthritis, occurring because of the equivocal causes, including ecological factors, genetic variations, etc. Unfortunately, it is winning pretty much in every stratum of the society in undefined age group of the population. Engineered drugs are accessible for the treatment; however, they do experience adverse effects as the treatment requires a prolonged duration worsened by noncompliance. To overwhelm it, certain pharmacological and molecular pathways are explored in the wake of Chinese herbs that prompted the prevention of this deteriorating autoimmune disease. The alcoholic extracts and decoctions are procured from Chinese herbs, such as Paeonia lactiflora, Glycyrrhiza uralensis, Tripterygium wilfordii, etc., which have been proved to manifest constructive pharmacological actions. The activities that were exhibited by extracts are significantly innocuous, non- toxic and potent to fix the affliction in contrast with the chemosynthetic drugs. Therefore, these Chinese herbs bring forth the potent anti-inflammatory, immune suppressing, anti-nociceptive, anti-neovascularizing, free radical scavenging activities and various other benefits to withstand several pathological events that usually endure the infirmity. It can be abridged that Chinese herbs possess assorted and selective therapeutic properties with profound safety and viability to treat this rheumatic disorder. Thus, this review aims to shed a light naturally originated treatment that is pertinent to provide invulnerable therapy exonerating from adverse effects, by restraining the occurrences of joint deformities, production of auto-antibodies, and inflammation.

Ginkgo biloba: A Treasure of Functional Phytochemicals with Multimedicinal Applications

Ginkgo biloba is an ancient plant species that is thought to provide a variety of health benefits to living organisms and contains plenty of bioactive components, making it a chemically diversified plant. G. biloba has been shown to have a variety of medicinal and pharmacological properties, including anticancer, antidementia, antidiabetic, antiobesity, antilipidemic, antimicrobial, antioxidant, antilipid peroxidation, antiplatelet, anti-inflammatory, hepatoprotective, antidepressant, antiaging, immunomodulatory, antihypertensive, and neuroprotective effects and is frequently used to treat neurological, cardiovascular, and respiratory diseases, such as tardive dyskinesia. Therefore, this review described the therapeutic applications of G. biloba. In addition to describing the therapeutic potential, this review also evaluates the chemical constituents, toxicity, adverse effect, synergistic effect, and the clinical studies of this plant which have been utilized for therapeutic benefits but have demonstrated other consequences. The capacity of G. biloba components to act as free radical scavengers is critical, and combining its extract with other plant extracts has been shown to synergistically boost antioxidant properties. G. biloba used long-term or at high doses that resulted in some adverse effects. Severe drug interactions have also been reported in both animals and humans when combined with other medications. The available data established from both preclinical and clinical studies confirm the potential of G. biloba plant extract in various diseases. Besides, the safety and efficacy of G. biloba continue to require verification through additional experimentation to guide medicinal use.

Effect of Ginkgo Biloba Powder on the Physicochemical Properties and Quality Characteristics of Wheat Dough and Fresh Wet Noodles

Effects of ginkgo biloba powder (GBP) on the chemical, physicochemical properties and quality of dough and fresh wet noodles were investigated. Lower contents of gluten and starch, and higher contents of fibre, amylose and flavonoids in GBP than wheat flour, were detected. Water absorption of dough increased and the development time and stability time of dough were decreased with GBP addition. Meanwhile, the pasting properties results showed that the addition of GBP reduced the aging degree of starch and improved the thermal stability of dough. Scanning electron microscopy results showed that addition of GBP smoothed the surface of raw noodles while increasing the hole size of the cooked noodles. With increased GBP addition (0~40%), the chewiness and extensibility of the fresh wet noodles increased significantly (p < 0.05), and the sensory scores changed, ascending from 0~20% substitution, and then descending from 20~40% substitution. The digestibility and estimated glycemic index (eGI) values of the GBP fresh wet noodles decreased significantly (p < 0.05). In general, 20% GBP addition could improve the chewiness, extensibility, taste and nutrition of fresh wet noodles, and decrease the digestibility and eGI values of noodles. Thus, GBP has potential for application in the noodle industry.

A critical review of Ginkgolic acid in Ginkgo biloba leaves extract (EGb). Toxicity, technologies to remove the ginkgolic acids and its promising bioactivities

Ginkgo biloba leaves extract (EGb) is high in bioactive components (over 170), which are used in food additives, medicine, cosmetics, health products, and other sectors. Nonetheless, ginkgolic acids (GAs) in...

Non-thermal pretreatment affects Ginkgo biloba L. seed's product qualities, sensory, and physicochemical properties

Drying plays a significant role in Ginkgo biloba seed's (GBS) processing, and the previous research showed drying affected the product quality. A combined hurdle drying technology (integrated non-thermal pretreatment and drying) could be applied on GBS to achieve better product quality. Osmotic (OS), osmo-vacuum (OS + V), sonication (US), and osmosonication (OS + US) pretreatment followed by infrared drying was performed on GBS, and the product qualities (texture, color, enzyme inactivation, water activity, and microstructure), physicochemical properties (titrable acidity, reducing sugar, soluble solids, total sugar, free amino acid, and ascorbic acid), and organoleptic qualities were evaluated. Results showed pretreatment had various effects on physicochemical and product quality, and was confirmed by principal component analysis (PCA). The sensory scores, acceptability index combined with Pearson's correlation, and PCA showed that different pretreatments influenced the likeness and acceptability, and color, taste, and odor were the key determinants and strongly associated with the consumers' preferences. The untreated GBS (no pretreatment before drying) had a higher color change and lower enzyme inactivation. Pretreatment increased texture preservation after thermal processing, although it had a negative effect on soluble solids, reducing sugar and total sugar content. While the US improved the texture, it resulted in shrinkage (from the microstructure) and total sugar degradation. Among the various hurdle technologies, osmosonication (OS + US, followed by infrared drying) had the highest sensory attributes, free amino acid, slight structure deformation, and lowest water activity. The present study showed that osmosonication is a promising hurdle technology for GBS because it provides better quality attributes. PRACTICAL APPLICATION: Previous research showed that Ginkgo biloba seed (GBS) drying has an impact on product quality, which will ultimately determine GBS acceptance. This research was set out to envisage and advance current dryer design by merging the sequential operations (integrated non-thermal pretreatment and drying), also known as hurdle drying technology on GBS, to achieve better process efficiency, product quality, and make GBS's drying process more sustainable. The various pretreatments improved ginkgo seed's product qualities compared to the control (no pretreatment prior to drying). Osmosonication is a promising hurdle technology for GBS processing.

Ginkgo seed extract promotes longevity and stress resistance of Caenorhabditis elegans

Ginkgo seeds are a traditional food in China valued for their nutritional and health benefits. However, little is known about the anti-aging and health-promoting effects of ginkgo seed products. Here, we showed that ginkgo seed powder extract (GSP-E) is abundant in alkaloids and flavonoids, and can extend the lifespan of Caenorhabditis elegans. GSP-E improved most physiological indicators related to aging of C. elegans, including locomotor activity, reproductive capacity, and resistance to oxidation and heat. Moreover, GSP-E reduced the accumulation of lipofuscin and reactive oxygen species (ROS) in C. elegans. Further studies demonstrated that GSP-E improved longevity and stress resistance by mediating lipid metabolism and autophagy, as well as by regulating gene expression (e.g., FASN-1, POD-2, GPX-7, FAT-5). GSP-E has an anti-amyloid effect and delayed amyloid-induced paralysis of C. elegans. These findings could support the utilization of ginkgo seed as a potential dietary supplement for the health food industry, and provide a novel health-promoting resource against aging and aging-related diseases.

A Facile Method to Determine the Native Contents of 4'-O-Methylpyridoxine and 4'-O-Methylpyridoxine-5'-glucoside in Ginkgo biloba Seeds

4'-O-Methylpyridoxine (MPN) and MPN-5'-glucoside (MPNG) are collectively known as ginkgotoxin, which are the main toxic ingredients of excessive consumption of Ginkgo biloba seeds. Water extraction is the generally adopted sample preparation method for high-performance liquid chromatography determination of ginkgotoxin. However, endogenous enzymes such as glycosidases in Ginkgo biloba seeds can hydrolyze MPNG to MPN in the process of water extraction, which will result in the measured contents of MPN and MPNG but not their natural contents in Ginkgo biloba seeds. In this work, inhibitors for the endogenous enzymes were first screened, and it was found that silver fluoride could effectively inhibit endogenous enzymes such as glucosidase and phosphatase. The optimized concentration of silver fluoride was 25 mmol/L, which could effectively inhibit the endogenous enzymes for more than 60 h. A new sample preparation method based on water extraction with 25 mmol/L silver fluoride addition was thus developed. This method was employed to determine the native contents of MPN and MPNG in the exotesta and kernel of five Ginkgo biloba seed cultivars. The result showed that the contents of MPNG in the exotesta and kernel of five cultivars were significantly higher than those of MPN. MPNG was present at high content in raw seeds, which was the main form of ginkgotoxin in seeds. The method established in this work is simple and effective and can be used to accurately quantify the native contents of MPN and MPNG.

Osmotic, osmovacuum, sonication, and osmosonication pretreatment on the infrared drying of Ginkgo seed slices: Mass transfer, mathematical modeling, drying, and rehydration kinetics and energy consumption

This study evaluated the mass transfer, drying, and rehydration kinetics (drying and rehydration curve, moisture diffusivity [D_eff ]), energy consumption (specific energy consumption [SEC], moisture extraction rate (MER), and specific moisture extraction rate [SMER]), and mathematical modeling of infrared dried Ginkgo biloba seed (GBS) using the various nonthermal pretreatments namely: osmotic (OS), osmovacuum (V + OS), ultrasound (US, ginkgo seed immersed in a distilled water with US), and osmosonication (US + OS, ginkgo seeds immersed in an OS solution with US). Results showed that various pretreatments affected mass transfer, drying, and rehydration characteristics, and energy consumption, which was confirmed by principal component analysis. In terms of mass transfer, US pretreatment recorded the highest weight loss while the osmosonication pretreatment registered the highest solid gain. The entire drying process occurred in the falling-rate period. The D_eff values were within the normal range of agroproducts (10^-11 to 10^-8 m² /s). The modified Page-I and Weibull model best fitted the drying and rehydration kinetics, respectively, with the coefficient of determination (R² ) > 0.991, root mean square error, residual sum of squares, and reduced chi-square closer to zero, compared with the other models. The untreated GBS (control) had the lowest energy efficiency (lowest SMER and MER) and the highest SEC than the pretreated GBS. Among the various pretreatments, the US pretreatment of GBS was superior, with the highest D_eff , MER, SMER, and drying rate, and lowest drying time and SEC. Based on the findings, sequential US pretreatment and infrared drying is a feasible drying technique for GBS that could be used commercially. PRACTICAL APPLICATION: Ginkgo tree cultivation in China has exceeded market needs with 60,000 tons per annum of GBS produced. Hence, there is a compelling need to explore new chances to use GBS availability irrespective of the seasonality and address the problem where GBS utilization is limited to the early phases of home-cooked dishes. Although drying increases the shelf life of ginkgo seeds, there is a higher operation cost. Thus, pretreatment can reduce energy consumption and augment the product quality is ideal. This research reported the impact of nonthermal pretreatments on ginkgo seeds' mass transfer, drying, and rehydration characteristics. The present results will provide a comprehensive understanding of the engineering application of ginkgo seed pretreatment, allowing for the best technique to be selected.

Improving the oxidative stability of breadsticks with ginkgo (Ginkgo biloba) and ginseng (Panax ginseng) dried extracts

Recently, there has been a growing interest in the use of natural antioxidants instead of synthetic ones. The aim of this work was to determine the effect of ginkgo and ginseng dried extracts as natural antioxidants on the stability of lipids in breadsticks over 55 days of storage at room temperature compared to butylated hydroxytoluene. Ginkgo and ginseng dried extracts were incorporated individually into breadstick formulae at levels of 0.5 and 1% to enhance its oxidative stability in storage. The increases in peroxide, p-anisidine and Totox values in the oil phase of the samples during storage were monitored. The changes in hydroperoxide, trans fatty acid and aldehyde contents were investigated by Fourier transform infrared spectroscopy. The sensory analysis was performed to evaluate the perceptible changes occurring during storage. The results indicated that the oxidation of oil in breadstick samples can be retarded by enriching the breadstick formula with dried ginseng extract at a 1% level.

Ginkgo Seed Proteins: Characteristics, Functional Properties and Bioactivities

Ginkgo biloba L. is an ancient plant relic, which is known as a "living fossil", and is widely cultivated in China. This plant with medical potential and health benefits has drawn the attention of researchers. Ginkgo seeds are rich in protein. Ginkgo seed proteins (GSPs) have good functional properties over many other seed proteins, which have the potential to be utilized as food ingredients. Moreover, GSP contains no restricted amino acids and is easy to be separated. Several GSP isolate with various bioactivities, such as antimicrobial and antioxidative activities, have been purified and evaluated for their bioactive potential. In this review, the separation methods and bioactivities of GSP were summarized, physicochemical characteristics and functional properties were comprehensively reviewed and compared with other seed proteins. Some food applications of GSP were also briefly introduced. Besides, some suggestions and prospects were discussed in this review.

Effects of preheating and drying methods on pyridoxine, phenolic compounds, ginkgolic acids, and antioxidant capacity of Ginkgo biloba nuts

Although ginkgo nuts are very nutritious and loaded with numerous bioactive compounds, the nuts contain significant levels of unwanted compounds (ginkolic acids) which are toxic to consumption. To reduce or eliminate these toxic compounds without impacting the nutritional value and the bioactivity of the final product, an appropriate processing technology is needed. Thus, the effect of preheating (90 and 120°C) prior to drying (freeze drying: FD, hot air drying: HAD, and HAD in tandem with FD: HAD-FD) was evaluated on ginkgolic acids, pyridoxine analogues, phenolic compounds, and antioxidant properties of ginkgo nuts. Our results pointed out a significant decrease (below 50%) of ginkgolic acids in ginkgo nuts samples processed at 90°C compared to the control. The major compounds found after treatments were respectively, kaempferol (36.66-354.38 µg/g), quercetin (9.04-183.71 µg/g), and caffeic acid (19.66-106.88 µg/g). Principal component analysis (PCA) revealed that preheating at 90°C prior to HAD-FD would be a proper and reasonable approach for preserving the bioactive compounds and antioxidant capacity of ginkgo nuts (EC₅₀ ranged from 2.25 to 4.60 mg/mL) while significantly reducing their content in toxic compounds.

Ginkgo biloba Seeds—An Environmental Pollutant or a Functional Food

Ginkgo biloba has been cultivated in Bulgaria since the end of the 19th century. Ividual specimens can be seen in almost every park. Females of the tree are considered contaminants of the landscape because their ripe seeds have a strong odor and are not utilized. We undertook this study to clarify whether ginkgo seeds of local origin can be converted from an unwanted and unused environmental pollutant into a source of beneficial compounds. Various analytical and chromatographic methods were used to quantify the major constituents and ten biologically active compounds in methanol seed extract. The results showed that the seeds are low in proteins (5%) and fats (1%); the seeds were also rich in unsaturated fatty acids and tocopherols. About 44% of nut starch was resistant to in vitro enzymatic hydrolysis. The amount of terpene trilactones in an aqueous-methanol seed extract was significantly higher than the number of flavonoids. Ginkgotoxin and ginkgolic acid were also found. The extract demonstrated weak antimicrobial activity against thirteen microorganisms. This study revealed that seeds of locally grown Ginkgo trees can be used as a source of biologically active substances. The chemical composition show similarity to those of seeds from other geographical areas.

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.

Modification of structure and functionalities of ginkgo seed proteins by pH-shifting treatment

Modification and improvement of protein functionalities are important for expanding the applications of proteins in food. The objective of this study was to investigate the effects of pH-shifting treatments on the structural and functional properties of ginkgo seed protein isolate (GSPI). GSPI was exposed to acidic (pH 2.0-4.0) and basic (pH 10.0-12.0) pHs for 0, 0.5, 1, 2, and 4 h and subsequently neutralized for refolding. The pH-shifting treatments significantly increased GSPI solubility by 43-141% except for the treatment at pH 2.0, which decreased protein solubility by 16-39%. All pH-shifting treatments more than doubled the surface hydrophobicity of GSPI and significantly improved the emulsifying activity. The highest emulsifying activity was observed in the pH 2.0-treated GSPI, which was 4.9-fold higher than the control. Acid-induced GSPI degradation likely promoted protein adsorption to the oil-water interface. In summary, the pH-shifting-modified GSPI may serve as a promising emulsifier in various food systems.

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.