This study presents a novel approach for enhancing the survivability of Lactiplantibacillus plantarum BXM2 using bamboo shoot-derived nanocellulose hydrogels. Nanocellulose hydrogels, composed of cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and polyvinyl alcohol (PVA), were developed as protective matrices for probiotics. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) confirmed the successful formation of hydrogen-bonded networks between PVA and nanocelluloses, while scanning electron microscopy (SEM) revealed that the ternary PVA-CNF-CNC hydrogel exhibited a dense, hierarchical porous structure, effectively encapsulating probiotics with an encapsulation efficiency of 92.56 ± 0.53%. Under simulated gastrointestinal digestion, the encapsulated probiotics maintained 8.04 log CFU/g viability, significantly higher than that of free bacteria (3.54 log CFU/mL). The hydrogel also enhanced heat tolerance (6.58 log CFU/mL at 70 °C) and freeze-drying survival (86.92% viability), outperforming binary systems. During 60-day storage at 4 °C and 25 °C, encapsulated probiotics retained viability above the critical threshold (≥6 log CFU/unit), whereas free cells declined rapidly. These findings highlight the potential of PVA-CNF-CNC hydrogel as an efficient delivery system to improve probiotic stability in food applications.

Oyster peptides (OPs) have gained increasing attention for their excellent biological activities, especially immunomodulatory effects. In this study, oyster proteins were fermented using Lactobacillus casei to prepare bioactive peptides, and the effects of fermentation parameters (time, temperature, and inoculum amount) on the degree of hydrolysis (DH) were optimized. The optimal fermentation conditions were determined as 30 h, 35 °C, and 5% inoculum amount, resulting in a DH of 28.24%. Structural characterization showed that OPs were mainly composed of low-molecular-weight peptides (<1000 Da) with high hydrophobic amino acid content, and they exhibited good stability during in vitro gastrointestinal digestion. In vitro immunological evaluation using RAW264.7 macrophages demonstrated that OPs significantly enhanced phagocytic activity and nitric oxide (NO) production, and upregulated the mRNA expression levels of pro-inflammatory cytokines including interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α. Mechanistically, OPs exerted immunostimulatory effects by specifically activating the extracellular signal-regulated kinase (ERK) pathway within the mitogen-activated protein kinase (MAPK) signaling cascade, without significant alterations in the phosphorylation levels of p38 and c-Jun N-terminal kinase (JNK). These findings highlight the potential of Lactobacillus casei-fermented oyster peptides as natural immunomodulatory ingredients for functional food development.

The edible tree peony (Paeonia suffruticosa Andrews) flowers are rich in bioactive components with potential health benefits, but the skin-health-promoting effects of their protein hydrolysates remain understudied. The present research sought to evaluate the antioxidant, anti-wrinkle, moisturizing, and whitening properties of tree peony flower protein hydrolysate (TPFP). TPFP was prepared via enzymatic hydrolysis and ultrafiltration, and its peptide sequences were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing 54 unique small-molecule peptides with an average amino acid length of 8.2 residues and a molecular weight of 914.51 Da. In vitro safety evaluation using CCK-8 assay showed TPFP (20–100 μM) did not induce substantial cytotoxic effects in either HaCaT keratinocytes or B16F10 melanoma cell lines. Functional assays demonstrated that TPFP dose-dependently inhibited UVB-induced reactive oxygen species (ROS) overproduction and restored superoxide dismutase (SOD) and catalase (CAT) activities in HaCaT cells, exerting antioxidant effects. Additionally, TPFP protected pro-collagen I from UVB-induced loss, suppressed the expression of matrix metalloproteinase 1 (MMP-1), and restored hyaluronic acid (HA) content, showing anti-wrinkle and moisturizing potentials. In α-MSH-stimulated B16F10 cells, TPFP suppressed melanin synthesis by downregulating the protein expression of tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and TRP-2, achieving a whitening effect. These findings indicate that TPFP possesses comprehensive skin-health-promoting activities with good biocompatibility, highlighting its potential as a natural functional ingredient in cosmetics and functional foods.

Pectic polysaccharides from tea residues represent a promising class of prebiotic dietary fibers. This study aimed to optimize the extraction of Oolong tea (Camellia sinensis ‘Foshou’) polysaccharides (FCTP), elucidate the structural alterations induced by ultrasonic degradation, and evaluate the consequent in vitro utilization using Lactobacillus salivarius BXP5. Enzyme-assisted extraction significantly improved the yield of FCTP to 11.10%, compared to 6.74% via conventional hot-water extraction. Ultrasonic treatment (120–240 W, 20–45 min) reduced the molecular weight (Mw) from 1079.9 kDa to 690.7–824.4 kDa, increased the uronic acid content, disrupted the triple-helix conformation, and transformed the polysaccharide into a looser and more water-accessible structure. Structural characterization by FTIR, methylation, and NMR further indicated that uFCTP remained an acidic pectic polysaccharide enriched in homogalacturonan (HG)-like domains. In vitro fermentation demonstrated that ultrasonically degraded FCTP (uFCTP) more effectively promoted BXP5 proliferation than native FCTP. Non-targeted metabolomics and proteomics revealed that uFCTP exerted more pronounced regulatory effects on nucleotide metabolism, carbon metabolism, and ribosomal biogenesis. Correlation analysis identified key metabolites (e.g., gallic acid, xanthosine monophosphate) tightly associated with differentially expressed proteins involved in carbohydrate utilization and cellular growth. These findings indicate that ultrasonic degradation is an effective physical modification strategy to improve utilization by L. salivarius BXP5 of tea-derived pectic polysaccharides by tailoring their molecular architecture for improved probiotic fermentation and metabolic cross-talk.

Bamboo shoot boiled liquid (BSBL), a processing byproduct containing soluble proteins, peptides, amino acids, carbohydrates, and phenolics, is typically discarded, causing resource waste and environmental issues. This study analyzed metabolic changes in BSBL during Pediococcus pentosaceus B49 fermentation. The result of partial least squares discriminant analysis (PLS-DA) revealed significant metabolite profile differences across fermentation times (0 h, 24 h, 48 h, 72 h, 96 h). The most substantial alterations occurred within the first 24 h, followed by stabilization. Compared to unfermented BSBL, fermented samples exhibited significantly elevated signal intensities for 5,7-dimethoxyflavone, cinnamic acid, 3,4-dihydro-2H-1-benzopyran-2-one, 6,8-dimethyl-4-hydroxycoumarin, and 2-hydroxycinnamic acid (p < 0.05), showing upward trends over time. Conversely, (+)-gallocatechin intensity decreased gradually. Bitter peptides, such as alanylisoleucine, isoleucylisoleucine, leucylvaline, and phenylalanylisoleucine, in BSBL exhibited a significant reduction following fermentation with P. pentosaceus B49 (p < 0.05). KEGG enrichment indicated tyrosine metabolism (ko00350) and arginine/proline metabolism (ko00330) as the most impacted pathways. These findings elucidate metabolic regulation in BSBL fermentation, supporting development of functional fermented bamboo products.