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Author(s): Xiaoyue Ji [sup.1] Author Affiliations: (1) grid.410625.4, 0000 0001 2293 4910, Advanced Analysis & Testing Center, Nanjing Forestry University, , 210037, Nanjing, P. R. China Vinegar, an indispensable acidic [...], Vinegar is a widely used acidic condiment in the world with wide varieties and different flavors. Aroma can be used as an important factor to measure the quality of vinegar and affect consumer acceptance. Volatile organic compounds provide different aroma characteristics of vinegar and have an important impact on the sensory quality. Solid-phase microextraction is an effective sample pretreatment technology which is widely used to determine volatile and semi-volatile organic compounds in various matrices. In recent years, solid-phase microextraction has made rapid development in vinegar flavor analysis, quality control and production. This review focuses on the application of solid-phase microextraction in the determination of volatile organic compounds in vinegar in recent years.

The inherent complexity of the human biological matrix and its importance in modern medical diagnosis and medical research promote the development of modern analytical technology. Solid-phase microextraction technology has been widely used in the treatment and analysis of different complex biological matrices due to its smaller sample size, simpler sample preparation and setting, and lower consumption of harmful chemicals. This review provides updated information on headspace solid-phase microextraction combined with gas chromatography technique applications, focusing on the analysis of volatile and semivolatile compounds in human biological matrices. The application of headspace solid-phase microextraction combined with gas chromatography techniques in human biological matrix analysis is mainly summarized into three aspects, namely, to discover biomarkers, to investigate volatile metabolomics, and to explore the effect of the external environment on volatile metabolomics of the human biological matrix. In addition, the frequently used statistical analytical methods are summarized, and the application prospect of solid-phase microextraction in the analysis of human biological matrices is proposed.

Objective: Fungal keratitis (FK) usually develops to a poor clinical prognosis due to the fungal invasion and excessive inflammatory reaction. In order to enhance the therapeutic effect of natamycin (NAT), we used the anti-inflammatory biological polysaccharide bletilla striata polysaccharide (BSP) combined with NAT to prepare a new eye drop —— oxidized bletilla striata polysaccharide-natamycin (OBN). Methods: UV-vis, FT-IR, and fluorescence spectroscopy were used to identify the synthesis of OBN. Biocompatibility of OBN was determined by CCK-8, scratch assay, and corneal toxicity test. RAW264.7 cells and C57BL/6 mice were stimulated with A. fumigatus and treated with PBS, OBN, or NAT. The anti-inflammatory activity of OBN was detected by RT-PCR and ELISA. In mice with FK, the clinical scores were used to evaluate the effect of OBN; HE staining was performed to assess the corneal pathological changes; MPO assay and immunofluorescence staining were used to investigate neutrophil infiltration. Results: OBN was synthesized by combining oxidized bletilla striata polysaccharide (OBSP) with NAT through Schiff base reaction. OBN did not affect cell viability at a concentration of 160 μg/mL in HCECs, RAW264.7 cells, and mouse corneas. OBN versus NAT significantly improved the prognosis of A. fumigatus keratitis by reducing disease severity, neutrophil infiltration, and expression of inflammatory factors in vivo. Additionally, OBN treatment down-regulated the mRNA and protein expression levels of inflammatory factors IL-1β, TNF-α, and IL-6 in RAW264.7 and mouse models. Conclusion: OBN is a compound prepared by covalently linking OBSP to the imino group of NAT through Schiff base reaction. OBN treatment down-regulated inflammation and improved the prognosis of mice with A. fumigatus keratitis. [ABSTRACT FROM AUTHOR]

AbstractThe utilization of celery seeds as seasonings and in herbal teas is widespread due to their significant nutritional and medicinal value. The determination of volatile organic compounds (VOCs) is a valuable tool for species identification and classification. Currently, there is an absence of information investigating the volatile constituents present in the cultivars of celery seeds. To analyze the varietal differences of celery seeds, VOCs were isolated using headspace solid-phase microextraction with by determination by gas chromatography-mass spectrometry. The samples underwent further comparison using multivariate statistical analysis to determine the changes in VOCs. Cluster analysis and principal component analysis were used to conduct correlation measurements on the samples. An orthogonal partial least squares discriminant analysis (OPLS-DA) model was developed to discriminate between samples and identify differential compounds. The distribution of these key compounds in these seeds was analyzed using a Sankey diagram. The samples contained 30 volatile components, mainly terpenes and esters. Correlation analysis revealed distinct variations in the VOCs. Furthermore, the utilization of the OPLS-DA model facilitated the identification of 11 differential compounds. The Sankey diagram illustrated significant disparities in the distribution patterns of these key compounds in the celery seeds. [ABSTRACT FROM AUTHOR]

Douchi is a highly appreciated product due to its unique flavor, high nutritional value, and health benefits. Douchi from different regions exhibits distinct characteristics. The objective of this study was to investigate the volatile profiles in douchi produced from different geographical origins using gas chromatography-mass spectrometry (GC-MS) and chemometrics. The volatiles were extracted by headspace solid-phase micro-extraction (HS-SPME) and subsequently determined by GC-MS. A comparative analysis was further conducted to identify the variations in volatile compounds among the samples. The correlation between the samples was investigated by employing cluster analysis (CA) and principal component analysis (PCA). An orthogonal partial least squares-discriminant analysis (OPLS-DA) model was established to discriminate samples from different regions and identify key differential compounds. A total of 46 volatile compounds were detected, among which terpenes, alcohols were the main compounds. Furthermore, 14 key differentiating compounds were screened out based on the OPLS-DA modle. The application of GC-MS combined with chemometrics offers a theoretical framework for douchi quality control and classification. [ABSTRACT FROM AUTHOR]

AbstractDeveloping robust analytical methodologies for the discrimination of craft and industrial beer presents a significant yet formidable challenge. The identification and differentiation of products necessitate the utilization of reliable analytical methods, which are indispensable for ensuring market stability and safeguarding consumer interests. In this study, representative samples with a significant market share were selected for headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis to compare the volatile substance characteristics of craft and industrial beers. The findings suggested that alcohols and esters constituted the primary volatiles. Craft beer exhibited a higher abundance of both types and concentrations compared to industrial beer. Subsequently, unsupervised and supervised chemometric techniques were employed for further analysis of the data matrix. An orthogonal partial least squares discriminant analysis (OPLS-DA) method was established to effectively discriminate between industrial and craft beers, enabling the identification of characteristic volatile markers. The untargeted GC-MS metabolomics coupled with multivariate statistical analysis holds promise for the authentication of craft and industrial beers. [ABSTRACT FROM AUTHOR]