Discrimination of Adzuki Bean (Vigna angularis) Geographical Origin by Targeted and Non-Targeted Metabolite Profiling with Gas Chromatography Time-of-Flight Mass Spectrometry

A fundamental study on postmortem submersion interval estimation by metabolomics analyzing of gastrocnemius muscle from submersed rat models in freshwater

In forensic practice, determining the postmortem submersion interval (PMSI) and cause-of-death of cadavers in aquatic ecosystems has always been challenging task. Traditional approaches are not yet able to address these issues effectively and adequately. Our previous study proposed novel models to predict the PMSI and cause-of-death based on metabolites of blood from rats immersed in freshwater. However, with the advance of putrefaction, it is hardly to obtain blood samples beyond 3 days postmortem. To further assess the feasibility of PMSI estimation and drowning diagnosis in the later postmortem phase, gastrocnemius, the more degradation-resistant tissue, was collected from drowned rats and postmortem submersion model in freshwater immediately after death, and at 1 day, 3 days, 5 days, 7 days, and 10 days postmortem respectively. Then the samples were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the dynamic changes of the metabolites. A total of 924 metabolites were identified. Similar chronological changes of gastrocnemius metabolites were observed in the drowning and postmortem submersion groups. The difference in metabolic profiles between drowning and postmortem submersion groups was only evident in the initial 1 day postmortem, which was faded as the PMSI extension. Nineteen metabolites representing temporally-dynamic patterns were selected as biomarkers for PMSI estimation. A regression model was built based on these biomarkers with random forest algorithm, which yielded a mean absolute error (± SE) of 5.856 (± 1.296) h on validation samples from an independent experiment. These findings added to our knowledge of chronological changes in muscle metabolites from submerged vertebrate remains during decomposition, which provided a new perspective for PMSI estimation.

Analysis of Genetic Diversity in Adzuki Beans (Vigna angularis): Insights into Environmental Adaptation and Early Breeding Strategies for Yield Improvement

Adzuki beans are widely cultivated in East Asia and are one of the earliest domesticated crops. In order to gain a deeper understanding of the genetic diversity and domestication history of adzuki beans, we conducted Genotyping by Sequencing (GBS) analysis on 366 landraces originating from Korea, China, and Japan, resulting in 6586 single-nucleotide polymorphisms (SNPs). Population structure analysis divided these 366 landraces into three subpopulations. These three subpopulations exhibited distinctive distributions, suggesting that they underwent extended domestication processes in their respective regions of origin. Phenotypic variance analysis of the three subpopulations indicated that the Korean-domesticated subpopulation exhibited significantly higher 100-seed weights, the Japanese-domesticated subpopulation showed significantly higher numbers of grains per pod, and the Chinese-domesticated subpopulation displayed significantly higher numbers of pods per plant. We speculate that these differences in yield-related traits may be attributed to varying emphases placed by early breeders in these regions on the selection of traits related to yield. A large number of genes related to biotic/abiotic stress resistance and defense were found in most quantitative trait locus (QTL) for yield-related traits using genome-wide association studies (GWAS). Genomic sliding window analysis of Tajima's D and a genetic differentiation coefficient (Fst) revealed distinct domestication selection signatures and genotype variations on these QTLs within each subpopulation. These findings indicate that each subpopulation would have been subjected to varied biotic/abiotic stress events in different origins, of which these stress events have caused balancing selection differences in the QTL of each subpopulation. In these balancing selections, plants tend to select genotypes with strong resistance under biotic/abiotic stress, but reduce the frequency of high-yield genotypes to varying degrees. These biotic/abiotic stressors impact crop yield and may even lead to selection purging, resulting in the loss of several high-yielding genotypes among landraces. However, this also fuels the flow of crop germplasms. Overall, balancing selection appears to have a more significant impact on the three yield-related traits compared to breeder-driven domestication selection. These findings are crucial for understanding the impact of domestication selection history on landraces and yield-related traits, aiding in the improvement of adzuki bean varieties.

Metabolomics approach to growth-age discrimination in mountain-cultivated ginseng (Panax ginseng C. A. Meyer) using ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry

Mountain-cultivated ginseng is typically harvested after 10 years, while ginseng aged over 15 years is considered wild ginseng. This study aims to differentiate mountain-cultivated ginseng by age, as the fraudulent practice of selling low-aged cultivated ginseng disguised as high-aged one is damaging the market. In this study, LC-MS analyzed 98 ginseng samples, and multivariate statistical analysis identified patterns between samples to select influential components. Machine learning models were developed to identify ginseng samples of different ages. The untargeted metabolomic analysis clearly divided samples aged 4-20 years into three age groups. Twenty-two potential age-dependent biomarkers were discovered to differentiate the three sample groups. Three machine learning models were used to predict new samples, and the optimal model was selected. Some biomarkers could determine age phases according to the differentiation of mountain-cultivated ginseng samples. These biomarkers were thoroughly analyzed for variation trends. The machine learning models established using the screened biomarkers successfully predicted the age group of new samples.

Proliferation and Metabolic Profiling of Cynanchum wilfordii Adventitious Roots Using Explants from Different Cultivation Methods

Cynanchum wilfordii root is used in traditional herbal medicine owing to its various pharmacological activities. However, C. wilfordii roots are misused owing to their morphological similarities with C. auriculatum. Adventitious root (AR) culture can prevent such misuse, and the selection of plant materials is an important procedure for producing high-quality ARs. This study aimed to compare the proliferation and metabolic profiles of C. wilfordii ARs in two types of explants from different cultivation methods (either cultivated in open field (ECF) or cultivated on a heap of C. wilfordii (ECH)). After 4 weeks of culture, the proliferation rate and number and length of secondary ARs were determined, and 3/4 Murashige and Skoog (MS) salt medium, 4.92 μM indole-3-butyric acid (IBA), and 5% sucrose were suggested as the best proliferation conditions for ARs originating from both ECF and ECH. Through metabolic profiling, ARs from ECH were found to show higher accumulation patterns for flavonoids, polysaccharides, hydroxyacetophenones, aromatic amino acids, and mono-unsaturated fatty acids, which were ascribed to the activation of flavonoid biosynthesis, the phenylpropanoid pathway, and fatty acid desaturase, stimulated by abiotic stresses. In contrast, ARs from ECF had higher levels of TCA cycle intermediates, amino acids in the aspartate-glutamate pathway, and saturated and polyunsaturated fatty acids, indicating energy metabolism and plant development. Overall, the current study provided information on the optimal conditions for inducing C. wilfordii ARs with higher amounts of bioactive compounds.

Monitoring the lipid oxidation and flavor of Russian sturgeon fillets treated with low temperature vacuum heating: formation and relationship

BACKGROUND

Sturgeon is one of the most precious fish resources worldwide. Low temperature vacuum heating (LTVH) has been confirmed as a good way of maintaining food quality. However, there is a lack of in-depth studies assessing the impact of LTVH on lipid oxidation and flavor formation.

RESULTS

The present study compared the effect of LTVH and traditional cooking on lipid oxidation and flavor of sturgeon fillets. In total, 13 fatty acids were detected, of which polyunsaturated fatty acids content was the highest (P < 0.05). LTVH prevented the formation of conjugated diene and thiobarbituric acid reactive substances (P < 0.05), as manifested by an increased signal intensity of free radicals of electron spin resonance. The characteristic peaks intensity of lipid by Raman at 970 cm^-1 , 1080 cm^-1 and 1655 cm^-1 were reduced, whereas peaks at 1068 cm^-1 and 1125 cm^-1 displayed the opposite trend. Confocal fluorescence microscopy showed that the lipids particles were reduced and distributed more evenly with an increase in heating temperature. Principal component analysis of electronic nose cannot effectively separate all groups; however, gas chromatography-ion migration spectrometry showed that the volatile flavor compounds were relatively stable during LTVH. Correlation analysis of all the above lipid oxidation indices and characteristic flavor substances showed that each treatment group was located in different quadrants and demonstrated great differentiation.

CONCLUSION

Overall, the results of the present study support the view that LTVH is a healthier way of cooking. © 2022 Society of Chemical Industry.

Variability of Anthocyanin Concentrations, Total Metabolite Contents and Antioxidant Activities in Adzuki Bean Cultivars

In this study, adzuki bean cultivars including Arari, Chilbopat, Geomguseul, and Hongeon were recently cultivated, and the concentrations of seven individual anthocyanins were determined in their seed coats for the first time. Moreover, the variations of total saponin content (TSC), total phenolic content (TPC), 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) between defatted and undefatted extracts of whole seeds, seed coats, and dehulled seeds of each were analyzed. The anthocyanins were detected only in the black seed-coated cultivars and delphinidin-3-O-glucoside was dominant in both Geomguseul (12.46 mg/g) and Chilbopat (10.88 mg/g) followed by delphinidin-3-O-galactoside. TSC and TPC were in the ranges of 16.20−944.78 mg DE/g and 0.80−57.35 mg GAE/g, respectively, and each decreased in the order of seed coats > whole seeds > dehulled seeds regardless of extract type. The antioxidant activities also showed similar patterns of variation. Geomguseul seed coats outweighed the remaining cultivars in terms of TPC and FRAP activity (p < 0.05). Generally, significant variations of metabolite contents and antioxidant activities were observed between cultivars and across their seed parts (p < 0.05). Thence, black seed-coated adzuki beans could be excellent sources of anthocyanins and antioxidants.

Metabolomics Analysis of Morchella sp. From Different Geographical Origins of China Using UPLC-Q-TOF-MS

The morel mushroom (Morchella sp.) is reputed as one of the most highly-prized edible fungi with mounting cultivated area as well as commercial popularity in China. To date, optimized methods specific for quality evaluation and constituent analysis of Morchella sp. are still non-available, impeding the healthy and sustainable development of this industry. Herein, an untargeted UPLC-Q-TOF-MS-based metabolomics approach was performed to characterize the metabolite profiles of morel samples from four distinct geographical origins of China, viz. Gansu, Guizhou, Liaoning, and Henan province. A total of 32 significantly different metabolites assigned to lipids (19), organic acids (9), amino acids (3), and ketones (1) were identified to distinguish the geographic-segregation samples amenable to multivariate analysis. These metabolites may serve as molecular markers indicative of specific regions. More importantly, the lipid, protein and amino acid metabolism were responsible for geographic differences as revealed by KEGG pathway enrichment analysis. Collectively, this study not only pioneered high-throughput methodology to evaluate quality of Morchella sp. and distinguish geographical origins in a sensitive, rapid and efficient manner, but also shed light on the potential link between physiochemical variation and geological origins from a metabolic perspective, which may be conducive to the advancement of edible fungi industry and establishment of food traceability system.

Omics analyses indicate the routes of lignin related metabolites regulated by trypsin during storage of pitaya (Hylocereus undatus)

The storage quality of Hylocereus undatus was significantly improved by trypsin, a novel preservative. The transcriptomic results revealed that antioxidant signal pathways were induced, while lignin catabolic process was impeded by trypsin. In addition, the results of protein-protein interaction (PPI) network networks suggested that flavone 3'-O-methyltransferase 1 (OMT1), ferulic acid 5-hydroxylase 1 (CYP84A1), cellulose synthase isomer (CEV1), and 4-coumarate-CoA ligase 3 (4CL3) act as hubs of peroxidases, lignin related proteins, and proteins involved in the phenylpropanoid metabolism (PLPs) induced by trypsin. Trypsin also regulated the biosynthesis of lignin, chlorogenic acid, and flavonoids. Caffeic acid might be the hub in the metabolic network of the early pathways of phenylpropanoid biosynthesis. It has been hypothesized that trypsin might quickly induce lignin biosynthesis and then up-regulated bioactive metabolites to enhance storage quality of H. undatus.

Untargeted Metabolomics Analysis Using FTIR and UHPLC-Q-Orbitrap HRMS of Two Curculigo Species and Evaluation of their Antioxidant and α-Glucosidase Inhibitory Activities

Curculigo orchioides and C. latifolia have been used as traditional medicines such as antidiabetic and anticancer. This study measured the total phenolics and flavonoid contents as well as analyzed the functional groups and chemical compounds using Fourier-transform infrared (FTIR) spectra and UHPLC-Q-Orbitrap-HRMS profiling for the discrimination of plant parts, geographical origin, and compounds that presumably have a significant contribution as antioxidant and α-glucosidase inhibitors on both plants. The total phenolics and flavonoids contents in Curculigo species varied from 142.09 to 452.47 mg gallic acid equivalent (GAE/g) and from 0.82 to 5.44 mg quercetin equivalent (QE/g), respectively. The lowest IC₅₀ for antioxidant and α-glucosidase inhibitory activities is presented by C. latifolia from a higher altitude region. Principal component analysis (PCA) from FTIR and UHPLC-Q-Orbitrap-HRMS data could discriminate the plant parts and geographical origin. Partial least squares (PLS) analysis has identified several functional groups, such as O–H, C–H, C=O, C–C, C–O, and chemical compounds, unknown-185 and unknown-85, that are most likely to contribute to the antioxidant and α-glucosidase inhibitory activities.

Metabolite Profiling and Chemometric Study for the Discrimination Analyses of Geographic Origin of Perilla (Perilla frutescens) and Sesame (Sesamum indicum) Seeds

Perilla and sesame are traditional sources of edible oils in Asian and African countries. In addition, perilla and sesame seeds are rich sources of health-promoting compounds, such as fatty acids, tocopherols, phytosterols and policosanols. Thus, developing a method to determine the geographic origin of these seeds is important for ensuring authenticity, safety and traceability and to prevent cheating. We aimed to develop a discriminatory predictive model for determining the geographic origin of perilla and sesame seeds using comprehensive metabolite profiling coupled with chemometrics. The orthogonal partial least squares-discriminant analysis models were well established with good validation values (Q² = 0.761 to 0.799). Perilla and sesame seed samples used in this study showed a clear separation between Korea and China as geographic origins in our predictive models. We found that glycolic acid could be a potential biomarker for perilla seeds and proline and glycine for sesame seeds. Our findings provide a comprehensive quality assessment of perilla and sesame seeds. We believe that our models can be used for regional authentication of perilla and sesame seeds cultivated in diverse geographic regions.

A high-throughput platform for interpretation of metabolite profile data from pepper (Capsicum) fruits of 13 phenotypes associated with different fruit maturity states

Nowadays, novel tools have been developed for efficient analysis and visualization of large-scale metabolite profile data associated with metabolic pathways. A high-throughput platform using PathVisio 3 combined with multivariate analysis is proposed for the first time. Additionally, this is the first analysis of the relationships among terpenoids monoterpene, sesquiterpene, triterpene, and tetraterpene during pepper fruit ripening, and their changes. This platform was successfully applied to interpret large-scale data related to 131 metabolites from mature and immature fruits of 13 pepper phenotypes. The carotenoid-derived volatiles, such as dihydroactinidiolide and β-ionone were closely correlated with carotenoids, indicating that the synthesis and degradation of carotenoids occurred in pepper fruit mature stage. Using PathVisio 3, the metabolic changes in pathway could be presented quickly, revealing the accumulation of stress-related metabolites, such as proline, capsaicin, and phenylalanine, in the mature stage. This approach could provide useful information about comprehensive biochemical regulation of fruit ripening.