Metabolomics workflow for quality control of differently-processed pre-cooked chicken fillets

Metabolomic signatures of pathogen suppression effect of Baltic eelgrass meadows in surrounding seawater

Organic molecules exuded into water column by marine organisms represent a significant portion of marine dissolved organic matter (DOM) that modulates biochemical interactions. Secreted allelochemicals have been suggested to be involved in regulation of pathogen abundance in seagrass meadows, however, seagrass exometabolome has remained unstudied. We aimed to identify seagrass exometabolites, within and outside meadows, and explore their potential involvement in pathogen suppression under varying environmental conditions. We collected seawater (SW) samples from eelgrass (Zostera marina)-vegetated (V) and non-vegetated (NV) areas across 5 locations spanning 270 km of coastline along the German Baltic Sea. Comparative LC-MS/MS-based untargeted computational metabolomics combined with statistical analyses and machine learning tools were employed to pinpoint (exo)metabolomic signatures of eelgrass leaves. Simultaneously, we measured abiotic parameters and the abundance of three common pathogenic taxa in seawater, and investigated spatiotemporal variations. Here we show the correlation of pathogen biomass and eelgrass pathogen reduction effect with increasing seawater temperature, eutrophication and anthropogenic influences. Exometabolomics studies revealed that eelgrass exudates contributed significantly to overall seawater DOM at molecular level, while SW overlying eelgrass meadows contained many chemical features unique to the eelgrass leaf metabolome. We identified four flavone aglycones as key biomarkers distinguishing SW-V and SW-NV samples. Their drastically increased concentrations correlated with the lowest pathogen biomass, suggesting their role in pathogen regulation. These combined analytical and microbiological approaches indicate that flavones are defensive allelochemicals released into eelgrass meadows upon environmental stress and serve as potential bioindicators of eelgrass' sanitation effect.

Preparation of sulfonic acid functionalized metal organic frameworks and their application in the online solid phase extraction of parabens and sulfonamides in pre-cooked foods

Mixed-mode sorbents exhibit two or more primary retention mechanisms, which can enhance the selectivity and capacity of the extraction process in a single step. In this study, a facile approach was proposed to prepare functionalized metal-organic frameworks (MOFs) by post-synthetic oxidation. The composites could be varied independently for each processing step, resulting in four frameworks to meet different sample pretreatment requirements. Then, the fabricated MOFs were used as sorbents for the extraction and enrichment acidic and neutral compounds on an online solid phase extraction. The sorbents exhibited a dual retention mechanism combining hydrophilic-lipophilic balance and cation exchange interactions. Excellent linearity was observed over a range of 0.5-5000 μg kg-1 for the parabens and 10-50,000 μg kg-1 for the sulfonamides in pre-cooked foods. The detection limits were 0.02 and 1.27 μg kg-1, respectively. This method provided a novel mixed-mode framework for simultaneous determination of acidic and neutral compounds in complex samples.

Keywords

Sulfonic acid functionalized metal-organic frameworksParabensSulfonamidesOnline solid phase extractionPre-cooked foods.

Dynamic microbial community and metabolic profiling in refrigerated beef: Insights from diverse packaging strategies

Extending the shelf life of fresh beef is essential for meat industry. This study explored the microbial community succession, metabolic profile changes, and their interactions during refrigerated storage of beef under different packaging methods. The results showed that compared with air packaging (AP), vacuum packaging (CV) and vacuum skin packaging (VS) maintained higher microbial diversity over longer periods. Among 1,106 metabolites identified, lipids and lipid-like molecules were most prominent. Unique pathways in VS beef, such as oxidative phosphorylation and calcium signaling pathways, underscored its advantages in maintaining beef flavor and oxidation stability. Moreover, dozens of metabolites were identified as potential biomarkers of the treatment effects of different packaging methods. Correlation analysis presented a significant positive correlation between bacterial genera like Brochothrix, Acinetobacter, Serratia, and metabolites such as lipids, organic acids, and nucleotides. This research offers essential insights for optimizing product safety and extending shelf life in the future meat industry.

In situ encapsulation of capsaicinoids in MIL-88A as a food-grade nanopreservative for meat safety

The biocompatible MIL-88A metal-organic framework (MOF), synthesized from food-grade fumaric acid and ferric chloride, was introduced for the efficient one-step in situ encapsulation of capsaicinoids as a nanopreservative. The resulting MIL-88A@Caps nanoparticles can load 61.43 mg/g of capsaicinoids, surpassing conventional MOF-based encapsulation. The potent MIL-88A@Caps nanoformulations synergize the intrinsic antimicrobial properties of MIL-88A and capsaicinoids. At the same concentration (0.5 mg/mL), MIL-88A@Caps was highly effective against S. aureus and Salmonella, with inhibition rates of 94.90 ± 0.58% and 94.30 ± 1.24%, respectively, compared to MIL-88A (62.28 ± 5.04% and 70.46 ± 1.96%) and capsaicinoids (63.68 ± 1.25% and 49.53 ± 1.22%), respectively. Model precooked-chicken preservation experiments revealed that MIL-88A@Caps significantly delayed spoilage parameters compared to untreated samples, with more favorable viable counts (8.08 lgCFU/g), pH value (6.60 ± 0.02), TVB-N value (8.59 ± 0.21 mg/100 g), and color changes on day 9. Our findings yield a green nanopreservative for meat safety.

Untargeted-based metabolomics analysis and in vitro/in silico antiviral activity of extracts from Phyllanthus brasiliensis (Aubl.) Poir

INTRODUCTION

This study describes the molecular profile and the potential antiviral activity of extracts from Phyllanthus brasiliensis, a plant widely found in the Brazilian Amazon. The research aims to shed light on the potential use of this species as a natural antiviral agent.

METHODS

The extracts were analysed using liquid chromatography-mass spectrometry (LC-MS) system, a potent analytical technique to discover drug candidates. In the meantime, in vitro antiviral assays were performed against Mayaro, Oropouche, Chikungunya, and Zika viruses. In addition, the antiviral activity of annotated compounds was predicted by in silico methods.

RESULTS

Overall, 44 compounds were annotated in this study. The results revealed that P. brasiliensis has a high content of fatty acids, flavones, flavan-3-ols, and lignans. Furthermore, in vitro assays revealed potent antiviral activity against different arboviruses, especially lignan-rich extracts against Zika virus (ZIKV), as follows: methanolic extract from bark (MEB) [effective concentration for 50% of the cells (EC50 ) = 0.80 μg/mL, selectivity index (SI) = 377.59], methanolic extract from the leaf (MEL) (EC50  = 0.84 μg/mL, SI = 297.62), and hydroalcoholic extract from the leaf (HEL) (EC50  = 1.36 μg/mL, SI = 735.29). These results were supported by interesting in silico prediction, where tuberculatin (a lignan) showed a high antiviral activity score.

CONCLUSIONS

Phyllanthus brasiliensis extracts contain metabolites that could be a new kick-off point for the discovery of candidates for antiviral drug development, with lignans becoming a promising trend for further virology research.

Ex vivo study of molecular changes of stained teeth following hydrogen peroxide and peroxymonosulfate treatments

White teeth can give confidence and tend to be associated with a healthier lifestyle in modern society. Therefore, tooth-bleaching strategies have been developed, including the use of hydrogen peroxide. Recently, peroxymonosulfate has been introduced as an alternative bleaching method to hydrogen peroxide. Although both chemicals are oxidizing agents, their effects on the molecular composition of the stained teeth are yet unknown. In this study, the molecular profiles of teeth bleached with hydrogen peroxide and peroxymonosulfate were compared using Liquid Chromatography-Tandem Mass Spectrometry. Statistical analyses were used to assess the samples. In addition, reference spectral libraries and in silico tools were used to perform metabolite annotation. Overall, principal component analysis showed a strong separation between control and hydrogen peroxide and peroxymonosulfate samples (p < 0.001). The analysis of molecular changes revealed amino acids and dipeptides in stained teeth samples after hydrogen peroxide and peroxymonosulfate treatments. Noteworthy, the two bleaching methods led to distinct molecular profiles. For example, diterpenoids were more prevalent after peroxymonosulfate treatment, while a greater abundance of alkaloids was detected after hydrogen peroxide treatment. Whereas non-bleached samples (controls) showed mainly lipids. Therefore, this study shows how two different tooth-whitening peroxides could affect the molecular profiles of human teeth.

Ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomics reveals key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia in a hamster model

Polygonum cuspidatum is a homology of traditional medicine and functional food widely distributed around the world. Our previous study on the hyperlipidemic animal model demonstrated that Polygonum cuspidatum was effective in ameliorating hyperlipidemia, which is characterized by lipid disorders. Herein, the regulatory effect of Polygonum cuspidatum on lipid metabolism needs to be known if its hypolipidemic mechanism is desired to clarify. In this study, an ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomic strategy was first applied to investigate the lipidomic patterns of high-fat diet-induced hyperlipidemic hamsters when treated with Polygonum cuspidatum. The results showed that Polygonum cuspidatum improved the lipidomic profile of hyperlipidemia. A total of 65 differential lipids related to the hypolipidemic effect of Polygonum cuspidatum were screened out and identified, and these differential lipids covered various categories, such as phosphatidylcholines, phosphatidylethanolamines, triacylglycerols, sphingomyelins and so on. Orally administrated Polygonum cuspidatum restored these differential lipids back to normal or nearly normal levels. This study adopted lipidomics to reveal the key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia, which would provide a scientific basis for its clinical application.

Impact of dielectric barrier discharge cold plasma on the lipid oxidation, color stability, and protein structures of myoglobin-added washed pork muscle

Cold plasma has been considered a novel non-thermal processing technique and attracted a high attention by the food industry. In this study, the influences of dielectric barrier discharge cold plasma (DBD-CP) on the myoglobin (Mb)-added washed pork muscle (WPM) were evaluated. The electrophoresis pattern, autoxidation, and secondary structure of Mb were analyzed. The results found that DBD-CP caused the decrease of the redness and total sulfhydryl (T-SH) in WPM, while the increase of non-heme, peroxide value (PV), and thiobarbituric acid reactive substances (TBARS), suggested that treatment triggered protein oxidation and heme degradation. Additionally, DBD-CP treatment enhanced the autoxidation of Mb, induced the release of intact heme from the globin, rearranged the charged groups, and promoted Mb aggregation. The transformation of α-helix into the random coil of Mb demonstrated that DBD-CP weakened the tensile strength. Overall, data indicated that DBD-CP promoted autoxidation and changed the secondary structure of Mb, accelerating Mb-mediated lipid oxidation in WPM. Thus, further studies about the optimization of processing conditions by DBD-CP need to be performed.

Comparative phytochemical analysis of Ferula assa-foetida with Ferula jaeschkeana and commercial oleo-gum resins using GC-MS and UHPLC-PDA-QTOF-IMS

Ferula assa-foetida is an important species of the genus Ferula, best known for its oleo-gum resin, mainly used as a flavoring agent. Ferula jaeschkeana is another Himalayan medicinal plant of this genus, known for its contraceptive effect but not used in food applications. This study aimed to do a detailed phytochemical analysis of F. assa-foetida growing under controlled conditions in India using GC-MS/headspace and UHPLC-PDA-QTOF-IMS. Further, a comparative analysis of F. assa-foetida was performed with F. jaeschkeana (collected from its natural habitat) and commercial samples of F. assa-foetida oleo-gum resin (collected from the local market). UHPLC-QTOF-IMS profiling of F. assa-foetida led to the identification of foetisulfide C, assafoetidnol A, gumosin, flabellilobin (A/B), and foetisulfide A. In total, 141 metabolites were identified, including vitamins, nucleosides, sulfur compounds, flavonoids, sugars derivatives, and others, using METLIN database. Serine, arginine, asparagine, isoleucine, and phenylalanine were major amino acids quantified among the samples for the nutritional aspect. Characteristic sulfurous compounds (n-propyl-sec-butyl disulfide, trans-propenyl-sec-butyl disulfide, cis-propenyl-sec-butyl disulfide, and bis[1-(methylthio)propyl] disulfide) were identified in all samples except F. jaeschkeana. PCA and cluster analysis showed a significant difference in the volatile constituents of rhizomes of both species. Metabolomics studies also revealed the association of sesquiterpenoid and triterpenoid biosynthesis, phenylpropanoid, flavon, and flavanol biosynthesis. The current study demonstrates, "why only F. assa-foetida is used in culinary applications instead of F. jaeschkeana"?

MS-FINDER Assisted in Understanding the Profile of Flavonoids in Temporal Dimension during the Fermentation of Pu-erh Tea

Flavonoid represents a significant class of secondary metabolites in Pu-erh tea with benefits to human health. For a rapid and complete discovery of such compounds, we established a data mining workflow that integrates software MS-DIAL, MS-FINDER, and molecular networking analysis. As a result, 181 flavonoids were tentatively annotated including 22 first found in Pu-erh tea, and two of them were potentially new molecules. The dynamic alteration of these flavonoids during Pu-erh fermentation was further investigated. They all showed a trend of first increasing and then decreasing. Moreover, statistical analysis showed that the first to third pile turnings of the fermentation process had a greater impact on the changes of flavonoids. Partial metabolic pathways were proposed. This study provides a quick and automatic strategy for flavonoid profiling. The temporal dimension of flavonoids during fermentation may serve as a theoretical basis for Pu-erh tea manufacturing technology and study on substance foundation.

Protective effects of chlorogenic acid on the meat quality of oxidatively stressed broilers revealed by integrated metabolomics and antioxidant analysis

Oxidation is a major cause of meat quality deterioration during broiler production, which leads to undesirable meat color and impaired water holding capacity (WHC), thereby impacting consumer appeal and satisfaction. Chlorogenic acid (CGA), a natural phenolic acid, is regarded as a potential, safer and healthier antioxidant to improve meat quality. To investigate the protective effects of CGA on the meat quality of oxidatively stressed broilers, 240 one-day-old male Cobb broiler chickens were allocated to four treatments: basal diet (control group), basal diet + dexamethasone (DEX) injection (DEX group), basal diet containing 500 mg kg^-1 CGA (CGA group), and basal diet containing 500 mg kg^-1 CGA + DEX injection (DEX_CGA group). Meat quality, antioxidant capacity, the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, and metabolomic profile were detected in the breast muscle of broilers. Then, correlation analysis between meat quality and antioxidant capacity, antioxidant-related genes, and metabolites was performed. The results indicated that CGA supplementation improved the growth performance and meat quality traits (pH, WHC, and meat color) and enhanced the antioxidant enzyme activity by activating the Nrf2 pathway in the breast muscle of oxidatively stressed broilers. A total of 619 metabolites were identified, among which 93 differential metabolites were found between control and DEX groups, and 65 differential metabolites were observed between DEX and DEX_CGA groups. Breast metabolic profiles were changed by DEX treatment, while CGA supplementation could normalize the metabolic changes in DEX-challenged broilers. Metabolic pathway analysis revealed that most of the differential metabolites between DEX and DEX_CGA groups were involved in pyrimidine/purine, propanoate and phenylalanine metabolism, primary bile acid biosynthesis, and lysine metabolism, which may contribute to explain the protective effects of CGA on meat quality. Moreover, according to the correlation analysis, four metabolites were identified as potential biomarkers to predict the meat quality. In conclusion, our findings demonstrate that CGA is an effective, natural and safe antioxidant to enhance the quality of meat from intensive industrial poultry production.

Impact of Plasma-Activated Water Treatment on Quality and Shelf-Life of Fresh Spinach Leaves Evaluated by Comprehensive Metabolomic Analysis

Fresh baby spinach leaves are popular in salads and are sold as chilled and plastic-packed products. They are of high nutritional value but very perishable due to microbial contamination and enzymatic browning resulting from leaf senescence. Therefore, innovative food processing methods such as plasma-activated water (PAW) treatment are being explored regarding their applicability for ensuring food safety. PAW’s impact on food quality and shelf-life extension has, however, not been investigated extensively in vegetables so far. In the present study, a comprehensive metabolomic analysis was performed to determine possible changes in the metabolite contents of spinach leaves stored in a refrigerated state for eight days. Liquid chromatography high-resolution mass spectrometry, followed by stringent biostatistics, was used to compare the metabolomes in control, tap-water-rinsed or PAW-rinsed samples. No significant differences were discernible between the treatment groups at the beginning or end of the storage period. The observed loss of nutrients and activation of catabolic pathways were characteristic of a transition into the senescent state. Nonetheless, the presence of several polyphenolic antioxidants and γ-linolenic acid in the PAW-treated leaves indicated a significant increase in stress resistance and health-promoting antioxidant capacity in the sample. Furthermore, the enhancement of carbohydrate-related metabolisms indicated a delay in the senescence development. These findings demonstrated the potential of PAW to benefit food quality and the shelf-life of fresh spinach leaves.