Digestion and absorption characteristics of iron-chelating silver carp scale collagen peptide and insights into their chelation mechanism.

Iron deficiency is widespread throughout the world, supplementing sufficient iron or improving the bioavailability of iron is the fundamental strategy to solve the problem of iron scarcity. Herein, we explored a new form of iron supplement, iron chelates of silver carp scales (SCSCP-Fe) were prepared from collagen peptide of silver carp scales (SCSCP) and FeCl2·4H2O, the effects of external environment and simulated gastrointestinal digestive environment on the stability of SCSCP-Fe and the structural changes of peptide iron chelates during digestion were investigated. The results of in vitro iron absorption promotion showed that the iron bioavailability of SCSCP-Fe was higher than that of FeSO4. Two potential high iron chelating peptides DTSGGYDEY (DY) and LQGSNEIEIR (LR) were screened and synthesized from the SCSCP sequence by molecular dynamics and LC-MS/MS techniques. The FTIR results displayed that the binding sites of DY and LR for Fe2+ were the carboxyl group, the amino group, and the nitrogen atom on the amide group on the peptide. ITC results indicated that the chelation reactions of DY and LR with Fe2+ were mainly dominated by electrostatic interactions, forming chelates in stoichiometric ratios of 1:2 and 1:1, respectively. Both DY and LR had a certain ability to promote iron absorption. The transport of DY-Fe chelate may be a combination of the three pathways: PepT1 vector pathway, cell bypass, and endocytosis, while LR-Fe chelate was dominated by bivalent metal ion transporters. This study is expected to provide theoretical reference and technical support for the high-value utilization of silver carp scales and the development of novel iron supplements.

Perilla juice and ginger juice reduced warmed-over flavor (WOF) in surimi gels: Due to the inhibition of the formation of the WOF compounds and the masking of the WOF.

The effects and reasons of perilla juice (PJ) and ginger juice (GJ) on the reduction of "warmed-over flavor" (WOF) in surimi gels were revealed by detecting odor profiles and protein and lipid oxidation degrees of surimi gels, concentrations and odor activity values (OAVs) of WOF compounds. Adding PJ and GJ to surimi gels significantly reduced the WOF and improved the fish fragrance odor, but sodium ascorbate (SA) only weakened the WOF. The (E,E)-2,4-heptadienal's OAVs in the PJ and GJ groups were decreased by >50% compared with the control check (CK) and SA groups. Meanwhile, surimi gels added with PJ and GJ presented lower lipid and protein oxidation degrees. The verification test indicated that PJ and GJ's aroma had a masking effect on the WOF. In conclusion, PJ and GJ reduced the WOF in surimi gels by preventing WOF compounds' production and masking the WOF with their distinct aroma.

Gelling properties of acid-induced tofu (soybean curd): Effects of acid type and nano-fish bone.

The effects of different types of acid coagulants and nano fish bone (NFB) additives on the characteristics of tofu were investigated using texture analyzers, SEM, FT-IR, and other techniques. The breaking force and penetration distance, in descending order, were found in the tofu induced by glucono-d-lactone (GDL) (180.27 g and 0.75 cm), citric acid (152.90 g and 0.74 cm), lactic acid (123.33 g and 0.73 cm), and acetic acid (69.84 g and 0.58 cm), respectively. The syneresis of these tofu samples was in the reverse order (35.00, 35.66, 39.66, and 44.50%). Lightness and whiteness were not significantly different among the different samples. Regardless of the acid type, the soluble calcium content in the soybean milk was significantly increased after adding NFB. As a result, the breaking force and penetration distance of all tofu samples increased significantly, but the syneresis decreased. Compared with tofu coagulated by other acids, GDL tofu formed a more uniform and dense gel network maintained by the highest intermolecular forces (especially hydrophobic interactions). Regarding the secondary structure, the lowest percentage of α-helix (22.72%) and, correspondingly, the highest ß-sheet (48.32%) and random coil (18.81%) were noticed in the GDL tofu. The effects of NFB on the tofu characteristics can be explained by the changes in the gel network, intermolecular forces, and secondary structure, which were in line with the acid type. The characteristics of acid-induced tofu can be most synergistically improved by coagulation with GDL and NFB.

Synthesis and application of gelatin-based controlled-release antibacterial films containing oregano essential oil/ß-cyclodextrin microcapsules for chilling preservation of grass carp fillets.

This work aimed to synthesize oregano essential oil/ß-cyclodextrin microcapsules (OEO/ß-CDs) and then prepare gelatin-based controlled-release antibacterial films with different OEO/ß-CDs contents (0%-2%) for chilling preservation of grass carp fillets. The results of FTIR, XRD, DSC and accelerated release ratio showed that OEO was successfully encapsulated in OEO/ß-CDs and its thermal stability was effectively improved. Moreover, at 2% of addition amount of OEO/ß-CDs, the tensile strength of the films increased from 14.43 MPa to 18.72 MPa. In addition, the films showed significant antibacterial activity against Pseudomonas (61.52%), Aeromonas (62.87%), and Shewanella putrefaciens (66.67%). Preservation experiments showed that the films effectively prevented the increase of TVB-N, and TBA value of the refrigerated fillets and significantly suppressed the growth of spoilage organisms, thus extending the shelf life by 2-3 days. Therefore, the synthesized film has promising potential as an active packaging material for the preservation of grass carp.

A comprehensive review of the mechanisms on fish stress affecting muscle qualities: Nutrition, physical properties, and flavor.

Fish inevitably face numerous stressors in growth, processing, and circulation. In recent years, stress-related change in fish muscle quality has gradually become a research hotspot. Thus, the understanding of the mechanism regarding the change is constantly deepening. This review introduces the physiological regulation of fish under stress, with particular attention devoted to signal transduction, gene expression, and metabolism, and changes in the physiological characteristics of muscular cells. Then, the influences of various stressors on the nutrition, physical properties, and flavor of the fish muscle are sequentially described. This review emphasizes recent advances in the mechanisms underlying changes in muscle quality, which are believed to be involved mainly in physiological regulation under stress. In addition, studies are also introduced on improving muscle quality by mitigating fish stress.

Pre-rigor salting improves gel strength and water-holding of surimi gel made from snakehead fish (Channa argus): The role of protein oxidation.

The purpose of this study was to determine the effect of pre-rigor salting on the quality characteristics of surimi gels prepared from snakehead fish muscle. Pre-rigor and post-rigor muscle were mixed with 0.3% or 3% NaCl (w/w) and made into surimi gels, respectively. Results showed that pre-rigor muscle had a higher content of ATP, longer sarcomere, higher pH and greater protein solubility. Metabolic profile suggested that pre-rigor muscle had higher content (a 28-fold increase) of antioxidants such as butyryl-l-carnitine. Transmission electron microscopy showed more damage of mitochondria in post-rigor muscle. Surimi paste from pre-rigor meat chopped with 3% NaCl generally showed greater radical scavenging ability and had higher content of free sulfhydryl. Surimi gel made from pre-rigor muscle salted with 3% NaCl showed a larger gel strength (3.18 kg*mm vs. 2.22 kg*mm) and better water-holding (86% vs. 80%) than that of post-rigor group. Based on these findings, we hypothesized that: In addition to other factors such as pH, degree of denaturation, etc., less protein oxidation in pre-rigor salted surimi also contributes to the improved gel properties.

Study by means of 1H nuclear magnetic resonance of the oxidation process in high oleic sunflower oil and palm oil during deep-frying of fish cakes.

This study aimed to compare the frying performance of palm oil (PO) and high oleic sunflower oil (HOSO) during frying aquatic products. The quality change and frying performance of HOSO and PO during frying of fish cakes were investigated. The oxidation and hydrolysis products of both oils were explored by the nuclear magnetic resonance technique. The results showed that the color deepening rate of PO was higher than that of HOSO. After 18 h of frying, the total polar compound content of PO and HOSO reached 25.67% and 27.50%, respectively. HOSO had lower degree of oxidation than PO after 24 h of continuous frying. The polyunsaturated fatty acid content in HOSO and PO significantly decreased. The oleic acid content in HOSO remained above 80% during the frying process. The major aldehydes in both oils were (E, E)-2,4-alkadienals and n-alkanals and glycerol diesters (DAGs) were abundant in PO. Furthermore, the addition of fish cakes had slight effect on the quality of the frying oil. Therefore, HOSO is an appropriate candidate for frying owing to its excellent frying stability and nutritional value.

Exploring the versatility of carbohydrates in surimi and surimi products: novel applications and future perspectives.

Carbohydrate is one kind of the most important additives in the production of surimi and surimi products, mainly due to its wide range of sources and superior functionality. In recent years, new carbohydrates (oligosaccharides and polysaccharides) have been gradually applied in the production of surimi and surimi products which is mainly driven by consumer requirement on nutritional and the flavors or taste quality and producer requirement on extending the shelf life, like low calorie intake, dietary fiber enrichment, rich taste and improvement of antioxidant properties. Besides anti-freezing and improvement in gelling ability, novel functionalities have been explored such as fat substitution, improving flavor, antibacterial effect, antioxidant effect and improving three-dimensional printability. With an in-depth study of the mechanism of carbohydrate improving the qualities of surimi and surimi products, the application of carbohydrates in surimi would be more effective. Therefore, this review summarizes the new carbohydrates applied in the processing of surimi and surimi products, and their novel functionalities. Additionally, progress of the research on the mechanism of carbohydrate improving the qualities of surimi is also reviewed. © 2023 Society of Chemical Industry.

A mini review on manipulation of carbohydrate for better use in surimi and surimi products: modification and compounding.

Carbohydrate is widely used in the production of surimi and surimi products to improve their qualities, such as anti-freezing capability, gelling ability, nutrition, flavor and 3D printability. More and more native carbohydrates have been modified through physical methods (e.g., ball milling, irradiation and differential sedimentation), chemical method (e.g., deacetylation, hydroxypropylation and acetic acid esterification) or enzymatic method (e.g., chitosanase) before being used in the processing of surimi and surimi products in recent years. At the same time, different carbohydrates are compounded and applied to surimi and surimi products. The modified and compounded carbohydrates in surimi have been proved to improve quality of surimi and surimi products more pronouncedly than native carbohydrates. Therefore, this review summarizes the manipulation of carbohydrate by modification and compounding to improve the qualities of surimi and surimi products. Moreover, the prospects for carbohydrate modification and compounding for use in surimi and surimi products are discussed. © 2023 Society of Chemical Industry.

Effects of Phenolics on the Physicochemical and Structural Properties of Collagen Hydrogel.

In the current era, the treatment of collagen hydrogels with natural phenolics for the improvement in physicochemical properties has been the subject of considerable attention. The present research aimed to fabricate collagen hydrogels cross-linked with gallic acid (GA) and ellagic acid (EA) at different concentrations depending on the collagen dry weight. The structural, enzymatic, thermal, morphological, and physical properties of the native collagen hydrogels were compared with those of the GA/EA cross-linked hydrogels. XRD and FTIR spectroscopic analyses confirmed the structural stability and reliability of the collagen after treatment with either GA or EA. The cross-linking also significantly contributed to the improvement in the storage modulus, of 435 Pa for 100% GA cross-linked hydrogels. The thermal stability was improved, as the highest residual weight of 43.8% was obtained for the hydrogels cross-linked with 50% GA in comparison with all the other hydrogels. The hydrogels immersed in 30%, 50%, and 100% concentrations of GA also showed improved swelling behavior and porosity, and the highest resistance to type 1 collagenase (76.56%), was obtained for 50% GA cross-linked collagen hydrogels. Moreover, GA 100% and EA 100% obtained the highest denaturation temperatures (Td) of 74.96 °C and 75.78 °C, respectively. In addition, SEM analysis was also carried out to check the surface morphology of the pristine collagen hydrogels and the cross-linked collagen hydrogels. The result showed that the hydrogels cross-linked with GA/EA were denser and more compact. However, the improved physicochemical properties were probably due to the formation of hydrogen bonds between the phenolic hydroxyl groups of GA and EA and the nitrogen atoms of the collagen backbone. The presence of inter- and intramolecular cross-links between collagen and GA or EA components and an increased density of intermolecular bonds suggest potential hydrogen bonding or hydrophobic interactions. Overall, the present study paves the way for further investigations in the field by providing valuable insights into the GA/EA interaction with collagen molecules.

Effect of material temperatures on quality of fish vermicelli, a noodle-shaped surimi product.

The study investigated the effect of material temperatures (15°C, 20°C, 25°C, 30°C, 35°C, and 40°C) on the quality of fish vermicelli (FV) in terms of morphological, cooking, textural, microstructural, and water distribution properties. Results showed that as the material temperatures increased, the surface smoothness, cooking characteristics, and textural properties of FV significantly increased, followed by a decrease. Especially, when the material temperatures were 25°C and 30°C, the FV samples exhibited denser and more continuous gel networks with more embedded starch particles, resulting in decreased cooking loss and improved tensile strength. However, at material temperatures above 35°C, the continuity of the protein phase was disrupted by overswelling starch granules, leading to the worst cooking characteristics and textural properties. Especially at material temperatures of 40°C, the water holding capacity, hardness, and springiness of FV decreased by 25.59%, 73.48%, and 47.98%, respectively, compared to the samples at 25°C. Additionally, the cooking loss increased by 91.40%. In conclusion, the critical material temperature for the quality deterioration of FV was 35°C, and it was recommended to produce FV below this temperature.

Plant-Derived Exosome-Like Nanovesicles: Current Progress and Prospects.

Exosomes are small extracellular vesicles, ranging in size from 30-150nm, which can be derived from various types of cells. In recent years, mammalian-derived exosomes have been extensively studied and found to play a crucial role in regulating intercellular communication, thereby influencing the development and progression of numerous diseases. Traditional Chinese medicine has employed plant-based remedies for thousands of years, and an increasing body of evidence suggests that plant-derived exosome-like nanovesicles (PELNs) share similarities with mammalian-derived exosomes in terms of their structure and function. In this review, we provide an overview of recent advances in the study of PELNs and their potential implications for human health. Specifically, we summarize the roles of PELNs in respiratory, digestive, circulatory, and other diseases. Furthermore, we have extensively investigated the potential shortcomings and challenges in current research regarding the mechanism of action, safety, administration routes, isolation and extraction methods, characterization and identification techniques, as well as drug-loading capabilities. Based on these considerations, we propose recommendations for future research directions. Overall, our review highlights the potential of PELNs as a promising area of research, with broad implications for the treatment of human diseases. We anticipate continued interest in this area and hope that our summary of recent findings will stimulate further exploration into the implications of PELNs for human health.

Changes in the Quality of High-Oleic Sunflower Oil during the Frying of Shrimp (Litopenaeus vannamei).

Shrimp fried in vegetable oil is a very popular food, so it is important to study the changes in the quality of the oil during frying. In order to more precisely study the nature of frying oil during the cooking process, this study investigated the quality changes of high-oleic sunflower oil during the frying of South American white shrimp (Litopenaeus vannamei). The oxidation and hydrolysis products of frying oils were investigated by integrating the proton nuclear magnetic resonance technique with traditional oil evaluation indexes in an integrated manner. The results showed that the color difference as measured using the ΔE* value increased gradually during the process. Moreover, the acid value, carbonyl value, and total oxidation significantly increased with prolonged frying time. The major oxidation products formed during frying were (E,E)-2-alkenals, (E,E)-2,4-alkadienals, and E,E-conjugated hydroperoxides. This indicated that longer treatment times corresponded with an increased accumulation of aldehydes and ketones, and an increased degree of oxidative deterioration of the oil. However, the proportion of oleic acid in the frying oil increased with the frying of shrimp, reaching 80.05% after 24 h. These results contribute to our understanding of the oxidative deterioration of high-oleic oils during frying, and provide an important reference for the application properties of high-oleic oils.

Concomitant Diseases and Co-contribution on Progression of Liver Stiffness in Patients with Hepatitis B Virus Infection.

BACKGROUND: The association between hepatitis B and concomitant diseases, such as fatty liver, T2DM, MetS, and Hp infection, remains unclear. AIM: The present study was to illustrate the association and explore the co-contribution on abnormal transaminase and progression of liver stiffness. METHODS: A total of 95,998 participants underwent HBsAg screening in West China Hospital from 2014 to 2017. Multivariable logistic regression was used to determine the adjusted odds ratios. RESULTS: The prevalence of HBsAg-positive rate was 8.30% of our included study population. HBsAg positive was associated with negative risk of fatty liver (odds ratio [OR] 0.71, 95% confidence interval [CI] 0.65-0.78, p < 0.001) and MetS (OR 0.74, 95% CI 0.67-0.84, p < 0.001), and with positive risk of Hp infection (OR 1.09, 95% CI 1.02-1.17, p = 0.012) and T2DM (OR 1.18, 95% CI 1.01-1.40, p = 0.043). Besides, HBsAg-positive patients with T2DM had higher risk of elevated ALT (OR 2.09, 95% CI 1.69-2.83, p < 0.001 vs OR 1.59, 95% CI 1.51-1.68, p < 0.001), AST (OR 2.69, 95% CI 1.98-3.65, p < 0.001 vs OR 1.89, 95% CI 1.76-2.02, p < 0.001) than HBV alone. In addition to HBV, T2DM also can increase the risk of liver fibrosis (OR 3.23, 95% CI 1.35-7.71, p = 0.008) and cirrhosis (OR 4.31, 95% CI 1.41-13.20, p = 0.010). CONCLUSION: Hepatitis B patients have a lower risk of fatty liver and MetS, and a higher risk of T2DM and Hp infection. Besides, T2DM might be possibly associated with abnormal liver transaminase and fibrosis progression in HBsAg-positive patients.

Simultaneous effect of high intensity ultrasound power, time, and salt contents on gelling properties of silver carp surimi.

Recently, the demand for salt-reduced products is rising. The objective of this study was to investigate the simultaneous effect of high intensity ultrasound (HIU) power (120-240 W), time (0-30 min), and salt (0-3.0 %) on the gelling properties of surimi gels through quadratic rotation orthogonal design. Results showed that the contribution to puncture properties was: salt > HIU time > HIU power. Moreover, low salt and HIU had a synergistic effect on the puncture properties of surimi gels by the formation of more non-disulfide covalent bonds. Furthermore, HIU induced formation of denser microstructures which decreased the mobility of free water of salt-reduced surimi gels. As a result, the water holding capacity significantly increased (P < 0.05). Likewise, the cooking loss of salt-reduced surimi gels (1 %) subjected to HIU decreased by 44.85 %, as compared to the control. In conclusion, HIU might be useful for the production of salt-reduced surimi gels.

Myosin head as the main off-odors binding region: Key binding residues and conformational changes in the binding process.

This study aims to elucidate the dynamic binding characteristics between off-odors (hexanal, 1-octen-3-ol, nonanal) and myosin at cold storage (277 K) and oral temperatures (310 K) through spatial-temporal molecular dynamics (MD) simulation. Conformational analysis indicated that binding with off-odors could not significantly change the myosin secondary structure, and the myosin/(off-odors) structure became a stable and compact state in the later binding stages. Myosin head was the primary binding region with hydrophobic interactions as the dominant force rather than hydrogen bonds (average bond number 202.62 vs 55.20). Furthermore, the myosin/(off-odors) had larger binding energy at 310 than 277 K, and the myosin-nonanal showed the highest binding strength of 4050.93 kJ/mol at 310 K. The binding sites were observed to be concentrated in the 180-249, 350-410, 800-950 amino acid regions of myosin head, especially, Lys185, Tyr347, Leu901. These results provide accurate linkages between off-odors and myosin, laying a theoretical foundation for deodorization of fish products.

Gelation properties of tofu induced by different coagulants: Effects of molecular interactions between nano-sized okara dietary fiber and soybean proteins.

Gelation of soybean proteins with different coagulates as affected by okara nano-sized dietary fiber (NDF) were investigated. As compared with the MgCl2 tofu, the tofu induced by glocono-δ-lactone was softer with higher moisture and denser microstructure. As the volumetric ratio of NDF increased, pH, viscosity, particle size, and zeta potential of the NDF soymilk steadily increased. Regardless of coagulate type, tofu proteins' prevalence of α-helix + ß-turn increased with the NDF ratio up to 40 % while ß-sheet + random coil decreased. At the same time, intermolecular interactions (predominate hydrophobic interaction) significantly decreased, leading to form more porous structures in the two types of tofu. Accordingly, yield and moisture of tofu increased gradually with the NDF ratio, water holding capacity increased and then decreased, hardness decreased continuously. Results suggested that NDF affected the secondary structure and intermolecular interactions of soymilk proteins, which was independent of coagulate.

Insight into the mechanism on texture change of Wuchang bream muscle during live transportation using a UPLC-QTOF-MS based metabolomics method.

Mechanism on texture change of Wuchang bream (Megalobrama amblycephala) muscle during live transportation was explored by UPLC-QTOF-MS. The shear force (hardness) of fish muscle decreased gradually as the transportation time was extended from 3 to 24 h, with a maximum decrease of 43.49 %. With the extension of the time, the cellular and ultrastructure of fish muscle fiber were gradually disrupted. There was a significant difference between metabolites of the samples after transporting for 6, 12, 24 h versus 3 h, with organic acids and their derivatives upregulated while nucleotide metabolites downregulated. The texture deterioration might be related to metabolism of amino acids, purine, histidine, and choline. The results showed that the deterioration of Wuchang bream texture during live transportation might be mainly related to the changes of the above metabolic pathways caused by oxidative stress, which resulting in the destruction of the muscle cells and fibers.

The mediating effect of perceived social support in the relationship between maternal personality traits and pregnancy-related anxiety / 中华预防医学杂志

Objective: Exploring the mediating effect of perceived social support between the maternal personality traits and pregnancy-related anxiety. Methods: Singleton pregnant women who underwent antenatal checkups in the obstetrics department of general hospital affiliated to Ningxia Medical University from July to December 2021 were enrolled in this study to investigate perceived social support, pregnancy-related anxiety and conscious personality traits. Pearson correlation analysis was used to analyze the association between the maternal personality traits, perceived social support, and pregnancy-related anxiety, and the mediating effect of perceived social support was analyzed using Bootstrap method. Results: A total of 1 259 subjects were included in the study, of which 170 (13.50%) pregnant women felt introverted. The total score of perceived social support was (46.37±8.38), and 31.45% of pregnant women had high perceived social support. The total score of pregnancy-related anxiety was (21.48±5.53). The score of worry about fetal health was (10.09±3.24), and 368 (29.23%) of pregnant women had pregnancy-related anxiety. Maternal personality traits and pregnancy-related anxiety were negatively correlated (r=-0.076, P<0.05) and positively correlated with perceived social support during pregnancy (r= 0.127, P<0.05). Perceived social support during pregnancy and pregnancy-related anxiety were negatively correlated (r=-0.236, P<0.05). Perceived social support partially mediated the relationship between the maternal personality traits and pregnancy-related anxiety, with a relative effect value of 37.50%. Conclusion: The maternal personality traits, level of perceived social support and pregnancy-related anxiety are all related. Perceived social support could mediate the relationship between the maternal personality traits and pregnancy-related anxiety.

Changes in Gelation Properties of Silver Carp Myosin Treated by Combination of High Intensity Ultrasound and NaCl.

The molecular behavior of myosin in a low-salt environment limited the production of surimi-based products. This study aimed to investigate the effect of the combination of high intensity ultrasound (HIU) and NaCl (0.1, 0.3, 0.5 mol/L) on the physicochemical indexes of myosin. The changes were evaluated by solubility, ultraviolet (UV) spectroscopy, dynamic rheological properties, water holding capacity (WHC), microstructures, etc. For control samples, the gelation properties of myosin strengthened upon NaCl increasing. Combination of HIU and NaCl significantly improved the solubility of myosin, which was due to the conformational changes and the exposure of reactive groups. Meanwhile, the particle size of myosin obviously decreased when observed by atomic force microscope, which in turn promoted the stability of myosin. Furthermore, the improvement in solution behaviors of myosin treated by combination of HIU and NaCl contributed to the gelation properties as well as the formation of compact microstructures, which obtained high WHC and low cooking loss of myosin gels. In conclusion, combination of HIU and NaCl induced the unfolding of myosin with the exposure of reactive groups, consequently facilitating the formation of denser microstructures. Moreover, the biggest degree of improvement in gelation properties was observed at 0.1 mol/L NaCl combined with HIU.