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BACKGROUND: Laboratory scale experiments have shown that curdlan and gellan gum gelled together as curdlan/gellan gum (CG) hybrid gels showed better gel properties than the individual curdlan and gellan gum. In this study, CG and black wolfberry anthocyanin (BWA), CG and maltitol (ML) hybrid gels were constructed using CG hybrid gel as matrix. The effects of BWA or ML on the gel properties and microstructure of CG hybrid gels were investigated and a confectionery gel was developed. RESULTS: The presence of BWA increased the storage modulus (G') value of CG at 0.1 Hz, whereas ML had little effect on the G' value of CG. The addition of BWA (5 g L−1) and ML (0.3 mol L−1) increased the melting and gelling temperatures of CG hybrid gels to 42.4 °C and 34.1 °C and 44.2 °C and 33.2 °C, respectively. Meanwhile, the relaxation time T22 in CG‐ML and CG‐BWA hybrid gels was reduced to 91.96 and 410.27 ms, indicating the strong binding between BWA and CG, ML and CG. The hydrogen bond interaction between BWA or ML and CG was confirmed by the shift in the hydroxyl stretching vibration peak. Moreover, the microstructures of CG‐ML and CG‐BWA hybrid gels were denser than that of CG. In addition, confectionery gel containing CG‐BWA‐ML has good chewing properties. CONCLUSION: These results indicated that the incorporation of BWA or ML could improve the structure of CG hybrid gels and assign a sustainability potential for the development of confectionery gels based on CG complex. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The gelation of scallop Patinopecten yessoensis male gonad hydrolysates (SMGHs) and κ-carrageenan (KC) subjected to pH (2–8, 3–9) and NaCl/KCl stimuli-response was investigated. SMGHs/KC gels subjected to a NaCl response exhibited an increasing storage modulus G′from 2028.6 to 3418.4 Pa as the pH decreased from pH 8 to 2, with corresponding T23 fluctuating from 966.40 to 365.64 ms. For the KCl-treated group, SMGHs/KC gels showed an even greater G′ from 4646.7 to 10996.5 Pa, with T23 fluctuating from 622.2 to 276.98 ms as the pH decreased from 9 to 3. The improved gel strength could be ascribed to the blueshift and redshift of hydroxyl groups and amide I peaks, enhanced enthalpy and peak temperature, and gathered characteristic diffraction peaks from SMGHs, KC, NaCl, and KCl. The CLSM and cryo-SEM images further reflected that SMGHs/KC gels showed more flocculation formation and denser and more homogeneous networks with smaller pore sizes in more acidic domains, especially when subjected to the KCl response. This research gives a theoretical and methodological understanding of the construction of salt- and pH-responsive SMGHs/KC hydrogels as novel functional soft biomaterials applied in food and biological fields. [ABSTRACT FROM AUTHOR]

In this study, hydrolysates of large yellow croaker (Pseudosciaena crocea) roe were prepared by trypsin (Try‐pcRHs) and papain (Pap‐pcRHs). The degree of hydrolysis (DH), molecular weight distribution and iron chelating capacity of hydrolysates were investigated. Moreover, the chelation mechanism of iron‐hydrolysates complex also was investigated by amino acid composition analysis, fourier transform infrared spectrophotometer, fluorescence spectrophotometer and ultraviolet–visible spectroscopy. These results showed that Try‐pcRHs exhibited higher iron chelating ability with the EC50 value of 0.14 mg/ml than Pap‐pcRHs, which may be due to the higher DH and content of peptide <1 KDa. Furthermore, the Asp, Glu, Ser, Pro, Ile, Phe and His in Try‐pcRHs might contribute to the chelation reaction, and the groups of ‐COOH, C=O, N‐H and C‐O were involved in chealtiong of Try‐pcRHs with iron. Therefore, Try‐pcRHs have the potential to be used as iron supplements in food industries. Practical Applications: Large yellow croaker (Pseudosciaena crocea) roes are the main by‐products in the large yellow croaker processing. Previous studies have found that protein isolates from P. crocea roes composed of vitellogenin B, vitellogenin C and vitellogenin contain a large number of serine residues. In this study, we prepared hydrolysates from large yellow croaker roes, and the results showed that trypsin‐hydrolyzed large yellow croaker roes exhibited great iron‐chelating ability and has the potential to be used as a safe and healthy iron supplements in the food industry. [ABSTRACT FROM AUTHOR]

The combination of κ‐Carrageenan (KC) and konjac gum (KGM) were introduced to examine the impact on gelation and microstructural behaviors of scallop male gonads hydrolysates (SMGHs) and the involvement of intermolecular forces. In terms of G′ response of SMGHs/KGM/KC, it obviously enhanced by 3.6‐ and 108.5‐fold than controls of KGM/KC and SMGHs/KC at 0.1 Hz, accompanying increasing melting temperatures from 27.9 (KGM/KC) and 30.0 (SMGHs/KC) to 33.7°C (SMGHs/KGM/KC), respectively. Additionally, SMGHs/KGM/KC with decreasing relaxation time T23 and blue shift of hydroxyl group than controls suggested higher water retention capacity and ordered conformation. Moreover, SMGHs/KGM/KC formed compact networks with thick walls as reflected by cryo‐SEM and showed rougher surface with more aggregation as reflected by AFM. Furthermore, electrostatic in couple with hydrophobic interactions were dominant interactions, while hydrogen bonds were involved in subordinately in SMGHs/KGM/KC. Practical Application: Scallop (Patinopecten yessoensis) male gonads are always discarded during processing despite high‐protein content and edibility. In the current research, scallop male gonad hydrolysates (SMGHs) exhibited gelation behavior, which have a potential role in developing marine source protein as a functional food base such as kamaboko gels, can, sausage and spread and even delivery vehicles for bioactive compounds. [ABSTRACT FROM AUTHOR]

The complex coacervation between scallop (Patinopecten yessoensis) female gonad protein isolates (SFGPIs) and sodium alginate (SA) was determined by the turbidimetric method. The impact of pH, total biopolymer concentration, biopolymer blend ratio, and various salt ionic on the mechanisms governing the complex coacervation of SFGPIs–SA complexes were also investigated. For the SFGPIs:SA ratio of 2:1 without adding NaCl, insoluble and soluble complexes were observed at pH 5.8 (pHφ1) and pH 8.2 (pHc) with the optimum biopolymer interactions appearing at pH 2.6 (pHopt). The maximum turbidity value increased with the increment of the total biopolymer concentration from 0.37 to 1.83 until attaining the critical value (0.75%). As the blend ratios rose from 1:3 to 12:1, the critical pH values (pHc, pHφ1, and pHopt) moved to higher pH. Furthermore, the addition of NaCl led to a remarkable decrease in turbidity over the whole pH region in SFGPIs–SA complexes. Moreover, monovalent ions (Na+ and K+) had the same effect on the formation of the SFGPIs–SA complex, whereas the divalent cations (Mg2+ and Ca2+) lessened the complex formation in comparison with the monovalent ions. This study offers a methodological and theoretical basis for the design of complex SFGPIs–SA systems by understanding the complex coacervation under different conditions. Practical Application: In recent years, several protein–polysaccharides complexes have been widely applied in food and biological systems. Scallop (Patinopecten yessoensis) female gonads are deemed as good marine sources for developing protein matrices on account of their high protein content and nutrients. In our study, the effects of different conditions on the mechanisms governing the complex coacervation of SFGPI–SA mixtures were investigated, and the instability of the system could be overcome by understanding the conditions for SFGPIs/SA complex formation, which have a feasible role in developing marine source‐protein as a functional food base such as kamaboko gels, can, sausage, fat substitutes, and delivery vehicles for bioactive compounds. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the properties of ternary composite gel of scallop (Patinopecten yessoensis) protein hydrolysates (SMGHs)/κ‐carrageenan (KC)/xanthan gum (XG). The rheological properties, moisture‐distribution, molecular structure, and microstructure of SMGNs/KC/XG gels were analyzed. The results showed that the G′ value, melting temperature, and water holding capacity of SMGHs/KC/XG were higher than those of SMGHs, SMGHs/KC, and SMGHs/XG. FTIR spectrum showed the generation of hydrogen bonds between SMGHs and KC/XG, and the carboxylic acid group of XG interacts with SMGHs. Moreover, the cryo‐SEM results showed that SMGHs/KC/XG exhibited a tighter, smoother, and more aggregated microstructure than those of SMGHs, SMGHs/KC, and SMGHs/XG. These results indicate that the gel and microstructural properties of SMGHs are significantly improved by addition of KC and XG, and SMGHs/KC/XG has potential to be used as functional hydrogels for food, pharmaceutical, and biomedical applications. Practical Application: Scallop (Patinopecten yessoensis) male gonads are rich in protein and usually regarded as byproducts during adductor processing. Because of its gelation properties, scallop male gonads have potential to be used as functional hydrogels for food. The SMGHs/KC/XG ternary composite gel showed excellent gel properties, which would be potentially applied in delivery system in food and biological fields. Further study is undergoing to apply SMGHs/KC/XG to embed bioactive compounds, such as curcumin and β‐carotene. [ABSTRACT FROM AUTHOR]

BACKGROUND: Large yellow croaker (Pseudosciaena crocea) roe is the main by‐product in the processing of large yellow croaker. Previous studies have found that its protein isolates are composed of vitellogenin, as well as vitellogenin B and C, having good functional properties. (‐)‐Epigallocatechin‐3‐gallate (EGCG) is a natural antioxidant component that can be combined with protein to improve antioxidant activity and structural characteristics of protein. RESULTS: EGCG was bound with the P. crocea roe protein isolate (pcRPI) by the free radical method to prepare the conjugate. The formation of pcRPI–EGCG conjugates was confirmed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and gel permeation chromatography, which showed that the calculated weight‐average molar masses of native‐pcRPI and pcRPI–EGCG conjugates were 86.9 and 215.3 kDa, respectively. The results of fluorescence, ultraviolet, circular and infrared spectra indicated that the conjugation of EGCG with native‐pcRPI changed the secondary and tertiary structure of native‐pcRPI. The pcRPI–EGCG conjugates exhibited higher thermal stability than native‐pcRPI. The radical scavenging and reducing power of native‐pcRPI were increased by 2.0–2.5‐ and 1.4‐fold, respectively, after the EGCG‐grafting reaction. CONCLUSION: These results indicate that the binding of pcRPI and EGCG effectively improved the antioxidant properties and structural characteristics of the pcRPI. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Here, a novel decapeptide IVTNWDDMEK with Maillard reactivity derived from scallop Chlamys farreri mantle was identified. The structural characteristics and in vitro hepatoprotective effects of IVTNWDDMEK conjugated with ribose were further investigated. The changes in decapeptide structures were determined by ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR), and atomic force microscopy (AFM), and the modification sites induced by Maillard reaction of IVTNWDDMEK and ribose were monitored by high performance liquid chromatography/tandem mass spectrometry (HPLC‐MS/MS). Maillard reaction products (MRPs) of IVTNWDDMEK‐ribose demonstrate hepatoprotective benefits through the suppression of DNA damage and apoptosis induced by oxidative stress in human HepG2 cells in addition to enhancing the antioxidant activities. Moreover, after treatment with decapeptide‐ribose MRPs, the activities of cellular antioxidative enzymes, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), and glutathione reductase (GSH‐Rx) were remarkably increased, while the content of malondialdehyde (MDA) was decreased compared with H2O2‐treated group, thereby enhancing the intracellular antioxidant defenses. These findings demonstrate the potential utilization of decapeptide IVTNWDDMEK‐ribose MRPs as food antioxidants to suppress oxidative damage. Practical Application: In recent years, several food‐derived bioactive peptides and their derivatives are regarded as good dietary antioxidants for reducing oxidative stress and improving liver function. Here, a novel Maillard reactive decapeptide IVTNWDDMEK, identified from scallop mantle hydrolysates by peptidomics in the previous study was synthesized. Then, the correlation between intercellular antioxidant activities and chemical structure changes of IVTNWDDMEK‐ribose Maillard reaction conjugates was further studied. The preferable hepatoprotective activities of decapeptide IVTNWDDMEK‐ribose MRPs indicated that these MRPs could be potentially utilized as food antioxidants or additives in the production of nutritional foods. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize the electrostatic complexation between scallop Patinopecten yessoensis male gonad hydrolysates (SMGHs) and κ -carrageenan/xanthan gum (KC/XG) within pH 12–1 at different hydrolysate/polysaccharide ratios (9:1–1:9) and to investigate the influence of pH and ratios on gelation and microstructural properties for widening the application of marine-derived source. According to the phase diagram of SMGHs/KC/XG, pH c hold a constant value around pH 8.5, pH φ1 gradually shifted from 4.2 to 2.8, and pH max fluctuated within 2.4-1.4 as ratios decreasing from 9:1–2:8. Additionally, SMGHs/KC/XG showed higher gel strength in acid condition, as decreasing pH promoted the electrostatic attractive interactions within positively charged patches in SMGHs and negatively charged sulfate and carboxyl groups in KC/XG causing more tightly packed structures formation. Moreover, decreasing ratios from 9:1 to 3:7 could further enhance the gel strength of SMGHs/KC/XG, ascribing to the stronger gelation ability of polysaccharides and enough neutralization. Moreover, SMGHs/KC/XG exhibited well-organized microstructures with smaller pore sizes, denser and more homogeneous networks at more acid domains, supporting stronger gel strength. Therefore, this study provides theoretical and methodological basis for designing novel SMGHs/KC/XG hydrogels with considerable gel strength and microstructures through understanding the complex coacervation at different pH and ratios. • pH and ratio largely regulate turbidity changes of SMGHs/KC/XG complexes. • pH c exhibits ratio-independent, and pH φ1 , pH max exhibit ratio-dependent behaviors. • Higher KC/XG proportion supports stronger gel strength in soluble phases. • More SMGHs/KC/XG neutralization promotes gel formation in insoluble coacervate phase. • SMGHs/KC/XG exhibits well-organized and compact networks at acid condition. [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]

Dysphagia has emerged as a serious health issue facing contemporary society. Consuming thickened liquids is an effective approach for improving the swallowing safety for dysphagia patients. The thickening effect of chia seed gum (CSG), a novel thickener, in different dispersing media (water, orange juice, and skim milk) was investigated. Moreover, the potential application of CSG for dysphagia management was evaluated by comparison with xanthan gum (XG) and guar gum (GG). The thickened liquids prepared with 0.4 %-1.2 % (w/v) CSG, XG, and GG could be classified into levels 1-4, 2-4, and 1-3, respectively, according to the International Dysphagia Diet Standardization Initiative (IDDSI) framework. All the thickened liquids displayed shear-thinning characteristics that facilitated safe swallowing. The viscosities (η 50 ) of CSG dissolved in water (0.202-1.027 Pa·s) were significantly greater than those of CSG dissolved in orange juice (0.070-0.690 Pa·s) and skim milk (0.081-0.739 Pa·s), indicating that CSG had a greater thickening effect in water than in orange juice and skim milk. Compared with those prepared with GG, the thickened liquids prepared with CSG and XG exhibited greater viscoelasticity, better water-holding capacity, and more compact networks. The findings suggested that CSG can be used as a potential thickener for thickening liquid foods to manage dysphagia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Skin-derived precursor Schwann cells have been reported to play a protective role in the central nervous system. The neuroprotective effects of skin-derived precursor Schwann cells may be attributable to the release of growth factors that nourish host cells. In this study, we first established a cellular model of Parkinson's disease using 6-hydroxydopamine. When SH-SY5Y cells were pretreated with conditioned medium from skin-derived precursor Schwann cells, their activity was greatly increased. The addition of insulin-like growth factor-2 neutralizing antibody markedly attenuated the neuroprotective effects of skin-derived precursor Schwann cells. We also found that insulin-like growth factor-2 levels in the peripheral blood were greatly increased in patients with Parkinson's disease and in a mouse model of Parkinson's disease. Next, we pretreated cell models of Parkinson's disease with insulin-like growth factor-2 and administered insulin-like growth factor-2 intranasally to a mouse model of Parkinson's disease induced by 6-hydroxydopamine and found that the level of tyrosine hydroxylase, a marker of dopamine neurons, was markedly restored, α-synuclein aggregation decreased, and insulin-like growth factor-2 receptor down-regulation was alleviated. Finally, in vitro experiments showed that insulin-like growth factor-2 activated the phosphatidylinositol 3 kinase (PI3K)/AKT pathway. These findings suggest that the neuroprotective effects of skin-derived precursor Schwann cells on the central nervous system were achieved through insulin-like growth factor-2, and that insulin-like growth factor-2 may play a neuroprotective role through the insulin-like growth factor-2 receptor/PI3K/AKT pathway. Therefore, insulin-like growth factor-2 may be an useful target for Parkinson's disease treatment., Competing Interests: None

Autophagy has been shown to play an important role in Parkinson's disease. We hypothesized that skin-derived precursor cells exhibit neuroprotective effects in Parkinson's disease through affecting autophagy. In this study, 6-hydroxydopamine-damaged SH-SY5Y cells were pretreated with a culture medium containing skin-derived precursors differentiated into Schwann cells (SKP-SCs). The results showed that the SKP-SC culture medium remarkably enhanced the activity of SH-SY5Y cells damaged by 6-hydroxydopamine, reduced excessive autophagy, increased tyrosine hydroxylase expression, reduced α-synuclein expression, reduced the autophagosome number, and activated the PI3K/AKT/mTOR pathway. Autophagy activator rapamycin inhibited the effects of SKP-SCs, and autophagy inhibitor 3-methyladenine had the opposite effect. These findings confirm that SKP-SCs modulate the PI3K/AKT/mTOR pathway to inhibit autophagy, thereby exhibiting a neuroprotective effect in a cellular model of Parkinson's disease. This study was approved by the Animal Ethics Committee of Laboratory Animal Center of Nantong University (approval No. S20181009-205) on October 9, 2018., Competing Interests: None