Jie Zhang

Background: Lactopontin (L-OPN) is a pivotal bioactive protein present in breast milk that supports bone development, but its efficacy in a formula matrix is unknown. This study aimed to evaluate the effects of L-OPN-fortified formula on bone growth in a growing rat model and to explore the underlying mechanisms. Methods: Weanling rats (n = 8/group) received daily gavage for four weeks: (1) CON—deionized water; (2) PRO—750 mg/kg·BW mixed protein; or (3) L-OPN—750 mg/kg·BW of the PRO formula fortified with L-OPN. Results: The results showed that the formula fortified with L-OPN could significantly increase bone volume and trabecular bone number (p < 0.05). Furthermore, both femur length and thickness, as well as overall body length, were significantly increased (p < 0.001). In addition, the L-OPN-fortified formula specifically increased the relative abundance of Bacteroides and Parabacteroides in rat feces (p < 0.05). Metabolomic analysis revealed that L-OPN supplementation significantly altered bile acid metabolism, notably increasing serum levels of 12-ketolithocholic acid (12-KLCA), which correlated strongly with bone metrics. Conclusions: These preclinical findings provide a basis for future research in infant formula.

Lactopontin (LPN) plays a critical role in the growth and development of infants. Caprine milk and bovine milk are the primary raw materials for infant formulas. However, the differences between caprine and bovine LPN have not been studied. In this study, the structure, digestive characteristics, and active peptide composition of LPN from different sources were compared. Two N-glycosylation sites, Asn101 and Asn208, were identified in bovine LPN, while a single N-glycosylation site, Asn79, was found in caprine LPN. The in vitro infant digestion simulation results indicated that caprine LPN released a greater quantity of small peptides and amino acids. The intestinal digestion products were subsequently analyzed. The digestive peptides derived from caprine LPN may possess various potential biological functions. These findings provide insights into optimizing protein digestion and nutrient absorption in infant formula.

As a key bioactive protein in dairy, lactopontin (LPN) possesses bone-growth properties, but the role of its digestive peptides is unknown. This study investigated the generation and osteogenic activity of LPN-derived peptides using a simulated infant digestion model and peptidomic analysis. Over 90% of LPN was hydrolyzed, generating 242 peptides, with phosphorylated species constituting 76%. Virtual screening with AutoDock Vina selected six candidate peptides with a strong binding affinity for bone morphogenetic protein receptor 1A (BMPR1A). In MC3T3-E1 osteoblasts, two peptides, WLKPDPS and NEpSPEQTDDL, exhibited pronounced osteogenic effects. They significantly enhanced the cell proliferation, alkaline phosphatase activity, and calcium nodule formation. Concurrently, both peptides upregulated the expression of key osteogenic markers, including Bmpr, Runx2, and Ocn. These results highlight LPN-derived digestive peptides as promising bioactive agents for bone health and offer novel nutritional insights.

Spoilage and deterioration of aquatic products during storage are inevitable, posing significant challenges to their suitability for consumption and the sustainability of the aquatic products supply chain. Research on the nonthermal processing of fruit juices, probiotics, dairy products, and meat has demonstrated positive outcomes in preserving quality. This review examines specific spoilage bacteria species and mechanisms for various aquatic products and discusses the principles, characteristics, and applications of six nonthermal processing methods for bacterial inhibition to maintain microbiological safety and physicochemical quality. The primary spoilage bacteria groups differ among fish, crustaceans, and shellfish based on storage conditions and durations. Four metabolic pathways utilized by spoilage microorganisms—peptides and amino acids, nitrogen compounds, nucleotides, and carbohydrates—are crucial in explaining spoilage. Nonthermal processing techniques, such as ultrahigh pressure, irradiation, magnetic/electric fields, plasma, and ultrasound, can inactivate microorganisms, thereby enhancing microbiological safety, physicochemical quality, and shelf life. Future research may integrate nonthermal processing with other technologies (e.g., modified atmosphere packaging and omics) to elucidate mechanisms of spoilage and improve the storage quality of aquatic products.

The quality and safety of sufu fermented using Mucor racemosa M2 was studied and compared with naturally fermented sufu. After 90 days post-fermentation, both naturally fermented and inoculated fermented sufu reached the maturity standard of sufu, and the degree of protein hydrolysis of natural sufu (WP/TP: 34% ± 1%; AAN/TN: 33% ± 1%) was slightly higher than that of the inoculated sufu (WP/TP: 28.2% ± 0.4%; AAN/TN: 27% ± 1%). The hardness and adhesiveness of inoculated sufu (Hadness: 1063 g ± 211 g; Adhesiveness: −80 g ± 47 g) were significantly greater than those of natural sufu (Hadness: 790 g ± 57 g; Adhesiveness: −23 g ± 28 g), and the internal structure of natural sufu was denser and more uniform than that of inoculated sufu. A total of 50 aroma compounds were detected in natural and inoculated sufu. The total number of bacterial colonies in naturally fermented sufu was significantly higher than that in inoculated sufu, and the pathogenic bacteria in both types of fermented sufu were lower than the limit of pathogenic bacteria required in fermented soybean products. The content of biogenic amines in sufu was determined by high performance liquid chromatography (HPLC), and the results showed that the content of biogenic amines (Putrescine, Cadaverine, Histamine, Tyramine, etc.) in naturally fermented sufu was significantly higher than that in inoculated fermented sufu. Especially the histamine content, after 90 days of fermentation, was found to be 64.95 ± 4.55 for inoculated fertilization and 44.24 ± 0.71 for natural fertilization. Overall, the quality of inoculated sufu was somewhat better than that of natural sufu, and the M2 strain can be used to ferment sufu.

This study aimed to investigate the properties of acidic whey tofu gelatin generated from two acidic whey coagulants by pure fermentation of Lactiplantibacillus paracasei and L. plantarum, as well as the characteristics of acidic whey tofu. The optimal holding temperature and the amount of coagulants added were determined based on the pH, water-holding capacity, texture, microstructure, and rheological properties of tofu gelation. Then, the differences in quality between tofu produced by pure bacterial fermentation and by natural fermentation were investigated under optimal tofu gelatin preparation conditions. The tofu gelatin presented the best texture at 37 °C with a 10% addition of coagulants fermented by both L. paracasei and L. plantarum. Under these conditions, the coagulant produced by the fermentation of L. plantarum resulted in a shorter formation time and stronger tofu gelatin compared with that produced from L. paracasei. Tofu produced by the fermentation of L. paracasei had higher pH, less hardness, and a rougher network structure, whereas tofu produced by the fermentation of L. plantarum was closer to tofu produced by natural fermentation in terms of pH, texture, rheology, and microstructure.

Background: The most utilized pasteurization method in donor human milk banks is Holder pasteurization (heating 62.5 °C for 30 min). However, many bioactive proteins are heat sensitive and are inactivated. Research Aim: To determine the results of a range of heating regimes on the activities of xanthine oxidase, lactoperoxidase and lysozyme, the concentrations of immunoglobulin A and lactoferrin, as well as bacterial inactivation. Method: This prospective, cross-sectional, intervention study was designed to measure the influence of heating temperatures on bioactive components in donor human milk. Milk samples were processed at 40, 50, 55, 62.5, 75, 127 °C and the activities of the enzymes, and the concentration of immune proteins, were measured. Results: No bacterial colonies were detectable, using standard culture methods, after heating above 50 ºC. All proteins studied retained over 60% concentrations or activities when the pasteurization temperature was 50 ºC or lower, while their concentrations or activities were lost at higher temperatures. For lactoferrin, the residual concentration was above 80% when heating temperature was under 55 °C, while only 20% remained after Holder pasteurization. Both xanthine oxidase and lactoperoxidase had little residual activity when temperatures were above Holder pasteurization. Lysozyme retained a greater proportion of residual activity than other proteins, following heating at all temperatures. Conclusions: The concentrations or activities of immune proteins and bioactive enzymes decreased when heated above 50 °C. The results of this study can be used to design temperature control guidance during alternative methods of pasteurization.

This study investigated the effects of atmospheric spray drying (ASD), low-pressure spray drying (LPSD) and freeze drying (FD) on the properties of serum protein powder, including the basic characteristics of the powder, bioactive proteins and changes in protein profile, using a proteomics approach. The total solid and water activity of the powder obtained by FD was significantly higher than that obtained by ASD and LPSD. There was no significant difference in the content of fat, lactose or solubility between the three kinds of powders. The concentration and activity of the proteins/enzymes in the serum protein powder made from LPSD were not altered after drying, similar to FD, although both parameters decreased after ASD. The microstructure of the powder observed by scanning electron microscopy indicated that the powder manufactured by ASD and LPSD was spherical in structure, while that manufactured by FD was flake-like. In total, there were 245 proteins identified in the serum protein concentrate and powder from the three drying methods. These findings indicate that LPSD is an effective and cost-saving method for producing serum whey protein powder.