Egg products after thermal treatment possess a unique flavor and are favored by consumers. In this study, the key aroma-active compounds of egg yolk products and their formation mechanism during thermal treatment were investigated. The volatile aroma compounds in egg yolks were monitored using an electronic nose, gas chromatography-mass spectrometry (GC–MS) and gas chromatography–olfactometry–mass spectrometry (GC–O–MS), and the lipid molecular species were explored using ultra-high-performance liquid chromatography– mass spectrometry with a Q-Exactive HF-X Orbitrap (UPLC-Q-Exactive HF-X). A total of 68 volatile compounds were identified. Boiled eggs mainly derived their flavor from hexanal, 2-pentyl-furan, 2-butanone, 3-methyl-butanal and heptane. Meanwhile, fried eggs relied mainly on 14 compounds, the most important of which were 2-ethyl-3-methyl-pyrazine, 3-ethyl-2,5-dimethyl-pyrazine, 2-ethyl-3,5-dimethyl-pyrazine, nonanal and 2,3-diethyl-5-methyl-pyrazine, providing a baked and burnt sugar flavor. A total of 201 lipid molecules, belonging to 21 lipid subclasses, were identified in egg yolks, and 13 oxidized lipids were characterized using a molecular network. Phosphoethanolamines (PEs) containing polyunsaturated fatty acids were the primary flavor precursors contributing to the development of egg yolks’ flavor, participating in lipid oxidation reactions and the Maillard reaction and regulating the production of aldehydes and pyrazine compounds. This study provides reference and guidance for the development of egg yolk flavor products.

Type 2 diabetes mellitus (T2DM) has developed into an important health concern worldwide. The discovery of phlorotannins and their efficacy in the treatment of T2DM has become a hotspot for research in various fields. In this study, the potential phlorotannins and mechanism of six brown algae against T2DM were in-depth investigated using biological activity assays, LC-MS, and network pharmacology. First, the ethyl acetate fraction (EA frac.) showed high polyphenolic content and possessed significantly antioxidant and enzyme inhibitory abilities. Further, a total of fifty-nine peaks were obtained from six EA fracs. via UPLC-QE-MS/MS analysis, and fifteen of them were identified as phlorotannins and their isomers or derivatives. In detail, the chemical structures of six phlorotannins were inferred as dibenzodioxine-1,3,6,8-tetraol, bifuhalol, dioxinodehydroeckol, eckol, fucofurodiphlorethol, and fucotriphlorethol; three phlorotannin isomers were deduced to be fucophlorethol, trifucol, triphlorethol A, or triphlorethol B; and the phlorotannin derivative of m/z 263 was determined to be dibenzodioxine-1,2,3,6,8-pentanol or dibenzodioxine-1,2,4,5,7-pentanol. Moreover, 43 T2DM-related targets acted on by these chemicals were identified, and the function of phlorotannin to prevent and treat T2DM was elucidated in a holistic way based on the established compound-target-disease network, and GO function and KEGG pathway enrichment analysis.

Sulfur fumigation, as a highly effective method for preservation and appearance enhancement, has been widely applied in fruits, vegetables, and food products. However, excessive sulfur fumigation can pose safety risks. Currently, there is limited research on the bound sulfites produced by sulfur fumigation, and no consensus has been reached regarding their structure and toxicity. Using ultra-performance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS), a total of 34 compounds were identified in 12 lily bulb samples subjected to different sulfur fumigation durations. These derivatives were all hypothesized to form via nucleophilic addition to carbon–carbon double bonds. Based on multivariate statistical analysis, 9 characteristic markers were established to rapidly differentiate between non-fumigated (NF) and sulfur-fumigated (SF) samples. The practicality of this strategy was validated using 18 commercial batches. Molecular docking simulations predicted that the modifications might enhance toxicity toward liver injury-related targets, both by altering the spatial conformation of the compounds and because the sulfonic acid group itself serves as an ideal hydrogen-bond acceptor. Overall, mild fumigation led to a gradual accumulation of free sulfur dioxide in lily bulbs, increased the total content of phenolic components and antioxidant capacity, and did not generate excessive bound sulfur dioxide. However, with further extension of fumigation time, the content of sulfur-containing derivatives rose rapidly, accompanied by a noticeable decline in antioxidant activity. This study elucidates the sulfur-driven chemical transformation mechanisms in lily bulbs and establishes a targeted methodology for the quality control and safety assessment of processed herbal products.

This study aimed to screen lactic acid bacteria (LAB) with enhanced antioxidant activity and evaluate their potential as starter cultures for dry-cured fermented sausages by assessing their effects on oxidative stability and physicochemical quality during processing. The antioxidant activities of different cellular fractions of five LAB strains were first compared, and the results indicated that the antioxidant activity was mainly associated with extracellular metabolites. Based on their good in vitro antioxidant activities and oxidative tolerance, Leuconostoc carnosum AMS1 and Lactiplantibacillus plantarum P4 were subsequently selected as starter cultures for sausage fermentation. Individual inoculation with AMS1 and P4 modulated the bacterial community structure during fermentation and reduced the abundance of opportunistic pathogens. Compared with the uninoculated control, starter inoculation accelerated acidification, reduced water activity, and positively modulated color and texture properties. Moreover, inoculation improved oxidative stability, as indicated by reduced thiobarbituric acid reactive substances (TBARS) levels and lipoxygenase (LOX) activity, and alleviated protein oxidative changes, as evidenced by lower carbonyl accumulation, reduced sulfhydryl group loss, and a lower increase in surface hydrophobicity. In conclusion, AMS1 and P4, particularly AMS1, showed potential as antioxidative starter cultures for dry-cured fermented sausages by improving physicochemical quality and oxidative stability during fermentation and maturation.