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This study investigated the influence of heat treatment on the interaction of large yellow croaker (Pseudosciaena crocea) roe protein isolate (pcRPI) with curcumin (Cur), and heated pcRPI (HpcRPI)-Cur and pcRPI-Cur complexes were also prepared. Fourier transform infrared spectroscopy, fluorescence spectroscopy, and surface hydrophobicity analysis indicated that pcRPI and HpcRPI bind to Cur mainly by hydrogen bonds, van der Waals forces, and hydrophobic interactions, and compared with pcRPI, HpcRPI showed better binding effects with Cur. Molecular docking analysis also evaluated the binding site and the forces between vitellogenin, vitellogenin B and C in pcRPI and Cur. Furthermore, HpcRPI-Cur could form gels induced by glucono-δ-lactone (GDL), while pcRPI-Cur-GDL exhibited a fluid state. The HpcRPI-Cur-GDL gels showed great protective effects on Cur in the resistant gastrointestinal environment. These results indicated that heat treatment will improve the application of pcRPI as a functional material in the food field. [Display omitted] • The pcRPI can bind to curcumin via noncovalent interactions and form complexes. • The heat treatment promoted the noncovalent interactions of pcRPI with curcumin. • The heat treatment enhanced the formation of pcRPI cold-set gels. • The heated-pcRPI gel significantly improved the delivery effect of curcumin. [ABSTRACT FROM AUTHOR]

To develop composite hydrogels based on low acyl gellan gum (GG), the effect of puerarin (PUE) on the gel properties of GG was investigated. The results showed that the maximum storage modulus (G ′) of the 1.2 % GG/0.8 % PUE composite hydrogel was 377.4 Pa at 0.1 Hz, which was enhanced by 4.7-fold compared with that of 1.2 % GG. The melting temperature of this composite hydrogel increased from 74.1 °C to >80.0 °C. LF-NMR results showed that a significant amount of free water was present in the hydrogel matrix. The surface structure aggregation and the shrinkage of the honeycomb meshes in the composite hydrogel proved the cross-linking of PUE and GG. XRD, FTIR and molecular simulation results illustrated that hydrogen bonds were the most important factor controlling the interaction between GG and PUE. Thus, the GG/PUE composite hydrogel has good elasticity, thermal stability and water retention, which lays a good foundation for further application in the food industry. [ABSTRACT FROM AUTHOR]

• Gellan gum (GG) improved gel formation of protein isolate from P. crocea roe (pcRPI). • GG improved the rheological properties and water holding ability of pcRPI gels. • The pcRPI-GG binary gels showed denser, more aggregated network structure. • GG improved the protective effects of curcumin by pcRPI gels with control release. The aim of this study was to investigate the effect of gellan gum (GG) on the cold gelation of large yellow croaker roe protein isolate (pcRPI). The water-holding ability and storage modulus of the pcRPI-GG binary gels increased with the GG concentration, where the storage modulus of the pcRPI-0.2% GG gel was approximately 30.7 times that of the pure pcRPI gel. Compare to the other binary gels, pcRPI-0.2% GG gels exhibited a lower lacunarity and higher junction density, with a denser, more aggregated microstructure. Consequently, curcumin was embedded in pcRPI-0.2% GG gels, and simulated gastrointestinal digestion test results showed that GG addition effectively protected and slowed curcumin release in the gastrointestinal environment. These findings may contribute to elucidating the interaction of pcRPI with GG and demonstrate the potential of binary gels for the embedding and delivery of active substances. [ABSTRACT FROM AUTHOR]

A composite hydrogel composed of scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs) and κ -carrageenan (KC) was fabricated with a designed microstructure to preserve curcumin (Cur) during the upper gastrointestinal tract (GIT). The presence of KC obviously increased the initial elastic moduli (8.2–761.8 Pa), shortened the relaxation time T 23 (517.37–420.10 ms) as well as caused the blue shift of the emission peak and quenched the intrinsic fluorescence of Cur in SMGHs/KC-Cur system, signifying the solid combination within SMGHs and KC. In addition, the red shift in O–H stretching bands and blue shift in amide I bands in SMGHs/KC-Cur further accentuated the involvement of hydrogen bonds and electrostatic interactions within SMGHs, KC and Cur. The disappearance of crystalline structures suggested the successful embedment of Cur in the hydrophobic core of SMGHs. Moreover, the microstructure of the hydrogels varied from heterogeneous with tattered large pore cavities and scattered patches to homogeneous distribution with dense mesh and solid network wall. These scenarios caused a more compact network of SMGHs/KC-Cur than SMGHs-Cur to protect Cur from releasing in simulated intestinal and simulated colonic phases with slower released rate, both of which had the final extent of Cur release exceeding 90%. Furthermore, cryo-SEM showed that the significant release of Cur from hydrogels in the simulated intestinal phase was due to SMGHs matrix erosion with even larger pore sizes, tattered network and thinner network wall. Therefore, it is suggested that SMGHs/KC hydrogels with biocompatibility and good tolerance to acid environment could be reliable and desirable soft materials to embed and deliver Cur to the colon, having potential applications in functional foods and biological therapeutic purposes. [Display omitted] - Enhancement of gel elasticity in SMGHs/KC confirmed a feasible Cur-loaded carrier. - Migration of water in SMGHs/KC to bound water direction supported the Cur embedment. - Compact and dense porous networks of SMGHs/KC contributed to the Cur embedment. - Better sustained release of Cur in SMGHs/KC promised the delivery of Cur in colon. [ABSTRACT FROM AUTHOR]

• Low-acyl gellan gum had effect on gelation of scallop male gonad hydrolysates (SMGHs). • Gel strength of SMGHs was increased with increasing of low-acyl gellan gum (GG) dose. • The thermal stability of SMGHs gel was improved by the addition of GG. • The promoting effect of GG on SMGHs gel was related to the water migration. • The SMGHs/GG composite gels showed a regular and homogenous network. This study aimed to examine the gelation and microstructural properties of scallop male gonad hydrolysates (SMGHs) in the presence of low-acyl gellan gum (GG) at different mass ratios. The rheological results showed that both elastic modulus and thermal stability of SMGHs were significantly improved by the addition of GG. Meanwhile, the relaxation time T 23 was significantly reduced in SMGHs/GG by low-field nuclear magnetic resonance, indicating a strong interaction between SMGHs and GG. Fourier transform infrared spectroscopy indicated the blueshift of amide I and II peaks in SMGHs/GG further demonstrated the electrostatic interaction between SMGHs and GG. The network structure of SMGHs/GG binary complexes was more compact and the surface was smoother than that of SMGHs by cryo-scanning electron microscopy. Furthermore, increasing the content of GG in the SMGHs/GG binary complex significantly reinforced the gel strength and promoted the gelation process. [ABSTRACT FROM AUTHOR]

• Protein isolates (pcRPIs) and lipids (pcRLs) of large yellow croaker roes were extracted simultaneously. • The purity of pcRPIs was greater than 70% with vitellogenin, vitellogenin B and vitellogenin C as main proteins. • pcRLs were mainly composed of triglyceride with high level of EPA and DHA content. • pcRPIs exhibited better physicochemical and functional properties than pcR. • pcRPIs had the better oil holding capacity and emulsifying abilities than soy protein isolate. The objective of this study was to simultaneously obtain protein isolates and lipids from the dried powder of large yellow croaker (Pseudosciaena crocea) roes (pcRs) to achieve high-value utilization. Protein isolates and lipids were extracted simultaneously from pcRs by saline and acidic solutions. The purity of the protein isolates from the pcRs (pcRPIs) was greater than 70%, with vitellogenin, vitellogenin B and vitellogenin C as the main proteins. The lipids from pcRs (pcRLs) were mainly composed of triglycerides with high levels of EPA and DHA. The pcRPIs exhibited a higher surface hydrophobicity, water/oil holding capacity and emulsifying ability than those of the pcRs. Moreover, pcRPIs had a better oil holding capacity and emulsifying ability than soy protein isolate. These results suggest that protein isolates and lipids can be simultaneously extracted by saline and acidic solutions, and pcRPIs and pcRLs can be used as functional materials in the food industry. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) offer diverse applications in the food industry, facilitating loading, protection, and controlled release of functional ingredients despite encountering loading capacity and functional activity limitations. This study focuses on curcumin‑zinc MOFs, harnessing curcumin's renowned health benefits and zinc to enhance pharmacological properties. We evaluated their synthesis efficiency, stability under varying conditions (pH, salt concentration, temperature), loading and antioxidant capacity. The results showed that microwave synthesis yielded MOFs with a 23.2 ± 4.5% yield, stable within pH 4–10, gradually decomposing in PBS. DPPH, ABTS, and H₂O₂ assays revealed varying free radical scavenging abilities. MOFs disintegrate in either acidic environments or contain H 2 O 2 (at a concentration threshold of 10 μM). Post-disintegration, these MOFs significantly inhibiting the secretion of TNF-α by RAW264.7 cells induced by LPS. These findings highlight the potential of novel curcumin‑zinc MOF materials for nutrient delivery, addressing challenges in effectively delivering functional ingredients. • Cur-Zn MOFs offer a platform for curcumin or other bioactive component delivery. • The physical properties and antioxidant activity of MOF were studied through simulation and experiment. • Microwave synthesis yielded MOFs with a 23.2 ± 4.5% yield, stable within pH 4–10. • MOF responds to acidic and inflammatory H 2 O 2 environments, in turn scavenging free radicals. [ABSTRACT FROM AUTHOR]

Gel properties of hydrogel-forming by Ala-Lys dipeptide (AK) and iota-carrageenan (ι-C) were investigated by rheological behavior, fourier transform infrared analysis, cryo-scanning electron microscopy, low field-NMR relaxometry and magnetic resonance imaging. Iota-carrageenan was changed from a liquid to a gel with the addition of AK, and the existence of AK significantly increased the storage modulus (G') of ι-C from 590.4 to 1077.8 Pa. In the ι-C/AK gel, the blue-shift of O H stretching and water deformation were observed, meanwhile, the presence of amide I band at 1682 cm−1 was observed. The network of ι-C/AK gel showed a dense honeycomb structure with flocculating continuous phase and rough entanglement morphology. After adding AK, the water free in the pores of ι-C entered the ι-C/AK gel matrix, and the binding capacity of bound water was enhanced. These scenarios proved that the AK as the cationic dipeptide could control the conversion of negatively charged ι-C from an original random structure to a helical structure due to electrostatic interactions and hydrogen bonds. This study provides a new opportunity for the peptides into carbohydrate-based gel matrices, which could provide insights for the further application of ι-C/AK gels in the fields of food industry, tissue engineering and drug delivery. • AK dipeptide enhanced the gel properties of iota-carrageenan. • Electrostatic interactions was the main force in AK/ ι-C gel. • The hydrogen bond stabilized the AK/ι-C gel structure. • AK induced regular and homogenous network structure in the ι-C gel. [ABSTRACT FROM AUTHOR]

[Display omitted] • -KC hydrogel beads with more SMGHs can increase Cur load due to tight cross-linking. • -Modified FTIR and amorphous structure in SMGHs/KC/KCl prove successful Cur embedment. • -SMGHs/KC/KCl-Cur hydrogel beads have heterogeneous networks with backbone and voids. • -SMGHs/KC/KCl hydrogel beads perform as effective colon-targeting Cur delivery system. • -SMGHs/KC/KCl hydrogel beads promise Cur preservation above 90% during 30 day at 4 °C. Scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs)/ κ -carrageenan (KC)/KCl beads with SMGHs:KC ratios (0:10–5:5) were investigated. SMGHs/KC/KCl-Cur bead (5:5) exhibited the most intact spherical morphology and highest Cur loading content of 0.063 mg/0.1 g bead, ascribing to a shortened T 23 from 1607.9 to 966.4 ms, and red and blueshifts of O H, NH, amide I and II bands. The undetected fingerprint region within 7.82°-28.90° of SMGHs/KC/KCl-Cur beads indicated successful Cur entrapment. Moreover, SMGHs/KC/KCl-Cur beads exhibited shrinkage network backbones and larger void pores as SMGHs increased, with vessel percentage area, total number of junctions, total vessel length decreasing from 52.1, 1446.8, 57931.4 to 39.7, 530.5, 34458.4, and lacunarity increasing from 0.048 to 0.111, respectively. Furthermore, Cur showed approximately 50% release contents in colon phase and above 90% retention rate during 30 days of storage at 4 °C. These results suggested that SMGHs/KC/KCl-Cur beads exhibited sustained-release of Cur and promised stable Cur preservation. [ABSTRACT FROM AUTHOR]

Seafood traceability is an important means of ensuring the quality of local seafood. Jellyfish are an important edible resource with a large yield on a global scale. Different species of pickled jellyfish, a traditional Chinese food, cannot be differentiated solely from the appearance of the product due to its special processing methods. In this paper, two species of jellyfish, R. esculentum and S. meleagris , were identified by PCR-RFLP technique. The genetic identification of the jellyfish R. esculentum and S. meleagris was based on PCR amplification of a common 651 bp fragment of the 16S rRNA gene, followed by digestion of four restriction enzymes, Hind III, Hpa I, Xho I and Dra I, respectively. The results showed that the two species of fresh jellyfish could be identified clearly, as could the pickled R. esculentum. To verify this result, PCR-RFLP was applied to authenticate four kinds of commercial pickled jellyfish. The electrophoretogram clearly showed that R. esculentum and S. meleagris were easily and accurately authenticated. This PCR-RFLP system has the potential to become an effective method for identifying the jellyfish products from Liaoning Province of China. • Seafood traceability is an important means to ensure the quality of local featured seafood. • Jellyfish is an important edible resource as palatable food for thousands years. • Fresh jellyfish must be processed into dry goods sales, known as pickled jellyfish. • PCR-RFLP method have high sensitivity and validity for provenance identification. [ABSTRACT FROM AUTHOR]

Abstract This article reported the gelation and microstructural properties of scallop male gonads hydrolysates (SMGHs) in the presence of κ-Carrageenan (κ-C) and treated or untreated with potassium chloride (KCl). The presence of κ-C significantly increased the elastic moduli (10.3–449.5 Pa) and melting temperature (32.7–46.7 °C) of SMGHs. The decrease in the relaxation time (T 21 , T 23) signified the strong binding between SMGHs and κ-C. The blue shift in the amide I and II peals coupled with a new band of 1159 cm−1 in SMGHs/κ-C further demonstrated the electrostatic interactions between SMGHs and κ-C. κ-C rose the percentage of β-sheets from 28.10% to 35.93% but at the expense of α-helix and β-turn fractions and highly ebbed the intrinsic fluorescence of SMGHs. Such scenarios resulted in a more compact network formation and flocculation of κ-C chains. The salt-treatment to κ-C promoted helical formation, however, presence of SMGHs created larger interstitial spaces in the κ-C network due to aggregates of SMGHs and decreased the overall gel strength. The outcome promises novel opportunities in the design and development of functional hydrogels based on protein and polysaccharide complexes for food, pharmaceutical and biomedical applications. Graphical abstract Image 1 • Synergistic effectongelation occursbetweenκ-carrageenan(κ-C)and SMGHs. • Synergistic effect of κ-C on SMGHs may be attributed to the water migration in gel system. • Positive patches of SMGHs and sulfate groups of κ-C entangle by electrostatic interaction. • κ-C-κ-C connections hold the entire networkwhile SMGHsentrapintothisnetwork. • SMGHs appear to create larger interstitial spaces inκC/KClnetwork decreasinggel strength. [ABSTRACT FROM AUTHOR]

Abstract In order to provide a foundation for comprehensive utilization of scallop (Patinopecten yessoensis) , the gel properties of hydrolysates from scallop male gonad (SMGHs) were studied. The hydrolysates were obtained from scallop male gonads (SMGs) by using trypsin. The changes in molecular mass of proteins were determined by SDS-PAGE and HPLC with a peptide separation column. The gel properties of SMGHs were investigated by using rheometer and texture instrument in comparison with that of ι-carrageenan and gelatin. The results showed that the proteins of SMGs were significantly degraded after hydrolysis with trypsin at a dosage of 3000 U/g protein. The SMGHs showed an appearance of gelation after hydrolysis for 30–180 min and cooling down. Under various sweep models, the values of storage modulus (G′), loss modulus (G″), viscosity (ƞ) of SMGHs were obvious higher than those of SMGs. The textural parameters containing firmness, cohesiveness and adhesive force of SMGHs at dosages of 50 and 75 mg/mL were similar to those of ι-carrageenan and gelatin at 25 mg/mL, respectively. For the mixtures, the gel property of SMGHs/ι-carrageenan SMGHs/gelatin increased significantly. The low-field NMR (LF-NMR) also reflected the T 23 of SMGHs/ι-carrageenan, T 21 of SMGHs/ι-carrageenan and SMGHs/gelatin mixture decreased significantly in comparison with SMGHs alone. These results suggest that SMGHs could be applied as a potential gelling and thickening agent in food formulations. Graphical abstract Image 1 Highlights • SMGHs treated by trypsin showed a specific gel property caused by peptides. • Gel property of SMGHs had hydrolysate time- and hydrolysate dose-dependent manners. • Gel strength of SMGHscan be comparable with ι-carrageenan and gelatin. • Synergistic effect on gelation was occurred betweenι-carrageenanand SMGHs. • Synergistic effect on water migration was foundbetweenι-carrageenanand SMGHs. [ABSTRACT FROM AUTHOR]

The objective of the present study was to improve the utilization of scallop ( Chlamys farreri ) byproducts by using Maillard reaction. Scallop mantle hydrolysates (SMHs) were prepared using neutrase then reacted with ribose. Thirty-four peptides were identified from SMHs by UPLC-Q-TOF-MS, and the abundance of Asp and Lys suggested the strong Maillard reactivity. The formation of Schiff’s base as well as modification of amide I, II and III bands in Maillard reaction products (MRPs) was confirmed by ultraviolet–visible, fluorescence, and Fourier transform infrared spectroscopy. Thirty volatile compounds were produced by the reaction of SMHs with ribose. Moreover, MRPs with enhanced radical scavenging and anti-linoleic acid peroxidation activities over SMHs promoted the survival and reduced the DNA damage of HepG2 cells treated with hydrogen peroxide. These results suggest that SMHs-ribose MRPs can be potentially used as food antioxidant for suppressing of lipid oxidation or protecting of cell from oxidative damage. [ABSTRACT FROM AUTHOR]

[Display omitted] • -Ca2+ and K+ binding to IC promotes gelation of AK/IC with dose-dependent manner. • -Different state of water in AK/IC could resist the salt interference. • -AK/IC mediated by salts appears well honeycomb structures and even denser under Ca2+. • -AK/IC mediated by salts exhibits highly aggregation and entanglement fibers chains. • -Hydrogen bonding combined electrostatic interactions govern the salt-mediated AK/IC. The gelation and microstructural behaviors of Ala-Lys dipeptide/iota-carrageenan (AK/IC) mediated by salts were investigated. Obviously, salt addition prominently exaggerated the synergistic gelation between AK and IC, with storage modulus (G') of AK/IC and IC increasing extensively from 1145 to 9516 Pa or 5919 Pa and from 615 to 9981 Pa or 4693 Pa at 0.1 Hz with 0.5 % CaCl 2 or KCl, respectively, in which CaCl 2 revealed superiority over KCl. Additionally, different states of water in AK/IC gels resisted salt interference. Moreover, a honeycomb structure with denser porous networks coupled with rough entanglement morphology of AK/IC was observed, in which the CaCl 2 -treated group exhibited even smaller pore sizes. The conformational changes of AK/IC induced by salts were reflected by the redshift of –OH groups in AK/IC, insinuating salt-mediated H-bonding in AK/IC. The blueshift of amide I bands and water deformation groups of AK/IC in comparison to AK and IC alone illustrated the electrostatic interactions between them. Furthermore, coordination interaction, hydrogen bonds and hydrophobic interactive were highlighted among IC, AK and CaCl 2 /KCl as reflected by molecular docking. [ABSTRACT FROM AUTHOR]

• pH and ratio largely governed turbidity changes of SMGHs/ κ -C complexes. • pH c exhibited ratio-independent, and pH φ1 , pH max exhibited ratio-dependent behaviors. • SMGHs aggregates and agglomerated SMGHs/ κ -C support the gel strength at acid pH. • SMGHs/ κ -C at acid pH had greater interaction with water to support the gel formation. • SMGHs/ κ -C formed a denser network at acid pH with stronger gel strength. The electrostatic complex coacervation between scallop Patinopecten. yessoensis male gonad hydrolysates (SMGHs) and κ -carrageenan (κ -C) were monitored by using turbidimetry at various pH (1–12) and biopolymer mixing ratio (9:1–1:9). The pH c exhibited ratio-independent behavior, and pH φ1 , pH max exhibited ratio-dependent behavior, respectively. The decreasing ratio enhanced the gel strength of SMGHs/ κ -C at higher pH while inversely at lower pH, ascribing to more SMGHs aggregates and stronger neutralization between positively charged patches in SMGHs and κ -C at lower pH and higher ratio. Moreover, SMGHs/ κ -C gel at acid condition exhibited lower relaxation times (T 21 and T 23). Furthermore, the rheological and relaxation time T 2 data were well associated with microscopy images which indicated that SMGHs/ κ -C gel showed a well-distributed network structure at more acidic domains, supporting stronger gel rigidity and water-holding capacity. [ABSTRACT FROM AUTHOR]

• Complex coacervation of SMGHs/ κ -C is largely governed by NaCl/KCl. • pH c and pH φ1 exhibited salt-dependent behaviors. • Optical density of SMGHs/ κ -C was regulated by salt-enhanced and -reduced effect. • Salt addition enhanced SMGHs/ κ -C gels mainly driven by electrostatic forces. • SMGHs/ κ -C showed more flocculation, larger pore and thicker network wall with salt. The complex coacervation between scallop Patinopecten yessoensis male gonad hydrolysates (SMGHs) and κ -carrageenan (κ -C) as influenced by ionic strength (NaCl and KCl) were monitored by using turbidimetric analysis at pH 1–12. The optical density of SMGHs/ κ -C complexes initially increased at lower ionic strength (0–0.5 M) whereas decreased at higher ionic strength (0.5–1.5 M) as a result of the salt-enhanced and salt-reduced effect, respectively. Both of pH c and pH φ1 exhibited ionic strength-dependent behavior that firstly shifted to acidic pH followed by an increase as salt increasing. Moreover, salt addition strongly promoted the gelation of SMGHs/ κ -C which was mainly driven by electrostatic forces, as reflected by increasing storage modulus G' from 3621 to 6559 Pa, 2681–25631 Pa at 0.1 Hz and decreasing T 23 relaxation time from 349.10 to 296.89 ms, 241.07–186.89 ms by 0–0.5 M NaCl/KCl, respectively. Furthermore, the rheological and relaxation time T 2 data were well associated with microscopy images that SMGHs/ κ -C gels with NaCl/KCl showed a denser network with more flocculation formation and larger pore sizes with thicker network wall, especially in KCl group, which indeed supported the gel elasticity. Taken together, this study could provide theoretical and methodological basis for new functional hydrogel products with modified gel strength and microstructure by understanding the complex coacervation in gel system. [ABSTRACT FROM AUTHOR]