Bacillus cereus is an important food-borne pathogenic bacteria and a putrid microorganism in the dairy industry. Raw and pasteurized buffalo milk play important roles in the dairy market in southwestern China. However, the reports on the prevalence and characterization of B. cereus strains isolated from the above sources are lacking. In this study, 150 raw buffalo milk samples and 300 pasteurized buffalo milk samples were collected from 3 provinces in southwestern China. The genotype, virulence gene distribution, antibiotic resistance, and biofilm-forming ability of isolates were analyzed. Ninety-six B. cereus strains were isolated and identified: 50 isolates (33.3%) from buffalo raw milk and 46 isolates (15.3%) from pasteurized buffalo milk. These strains were classified into 41 sequence types (ST) and 5 groups, of which ST857 was the predominant ST. The detection rates of virulence genes nheABC cluster, hblACD cluster, cytK, bceT, entFM, hlyII, and cesB were 89.6%, 13.5%, 64.6%, 71.9%, 84.4%, 62.5%, and 6.25%, respectively. The antimicrobial susceptibility testing showed that more than 90% of the isolates were susceptible to gentamicin, chloramphenicol, ciprofloxacin, erythromycin, vancomycin, and tetracycline, as well as resistant to ampicillin, cefepime, oxacillin, and rifampin. The results of biomass biofilm evaluation of the isolates on the stainless-steel tube showed that the optical density values at a wavelength of 595 nm of all strains in group I were greater than 1, with the strongest overall biofilm-forming ability among 5 groups, and the overall biofilm-forming ability of group III was the weakest. There was a relationship between the biofilm-forming ability and phylogenetic relationship of B. cereus strains. Taken together, our findings are the first to report the contamination situation and characterization of B. cereus isolated from raw and pasteurized buffalo milk in southwestern China as well as indicate the potential risk posed by this pathogen to dairy industry and public health.

The purpose of this study was to elucidate the antibacterial activity and possible mechanism of action of Amaranthus tricolor crude extract (ATCE) against Cronobacter sakazakii isolated from powdered infant formula (PIF). The antibacterial activity of ATCE was assessed by measuring the diameter of inhibition zone (DIZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The possible mechanism of action of ATCE was revealed by analyzing the effects of ATCE on growth curves and changes in cell membrane potential, intracellular pH, content of bacterial protein and genomic DNA, and cell morphology. Finally, ATCE was applied to the disinfection of C. sakazakii in biofilm on stainless steel tube. The results showed that the DIZ, MIC, and MBC of ATCE against C. sakazakii strains were from 14.35 ± 0.67 to 14.84 ± 0.67 mm, 20 mg/mL, and 40 mg/mL, respectively. Treatment with ATCE ended the logarithmic growth phase of C. sakazakii, and led to depolarization of the cell membranes, reducing intracellular pH and bacterial protein and genomic DNA contents, and resulting in cytoplasmic leakage and deformation. In addition, ATCE effectively inactivated C. sakazakii in biofilm, reducing viable bacteria by approximately 6.5 log cfu/mL bacterial count after treatment with 1 MIC (1 MIC = 20 mg/mL) of ATCE for 20 min at 25°C. Our findings showed that ATCE inactivated C. sakazakii strains isolated from PIF and has potential as a natural disinfectant to reduce the contamination of PIF by C. sakazakii.

This study systematically compared spray drying (SD) and freeze drying (FD) for microencapsulating Idesia polycarpa oil using a soy protein isolate/maltodextrin (SPI/MD) wall system. SD produced predominantly spherical and compact microcapsules with higher solubility (51.33%), encapsulation efficiency (81.9%), and superior oxidative stability (oxidation induction period, 6.05 h), together with improved thermal resistance, indicating its suitability for applications requiring enhanced stability and aroma retention. In contrast, FD yielded irregular and porous microcapsules with significantly higher emulsifying activity (29.12 m² g⁻¹, p < 0.05) but lower solubility and encapsulation efficiency. Integrated physicochemical characterization-including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), particle size and polydispersity index (PDI), ζ-potential, differential scanning calorimetry (DSC), oxidative stability index (OSI) measurements, and volatile profiling via odor activity value (OAV) analysis—revealed clear process-dependent structure–function relationships. The denser SPI/MD matrix formed during SD restricted lipid molecular mobility and oxygen diffusion, thereby suppressing lipid oxidation and promoting the retention of key lipid-derived odorants. Conversely, the porous structure generated by FD facilitated interfacial functionality but increased molecular diffusion pathways. Overall, this work demonstrates that SPI/MD-based microencapsulation functions as a molecular stabilization platform for highly unsaturated plant oils and provides mechanistic guidance for selecting drying strategies to tailor Idesia polycarpa oil microcapsules for specific food applications.

This study provides the first comparative analysis of the physicochemical and functional properties of oil body suspensions derived from different parts—entire fruit (EOB), peel (POB), and seed (SOB)—of Idesia polycarpa Maxim (IPM) during in vitro simulated gastrointestinal digestion. Results demonstrated that the properties of the different suspensions exhibited significant difference during digestion stages. The average particle size of all suspensions decreased, with the most significant reduction observed in POB (91.50%), which was attributable to its lower interfacial protein content and inferior stability. The absolute ζ-potential decreased in the model of gastric digestion (MGD) due to interface disruption but increased in the model of intestinal digestion (MID) following the adsorption of bile salts. Throughout the simulated digestion process, the protein hydrolysis degree, free fatty acid (FFA) release rate, reducing power, and inhibition rates against α-amylase and α-glucosidase all increased, concurrently with a decrease in DPPH radical scavenging activity. Notably, the POB suspension exhibited the highest extent of lipid digestion, with the highest cumulative FFA release rate (27.83%). In contrast, the SOB suspension showed the most significant enhancement in total reducing power (increased by 199.32% after intestinal digestion) and the highest α-glucosidase inhibitory activity. These findings clarify that the part source is a critical factor influencing the digestive properties and functional activities of IPM oil bodies, providing a theoretical foundation for the targeted application in functional foods.

As a novel woody oilseed, the application of Idesia polycarpa in oil processing has been limited by the lack of systematic research. In this study, the effects of different drying methods, impurity contents, and filtration cycles on the quality of Idesia polycarpa virgin oil were evaluated using physicochemical indicators such as acid value (AV), phospholipid content, color, etc. The thermal stability of the obtained Idesia polycarpa virgin oil was also assessed under high-temperature heating conditions in comparison with refined oil, soybean oil, and rapeseed oil. The results indicated that oil with higher transparency was obtained by microwave vacuum drying with zero impurity content and five filtration cycles with a peroxide value of 11.03 meq/kg and a phospholipid content of 1.07 mg/g. After high-temperature heating, lower total oxidation values (TOTOX = 106.05 ± 1.63) and polar compounds (7.99 ± 0.54 meq/kg) were detected in Idesia polycarpa virgin oil (IPVO) compared with soybean oil and rapeseed oil, confirming superior thermal stability. Overall, IPVO yield was improved and exceptional thermal stability was achieved by this pretreatment, underscoring its potential as a functional cooking oil for high-temperature culinary applications.

To unlock the potential value of the emulsified by-product from the aqueous enzymatic extraction (AEE) of Camellia oleifera seed oil, this study introduced an innovative approach for its food industrial application. We applied spray-drying microencapsulation technology to convert the emulsion-phase (EP) by-product into value-added microcapsules (EPM). The properties of EPM were systematically compared with those of microcapsules derived from the oil phase (OPM). The encapsulation efficiencies of EPM and OPM were 83.94% and 86.53%, respectively. Scanning electron microscopy revealed the formation of irregular spheroids with smooth surfaces and intact structures, with EPM exhibiting superior particle uniformity (D₅₀ = 1.11 μm) compared to OPM (D₅₀ = 2.30 μm). Fourier-transform infrared spectroscopy confirmed the successful encapsulation of EP. Differential scanning calorimetry indicated good thermal stability of the microcapsules, and the oxidative stability of EPM (24.75 h) was 9.2 times higher than that of the unencapsulated EP and 13.15 h longer than that of OPM. Lipidomic analysis using LC-MS/MS identified 477 lipid species across five subclasses—glycerolipids, glycerophospholipids, fatty acids, prenol lipids, and sphingolipids—revealing distinct lipid profiles between EPM and OPM. This microencapsulation strategy offers a sustainable approach to valorize aqueous enzymatic extraction by-products, with promising applications in functional foods and nutraceuticals, thereby enhancing the economic and environmental sustainability of Camellia oleifera seed oil processing.