In this paper, a novel and ultrasensitive lateral flow assay (LFA) based on aptamer–magnetic separation, and multifold Au nanoparticles (AuNPs) was developed for visual detecting Salmonella enterica ser. Typhimurium (S. Typhimurium). The method realized magnetic enrichment and signal transduction via magnetic separation and achieved signal amplification through hybridizing AuNPs–capture probes and AuNPs–amplification probes to form multifold AuNPs. Two different thiolated single-strand DNA (ssDNA) on the AuNPs–capture probe played different roles. One was combined with the AuNPs–amplification probe on the conjugate pad to achieve enhanced signals. The other was connected to transduction ssDNA1 released by aptamer–magnetic capture of S. Typhimurium, and captured by the T-line, forming a positive signal. This method had an excellent linear relationship ranging from 8.6 × 10² CFU/mL to 8.6 × 10⁷ CFU/mL with the limit of detection (LOD) as low as 8.6 × 10⁰ CFU/mL in pure culture. In actual samples, the visual LOD was 4.1 × 10² CFU/mL, which did not carry out nucleic acid amplification and pre-enrichment, increasing three orders of magnitudes than unenhanced assays with single–dose AuNPs and no magnetic separation. Furthermore, the system showed high specificity, having no reaction with other nontarget strains. This visual signal amplificated system would be a potential platform for ultrasensitive monitoring S. Typhimurium in milk samples.

Ultra-high temperature sterilized milk (UHT) is a popular dairy product known for its long shelf life and convenience. However, protein gel aging and fat quality defects like creaming and flavor deterioration may arise during storage. These problems are primarily caused by thermostable enzymes produced by psychrotrophic bacteria. In this study, four representative psychrotrophic bacteria strains which can produce thermostable enzymes were selected to contaminate UHT milk artificially. After 11, 11, 13, and 17 weeks of storage, the milk samples, which were contaminated with Pseudomonas fluorescens, Chryseobacterium carnipullorum, Lactococcus raffinolactis and Acinetobacter guillouiae, respectively, demonstrated notable whey separation. The investigation included analyzing the protein and fat content in the upper and bottom layers of the milk, as well as examining the particle size, Zeta potential, and pH in four sample groups, indicating that the stability of UHT milk decreases over time. Moreover, the spoiled milk samples exhibited a bitter taste, with the dominant odor being attributed to ketones and acids. The metabolomics analysis revealed that three key metabolic pathways, namely ABC transporters, butanoate metabolism, and alanine, aspartate, and glutamate metabolism, were found to be involved in the production of thermostable enzymes by psychrotrophic bacteria. These enzymes greatly impact the taste and nutrient content of UHT milk. This finding provides a theoretical basis for further investigation into the mechanism of spoilage.

Perilla (Perilla frutescens) seeds are emerging as a valuable resource for functional foods and medicines owing to their rich oil and protein content with diverse nutritional and health benefits. Perilla seed oil (PSO) possesses a high level of a-linolenic acid (ALA), a favorable ratio of unsaturated to saturated fatty acids, and other active ingredients such as tocopherols and phytosterols, which contribute to its antioxidant, anti-inflammatory, and cardiovascular protective effects. The balanced amino acid ratio and good functional properties of perilla seed protein make it suitable for a variety of food applications. The chemical composition, health benefits, and potential applications of PSO as well as the structural characterization, functional properties, modification methods, bioactivities, and application scenarios of perilla seed protein are comprehensively presented in this paper. Furthermore, the challenges as well as future prospects and research focus of PSO and perilla seed protein are discussed. The growing interest in plant-based diets and functional foods has made PSO and perilla seed protein promising ingredients for the development of novel foods and health products. The purpose of this paper is to highlight implications for future research and development utilizing these two untapped resources to improve human health and nutrition.

Salmonella typhimurium (S. typhimurium) is a foodborne pathogen that has caused numerous outbreaks worldwide, necessitating the development of on-site strategy to prevent early contamination. Here, we set up an enzyme-free strategy for aptamer-catalyzed hairpin assembly in which salt-induced aggregation of unmodified gold nanoparticles (AuNPs) served as a colorimetric signal output, allowing on-site detection of S. typhimurium in milk. The aptamer-functionalized magnetic beads were used as a vehicle of specifically enriching target bacteria which conjugated with target aptamer to trigger the “Y” shape catalytic hairpin assembly (Y-CHA) circuit. Due to the hairpins desorbing from the surface of AuNPs to the formation of a large amount of double-stranded DNA (dsDNA), AuNPs turned from dispersion to aggregation in the presence of S. typhimurium, resulting in a change of the colorimetric signal from red to blue-gray. The signal output showed a linear relationship for S. typhimurium over a concentration range of 10² to 10⁶ CFU/mL, with a sensitivity of 2.4 × 10² CFU/mL under optimal conditions. The visual protocol has excellent selectivity even in the presence of other competitive bacteria and has been validated in real milk samples with a sensitivity of 2.8 × 10³ CFU/mL.

The aim of this work was to systematically evaluate the effects of Lion’s Mane Mushroom powder (LMM, 0–40%) on the physicochemical properties, structural characteristics, and flavor profile of soy protein isolate-based high-moisture meat analogues (HMMAs). Optimal incorporation of 20% LMM significantly enhanced product quality by acting as a secondary phase that inhibited lateral protein aggregation while promoting longitudinal alignment, achieving a peak fibrous degree of 1.54 with dense, ordered fibers confirmed by scanning electron microscopy. Rheological analysis showed that LMM improved viscoelasticity (G′ > G″) through β-glucan; however, excessive addition (≥30%) compromised structural integrity due to insoluble dietary fiber disrupting protein network continuity, concurrently reducing thermal stability as denaturation enthalpy (_ΔH) decreased from 1176.6 to 776.3 J/g. Flavor analysis identified 285 volatile compounds in HMMAs with 20% LMM, including 98 novel compounds, and 101 flavor metabolites were upregulated. The mushroom-characteristic compound 1-octen-3-ol exhibited a marked increase in its Relative Odor Activity Value of 18.04, intensifying mushroom notes. Furthermore, LMM polysaccharides promoted the Maillard reaction, increasing the browning index from 48.77 to 82.07, while β-glucan induced a transition in protein secondary structure from random coil to β-sheet configurations via intramolecular hydrogen bonding. In conclusion, 20% LMM incorporation synergistically improved texture, fibrous structure, and flavor complexity—particularly enhancing mushroom aroma. This research offers valuable insights and a foundation for future research for developing high-quality fungal protein-based meat analogues

This work explores the impact of ergosterol (ERG) addition (0%, 0.5%, 1.0%, 1.5%, and 2.0%) on the physicochemical properties, conformational changes, and digestive characteristics of soy protein isolate (SPI) and wheat gluten (WG) processed by high-moisture extrusion. The results demonstrated that the incorporation of ERG significantly reduced the apparent viscosity and dynamic moduli of the feedstock system, enhancing melt fluidity and consequently reducing extrusion torque, die pressure, and specific mechanical energy. An appropriate amount of ERG (1.0%) effectively facilitated the development of a distinct fibrous morphology, increased the fibrous degree, lightened the color, and softened the texture. However, excessive addition weakened the fibrous structure due to excessively high fluidity. ERG influenced protein aggregation behavior through hydrophobic interactions, reduced thermal stability, and induced a transition in secondary structure from β-turns to α-helices. The in vitro digestibility initially decreased and then increased, with the lowest value observed at 1.0% ERG. This study indicates that ERG can elevate the performance and value of extruded products by modulating protein structure and rheological behavior, providing a theoretical basis for its application in plant-based meat analogue products.