Kombucha with yam: Comprehensive biochemical, microbiological, and sensory characteristics.

Consumer demand for functional foods has increased, helping to popularize and increase the consumption of Kombucha. Other substrates have been used together with tea to improve the functional and sensory properties of the beverage. Thus, this study evaluated the comprehensive biochemical, microbiological, and sensory characteristics of kombuchas fermented with green tea (Camellia sinensis) and different concentrations of yam (0, 10, and 20 % w/v). Based on pre-tests to detect the best concentration of yam in the beverage (10, 20, 30, and 40 %) and fermentation time (5, 7, and 14 days),the concentrations of 10 and 20 % of yam and five days of fermentation were selected through pH, °Brix, and sensory analysis. During the kombucha fermentation, there was a decrease in °Brix and pH. Sucrose, glucose, fructose, citric, and succinic acids were related to the beginning of fermentation, and lactic and acetic acids were more related to the end of fermentation in the treatment containing 20 % yam. The fermentation time did not change the color of the kombucha. Fatty acids, phenols, terpenoids, and alcohols were the volatile groups with the most compounds identified. Only two yeast genera were identified (Brettanomyces bruxellensis and Pichia membranifaciens), and bacteria of the genera Acetobacter, Lactobacillus, Pantoea, Pseudomonas, Azospirillum, and Enterobacter. The beverage control showed less turbidity and more clear. The fruity descriptor was more perceived in treatments with yam. However, the perception of the apple descriptor decreases as the yam concentration increases. The yam's concentration alters the kombucha's microbiota and sensory characteristics, mainly appearance and acidity. Kombucha fermentation using yam extract is viable, and the product is sensorially accepted. However, technological improvements, such as yam flour, could be made mainly for appearance and taste attributes.

Protection effect of Dioscoreae Rhizoma against ethanol-induced gastric injury in vitro and in vivo: A phytochemical and pharmacological study.

ETHNOPHARMACOLOGICAL RELEVANCE: Dioscoreae Rhizoma, a kind of Chinese yam, is a medicinal and edible plant used in China for strengthening the spleen and stomach. However, there is a lack of modern pharmacology studies regarding its anti-gastric injury activity. AIM OF THE STUDY: This study aimed to investigate the phytochemical composition of Chinese yam aqueous extract (CYW) and evaluate its gastroprotective effects against ethanol-induced gastric injury in vitro and in vivo. MATERIALS AND METHODS: The active components of CYW were identified using HPLC-QTOF-MS/MS in combination with the GNPS molecular networking and network pharmacology. In vitro studies were performed in the RAW264.7/GES-1 cell coculture system. In vivo study, mice were treated with CYW (0.31, 0.63, and 3.14 g/kg BW, orally) for 14 days, followed by a single oral dose of ethanol (10 mL/kg BW) to induce gastric injury. The biochemical, inflammation and oxidative stress markers were analyzed using commercial kits. Histopathology was used to assess the degree of gastric injury. Gene and protein expressions were studied using RT-qPCR and western blotting, respectively. RESULTS: CYW significantly restored the levels of SOD, GPx and CAT, and reduced the MDA content. Further analyses showed that CYW significantly alleviated the gastric oxidative stress by inhibiting the inflammation via decreasing p-NF-κB and p-IκB-α expression levels and inhibiting the generation of IL-6, TNF-α, and IL-1ß. At the same time, the fraction remarkably upregulated Bcl-2, downregulated Bax and increased growth factor secretion, thereby prevented gastric mucous cell. Besides, The combination of HPLC-QTOF-MS/MS, GNPS molecular networking analysis, and network pharmacology demonstrated that linoleic acid, 3-acetyl-11-keto-beta-boswellic acid, adenosine, aminocaproic acid, tyramine, DL-tryptophan, cycloleucine, lactulose, melibiose, alpha-beta-trehalose, and sucrose would be the main active compounds of CYW against ethanol-induced gastric injury. CONCLUSION: This study showed that CYW is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds. It showed efficacy against ethanol-induced gastric injury by inhibiting inflammation, oxidative stress, and apoptosis in the stomach. The results of the current work indicate that Dioscoreae Rhizoma could be utilized as a type of natural resource for production of new medicine and functional foods to prevent and/or ameliorate ethanol-induced gastric injury.

Effects of cold plasma pretreatment before different drying process on the structural and functional properties of starch in Chinese yam.

This article compared the effects of hot air drying (HAD), infrared drying (IRD), and cold plasma (CP) as a pretreatment on the structure, quality, and digestive characteristics of starch extracted from yam. As the most commonly used drying method, HAD was used as a control. SEM and CLSM images showed that all treatments preserve the integrity of the yam starch. CP caused some cracks and breaks in the starch granules. IRD did not destroy the crystal structure of starch molecules, but made the spiral structure tighter and increased short-range orderliness. However, CP led to the depolymerization and dispersion of starch molecular chains, resulting in a decrease in average molecular weight and relative crystallinity. These molecular conformation changes caused by different processes led to differences in solubility, swelling power, pasting parameters, digestion characteristics, and functional characteristics. This study provided an important basis for the reasonable drying preparation and utilization of yam starch.

Resistant starch from yam: Preparation, nutrition, properties and applications in the food sector.

Yam is a significant staple food and starch source, particularly in tropical and subtropical regions, holding the fourth position among the world's top ten tuber crops. Yam tubers are rich in essential nutrients and a diverse range of beneficial plant compounds, which contribute to their multifaceted beneficial functions. Furthermore, the abundant starch and resistant starch (RS) content in yam can fulfil the market demand for RS. The inherent and modified properties of yam starch and RS make them versatile ingredients for a wide range of food products, with the potential to become one of the most cost-effective raw materials in the food industry. In recent years, research on yam RS has experienced progressive expansion. This article provides a comprehensive summary of the latest research findings on yam starch and its RS, elucidating the feasibility of commercial RS production and the technology's impact on the physical and chemical properties of starch. Yam has emerged as a promising reservoir of tuber starch for sustainable RS production, with thermal, chemical, enzymatic and combination treatments proving to be effective manufacturing procedures for RS. The adaptability of yam RS allows for a wide range of food applications.

A high-permeability method for extracting purple yam saponins based on ultrasonic-assisted natural deep eutectic solvent.

The extraction of active ingredients from traditional Chinese medicine has received considerable attentions. In this study, 16 kinds of natural deep eutectic solvent (NADES) with ultrasonic were selected to extract saponins from purple yam root and the extraction mechanism was investigated. The results showed that chloride/acrylic acid (1:2; n/n) had the highest extraction yield for saponins. The optimal extraction process parameters were 24% water content, 20 mL/g liquid-solid ratio, and ultrasonic extraction for 85 min (81 °C, 600 W). The extraction rate (ER) of purple yam saponins was 0.935%, close to the fitted result of 96.5 mg/g. Molecular dynamics simulations and FT-IR results showed that the NADES may extract the saponin constituents from purple yam through hydrogen bonding. Compared with traditional extraction methods and molecularly imprinted polymer methods, NADES has a higher ER and lower cost (1.53 $/g), which provides a reference for subsequent industrial quantitative production.

Diarylheptanoid glycosides from Dioscorea nipponica rhizomes.

A group of previously undescribed diarylheptanoids with mono/di-glucose substitution, diodiarylheptosides A-F (1-6), together with six known diarylheptanoids (7-12) were isolated from the rhizomes of Dioscorea nipponica. Their structures were established by comprehensive UV, IR, HR-ESI-MS and NMR analyses, and their absolute configurations were determined by a comparison of calculated and experimental ECD, some with optical rotations, after acid-hydrolysis. Moreover, bioassay results showed that compounds 3 and 11 exhibited stronger NO inhibitions on lipopolysaccharides-induced RAW 264.7 cells, with the IC50 values of 14.91 ± 0.62 and 12.78 ± 1.12 µM.

Phytoecdysteroids from Dioscorea dumetorum (Kunth) Pax. and their antioxidant and antidiabetic activities.

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum, a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis-fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC50 = 0.10 mg/mL) and 6 (IC50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC50 = 0.63 mg/mL). In contrast, compounds 3, 4, and 5 showed reduced α-amylase inhibition, with IC50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species.

Alleviation of Menopausal Symptoms by Yam (Dioscorea japonica Thunb.) and Gromwell (Lithospermum erythrorhizon Sieb. Et Zucc.) Extracts in Ovariectomized Mice.

SCOPE: The decline in estrogen during menopause contributes to a variety of menopausal symptoms, for which hormone replacement therapy (HRT) has been extensively applied. Regarding side effects and limited effectiveness of HRT for specific individuals, there is a growing interest in safe alternatives such as phytoestrogens which are structurally analogous to estrogens. This study aims to investigate the efficacy of yam and gromwell extracts, rich in bioactive compounds, and the synergistic effect of extracts on symptoms induced by estrogen deficiency in ovariectomized (OVX) mice. METHODS AND RESULTS: OVX mice receive dietary intervention of either yam, gromwell extract, or their mixture for 14 weeks. Sham-operated mice and E2-injected OVX mice serve as positive controls. Following 14 weeks of oral administration, blood, adipose tissue, vagina, uterus, femurs, and tibias are harvested for further investigation. Consequently, yam and gromwell extracts ameliorate menopausal conditions such as weight gain, glucose intolerance, dyslipidemia, and osteoporosis in estrogen-deficient OVX mice. In addition, the mixture of yam and gromwell extracts synergistically aids in the relief of the indications. CONCLUSION: These results indicate the potential use of yam and gromwell extracts, as well as their mixture, for the development of healthy functional foods to modulate menopausal symptoms.

The anti-non-small cell lung cancer effect of Diosbulbin B: Targeting YY1 induced cell cycle arrest and apoptosis.

BACKGROUND: Toxic components frequently exhibit unique characteristics and activities, offering ample opportunities for the advancement of anti-cancer medications. As the main hepatotoxic component of Dioscorea bulbifera L. (DB), Diosbulbin B (DIOB) has been widely studied for its anti-tumor activity at nontoxic doses. However, the effectiveness and mechanism of DIOB against non-small cell lung cancer (NSCLC) remains unclear. PURPOSE: To evaluate the anti-NSCLC activity of DIOB and to elucidate the specific mechanism of action. METHOD: The effect of DIOB on NSCLCL in vitro was evaluated through CCK8, colony formation, and flow cytometry. The in vivo efficacy and safety of DIOB in treating NSCLC were assessed using various techniques, including HE staining, tunel staining, immunohistochemistry, and biochemical index detection. To understand the underlying mechanism, cell transfection, western blotting, molecular docking, cellular thermal shift assay (CESTA), and surface plasmon resonance (SPR) were employed for investigation. RESULTS: DIOB effectively hindered the progression of NSCLC both in vitro and in vivo settings at a no-observed-adverse-effect concentration (NOAEC) and a safe dosage. Specifically, DIOB induced significant G0/G1 phase arrest and apoptosis in A549, PC-9, and H1299 cells, while also notably inhibiting the growth of subcutaneous tumors in nude mice. Mechanistically, DIOB could directly interact with oncogene Yin Yang 1 (YY1) and inhibit its expression. The reduction in YY1 resulted in the triggering of the tumor suppressor P53, which induced cell cycle arrest and apoptosis in NSCLC cells by inhibiting the expression of Cyclin A2, B2, CDK1, CDK2, CDK4, BCL-2, and inducing the expression of BAX. In NSCLC cells, the induction of G0/G1 phase arrest and apoptosis by DIOB was effectively reversed when YY1 was overexpressed or P53 was knocked down. Importantly, we observed that DIOB exerted the same effect by directly influencing the expression of YY1-regulated c-Myc and BIM, particularly in the absence of P53. CONCLUSION: For the inaugural investigation, this research unveiled the anti-NSCLC impact of DIOB, alongside its fundamental mechanism. DIOB has demonstrated potential as a treatment agent for NSCLC due to its impressive efficacy in countering NSCLC.

Molecular mechanism for the influence of yam starch multiscale structure on the sensory texture of cooked yam.

Yam is a dual-purpose crop as both medicine and food. However, the mechanism controlling the eating quality of yam remains to be elucidated. This study explored the influence of starch multiscale structure on the texture of yam. The results indicated that FS and RC yam have higher hardness and chewiness, while BZ, XM, and PL yam possess waxiness, Fineness, and Stickiness. Statistically, high amylose (AM) can increase hardness, chewiness, and compactness; and average molecular size (Rh) is positively correlated with stickiness, fineness, and waxiness. Specifically, medium- and long-chain amylose (1000 < X ≤ 10,000) and amylopectin (24 < X ≤ 100), particularly medium-chain amylose (1000 < X ≤ 5000) and long-chain amylopectin (24 < X ≤ 36), primarily affect sensory and rheological stickiness. The long chains of amylose form a straight chain interspersed in the crystalline and amorphous regions to support the entire lamellar structure. Higher proportion of amylose long chains, promoting the starch's structural rigidity, which in turn enhanced its hardness-related attributes. Moreover, a higher ratio of long chains within amylopectin results in tightly intertwined adjacent outer chains, forming double helix crystalline zones. This consequently augmenting the texture quality linked to stickiness-related attributes.

[Study on mechanism of Chinese Yam polysaccharide synergizing nucleoside analogues against hepatitis B virus through p38 MAPK signaling pathway].

This study explore the molecular mechanism of the synergistic effect of Chinese Yam polysaccharides and nucleoside analogues(NAs) on hepatitis B virus(HBV) resistance. Different concentrations of Chinese Yam polysaccharide and entecavir were ad-ded to HepG2.2.15 cells. After the cytotoxicity was detected by cell counting kit-8(CCK-8), the optimal concentration and time of the two drugs to inhibit HepG2.2.15 cells were screened out. They were divided into control group, Chinese Yam polysaccharide group, entecavir group and combination drug group(Chinese Yam polysaccharide + entecavir). The drugs were added to HepG2.2.15 cells, ELISA was used to detect the effects of each group of drugs on the secretion of hepatitis B virus surface antigen(HBsAg) and hepatitis B virus e antigen(HBeAg) in cell supernatant, probe quantitative real-time PCR(probe qRT-PCR) was used to detect the effects of drugs on HBV-DNA in HepG2.2.15 cells, and Western blot was used to detect the effects of each group of drugs on the expression of p38 MAPK, p-p38 MAPK, NTCP proteins in HepG2.2.15 cells. The qRT-PCR was used to detect the effect of drugs on the expression of p38 MAPK and NTCP mRNA in HepG2.2.15 cells. The results showed that compared with control group, the concentrations of HBeAg and HBsAg in Chinese Yam polysaccharide group, entecavir group and combination group decreased(P<0.01 or P<0.001), and both of them inhibited HBV-DNA in HepG2.2.15 cells(P<0.01), and the HBV-DNA inhibition of HepG2.2.15 cells in the combination group was more obvious(P<0.001), and the protein expression levels of p-p38 MAPK and NTCP were significantly decreased(P<0.05 or P<0.01), the mRNA expression level of p38 MAPK increased, and the mRNA expression level of NTCP decreased(P<0.05 or P<0.01). To sum up, Chinese Yam polysaccharide can reduce the expression of NTCP protein and mRNA through p38 MAPK signaling pathway and cooperate with entecavir in anti-HBV.

Investigating the impact of ultrasound on the structural, physicochemical, and emulsifying characteristics of Dioscorin: Insights from experimental data and molecular dynamics simulation.

This study investigated the impact of ultrasound treatment on dioscorin, the primary storage protein found in yam tubers. Three key factors, namely ultrasound power, duration, and frequency, were focused on. The research revealed that ultrasound-induced cavitation effects disrupted non-covalent bonds, resulting in a reduction in α-helix and ß-sheet contents, decreased thermal stability, and a decrease in the apparent hydrodynamic diameter (Dh) of dioscorin. Additionally, previously hidden amino acid groups within the molecule became exposed on its surface, resulting in increased surface hydrophobicity (Ho) and zeta-potential. Under specific ultrasound conditions (200 W, 25 kHz, 30 min), Dh decreased while Ho increased, facilitating the adsorption of dioscorin molecules onto the oil-water interface. Molecular dynamics (MD) simulations showed that at lower frequencies and pressures, the structural flexibility of dioscorin's main chain atoms increased, leading to more significant fluctuations between amino acid residues. This transformation improved dioscorin's emulsifying properties and its oil-water interface affinity.

Antibacterial activity of Dioscorea bulbifera Linn. extract and its active component flavanthrinin against skin-associated bacteria.

BACKGROUND: Dioscorea bulbifera Linn. has been used for wound care in Thailand. However, a comprehensive evaluation of its antibacterial activity is required. This study aimed to investigate the antibacterial efficacy of D. bulbifera extract against skin-associated bacteria and isolate and characterize its active antibacterial agent, flavanthrinin. METHODS: Air-dried bulbils of D. bulbifera were pulverised and extracted with hexane, dichloromethane, ethyl acetate, methanol, ethanol, and distilled water; vacuum filtered; concentrated; freeze-dried; and stored at -20 ºC. Antibacterial activity of the extracts was assessed using microdilution techniques against several skin-associated bacteria. Thin-layer chromatography (TLC) bioautography was used to identify the active compounds in the extract, which were fractionated by column chromatography and purified by preparative TLC. The chemical structures of the purified compounds were analysed using nuclear magnetic resonance (NMR). The cytotoxicity of the extract and its active compounds was evaluated in Vero cells. RESULTS: The ethyl acetate extract exhibited distinct inhibition zones against bacteria compared to other extracts. Therefore, the ethyl acetate extract of D. bulbifera in the ethyl acetate layer was used for subsequent analyses. D. bulbifera extract exhibited antibacterial activity, with minimum inhibitory concentrations (MICs) of 0.78-1.56 mg/mL. An active compound, identified through TLC-bioautography, demonstrated enhanced antibacterial activity, with MICs of 0.02-0.78 mg/mL. NMR analysis identified this bioactive compound as flavanthrinin. Both D. bulbifera extract and flavanthrinin-containing fraction demonstrated potent antibacterial activity against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and S. epidermidis. The flavanthrinin containing fraction demonstrated low cytotoxicity against Vero cells, showing CC50 values of 0.41 ± 0.03 mg/mL. These values are lower than the MIC value, indicating that this fraction is safer than the initial ethyl acetate extract. CONCLUSIONS: Dioscorea bulbifera extract and its bioactive component flavanthrinin demonstrated significant antibacterial activity against the skin-associated bacteria Staphylococci, including MRSA. Flavanthrinin has potential as a complementary therapeutic agent for managing skin infections owing to its potent antibacterial effects and low cytotoxicity.

Effects of cooking methods on the physical properties and in vitro digestibility of starch isolated from Chinese yam.

The objective of this study was to compare the structural and functional attributes of Chinese yam starches obtained via different domestic cooking methods. Cooking changed the crystalline type from the C type to the CB type, and disrupted the short- and long-range molecular order of Chinese yam starch. The average chain length of amylopectin in BOS (boiling starch) was the smallest at 22.78, while RWS had the longest average chain length, reaching 24.24. These alterations in molecular structure resulted in variations in functional properties such as solubility, swelling power (SP), pasting characteristics, and rheological properties. Among these alterations, boiling was the most effective method for increasing the water-binding capacity and SP of starch. Specifically, its water holding capacity was 2.12 times that of RWS. In vitro digestion experiments indicated that BOS has a higher digestion rate (k = 0.0272 min-1) and lower RDS (rapidly digestible starch), which may be related to its amylopectin chain length distribution. This study can guide us to utilize yam starch through suitable cooking methods, which is relevant for the processing and application of Chinese yam starch.

Structural characterization and immunomodulatory activity of a polysaccharide from Dioscotea opposita.

The purified polysaccharides fraction, DOP-2, was prepared from Dioscorea opposita Thunb (D. opposita). This study combined in vitro and in vivo experiments to comprehensively investigate the index changes in RAW264.7 cells and immunocompromised mice under DOP-2 intervention, aiming to elucidate the potential mechanisms of immunomodulatory effects of DOP-2. DOP-2 (10 âˆ¼ 500 µg/mL) significantly elevated the levels of NO, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) factors secreted by RAW264.7 cells, and restored the body weight of immunosuppressed mice and improve the degree of injury to the immune organ index, resulting in significant immunomodulatory effects. Notably, DOP-2 promoted the production of short-chain fatty acids (SCFAs) in immunosuppressed mice and modulated the composition of their gut microflora. These findings highlight the potential benefits of DOP-2 therapy in improving immune function and gut health, and will provide a theoretical basis for the application of D. opposita polysaccharides as an immunomodulatory adjuvant.

The genus Dioscorea L. (Dioscoreaceae), a review of traditional uses, phytochemistry, pharmacology, and toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Dioscorea, a member of the Dioscoreaceae family, comprises approximately 600 species and is widely distributed across temperate and tropical regions such as Asia, South Africa, and North America. The traditional medicinal uses of Dioscorea have been documented in Asian and African pharmacological systems. In Asia, this genus is traditionally used to treat respiratory illnesses, rheumatism, diabetes, diarrhea, dysentery, and other conditions. In Africa, this genus has been used to treat human immunodeficiency virus and ring worms. However, the traditional medicinal practices in North America rarely mention the use of this genus. AIM OF THE STUDY: The aim of this review is to comprehensively review the genus Dioscorea, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. The research also aims to highlight the valuable bioactive compounds within Dioscorea and emphasize the need for further investigations into acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors to contribute to the discovery of novel pharmaceuticals. MATERIALS AND METHODS: A search for available information on Dioscorea was conducted using scientific databases, including PubMed, ISI-WOS, Scopus, and Google Scholar, as well as recent academic publications from reputable publishers and other literature sources. The search was not limited by language and spanned the literature published between 1950 and 2022. RESULTS: This article provides a comprehensive review of the Dioscorea genus, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. Extensive research has been conducted on this genus, resulting in the isolation and examination of over 1000 compounds, including steroids, terpenoids, and flavonoids, to determine their biological activities. These activities include anti-tumor, anti-inflammatory, immunomodulatory, neuroprotective, hypoglycemic, and hypolipidemic effects. However, some studies have indicated the potential toxicity of high doses of Dioscorea, highlighting the need for further investigations to assess the safety of this genus. Additionally, this review explores potential avenues for future research and discusses the challenges associated with a comprehensive understanding of the Dioscorea genus. CONCLUSIONS: Based on the existing literature, it can be concluded that Dioscorea is a valuable source of bioactive compounds that have the potential to treat various disorders. Future research should prioritize the investigation of acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors. This review provides a comprehensive analysis of the Dioscorea genus, emphasizing its potential to enable a deeper exploration of the biological activity mechanisms of these plants and contribute to the discovery of novel pharmaceuticals.

Effect of extrusion on the formation, structure and properties of yam starch-gallic acid complexes.

This paper investigated the effects of twin-screw extrusion treatment on the formation, structure and properties of yam starch-gallic acid complexes. Yam starch and gallic acid were extruded. The microstructure, gelatinization characteristics, and rheological properties of the samples were determined. The microstructure of extruded yam starch-gallic acid complexes presented a rough granular morphology, low swelling, and high solubility. The X-ray diffraction analysis showed that the extruded yam starch-gallic acid complexes exhibited A + V-type crystalline structure. Fourier transform infrared spectroscopy results showed that the extrusion treatment could destroy the internal orderly structure of yam starch, and the addition of gallic acid could further reduce its molecular orderliness. Differential scanning calorimetry analysis showed a decrease in the enthalpy of gelatinization of the sample. Dynamic rheological analysis showed that the storage modulus and loss modulus of the extruded yam starch-gallic acid complexes were significantly reduced, exhibiting a weak gel system. The results of viscosity showed that extrusion synergistic gallic acid reduced the peak viscosity and setback value of starch. In addition, extrusion treatment had an inhibitory effect on the digestibility of yam starch, and enhanced the interaction of gallic acid with yam starch or hydrolytic enzymes. Therefore, extrusion synergistic gallic acid has improved the structure and properties of yam starch-related products, which can provide new directions and new ideas for the development of yam starch.

Prospects of yam (Dioscorea) polysaccharides: Structural features, bioactivities and applications.

Yam (Dioscorea) is a tuber crop cultivated for food security, revenue, and medicinal purposes. It has been used to treat diabetes, asthma, diarrhea, and other diseases. The main active ingredients in yam, polysaccharides, are regarded to be the important reason for its widespread applications. Now, a comprehensive review of research developments of yam polysaccharides (YPs) was presented to explore their prospects. We outlined the structural characteristics, biological activities, structure-activity relationships, and potential applications. Around 13 neutral components and 17 acidic components were separated. They exhibited various bioactivities, including immunomodulatory, hypoglycemic, hypolipidemic, antioxidant, gastrointestinal protective, anti-fatigue, and senile disease treatment activities, as well as prebiotic effect. Structure-activity relationships illustrated that unique structural properties, chemical modifications, and carried biopolymers could influence the bioactivities of YPs. The potential applications in medicine, food, and other fields have also been summarized.

Unveiling the impact of harvest time on Dioscorea opposita Thunb. cv. Tiegun maturity by NMR-based metabolomics and LC-MS/MS analysis.

BACKGROUND: Dioscorea opposita Thunb. cv. Tiegun maturity (DM) is an important factor influencing its quality. However, there are few studies on the impact of harvest time on its maturation. In the present study, a NMR-based metabolomics approach was applied to investigate the dynamic metabolic changes of D. opposita Thunb. cv. Tiegun at six different harvest stages: stage 1 (S1), stage 2 (S2), Stage 3 (S3), stage 4 (S4), stage 5 (S5) and stage 6 (S6). RESULTS: Principal component analysis showed distinct segregation of samples obtained from S1, S2 and S3 compared to those derived from S4, S5 and S6. Interestingly, these samples from the two periods were obtained before and after frost, indicating that frost descent might be important for DM. Eight differential metabolites responsible for good separation of different groups were identified by the principal component analysis loading plot and partial least squares-discriminant analysis. In addition, quantitative analysis of these metabolites using liquid chromatography-tandem mass spectrometry determined the effects of harvest time on these metabolite contents, two of which, sucrose and allantoin, were considered as potential biomarkers to determine DM. CONCLUSION: The present study demonstrated that NMR-based metabolomics approach could serve as a powerful tool to identify differential metabolites during harvesting processes, also offering a fresh insight into understanding the DM and the potential mechanism of quality formation. © 2024 Society of Chemical Industry.

Efficient discovery of active isolates from Dioscorea spongiosa by the combination of bioassay-guided macroporous resin column chromatography and high-speed counter-current chromatography.

In the present study, twelve compounds from Dioscorea spongiosa were successfully purified by an efficient technique combined bioassay-guided fractionation macroporous resin column chromatography (MRCC) pretreatment and high-speed counter-current chromatography (HSCCC) separation for the first time. Then, D101 MRCC was used to fractionate the crude extract into five parts, which further applied the bioassay-guided fractionation strategy to screen the active fractions of 2 and 4. As for the separation, 200 mg Fr.2 was purified by HSCCC using EtOAc/n-BuOH/H2 O (2:2:3, v/v), leading to annulatomarin (1), dioscoresides C (2), diosniponol C (3), methyl protodioscin (4), pseudoprotodioscin (5), protogracillin (6), as well as 200 mg Fr.4 yielding montroumarin (7), dioscorone A (8), diosniponol D (9), protodioscin (10), gracillin (11), and dioscin (12) using CH2 Cl2 /MeOH/H2 O (3:3:2, v/v) with the purities over 95.0%. Finally, the isolates were assayed for their anti-inflammatory, urico-lowering, and anti-diabetic activities in vitro, which indicated that the steroidal saponins of 5, 6, and 11 showed all these three activities.