Gelatin-based emulsion gels with transglutaminase (TG) crosslinking exhibit significant potential for delivering fat-soluble bioactive compounds in functional foods. However, the effects of TG-induced structural modifications on the release behavior and stability of encapsulated compounds during storage and digestion have rarely been investigated. In this study, beta-carotene was encapsulated into emulsion-filled gelatin gels to investigate the influence of TG crosslinking time on their structural, mechanical, and functional properties. The result showed that at 4 degrees C, physically crosslinked FG emulsion gels were thermally reversible, exhibiting higher Young's modulus and storage modulus covalently crosslinked TG gels. Large amplitude oscillatory shear analysis revealed that gels formed by gelatin self-assembly were more fragile, more susceptible to nonlinear behavior, and transitioned more quickly to Newtonian fluid dissipation. Increasing the TG crosslinking duration enhanced gel rigidity, particularly at room (25 degrees C) and physiological (37 degrees C) temperatures, by forming a more compact network. However, excessive crosslinking reduced the flexibility and energy dissipation capacity of the gels. Importantly, TG crosslinking significantly improved the storage stability of beta-carotene, enhanced its bioaccessibility, and increased its stability during simulated gastric digestion. The findings of this study offer a promising strategy for structuring gelatin-based emulsion gels with enhanced stability, controlled release, and improved bioactive delivery performance.

In this study, we investigated the effects of whey protein isolate fibril systems (WPF) and soy protein isolate fibril systems (SPF) combined with fish gelatin (FG) on the formation of emulsion gels. The aim was to evaluate how the origin and concentration of these fibril systems influence the structural, interfacial, and rheological properties of FG-stabilized emulsion gels, as well as their impact on creaming stability. FG was mixed with varying concentrations (0-2%) of WPF and SPF at pH 7, forming electrostatic complexes due to the opposite charge interactions between FG and the protein fibril dispersions. The results revealed that adding WPF and SPF increased surface hydrophobicity and enhanced interfacial activity. Increasing WPF concentrations led to a gradual decrease in emulsion droplet size owing to the increased absorbed protein content at the interface. Additionally, there was a significant improvement in the storage modulus of the emulsion gels. Conversely, introducing a small amount (0.1%) of SPF to FG increased the particle size, suggesting potential coalescence, but further increases in SPF concentration considerably reduced the particle size. Furthermore, SPF enhanced the viscoelasticity at lower concentrations, possibly due to a more uniform distribution within the continuous phase. However, excess SPF reduced the storage modulus of the emulsion gels. Our study provides valuable theoretical insights for the application of protein fibril systems in emulsion gel systems.

Gallic acid–Antarctic krill peptides (GA-AKP) nanocapsules (GA-AKP-Ns) were prepared using a dual delivery system with complex emulsion as the technical method, a high-pressure microjet as the technical means, polylactic acid–hydroxyacetic acid (PLGA) as the drug delivery vehicle, and GA-AKP as the raw material for delivery. This study aimed to investigate the effects of microjet treatment and the concentration of PLGA on the physicochemical properties and stability of the emulsion. Under optimal conditions, the physicochemical properties and hypoglycemic function of nano-microcapsules prepared after lyophilization by the solvent evaporation method were analyzed. Through the microjet treatment, the particle size of the emulsion was reduced, the stability of the emulsion was improved, and the encapsulation rate of GA-AKP was increased. The PLGA at low concentrations decreased the particle size of the emulsion, while PLGA at high concentrations enhanced the encapsulation efficiency of the emulsion. Additionally, favorable results were obtained for emulsion preparation through high-pressure microjet treatment. After three treatment cycles with a PLGA concentration of 20 mg/mL and a microjet pressure of 150 MPa (manometric pressure), the emulsion displayed the smallest particle size (285.1 ± 3.0 nm), the highest encapsulation rates of GA (71.5%) and AKP (85.2%), and optimal physical stability. GA-AKP was uniformly embedded in capsules, which can be slowly released in in vitro environments, and effectively inhibited α-amylase, α-glucosidase, and DPP-IV at different storage temperatures. This study demonstrated that PLGA as a carrier combined with microjet technology can produce excellent microcapsules, especially nano-microcapsules, and these microcapsules effectively improve the bioavailability and effectiveness of bioactive ingredients.

In this work, fish gelatins (FG) were mixed with whey protein fibers (WPF) and native whey protein isolates (WPI) under acidic and neutral pH conditions, respectively. The objective of this study was to explore how binary protein FG and WPI/WPF cooperated to stabilize oil-in-water emulsion systems. The emulsion, stabilized solely by WPI, flocculated and coalesced easily at both pH values. Fibrillation could increase surface hydrophobicity and interfacial activity at pH 7, resulting in improved creaming stability of emulsions compared to natural WPI. However, the improvement in creaming stability was limited. When FG cooperated with WPI and WPF, FG could contribute to the formation of a 3D network to enhance the physical stability of emulsions. In addition, WPI and WPF could contribute to surface activity in binary proteins. FG-WPF exhibited better compatibility than FG-WPI and a faster gelation rate, superior viscoelastic properties, and greater deformation resistance. In addition, WPF may help to improve the gelation behavior of FG-WPF at pH 3. This research introduced a new binary protein system consisting of whey protein fibers and fish gelatins that might be used as promising emulsifiers and stabilizers in emulsion systems.

In this study, red lentil isolate protein (RLPI, 3 %, w/v) was treated at pH 2 and 7 at 85 degrees C for a period of 0-24 h. The TEM and SDS-PAGE results indicated that the molecular weight of RLPI was steadily reduced and hydrolyzed into peptides over the prolonged heating time, eventually forming fibrillar and particulate aggregates at pH 2 and 7, respectively. The FTIR results showed an increased level of the proteins' random coil motifs due to the excessive heating. According to the results of emulsifying properties, the emulsifying capabilities of fibrillar proteins were higher than those of the particle proteins at the same protein concentration due to the proteins' structure and their surface charge. Notably, the fibrillar aggregates formed a gel network structure and stronger interactions in fibrillar aggregates compared to the particulate aggregates at pH 2. This study provides references for the processing and utilization of plant proteins in beverages and dietary supplements.

The dietary intervention has demonstrated effectiveness in improving hyperlipidemia and obesity. Woody edible oils are rich in unsaturated fatty acids (UFAs) that could positively affect lipid metabolism. In this study, the blended oil (BLO), a balanced UFA supplement, constituted by Zanthoxylum bungeanum (Chinese Red Pepper) seed oil, walnut (Juglans regia) oil, camellia (Camema oleifera) seed oil and perilla (Perilla frutescens) seed oil was established referring to the Chinese dietary reference intakes, in which the ratios of monounsaturated/polyunsaturated fatty acids and ω-6/ω-3 polyunsaturated fatty acids were 1:1 and 4:1, respectively. The BLO was administrated to KM mice fed a high-fat diet (HFD) by gavage every day at a dose of 3.0 mL/kg·bw for 10 weeks to assess its effects on serum lipid levels, liver antioxidant activities and gut microbial composition. The results showed that the BLO improved hepatic steatosis, liver oxidative stress, and serum lipid levels. Additionally, there was an increased abundance of Lactobacillus, Allobaculum, and Blautia, along with a decreased abundance of Staphylococcus in cecal contents. These changes were found to be positively correlated with the metabolic improvements, as indicated by Spearman’s correlation analysis. These findings implied the practicality of the balanced unsaturated fatty acid consumption in preventing hyperlipidemia and obesity.

Being a natural active substance with a wide variety of sources, easy access, significant curative effect, and high safety, active peptides have gradually become one of the new research directions in food, medicine, agriculture, and other fields in recent years. The technology associated with active peptides is constantly evolving. There are obvious difficulties in the preservation, delivery, and slow release of exposed peptides. Microencapsulation technology can effectively solve these difficulties and improve the utilization rate of active peptides. In this paper, the commonly used materials for embedding active peptides (natural polymer materials, modified polymer materials, and synthetic polymer materials) and embedding technologies are reviewed, with emphasis on four new technologies (microfluidics, microjets, layer-by-layer self-assembly, and yeast cells). Compared with natural materials, modified materials and synthetic polymer materials show higher embedding rates and mechanical strength. The new technology improves the preparation efficiency and embedding rate of microencapsulated peptides and makes the microencapsulated particle size tend to be controllable. In addition, the current application of peptide microcapsules in different fields was also introduced. Selecting active peptides with different functions, using appropriate materials and efficient preparation technology to achieve targeted delivery and slow release of active peptides in the application system, will become the focus of future research.

Gelatin-stabilized emulsions, including conventional and Pickering emulsions, are gaining popularity. In this study, fish gelatins (FG) were modified with transglutaminase (TG) to prepare gelatin molecules, microgels, and their mixtures. The transition of emulsions from conventional to Pickering was observed as gelatins evolved from molecules to microgels. FG (3%) was cross-linked with TG at 0-30 U/g. FG evolved from gelatin molecules into thermo-irreversible hydrogels as TG increased. Without TG or at a low level of TG (10 U/g), FG mainly existed as gelatin molecules that were liquid at 25 degrees C. At high levels of TG (20 or 30 U/g), FG crosslinked and developed thermo-irreversible chemical hydrogels that were solid. As the concentration of TG increased, the protein molecular weights, zeta potentials, and surface hydrophobicity were significantly increased. Microfluidization was employed to prepare gelatin microgels. Different states of gelatins were mixed with sunflower oil to prepare conventional emulsions, Pickering emulsions, and mixtures. With increased TG, the emulsion droplets became more homogeneous, and protein networks formed around the oil droplets. Emulsions stabilized with modified FG displayed improved physical stability than those stabilized with unmodified FG. At 10 degrees C, the emulsions stabilized by a mixture of FG molecules and microgels presented higher physical stability. At 25 degrees C, Pickering emulsions stabilized by microgels showed improved anti-coalescence. The results of this work could provide valuable references for applying gelatin-stabilized conventional or Pickering emulsions with tunable properties, hence increasing the formulation flexibility of gelatin-based food products.