Carbon quantum dots (CQDs) are readily enriched in organs due to their abundant functional groups, small particle size, and high water-solubility, however, their biological effects remain a controversial issue at present. In this study, CQDs were prepared by hydrothermal method with glycine and anhydrous D-glucose as raw materials, and their structure was characterized. Co-incubation of CQDs with Lactobacillus plantarum ATCC 8014 (L. plantarum ATCC 8014) revealed that as the concentration of CQDs increased, the scavenging effect of the fermentation supernatant from L. plantarum ATCC 8014 on ·OH, ·ABTS⁺ and ·DPPH decreased. After CQDs treatment, the cells exhibited morphological damage characterized by elongation, folding, fracture, and aggregation. Their tolerance to simulated gastrointestinal fluid was compromised, and the intracellular active substance lactate dehydrogenase leaked. Concurrently, the content of reactive oxygen species (ROS) in L. plantarum ATCC 8014 increased with the rising concentration of CQDs. The activity of antioxidases decreased, while the content of malondialdehyde (MDA), a product of lipid peroxidation, increased. Furthermore, the expression of antioxidant-related genes, including Gpx, Gsh and Cat, was down-regulated. These results suggest that exposure to CQDs adversely affects the growth of L. plantarum ATCC 8014 by inducing oxidative stress and compromising cell integrity.

Fecal microbial contamination in the food chain is a significant concern in the field of food safety as it is one of the most important pathways causing foodborne diseases. Microbial source tracking (MST) is an effective approach to address this issue, which can track the sources and contamination of fecal microbes. MST methods can be categorized into two types: library-dependent methods (LDMs) and library-independent methods (LIMs), with LIMs including culturedependent and culture-independent methods. The non-culture-dependent method using 16S rRNA and host-microbial interaction genes as specific molecular markers has been widely used to investigate microbial contamination in the food chain. This review provides an overview of the basic principle and characteristics of MST, and focuses on recent advances in MST methods based on host-specific molecular markers for tracing microbial contamination in the food chain. Furthermore, future prospects of MST are discussed based on its unique advantages and disadvantages.

Screening of unknown risks is a challenge for food regulation. However, there are still some limitations in screening unknown risk compounds with traditional methods. In this study, a toxic-oriented biomimetic platform, high-expression epidermal growth factor receptor cell membranes coated magnetic nanoparticles (EGFR/MCMNs), was innovatively applied to screen potential risk substances from food samples. EGFR/MCMNs were constructed by covalently immobilizing cell membranes on the magnetic nanoparticles (MNPs). The resultant EGFR/MCMNs exhibited satisfactory bioactivity, enough magnetic properties and excellent adsorption capacity, enabling accurate targeting of the possible substances. Ultimately, two potential risk compounds, BPA and BPAF, were successfully captured from the canned food of long-term placement. Their preliminary toxicology was further validated that the screened compounds could activate EGFR downstream signaling pathways and lead to cellular oxidative damage. This proposed method highlights the potential of toxic-oriented platforms for screening risk substances from complicated food matrices.

China is one of the countries with the greatest consumption of edible oils, and eating habits affect health. The effects of the four most commonly consumed vegetable oils/animal fat with different fatty acid compositions on physiological changes were studied in a mouse model via a multimodel metabolomics approach in this work. An advanced platform combining LC‒MS/MS and bioinformatics was utilized to study the differences in the lipids of oils. Subsequent multimodel metabolomics, including liver aqueous metabolomics, liver lipidomics, and DESI‒MSI analysis combined with biochemical assays and histological studies, revealed the shared and distinct physiological changes caused by the oils at the molecular level. Phenotypiccally, lard feeding resulted in the smallest weight gain, with no corresponding TAG accumulation in the plasma. The sunflowerseed oil- and rapeseed oil-fed treatments significantly increased plasma LACT and LDH levels. Consumption of all the types of oil/fat demonstrated a trend of increasing plasma ALT and AST levels. The palm oil-fed treatment affected the fewest biochemical indicators. At the metabolomic level, lard-fed treatment suggested a carnitine-related increase in mitochondrial fatty acid oxidation, an increase in the tricarboxylic acid cycle and the inhibition of glycolysis, while the rapeseed-fed treatment markedly upregulated purine metabolism. Lard-fed treatment upregulated glutamate levels and downregulated the levels of GSH indirect precursor substances acetylglycine and dimethylglycine, whereas treatment with other vegetable oils upregulated glutamine or the GSH precursor substances. From the perspective of lipidomics, vegetable oil treatments promoted TAGs and DAGs accumulation in the liver. Comsuption of lard showed a trend of adjusting the abnormal metabolism of LPCs, SMs and PGs. All the oil/fat-fed treatments reduced the levels of PIs, PCs, and PEs. The changes in the metabolomics and lipidomics affected oxidative homeostasis, with the consumption of lard and rapeseed oil showing the most significant negative impact on the redex index.The present study can provide a reference for the nutritional evaluation of edible oils.