The use of low-temperature antibacterial technology is a processing method designed to preserve the biological activity of milk to the greatest extent. Traditional feeding and milking practices result in high levels of microbiological contamination of raw milk after extraction, mainly from cows and milking equipment, especially rubber cups. Ultrasonic treatment combined with antimicrobial agents combine cleaning and antibacterial technology, compared with traditional cleaning methods, more efficiently and in a environmentally friendly way. In this study, the technique was demonstrated to significantly reduce the total amount of bacteria in raw milk through simulation experiments on the surface of milking cups. It was shown that ultrasound-coupled slightly electrolytic water has a good potential for application in reducing bacterial contamination in the milk extraction process on farms. We investigated the synergistic mechanism of ultrasound (US) and slightly acidic electrolytic water (SAEW) and verified the bactericidal effect of milking cups. A 20 s treatment of milking cups with US (100 W) and SAEW (90 mg/L) led to an antibacterial rate of over 90%. The bactericidal mechanism causes fragmentation of the cell membrane of pathogenic bacteria, exudation of their intracellular contents such as nucleic acids and proteins, and increases in ROS.

2-acetylfuran is a product of the Maillard reaction and is widely found, especially in heat-processed foods such as grain products, baked goods, and dairy products. Although 2-acetylfuran contributes to flavor, high concentrations may be toxic. Its target organs and dose–response relationships remain poorly characterized. In this study, transgenic zebrafish with fluorescently labeled immune and neural systems were used to assess the effects of 2-acetylfuran on immune and neural development. Wild-type zebrafish were employed to assess the toxicity of 2-acetylfuran on locomotor ability, gastrointestinal development, and liver function. The maximum non-lethal concentration (MNLC) and the 10% lethal concentration (LC₁₀) for zebrafish embryos were 0.844 and 0.889 μL/mL, respectively. Regarding immunotoxicity, at concentrations of 0.281, 0.844, and 0.889 μL/mL, 2-acetylfuran significantly reduced the numbers of neutrophils, T cells, and macrophages. Regarding locomotor and neurotoxicity, motor speed and total locomotor distance were significantly reduced at 0.844 and 0.889 μL/mL. These findings were consistent with neurodevelopmental assessments, in which 0.844 μL/mL 2-acetylfuran resulted in a significant increase in apoptotic cells in the central nervous system and markedly shortened peripheral motor nerve lengths. Regarding gastrointestinal toxicity, 0.844 and 0.889 μL/mL 2-acetylfuran significantly reduced the gastrointestinal area, while neutrophil counts showed no significant changes, suggesting a relatively mild effect on the gastrointestinal tract. Regarding hepatic toxicity, all tested concentrations of 2-acetylfuran primarily increased the delayed yolk sac absorption area. Furthermore, at 0.844 μL/mL, histological examination revealed hepatic pathological changes characterized by hepatocyte nuclear swelling, vacuolar degeneration, and hepatocyte necrosis. In summary, this study reveals the multi-organ toxicity profile of 2-acetylfuran in the zebrafish model, with particularly high sensitivity in the immune system and liver. This research provides theoretical support for risk assessment and process control of 2-acetylfuran in foods.

Since infant formula (IF) manufacturers aim to produce a product as close to breast milk as possible, fortified nutrients are usually added. Generally, an IF is produced by adjusting the types and proportions of vitamins and minerals. This study comparatively examined the content of the six nutrients in different compound forms in vivo and evaluated the effect of different nutrient pack groups on immunity and growth. The results indicated that the simulated-human milk nutrients [minerals zinc (Zn), iron (Fe), calcium (Ca), and vitamins A, E, and B₁] were more easily absorbed by the body while effectively regulating immunity. This study provides a scientific foundation for developing, manufacturing, and applying imitation-breast formula milk powder.

Various Maillard reaction products (MRPs) are formed in infant formula during thermal processing and storage. However, safety assessments are often based on individual compounds, which may not adequately reflect the potential risks associated with exposure to multiple coexisting components in real food products. Therefore, this study used GC–MS to screen for typical MRPs in infant formula. Based on the detection results, glyoxal, 2-acetylfuran, 2-furfural, and 5-hydroxymethylfurfural (5-HMF) were selected to establish a mixed-exposure system. Subsequently, using zebrafish as a model, we systematically evaluated the toxic effects of two mixture concentrations, 1/9 maximum non-lethal concentration (MNLC) and 1/3 MNLC, on the immune system, nervous system, gastrointestinal tract, and liver. The results showed that these four MRPs coexisted in infant formula and that combined exposure induced significant biological damage even at low doses. Both mixture concentrations significantly reduced neutrophil and macrophage levels and promoted apoptosis in central nervous system cells. The higher-concentration mixture further reduced T-cell counts, suppressed motor neuron development, and decreased locomotor activity during the light phase. In addition, the higher-concentration mixture decreased the gastrointestinal area, increased the liver area, delayed yolk sac absorption, and caused marked histopathological damage. Compared with single-compound exposure, combined exposure exerted more pronounced effects on immune- and neuro-related endpoints, suggesting synergistic interactions among different MRPs and identifying the immune and nervous systems as the more sensitive targets of toxicity. In summary, mixed exposure to typical MRPs in infant formula may pose a greater biological risk than that predicted by evaluations based on individual components alone. This study provides experimental evidence for identifying combined toxicity and improving the safety risk assessment of MRPs in thermally processed infant foods.