Effects of shaking and fermentation processing technologies on polyphenols and volatile compounds in black tea.

To investigate the effects of different processing techniques on polyphenols and volatile compounds (VOCs) of black tea (BT), gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry were used to analyze BT samples with different processing techniques, including fermentation degree, shaking times, and drying temperature. In this study, a total of 220 polyphenols were annotated by database, and 38 polyphenols were annotated by mass spectrometry molecular network. A total of 43 VOCs were annotated by a database combined with a retention index.

Untargeted metabolomics combined with lipidomics revealed the effects of myocardial infarction and exercise rehabilitation on blood circulation metabolism of patients based on liquid chromatography-mass spectrometry.

Myocardial infarction (MI) is a major cause of death worldwide. Exercise rehabilitation (ER) is a powerful tool to improve life quality and prognosis of MI patients. Herein, we developed an untargeted metabolomics combined with lipidomics method to qualitatively and quantitatively detect metabolites in plasma.

Predicting Precursor Ions Combined with Fragmentation Pathway for Screening and Identification of Flavan-3-ol Oligomers in Tea (. var. ).

Flavan-3-ol oligomers (FLOs), including proanthocyanidins (PAs) and theasinensins (TSs), contribute greatly to the flavor and bioactivity of the tea beverage. Ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry has been widely used in profiling a wide range of compounds in tea. However, the detection and identification of FLOs with low concentration and high structural diversity remain meaningful yet challenging work.

Surface encapsulation of ZIF-8 on Ag nanoparticles modified cotton swab for highly rapid and selective surface-enhanced Raman spectroscopy analysis of glucose and lactic acid in human sweat.

Herein, ZIF-8 shell encapsulated Ag nanoparticles decorated cotton swab (CS@Ag@ZIF-8) was firstly designed and prepared for highly rapid and selective surface-enhanced Raman spectroscopy (SERS) analysis of glucose and lactic acid in human sweat. The CS not only act as support matrix for Ag modification and ZIF-8 encapsulation, but also provide great potential in-situ analysis of human sweat with low cost. The as-developed CS@Ag@ZIF-8 shows high SERS activity owing the good adsorption of ZIF-8 shell and electromagnetic enhancement of AgNPs.

Mannoproteins modulate olfactrory perception and copigmentation of organoleptic-active-components in wines: Effects and potential molecular mechanisms.

In this research, accelerated aroma release experiments and malvidin-3-O-glucoside copigmentation experiments in model red wine solutions were designed to investigate the abilities and molecular mechanisms of mannoproteins in modulating olfactory/chromatic properties of red wines. Results indicate that under orthonasal condition, mannoprotein MP2 was promising aroma modulator due to its predictable behaviors in expelling and retaining the aroma compounds during different periods. Low field nuclear magnetic resonance and molecular dynamic simulation proved that the modulation ability of MP2 should be explained by its transitionary interacting preferences with water/aroma compound molecules.

Organoleptic modulation functions and physiochemical characteristics of mannoproteins: Possible correlations and precise applications in modulating color evolution and orthonasal perception of wines.

Mannoproteins have traditionally been recognized as effective wine organoleptic modulators, however, ambiguous understanding of the relationship between their organoleptic functions and physiochemical characteristics often lead to inappropriate application in winemaking. To reveal the possible role the physiochemical characteristics of mannoproteins play in modulating wine color and aroma properties, three water-soluble mannoproteins (MP1, MP2, MP3) with different physiochemical characteristics have been prepared, and accelerated red wine aging, malvidin pigments formation experiments, accelerated aroma release experiments have been designed to observe their organoleptic modulating functions in this research. Results suggest that the phenolic/chromatic stability of red wines could be enhanced by MP3, probably due to its low steric hindrance potential, high reactivity, and good hydro-alcoholic stability conferred by its high Mannan/Glucan ratio (8.

Combinatory data-independent acquisition and parallel reaction monitoring method for revealing the lipid metabolism biomarkers of coronary heart disease and its comorbidities.

Disorders of lipid metabolism are a common cause of coronary heart disease (CHD) and its comorbidities. In this study, ultra-performance liquid chromatography-high-resolution mass spectrometry in data-independent acquisition (DIA) mode was applied to collect abundant tandem mass spectrometry data, which provided valuable information for lipid annotation. For the lipid isomers that could not be completely separated by chromatography, parallel reaction monitoring (PRM) mode was used for quantification.

Aroma and taste analysis of pickled tea from spontaneous and yeast-enhanced fermentation by mass spectrometry and sensory evaluation.

Anaerobically fermented pickled tea (PT) can be produced by spontaneous fermentation (SF) or yeast-enhanced fermentation (YF). Aroma and taste characteristics of PT during YF and SF were investigated using sensory evaluation, odour activity, aroma character impact values, HS-SPME-GC-MS, UPLC-QQQ-MS/MS, and spectrophotometry, annotating 198 volatile and 115 non-volatile components. The main contributing volatile components were β-ionone, and 1-octanol, promoted by YF and SF, and yielding floral and fruity aromas respectively.

An antifouling electrochemical aptasensor based on a polydopamine-polyzwitterion copolymer for tetracycline analysis.

Matrix interference resulting from the nonspecific adsorption of non-target components, particularly proteins (fouling), onto sensor surfaces poses a persistent challenge in electrochemical detection of food hazards. The development of antifouling sensor surfaces presents a viable approach to mitigate nonspecific adsorption. In this study, a novel antifouling electrochemical aptasensor, utilizing a zwitterionic polymer, was developed for the sensitive, accurate, and selective detection of tetracycline (TC) in milk.

Development and comparison of parallel reaction monitoring and data-independent acquisition methods for quantitative analysis of hydrophilic compounds in white tea.

In the present work, parallel reaction monitoring (PRM) and data-independent acquisition (DIA) methods were developed for the accurate quantitation of amino acids, alkaloids nucleosides and nucleotides in tea. The quality peaks were significantly enhanced by optimizing the LC elution procedure, HCD voltage, MS resolution, and scanning event. Both methods were validated with good liner linearity (0.

Engineering an Antifouling Electrochemical Sensing Platform Based on an All-in-One Peptide and a Hierarchical β-BiO-Au Microsphere for Vancomycin Detection in Food.

Challenges associated with interference aroused by nonspecific attachment of foulants in the food matrix steered the development of sensor surfaces capable of antifouling capacity. In this study, an antifouling electrochemical sensing platform based on an all-in-one peptide (DOPA-PPPPEKDQDKKaa) with anchoring, antifouling, and recognition functions and a hierarchical β-BiO-Au microsphere was proposed for vancomycin (Van) detection in food. The β-BiO-Au with excellent conductivity was synthesized and introduced as an electrode modifier to accelerate electron transfer on the sensor surface, enhancing sensing response.

Analysis of Volatile Profile and Aromatic Characteristics of Raw Pu-erh Tea during Storage Based on GC-MS and Odor Activity Value.

Volatile constituents are critical to the flavor of tea, but their changes in raw Pu-erh tea (RAPT) during storage have not been clearly understood. This work aimed to investigate the volatile composition and their changes at various storage durations. The volatile profile of RAPT was determined using headspace solid-phase microextraction in combination gas chromatography-mass spectrometry.

Nontargeted screening of aldehydes and ketones by chemical isotope labeling combined with ultra-high performance liquid chromatography-high resolution mass spectrometry followed by hybrid filtering of features.

Aldehydes and ketones are important carbonyl compounds that are widely present in foodstuffs, biological organisms and human living environment. However, it is still challenging to comprehensively detect and capture them using liquid chromatography - mass spectrometry. In this work, a chemical isotope labeling (CIL) coupled with ultra-high performance liquid chromatography - high resolution mass spectrometry (UHPLC-HRMS) strategy was developed for the capture and detection of this class of compounds.

Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and odor activity value (OAV) to reveal the flavor characteristics of ripened Pu-erh tea by co-fermentation.

Introduction: Pu-erh tea is a geographical indication product of China. The characteristic flavor compounds produced during the fermentation of ripened Pu-erh tea have an important impact on its quality.

Methods: Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and odor activity value (OAV) is used for flavor analysis.

Mass defect filtering combined with molecular networking to profile flavonoids in citrus fruit based on liquid chromatography-high resolution mass spectrometry platform: Citrus sinensis (L.) Osbeck as a case study.

Citrus flavonoids are attracting great interest due to their well-known beneficial effects, but many of them have not been characterized. In this work, ultra-high liquid chromatography coupled to high resolution mass spectrometry (UHPLCHRMS) was used for profiling flavonoids in citrus fruit. We proposed a strategy combining mass defect filtering (MDF) and MS/MS-based molecular networking (MMN) to handle complex UHPLC-HRMS data.

[Comprehensive analysis of chemical constituents of tea flowers by ultra-performance liquid chromatography-high resolution mass spectrometry combined with integrated filtering strategy].

Tea flowers and fresh tea leaves are biological products of tea, but tea flower is often regarded as waste during tea production, resulting in notable waste of tea flower resources. At present, analysis of the chemical components in tea flowers focuses on single types of chemical components such as amino acids and tea polyphenols, and there are only a few reports on the simultaneous analysis of numerous chemical components in tea flowers. Researchers are not completely clear about the types and amounts of the chemical components in tea flowers; this has hindered the in-depth development and effective utilization of tea flowers.

Targeted identification of glycosylated flavones and isomers in green tea through integrated ion-filtering strategy and mass-fragmentation characteristics based on the UPLC-Q-Orbitrap-MS/MS platform.

Glycosylated flavones (GFs) are important components of green tea and have various structures and isomers. The annotation of GFs' chemical structures is challenging. Ultrahigh-performance liquid chromatography-high resolution mass spectrometry can provide informative mass ions for GF annotation.

Analysis of coloration characteristics of Tunisian soft-seed pomegranate arils based on transcriptome and metabolome.

In this study, combining metabolome and transcriptome, color related attributes and phenolic compositions of Tunisian pomegranate arils from 7 Chinese regions at same developing stage were studied. The total anthocyanin (TAC), flavonoids, and percent polymeric color (PPC) were ranged at 8.93-28.

Development and validation of an efficient HILIC-QQQ-MS/MS method for quantitative and comparative profiling of 45 hydrophilic compounds in four types of tea (Camellia sentences).

Hydrophilic constituents are significant for the taste and nutrition of tea, but their simultaneous quantification remains challenging due to the lack of efficient methods. Based on the hydrophilic interaction chromatography coupled with triple quadrupole-tandem mass spectrometry, this work developed and validated an efficient (8.5 min per run), sensitive (LOQ: 0.

Electrochemiluminescence sensor based on cyclic peptides-recognition and Au nanoparticles assisted graphitic carbon nitride for glucose determination.

A glucose (Glu) sensor was designed by introducing synthetic cyclic peptides (CPs) as recognition receptors and Au nanoparticles assisted graphitic carbon nitride (AuNPs/g-CN) for electrochemiluminescence (ECL) enhancement. The synthetic CP receptor (cyclo-[-CNDNHCRDNDC-]) with natural active center of Glu binding protein can mimic the interactions between Glu and Glu binding protein to specifically capture Glu. The AuNPs were reduced on g-CN and formed a new nanohybrid that can be applied as an ECL emitter.

Screening of lipid metabolism biomarkers in patients with coronary heart disease via ultra-performance liquid chromatography-high resolution mass spectrometry.

Coronary heart disease (CHD) has a high mortality worldwide. This study aimed to screen lipid metabolism biomarkers in patients with coronary heart disease via ultra-performance liquid chromatography-high resolution mass spectrometry. Extraction and reconstitution solvents, liquid chromatographic and mass spectrometry conditions were optimized to detect more plasma lipid metabolites.

Chemical profiling and discrimination of green tea and Pu-erh raw tea based on UPLC-Q-Orbitrap-MS/MS and chemometrics.

To reveal the characteristic chemical profiles of Pu-erh raw tea (PRT) and traditional green tea (TGT), a high-throughput analytical method based on UPLC-Q-Orbitrap-MS/MS was proposed. 145 components were characterized with a three-level qualitative strategy and the integrated filtering strategy combining nitrogen rule, mass defect, and diagnostic ions information. 124 components were quantified using an internal standard method.

Uncovering the antioxidant characteristics of black tea by coupling in vitro free radical scavenging assay with UHPLC-HRMS analysis.

Black tea (BT) is rich in dietary antioxidants, but its antioxidant composition has not been fully understood. To identify the true antioxidants occurring in BT, we established an approach based on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay coupled with ultra-high performance liquid chromatography-high resolution mass spectrometry (DPPH-UHPLC-HRMS). The employment of HRMS enable us to detect trace antioxidants, resolve co-eluted antioxidants, and characterize chemical structures of unknown antioxidants.

Plasma fatty acid metabolic profiling coupled with clinical research reveals the risk factors for atherosclerosis development in type 2 diabetes mellitus.

Many publications have reported that the incidence of atherosclerotic cardiovascular diseases is higher in patients with type 2 diabetes mellitus (T2DM) than in the non-diabetic population; however, until now, the reason has been unclear. In this study, 25 males (25/64, 39.06%) and 19 females (19/54, 35.