Synergistic effects of tilapia head protein hydrolysate and walnut protein hydrolysate on the amelioration of cognitive impairment in mice.

BACKGROUND: Cognitive impairment (CI) is a significant public health concern, and bioactive peptides have shown potential as therapeutic agents. However, information about their synergistic effects on cognitive function is still limited. Here, we investigated the synergistic effects of tilapia head protein hydrolysate (THPH) and walnut protein hydrolysate (WPH) in mitigating CI induced by scopolamine in mice. RESULTS: The results showed that the combined supplementation of THPH and WPH (mass ratio, 1:1) was superior to either individual supplement in enhancing spatial memory and object recognition abilities in CI mice, and significantly lessened brain injury in CI mice by alleviating neuronal damage, reducing oxidative stress and stabilizing the cholinergic system. In addition, the combined supplementation was found to be more conducive to remodeling the gut microbiota structure in CI mice by not only remarkably reducing the ratio of Firmicutes to Bacteroidota, but also specifically enriching the genus Roseburia. On the other hand, the combined supplementation regulated the disorders of sphingolipid and amino acid metabolism in CI mice, particularly upregulating glutathione and histidine metabolism, and displayed a stronger ability to increase the expression of genes and proteins related to the brain-derived neurotrophic factor (BDNF)/TrkB/CrEB signaling pathway in the brain. CONCLUSION: These findings demonstrate that tilapia head and walnut-derived protein hydrolysates exerted synergistic effects in ameliorating CI, which was achieved through modulation of gut microbiota, serum metabolic pathways and BDNF signaling pathways. © 2024 Society of Chemical Industry.

A physicochemical double-cross-linked gelatin hydrogel with enhanced antibacterial and anti-inflammatory capabilities for improving wound healing.

BACKGROUND: Skin tissue is vital in protecting the body from injuries and bacterial infections. Wound infection caused by bacterial colonization is one of the main factors hindering wound healing. Wound infection caused by colonization of a large number of bacteria can cause the wound to enter a continuous stage of inflammation, which delays wound healing. Hydrogel wound dressing is composed of natural and synthetic polymers, which can absorb tissue fluid, improve the local microenvironment of wound, and promote wound healing. However, in the preparation process of hydrogel, the complex preparation process and poor biological efficacy limit the application of hydrogel wound dressing in complex wound environment. Therefore, it is particularly important to develop and prepare hydrogel dressings with simple technology, good physical properties and biological effects by using natural polymers. RESULTS: In this study, a gelatin-based (Tsg-THA&Fe) hydrogel was created by mixing trivalent iron (Fe3+) and 2,3,4-trihydroxybenzaldehyde (THA) to form a complex (THA&Fe), followed by a simple Schiff base reaction with tilapia skin gelatin (Tsg). The gel time and rheological properties of the hydrogels were adjusted by controlling the number of complexes. The dynamic cross-linking of the coordination bonds (o-phthalmictriol-Fe3+) and Schiff base bonds allows hydrogels to have good self-healing and injectable properties. In vitro experiments confirmed that the hydrogel had good biocompatibility and biodegradability as well as adhesion, hemostasis, and antibacterial properties. The feasibility of Tsg-THA&Fe hydrogel was studied by treating rat skin trauma model. The results showed that compared with Comfeel® Plus Transparent dressing, the Tsg-THA&Fe hydrogel could obvious reduce the number of microorganisms, prevent bacterial colonization, reduce inflammation and accelerate wound healing. Local distribution of the Tsg-THA&Fe hydrogel in the skin tissue did not cause organ toxicity. CONCLUSIONS: In summary, the preparation process of Tsg-THA&Fe hydrogel is simple, with excellent performance in physical properties and biological efficacy. It can effectively relieve inflammation and control the colonization of wound microbes, and can be used as a multi-functional dressing to improve wound healing.

Comparative Study on Curcumin Loaded in Golden Pompano (Trachinotus blochii) Head Phospholipid and Soybean Lecithin Liposomes: Preparation, Characteristics and Anti-Inflammatory Properties.

In this study, we compared the characteristics and in vitro anti-inflammatory effects of two curcumin liposomes, prepared with golden pompano head phospholipids (GPL) and soybean lecithin (SPC). GPL liposomes (GPL-lipo) and SPC liposomes (SPC-lipo) loaded with curcumin (CUR) were prepared by thin film extrusion, and the differences in particle size, ζ-potential, morphology, and storage stability were investigated. The results show that GPL-lipo and SPC-lipo were monolayer liposomes with a relatively small particle size and excellent encapsulation rates. However, GPL-lipo displayed a larger negative ζ-potential and better storage stability compared to SPC-lipo. Subsequently, the effects of phospholipids in regulating the inflammatory response of macrophages were evaluated in vitro, based on the synergistic effect with CUR. The results showed that both GPL and SPC exerted excellent synergistic effect with CUR in inhibiting the lipopolysaccharide (LPS)-induced secretion of nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory genes (tumor necrosis factor (TNF)-α, interleukin 1ß (IL-ß), and interleukin 6 (IL-6)) in RAW264.7 cells. Interestingly, GPL-lipo displayed superior inhibitory effects, compared to SPC-lipo. The findings provide a new innovative bioactive carrier for development of stable CUR liposomes with good functional properties.

Effect of citric acid on physicochemical properties and protein structure of low-salt restructured tilapia (Oreochromis mossambicus) meat products.

BACKGROUND: The growing consumer demand for healthy products has encouraged the development of low-salt meat products. In this study, to develop low-salt restructured tilapia (Oreochromis mossambicus) meat products, citric acid was used to improve the properties of restructured tilapia products. RESULTS: In comparison with control restructured fish products (RP) and surimi products (SP), 0.2% citric acid-treated restructured fish products (RPC) and surimi products (SPC) showed a significant decrease in expressible water and water activity and a remarkable increase in whiteness, dry matter, hardness, chewiness, gumminess, and acceptability. Mechanistic studies suggested that citric acid significantly changed the content of total protein and myofibrillar proteins and promoted degradation of heavy myosin chains. Fourier-transform infrared and Raman spectra revealed the citric acid-mediated alteration in the peak intensities of amide I and amide II bands, which changed the secondary structures of RPC and SPC. CONCLUSION: It is feasible to prepare low-salt restructured tilapia meat products using citric acid, which offers a means of using muscle by-products and exploiting new functional products with an added commercial value. © 2020 Society of Chemical Industry.

Holothuria Leucospilota Polysaccharides Ameliorate Hyperlipidemia in High-Fat Diet-Induced Rats via Short-Chain Fatty Acids Production and Lipid Metabolism Regulation.

Holothuria leucospilota polysaccharides (HLP) are expected to become potential resources for the treatment of hyperlipidemia because of their various bioactivities. In the study, the treatment of HLP on improving hyperlipidemia in rats was explored. Oral administration of HLP at 100 or 200 mg/kg body weight effectively alleviated serum lipid levels and liver histological abnormalities in high-fat-diet rats. HLP regulated abnormal mRNA, lipogenesis-related hormones and inflammatory cytokines (tumor necrosis factor-α, interleukin-6 and interleukin-12) levels. HLP improved the ability of gut microbiota to produce short-chain fatty acids (SCFAs). SCFAs have been found to ameliorate liver lesions. Therefore, HLP alleviated hyperlipidemia by improving the levels of SCFAs to regulate lipid metabolism. These results indicated that HLP could be used as beneficial polysaccharides to alleviate hyperlipidemia.

Isolation and Characterization of a Novel Sialoglycopeptide Promoting Osteogenesis from Gadus morhua Eggs.

Gadus morhua eggs contain several nutrients, including polyunsaturated fatty acids, lecithin and glycoproteins. A novel sialoglycopeptide from the eggs of G. morhua (Gm-SGPP) was extracted with 90% phenol and purified by Q Sepharose Fast Flow (QFF) ion exchange chromatography, followed by S-300 gel filtration chromatography. Gm-SGPP contained 63.7% carbohydrate, 16.2% protein and 18.6% N-acetylneuraminic acid. High-performance size exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that Gm-SGPP is a 7000-Da pure sialoglycopeptide. ß-elimination reaction suggested that Gm-SGPP contained N-glycan units. Amino acid N-terminal sequence analysis indicated the presence of Ala-Ser-Asn-Gly-Thr-Gln-Ala-Pro amino acid sequence. Moreover, N-glycan was connected at the third Asn location of the peptide chain through GlcNAc. Gm-SGPP was composed of D-mannose, D-glucuronic acid and D-galactose. Fourier transform-infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance spectroscopy (1H-NMR) and methylation analysis were performed to reveal the structure profile of Gm-SGPP. In vitro results showed that the proliferation activity of MC3T3-E1 cells was significantly promoted by Gm-SGPP. In vivo data revealed that Gm-SGPP increased the calcium and phosphorus content of tibias and promoted longitudinal bone growth in adolescent rats.

Liver-Targeted Nanoparticles Loaded with Cannabidiol Based on Redox Response for Effective Alleviation of Acute Liver Injury.

The purpose of this work was to construct liver-targeted nanoparticles based on the redox response to effectively deliver cannabidiol (CBD) for the prevention of acute liver injury (ALI). CBD-loaded nanoparticles (CBD NPs) with a particle size of 126.5 ± 1.56 nm were prepared using the polymer DA-PP-LA obtained by grafting pullulan polysaccharide with deoxycholic acid (DA) and α-lipoic acid (α-LA). CBD NPs showed typical redox-response release behavior. Interestingly, CBD NPs exhibited admirable liver targeting ability, significantly accumulated in the liver, and effectively promoted the internalization of CBD in liver cells, thus effectively reducing the H2O2-induced oxidative damage of HepG2 cells and avoiding apoptosis. More importantly, CBD NPs effectively prevented CCl4-induced ALI by protecting liver function, ameliorating oxidative stress levels, inhibiting the production of inflammatory factors, and protecting the liver from histological damage. This study provides a promising strategy for achieving targeted delivery of CBD NPs in the liver, thereby effectively preventing ALI.

Flavor formation of tilapia byproduct hydrolysates in Maillard reaction.

The Maillard reaction (MR) of tilapia byproduct protein hydrolysates was investigated for the use of byproduct protein as a food ingredient and to mask its fishy odor and bitter flavor. The flavor differences in tilapia byproduct hydrolysates before and after the MR were analyzed to explore the key flavor precursor peptides and amino acids involved in MR. The results suggested that eight key volatile substances, including 2,5-dimethylpyrazine, 2-pentylfuran, hexanal, octanal, nonanal, (E)-2-decenal, decanal, and 1-octen-3-ol contributed most to the MR products group (ROAV > 1). Ten volatile compounds, including 1-octen-3-ol, hexanal, 2-pentylfuran, 2,5-dimethylpyrazine, methyl decanoate, and 2-octylfuran, were the flavor markers that distinguished the different samples (VIP > 1). The four most consumed peptides were VAPEEHPTL, GPIGPRGPAG, KSADDIKKAF, and VWEGQNIVK. Umami peptides and bitter free amino acids (FAAs) were the key flavor precursor peptide and FAAs, respectively. Overall, the hydrolysates of tilapia byproducts with flavor improved by MR are a promising strategy for the production of flavorings.

Multi-targeting inulin-based nanoparticles with cannabidiol for effective prevention of ulcerative colitis.

The pathogenesis of ulcerative colitis (UC) is closely related to severe inflammation, damaged colonic mucosal barrier, increased oxidative stress and intestinal ecological imbalance. However, due to the nonspecific distribution and poor bioavailability of drugs, UC treatment is still a serious challenge. Here, a mitochondria/colon dual targeted nanoparticles based on redox response was developed to effectively alleviate UC. Cannabidiol nanoparticles (CBD NPs) with a particle size of 143.2 ± 3.11 nm were prepared by self-assembly using polymers (TPP-IN-LA) obtained by modifying inulin with (5-carboxypentyl) triphenyl phosphonium bromide (TPP) and α-lipoic acid (α-LA). Excitingly, the constructed CBD NPs showed excellent mitochondrial targeting, with a Pearson correlation coefficient of 0.76 at 12 h. The results of animal imaging in vivo showed that CBD NPs could be effectively accumulated in colon tissue. Not only that, CBD showed significant glutathione stimulated release in the presence of 10 mM glutathione at pH 7.4. The results of in vivo animal experiments showed that CBD NPs significantly ameliorated DSS-induced colonic inflammation by modulating the TLR4-NF-κB signaling pathway. Moreover, CBD NPs significantly improved the histological damage of colon in UC mice, increased the expression level of tight junction protein ZO-1, and effectively restored the intestinal mucosal barrier function and intestinal mucosal permeability. More importantly, CBD NPs significantly improved the species composition, abundance and amount of short chain fatty acids of intestinal flora in UC mice, thus effectively maintaining the balance of intestinal flora. The dual-targeted and glutathione-responsive nanoparticles prepared in this study provide a promising idea for achieving targeted delivery of CBD for effective treatment of UC.

Novel hydrocolloids synthesized by polyphenols grafted onto chitosan: A promising coating to inhibit PhIP formation during pan-frying of golden pompano fillets.

Hydrocolloids synthesized by gallic acid (GA) and ferulic acid (FA) grafting onto chitosan (CS) were characterized, and their effects on PhIP formation in pan-fried golden pompano were investigated. Spectrograms including nuclear magnetic resonance, Fourier transform infrared spectroscopy and ultraviolet-visible confirmed that GA and FA were successfully grafted onto CS via covalent bonds, with grafting degree of 97.06 ± 2.56 mg GA/g and 93.56 ± 2.76 mg FA/g, respectively. The CS-g-GA and CS-g-FA exerted better solubility and antioxidant activities than CS. For the 8-min pan-fried golden pompano fillets, CS-g-GA and CS-g-FA (0.5 %, m/v) significantly reduced the PhIP formation by 61.71 % and 81.64 %, respectively. Chemical models revealed that CS-g-GA and CS-g-FA inhibited PhIP formation mainly by decreasing the phenylacetaldehyde contents from Maillard reaction and competing with creatinine to react with phenylacetaldehyde. Therefore, it was suggested that CS-g-phenolic acids emerge as novel coating for aquatic products during processing and inhibit heterocyclic amines generation.

Effects of Mactra chinenesis Peptides on Alcohol-Induced Acute Liver Injury and Intestinal Flora in Mice.

Food-borne bioactive peptides have shown promise in preventing and mitigating alcohol-induced liver injury. This study was the first to assess the novel properties of Mactra chinenesis peptides (MCPs) in mitigating acute alcoholic liver injury in mice, and further elucidated the underlying mechanisms associated with this effect. The results showed that MCPs can improve lipid metabolism by modulating the AMPK signaling pathway, decreasing fatty acid synthase activity, and increasing carnitine palmitoyltransferase 1a activity. Meanwhile, MCPs ameliorate inflammation by inhibiting the NF-κB activation, leading to reduced levels of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-1ß). Additionally, a 16S rDNA sequencing analysis revealed that MCPs can restore the balance of gut microbiota and increase the relative abundance of beneficial bacteria. These findings suggest that supplementation of MCPs could attenuate alcohol intake-induced acute liver injury, and, thus, may be utilized as a functional dietary supplement for the successful treatment and prevention of acute liver injury.

Bovine serum albumin-liposome stabilized high oil-phase emulsion: Effect of liposome ratio on interface properties and stability.

This study aimed to solve the issue of poor lipophilicity of natural bovine serum albumin (BSA) by combining with liposomes (Lips) to stabilize high oil-phase emulsions (HOPEs). The interaction between BSA and Lips was mainly driven by hydrophobic forces, followed by hydrogen bonding. The secondary structure and tertiary structure of BSA were characterized and indicated that the addition of Lips promoted the structural expansion of BSA exposing the hydrophobic groups inside. Interfacial adsorption behaviours were assessed through dynamic interfacial tension, three-phase contact angle, and quartz crystal microbalance with dissipation. These results indicated that BSA-Lips crosslinking improved wettability, promoting adsorption and rearrangement at the oil-water interface, thereby resulting in a dense interfacial layer. The emulsifying efficacy of BSA-stabilized HOPEs also displayed a distinct Lips dependency. Varying the BSA-to-Lips ratio transformed their consistency from flowing to semi-solid, reinforcing the gel network. Under optimal conditions (BSA: Lips = 1:1), the droplet size of BSA-Lips stabilized HOPEs reached a minimum with a highly uniform distribution. Moreover, a 1:1 BSA to Lips ensured outstanding storage, thermal, and centrifugal stability for the HOPEs. This work provides valuable references for the interaction between protein and Lips, guiding the development of highly stable HOPEs stabilizers.

Development and characterization of defatted coconut flour based oleogels: A fat substitute for application in oil-fortified surimi.

This research examined the impact of defatted coconut flour (DCF)-based oleogels on the quality of surimi. Microscopic analysis indicated that the dietary fiber present in DCF could act as the main structure of the oleogels network. The formation of the oleogels network primarily relies on the tensile intramolecular or intermolecular hydrogen bonds between DCF and corn oil. The oleogels displayed oil binding capacity of up to 96.95% and exhibited favorable mechanical and rheological properties. Efforts were undertaken to integrate the acquired oleogels into silver carp surimi to create oil-fortified surimi products. Adding oleogels significantly enhanced the gel strength, texture, and water-holding capacity of surimi compared to adding corn oil. Especially, oleogels containing 5.0 % (w/v) DCF concentration elevated the lipid content in the surimi and preserved the gel and texture properties. Therefore, incorporating oleogels in surimi presents a potential solution for enhancing the nutritional content of surimi products.

Effect of non-covalent binding of tannins to sodium caseinate on the stability of high-internal-phase fish oil emulsions.

In this study, we designed the noncovalent binding of sodium caseinate (SC) to tannic acid (TA) to stabilize high internal phase emulsions (HIPEs) used as fish oil delivery systems. Hydrogen bonding was the dominant binding force, followed by weak hydrophobic interaction and weak van der Waals forces, as demonstrated by FTIR, fluorescence spectroscopy, and molecular docking experiments, with a binding constant of 3.25 × 106, a binding site of 1.2, and a static quenching of the binding. Increasing SC:TA from SC to 2:1 decreased the particle size from 107.37 ± 10.66 to 76.07 ± 2.77 nm and the zeta potential from -6.99 ± 2.71 to -22 ± 2.42 mV. TA increased the interfacial tension of SC, decreased the surface hydrophobicity from 1.3 × 104 to 1.6 × 103 and improved the oxidation resistance of SC. The particle size of high internal phase emulsions stabilized by complexes with different mass ratios (SC:TA from 1:0 to 2:1) increased from 4.9 ± 0.02 to 12.9 µm, the potential increased from -32.37 ± 2.7 to -35.07 ± 2.58 mV, and the instability index decreased from 0.75 to 0.02. Thicker interfacial layers could be observed by laser confocal microscopy, and an increase in the storage modulus indicated a formation of a stronger gel network. SC:TA of 1:0 showed emulsion breakage after 14 d of storage at room temperature. SC:TA of 2:1 showed the lowest degree of oil-water separation after freeze-thaw treatment. Especially, the most stable high endo-phase emulsion (at SC:TA of 2:1) prepared at each mass ratio was selected for further stability exploration. The emulsion particle size increased only from 15.63 ± 0.06 to 22.27 ± 0.35 µm at salt ion concentrations of 50-200 mM and to 249.33 ± 31.79 µm at 300 mM. The instability index and storage modulus of the high endo-phase emulsions increased gradually with increasing salt ion concentrations. At different heating temperatures (55-85 °C), the instability index of the high internal phase emulsion gradually decreased and the storage modulus gradually increased. Meanwhile, at 50 °C for 15 d of accelerated oxidation, the content of hydroperoxide decreased from 53.32 ± 0.18 to 37.48 ± 0.77 nmol/g, about 29.7 %, and the thiobarbituric acid value decreased from 1.06 × 103 to 0.8 × 103, about 24.5 %, in the high endo-phase emulsions prepared by 2:1 SC:TA compared to the fish oils, and the SC-stabilized high endo-phase only emulsion broke at the sixth day of oxidation. From the above findings, it was concluded that the high internal phase emulsion prepared with SC:TA of 2:1 can be used as a good delivery system for fish oil.

Raman spectroscopy and molecular dynamics simulations of protein microgels at the oil-water interface.

The real-time structural changes of the molecular space conformation of myofibrillar protein microgels (MPM) after heat treatment (90 °C, 30 min) were analyzed by molecular dynamics simulation, and the structural properties and changes of MPM at the oil-water interface were analyzed by the combination of Raman spectroscopy and molecular dynamics simulation. The shift in the oil ratio had a major impact on the transformation of disulfide bonds within the protein molecule. Simultaneously, it caused tryptophan and tyrosine residues (I850 cm-1/ I850 cm-1 > 1) to become exposed, increasing the locations of amino acid residues in the protein that interact with the oil phase. HIPE with different oil phases influenced the change in spatial structural conformation of MPM, and there was a flexible structural change in the molecular space. The HIPE system, which was stabilized by 3.0 wt% MPM and 0.75 oil phase, exhibited a thixotropic recovery of >70 % and the highest elastic modulus G' (822.14 Pa) based on the rheological behavior. It is expected to provide a theoretical basis for the development and utilization of high internal phase emulsion stabilized by microgel protein in food industry.

Relationship between the interfacial properties of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex and the macroscopic properties of emulsions.

This study explored the relationship between the interfacial behavior of lactoferrin-(-)-epigallocatechin-3-gallate covalent complex (LF-EGCG) and the stability of high internal phase Pickering emulsions (HIPPEs). The formation of covalent bond between lactoferrin and polyphenol was verified by the increase in molecular weight. In LF-EGCG group, the surface hydrophobicity, interfacial pressure, and adsorption rate were decreased, while the molecular flexibility, interfacial film viscoelasticity, and interfacial protein content were increased. Meanwhile, LF-EGCG HIPPE possessed reduced droplet size, increased ζ-potential and stability. Rheology showed the viscoelasticity, structural recovery and gel strength of LF-EGCG HIPPE were improved, giving HIPPE inks better 3D printing integrity and clarity. Moreover, the free fatty acids (FFA) release of LF-EGCG HIPPE (62.6%) was higher than that of the oil group (50.1%). Therefore, covalent treatment effectively improved the interfacial properties of protein particles and the stability of HIPPEs. The macroscopic properties of HIPPEs were positively regulated by the interfacial properties of protein particles. The result suggested that the stability of emulsions can be improved by regulating the interfacial properties of particles.

Interaction between liposome and myofibrillar protein in surimi: Effect on gel structure and digestive characteristics.

This study investigated the effects of the interaction between liposomes and myofibrillar protein (MP) on tilapia surimi. The strong interaction between liposomes and MP was primarily mediated through hydrogen bonding and hydrophobic interaction. Liposomes caused the unfolding of MP structure, resulting in the decrease of α-helix content and transformation of spatial structure. Notably, the appropriate ratio of liposomes improved the gel properties of tilapia surimi. The water distribution, microstructure, and texture characteristics further confirmed that liposomes strengthened the structure of surimi gel through non-covalent bonds. However, excessive liposomes (1.0 %) weakened gel characteristics and texture. Moreover, the proper ratio of liposomes enhanced the stability of surimi gels during digestion, reducing protein digestibility from 66.0 % to 54.8 %. Curcumin-loaded liposomes in gel matrix notably delayed digestion and improved bioavailability. This delay in digestion was attributed to the ability of liposomes to decrease the interaction between MP and digestive enzymes. This study provides new insight into the application of liposomes in protein-rich food matrixes.

Preparation of liposomes by glycolipids/phospholipids as wall materials: Studies on stability and digestibility.

Glycolipids may be potential materials to improve the instability of liposomes during storage and consumption. Curcumin-loaded liposomes with high stability were successfully prepared by glycolipids and phospholipids extracted from tilapia. The physicochemical properties analysed showed that glycolipids enhanced the surface charge of liposomes and the encapsulation ability of curcumin. The enhanced affinity of liposomes for curcumin was attributed to the stronger interaction between the head group of glycolipids and curcumin through hydrogen bonding. As predicted, glycolipids improved the storage stability of liposomes, and the thermal stability of curcumin increased from 35.95% to 54.13%. Moreover, glycolipids could resist the degradation of liposomes in the gastrointestinal tract, reducing the encapsulation efficiency changes of curcumin from 60.67% to 43.63%. Simultaneously, the liposomes formed by glycolipids could more effectively protect nerve cells from oxidative damage. Therefore, the substitution of phospholipids with glycolipids is an effective strategy to improve the stability and bioactivity of liposomes.

Emulsion gel stabilized by tilapia myofibrillar protein: Application in lipid-enhanced surimi preparation.

In this study, surimi products rich in lipids were prepared by using myofibril protein (MP) emulsion gel as carriers. The MP emulsion gel (MP concentration, c = 1.5%, oil fraction, ø = 0.68) was prepared by one-step homogenization. The emulsion gel maintained a high elastic modulus (G') after heating and freezing treatment. Confocal laser scanning microscopy revealed that the structure of the emulsion gel was a hybrid network consisting of polymers of cross-linked MP and aggregated protein-stabilized emulsion (W/O/W multiple structures) droplets. The double emulsification of the emulsion gel and MP stabilized the oil droplets in the surimi product, preventing water and oil from leaching out. The microstructure also showed smaller gaps between MPs with increased porosity, while oil droplets were stably embedded in the surimi gel matrix. Moreover, adding MP emulsion gel significantly reduced the surimi gel strength compared to adding oil directly (p < 0.05).