Chen Chen

Sufu, a traditional Chinese fermented soybean product, is known for its unique flavor, creamy texture, and rich nutrition, earning it the nickname “Oriental cheese” in the West. However, spontaneous fermentation often results in a monotonous flavor, insufficient floral/fruity volatile organic compounds (VOCs), and a tendency to develop off‐flavors. Here, Leuconostoc lactis C2/15 was used as an auxiliary starter to investigate its role in flavor formation from a sensomics perspective. VOCs were characterized using headspace solid‐phase microextraction coupled with gas chromatography–tandem mass spectrometry (HS‐SPME‐GC‐MS/MS), sensory evaluation, odor activity value (OAV) calculation, and aroma recombination and omission experiments. Inoculation with L. lactis C2/15 significantly promoted the accumulation of volatile compounds, resulting in a 2.2‐fold increase in total VOCs at the 35d stage, with ethyl butyrate showing a 56‐fold increase. Furthermore, 22 key VOCs (OAV > 1) were identified in the auxiliary group (including 13 newly emerged compounds, while 3 found in the spontaneous group were absent), compared to only 13 in the spontaneous group. Aroma recombination and omission experiments validated six VOCs as the core contributors to the overall aroma. Comprising primarily 1‐octen‐3‐ol, phenethyl alcohol, ethyl 2‐methylbutyrate, ethyl acetate, phenylacetaldehyde, and 2‐pentylfuran, these odorants synergistically imparted rich fruity, floral, and roasted characteristics. The formation of these key volatiles was closely linked to carbohydrate metabolism, amino acid catabolism, lipid oxidation, and subsequent esterification. Overall, this sensomics‐based study provides molecular‐level insights into flavor regulation, offering a practical basis for deploying targeted starter cultures to standardize sufu production. Practical Applications: Traditional spontaneously fermented sufu is appreciated for its characteristic traditional flavor; however, the formation of desirable fruity and floral aroma compounds can be limited during spontaneous fermentation. Using Leuconostoc lactis C2/15 as an auxiliary starter effectively enhanced the formation of ester and alcohol compounds, contributing to more pronounced fruity and floral notes. This starter enables manufacturers to produce sufu with an enhanced and differentiated aroma profile and strengthen market competitiveness.

Fenpropathrin (FPT) residues in tea pose a threat to consumers’ health. Lateral flow immunoassay (LFIA) offers a rapid and convenient approach for FPT detection. However, existing LFIA formats, particularly those employing fluorescent nanoparticles, are susceptible to interference from the tea matrix’s endogenous fluorescence, limiting their accuracy for FPT analysis. Here, two complementary LFIAs based on gold nanoparticle (AuNP) and carbon nanoparticle (CNP) tags were developed, both of which avoid matrix fluorescence effects due to their intrinsic coloration under ambient light. We systematically evaluated five cleanup materials and identified polyvinylpolypyrrolidone as the optimal cleanup material. Following PVPP-based purification, green tea extracts required only a four-fold dilution prior to LFIA analysis, effectively minimizing matrix interferences, such as tea polyphenols, and enhancing assay robustness and sensitivity. The visual limit of detection was 0.64 μg/g and a quantitative limit of detection (qLOD) was 0.11 μg/g for FPT in green tea using the AuNP-based LFIA. The CNP-based LFIA further improved sensitivity, with a visual limit of detection of 0.16 μg/g and a qLOD of 0.017 μg/g, a 6.4-fold enhancement in qLOD compared to the AuNP assay. Together, these two assays provide an efficient and accurate strategy for on-site screening of FPT residues in green tea.

4,4′-dinitrocarbanilide (DNC) is a key component and marker residue of nicarbazin, which forms residues in edible tissue and then causes nephrotoxicity and hepatotoxicity in humans if used excessively. To simplify sample preparation and monitor the DNC rapidly and accurately, a comparable icELISA and lateral flow immunoassay (LFIA) was developed in this study. Briefly, the reaction parameters were explored for improving the sensitivity of icELISA and LFIA. Under the optimal conditions, methanol was selected as the extracting solvent for DNC in chicken, and 20- and 10-fold dilutions of sample extraction eliminated the matrix effect for icELISA and LFIA, separately. After sample pretreatment, the analysis properties of icELISA and LFIA were compared. The limit of detection of icELISA for DNC was 0.8 μg/kg, and the visual and quantitative limits of detection of LFIA were 8 and 2.5 μg/kg. Compared with icELISA, LFIA showed lower sensitivity but obvious advantages in terms of matrix tolerance and detection time (within 15 min). The sensitivity, specificity, and accuracy of the developed assays satisfied the detection requirement even if using simple sample pretreatment. This comparable icELISA and LFIA provided mutual verifiability methods for the accurate detection of DNC in chicken.