To investigate the gelation process of direct ultra-high-temperature (UHT) milk, a pilot-scale steam infusion heat treatment was used to process milk samples over a wide temperature of 142–157 °C for 0.116–6 s, followed by storage at 4 °C, 25 °C, and 37 °C. The results of the physicochemical properties of milk showed that the particle sizes and plasmin activities of all milk samples increased during storage at 25 °C, but age gelation only occurred in three treated samples, 147 °C/6 s, 142 °C/6 s, and 142 °C/3 s, which all had lower plasmin activities. Furthermore, the properties of formed gels were further compared and analyzed by the measures of structure and intermolecular interaction. The results showed that the gel formed in the 147 °C/6 s-treated milk with a higher C* value had a denser network structure and higher gel strength, while the 142 °C/6 s-treated milk had the highest porosity. Furthermore, disulfide bonds were the largest contributor to the gel structure, and there were significant differences in disulfide bonds, hydrophobic interaction forces, hydrogen bonds, and electrostatic force among the gels. Our results showed that the occurrence of gel was not related to the thermal load, and the different direct UHT treatments produced different age gels in the milk.

Obejectives: This study explored the immunomodulatory effects of a prebiotic formula consisting of 2′-fucosyllactose (2′-FL), galacto-oligosaccharides (GOSs), and fructo-oligosaccharides (FOSs) (hereinafter referred to as 2FGF) in cyclophosphamide (CTX)-induced immunosuppressed BALB/c mice and its underlying mechanisms. Methods: Sixty healthy female BALB/c mice were randomly divided into the following groups: normal control (NC) group; CTX treatment (CTX) group; 2FGF low-dose (2FGF-L) group; 2FGF medium-dose (2FGF-M) group; and 2FGF high-dose (2FGF-H) group. An immunosuppressed model was established in the 2FGF-H group by intraperitoneal injection of 80 mg/kg CTX. After 30 days of 2FGF intervention, peripheral blood, spleen tissue, thymus tissue, and intestinal tissue from the mice were collected and analyzed. The changes in weight and food intake of the mice were recorded weekly. Hematoxylin-eosin (HE) staining was used to observe the histological change of the spleen tissue. Enzyme-linked immunosorbent assay (ELISA) was employed to detect cytokine levels in peripheral blood. Flow cytometry was used to analyze T lymphocyte subgroup ratio of splenic lymphocytes. Western blot analysis was conducted on intestinal tissues to assess the expression of proteins involved in the tight junction, toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathways. Additionally, molecular techniques were used to analyze the intestinal microbiota. Results: The results showed that 2FGF restored CTX-induced splenic injury, increased the number of splenic T lymphocytes, and elevated serum cytokines such as interleukin-4 (IL-4) and IL-10. In the intestine, 2FGF upregulated the expression of intestinal epithelial tight junction proteins such as Claudin-1 and zonula occludens 1 (ZO-1), thereby enhancing intestinal barrier function and activating the MAPK and NF-κB pathways via TLR4. Furthermore, 2FGF elevated the α-diversity (Shannon and Simpson indices) of the gut microbiota in CTX-induced immunosuppressed mice, enriching bacteria species positively correlated with anti-inflammatory cytokines (e.g., IL-4) such as g_Streptomyces and g_Bacillus and negatively correlated with pro-inflammatory cytokines (e.g., IL-1β) such as g_Saccharomyces. The results suggest that 2FGF may enhance immunity via the gut–immune axis. Conclusions: The 2FGF prebiotic formula showed an immunomodulatory effect in CTX-induced immunosuppressed mice, and the mechanism of which might involve optimizing the gut flora, enhancing intestinal homeostasis, strengthening the intestinal barrier, and promoting the expression of immune factors by regulating the TLR-4/MAPK/NF-κB pathway.

Background/Objectives: Hippocampal neuroinflammation (HNF) is a key pathological feature in neurodegenerative disorders. Milk-derived exosomes, as bioactive extracellular vesicles, have underexplored potential in regulating brain neuroinflammatory responses. This study aimed to characterize desert milk exosomes (D-Exo) and investigate their neuroprotective and anti-neuroinflammatory effects in LPS-induced HNF mice model and an LPS-stimulated BV2 microglia. Methods: Exosomes were isolated from desert and non-desert milk (ND-Exo) for proteomic analysis. After pretreating BV2 cells with exosomes and stimulating with LPS, their inflammatory responses and polarization were assessed by RT-PCR. Balb/c mice were orally gavaged with D-Exo or 0.9% NaCl for 28 days before LPS injection. Cognitive function was assessed via behavioral tests, with microglial/astrocyte activation analyzed by immunofluorescence. Results: D-Exo exhibited superior stability and a unique proteomic profile enriched with proteins linked to neuroinflammation and blood-brain barrier (BBB) integrity, notably within the AMPK signaling pathway. In vitro, D-Exo shifted LPS-stimulated microglia from the M1 to the M2 phenotype. In vivo, it alleviated HNF and cognitive decline, reduced Aβ_1-42 and Tau deposition, elevated BDNF and MAP2, and suppressed neuroinflammation and glial activation. Conclusions: D-Exo is enriched with specific proteins, attenuates neuroinflammation and cognitive decline by regulating microglial M1/M2 polarization and AMPK pathway, highlighting its preventive potential.

This study aimed to characterize the nutritional and sensory profiles of commercial liquid milk available in China (CN) from three different major global regions. Sixteen milk samples [six from CN, five from Western Europe (WEU), and five from Australia/New Zealand (ANZ)] were analyzed for macronutrients, minerals, vitamins, fatty acids (FAs), and sensory properties. CN milk had higher levels of fat, zinc, iodine, vitamin E, and vitamin B3, whereas imported milk contained more vitamin B2. Distinct FA profiles were observed: CN milk was richer in n-6 FAs, whereas imported milk had higher n-3 FAs and a more favorable n-3/n-6 ratio. Sensory analysis showed that imported milk exhibited stronger ‘cowy’ and ‘tea’ flavors. These variations were mainly caused by different feeding systems (total mixed rations-based confined production in CN vs. pasture-based grazing in WEU and ANZ), along with milk processing and supply chain factors. The results provide evidence for dairy product differentiation and help Chinese consumers make informed purchasing decisions.