Plasma-activated water in combination with coconut exocarp flavonoids emerge as promising preservation technique for golden pompano: Impact of the treatment sequence

In the current study, the preservation effect of plasma-activated water (PAW), coconut exocarp flavonoids (CF) and their combination on golden pompano fillets during refrigerated storage was investigated with emphasize on the treating sequence. PAW effectively inactivated spoilage bacteria and inhibited total volatile basic nitrogen (TVB-N) increase, while boosted the TBARS and carbonyl values. PAW+CF exerted synergistic effect on extending the period before total bacterial count and TVB-N content reaching acceptance limit than PAW or CF alone (P < 0.05). In addition, their combined treatment effectively reduced fillets discoloration and texture deterioration. Simultaneously, lipid and protein oxidation were significantly inhibited, which was comparable to CF. It was indicated that the treatment sequence of PAW and CF profoundly impact the preservation effect. Specifically, prior CF marinating followed by PAW was more effective than the opposite sequence. Thus, combination of CF followed by PAW served as promising technique for fish fillets preservation.

Comparative study on the enzymatic degradation of phenolic esters: The HPLC-UV quantification of tyrosol and gallic acid liberated from tyrosol acyl esters and alkyl gallates by hydrolytic enzymes

HPLC-UV analysis was used to evaluate the enzymatic degradation characteristics of tyrosol acyl esters (TYr-Es) and alkyl gallates (A-GAs). Among various hydrolytic enzymes, TYr-Es can be hydrolyzed by pancrelipase, while A-GAs cannot be hydrolyzed by pancrelipase. Interestingly, carboxylesterase-1b (CES-1b), carboxylesterase-1c (CES-1c) and carboxylesterase-2 (CES-2) are able to hydrolyze TYr-Es and A-GAs, and thus to liberate tyrosol (TYr) and gallic acid (GA). By contrast, the degrees of hydrolysis (DHs) of TYr-Es and A-GAs by CES-1b and CES-1c were significantly higher than those by CES-2. Meanwhile, the DHs of TYr-Es were much higher than those of A-GAs. Especially, the DHs firstly increased and then decreased with the increasing alkyl chain length. Besides, DHs positively correlated with the unsaturation degree at the same chain length. Through regulating carbon length, unsaturation degree and the ester bond structure, controlled-release of phenolic compounds and fatty acids (or fatty alcohols) from phenolic esters will be easily achieved.

Effects of calcium chloride on the gelling and digestive characteristics of myofibrillar protein in Litopenaeus vannamei

In this study, the effects of CaCl2 (0, 25, 50, 75, and 100 mM) on the gelling and digestive properties of the myofibrillar protein (MP) in Litopenaeus vannamei were investigated. The results showed that increasing CaCl2 concentration led to changes in the tertiary structure of MP. Specifically, compared with the control group, a 64.31 % increase in surface hydrophobicity and a 45.90 % decrease in the sulfhydryl group were observed after 100 mM CaCl2 treatment. Correspondingly, the water holding capacity and strength of the MP gel increased by 24.46 % and 55.99 %, respectively. These changes were positively correlated with the rheological properties, microstructure pore size, and content of non-flowable water. The mechanical properties of MP gel were improved, and the microstructure became more compact with the increase in CaCl2 concentration. Furthermore, the particle size of the digested MP gels decreased in the presence of CaCl2, which improved the digestion characteristics of MP gels.

Outcomes of stent grafts for treatment of central venous disease in hemodialysis patients

BACKGROUND

To evaluate the effectiveness of stent graft (SG) for the treatment of central venous disease (CVD) in hemodialysis patients.

METHODS

Between January 2014 and April 2022, 122 patients on hemodialysis with symptomatic CVD were treated with percutaneous transluminal angioplasty (PTA) and bare-metal stent (BMS) or SG placement. The mean follow-up was 14.5 months (IQR: 8.0, 24.2). Patency rates of the target sites were calculated using Kaplan-Meier and log-rank studies. Multivariate Cox proportional hazard models were used to evaluate the association between various characteristics and target site primary patency.

RESULTS

Technical success rate was 100%. At 3, 6, 12, and 24 months, the target sites primary patency rates were 86.4%, 74.2%, 45.1%, and 30.4% for PTA; 94.7%, 78.6%, 60.8%, and 45.6% for BMS; and 94.0%, 92.0%, 82.4%, and 66.8% for SG, respectively, and the assisted primary patency rates were 86.5%, 80.4%, 63.8%, and 46.0% for PTA; 94.7%, 89.5%, 77.5%, and 71.1% for BMS; 100%, 100%, 97.8%, and 83.4% for SG, respectively. The Kaplan-Meier analysis indicated that SGs achieved better primary and assisted primary patency than PTA or BMS (p<0.05). SG use and concomitant stenosis were the independent predictors of target site primary patency dysfunction in the multivariate analysis.

CONCLUSIONS

This study confirmed the better long-term patency of SG in comparison with PTA and BMS for the treatment of CVD in hemodialysis patients.

Molecular mechanism of color deepening of ready-to-eat shrimp during storage

Color deepening occurs during storage of ready-to-eat (RTE) shrimps, which seriously affects their marketing cycle. This study investigated the molecular mechanisms of color deterioration in RTE shrimps during accelerated storage, shedding light on the pattern of change in colored products and content. The findings revealed significant occurrences of phenolic oxidation, lipid oxidation, and Maillard browning reactions during accelerated storage. Qualitative and quantitative analyses were conducted on the colored products resulting from these chemical reactions. Multivariate mathematical models were employed to analyze the phenolic oxidation products (2-methylanthraquinone and p-benzoquinone), lipid oxidation products (lipofuscin-like pigments and hydrophobic pyrroles), and Maillard browning products (pyrazines and melanoidins). These products were identified as the main contributors to the deepening of the color of RTE shrimps during storage. The outcomes of this research could enhance our understanding of the color change mechanism in thermally processed marine foods, providing valuable insights for quality maintenance and industrial advancement.

A rice GT61 glycosyltransferase possesses dual activities mediating 2-O-xylosyl and 2-O-arabinosyl substitutions of xylan

MAIN CONCLUSION

A member of the rice GT61 clade B is capable of transferring both 2-O-xylosyl and 2-O-arabinosyl residues onto xylan and another member specifically catalyses addition of 2-O-xylosyl residue onto xylan. Grass xylan is substituted predominantly with 3-O-arabinofuranose (Araf) as well as with some minor side chains, such as 2-O-Araf and 2-O-(methyl)glucuronic acid [(Me)GlcA]. 3-O-Arabinosylation of grass xylan has been shown to be catalysed by grass-expanded clade A members of the glycosyltransferase family 61. However, glycosyltransferases mediating 2-O-arabinosylation of grass xylan remain elusive. Here, we performed biochemical studies of two rice GT61 clade B members and found that one of them was capable of transferring both xylosyl (Xyl) and Araf residues from UDP-Xyl and UDP-Araf, respectively, onto xylooligomer acceptors, whereas the other specifically catalysed Xyl transfer onto xylooligomers, indicating that the former is a xylan xylosyl/arabinosyl transferase (named OsXXAT1 herein) and the latter is a xylan xylosyltransferase (named OsXYXT2). Structural analysis of the OsXXAT1- and OsXYXT2-catalysed reaction products revealed that the Xyl and Araf residues were transferred onto O-2 positions of xylooligomers. Furthermore, we demonstrated that OsXXAT1 and OsXYXT2 were able to substitute acetylated xylooligomers, but only OsXXAT1 could xylosylate GlcA-substituted xylooligomers. OsXXAT1 and OsXYXT2 were predicted to adopt a GT-B fold structure and molecular docking revealed candidate amino acid residues at the predicted active site involved in binding of the nucleotide sugar donor and the xylohexaose acceptor substrates. Together, our results establish that OsXXAT1 is a xylan 2-O-xylosyl/2-O-arabinosyl transferase and OsXYXT2 is a xylan 2-O-xylosyltransferase, which expands our knowledge of roles of the GT61 family in grass xylan synthesis.

A novel machine learning-derived four-gene signature predicts STEMI and post-STEMI heart failure

High mortality and morbidity rates associated with ST-elevation myocardial infarction (STEMI) and post-STEMI heart failure (HF) necessitate proper risk stratification for coronary artery disease (CAD). A prediction model that combines specificity and convenience is highly required. This study aimed to design a monocyte-based gene assay for predicting STEMI and post-STEMI HF. A total of 1,956 monocyte expression profiles and corresponding clinical data were integrated from multiple sources. Meta-results were obtained through the weighted gene co-expression network analysis (WGCNA) and differential analysis to identify characteristic genes for STEMI. Machine learning models based on the decision tree (DT), support vector machine (SVM), and random forest (RF) algorithms were trained and validated. Five genes overlapped and were subjected to the model proposal. The discriminative performance of the DT model outperformed the other two methods. The established four-gene panel (HLA-J, CFP, STX11, and NFYC) could discriminate STEMI and HF with an area under the curve (AUC) of 0.86 or above. In the gene set enrichment analysis (GSEA), several cardiac pathogenesis pathways and cardiovascular disorder signatures showed statistically significant, concordant differences between subjects with high and low expression levels of the four-gene panel, affirming the validity of the established model. In conclusion, we have developed and validated a model that offers the hope for accurately predicting the risk of STEMI and HF, leading to optimal risk stratification and personalized management of CAD, thereby improving individual outcomes.

In vitro plasma hydrolysis of phenolic esters and their absorption kinetics in rats: Controlled release of phenolic compounds and enhanced health benefits

Phenolic esters are considered as promising functional food ingredients. However, their digestion, absorption and metabolism are still unclear. Tyrosol acyl esters (TYr-Es), hydroxytyrosol acyl esters (HTy-Es) and alkyl gallates (A-GAs) were hydrolyzed by carboxylesterase in plasma and exhibited slow release of polyphenols (phenolic acids). In vitro hydrolysis degrees initially increased and then decreased with the increasing carbon chain length (C2-C16). TYr-Es exhibited higher hydrolysis degrees compared to HTy-Es, and hydrolysis degrees of TYr-Es and HTy-Es were markedly higher than those of A-GAs. Due to the fast hydrolysis rates of TYr-Es and HTy-Es, they were undetectable in all rat plasma samples collected at several times within 24 h after administration. Whereas, A-GAs could be detected in rat plasmas and three absorption peaks were found in the pharmacokinetic profiles. Importantly, the T1/2, MRT, AUC0-∞, AUC0-t in octyl gallate group were longer (or stronger) than those in propyl gallate and dodecyl gallate groups.

Mechanism of salt effect on flavor formation in lightly-salted large yellow croaker by integrated multiple intelligent sensory and untargeted lipidomics analyses

Salt has a great influence on food flavor formation. In this study, electronic tongue and nose, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and lipid oxidation levels were used to investigate the influence of different NaCl concentrations on the flavor formation of lightly salted large yellow croaker. The results showed that salt improves the sensory characteristics of the product. Hexanal, 2,5-octanedione, octanal, 1-octen-3-ol, nonanal, and heptanal were key flavor compounds. Phospholipids containing 18-carbon fatty acids are major flavor precursor substances. The TBARS values in samples increase with the increase of salt levels significantly (p < 0.05). Products marinated in 6% NaCl showed the highest lipase activity. Thus, NaCl promotes the hydrolysis and oxidation of phospholipids by increasing lipase activity to produce key flavor substances. This study provides valuable insights into the effects of NaCl on flavor formation, which may help to regulate the flavor of salt-reduced food.

[Characteristics and clinical analysis of MLH1 c.463dupC gene mutation in a Lynch syndrome family]

In this study, a case of Lynch syndrome (LS) family line with a novel mutation site in the MLH1 c.463dupC gene was reported and the clinical and pathogenic genetic features of this family were analyzed. A 40-year-old female patient with colon cancer diagnosed at the First Affiliated Hospital of Kunming Medical University on October 2, 2020 was retrospectively included. The clinical data of the family were collected and the family lineage was drawn. The family tumor history met the Amsterdam Criteria Ⅱ and the diagnostic criteria of LS in Chinese, which was a typical LS family lineage. A germline code-shift missense mutation c.463dupC in the MLH1 gene located in exon 6, a possible pathogenic variant, was detected by second-generation sequencing (NGS) in the patient. Subsequently, Sanger sequencing was performed on a total of 20 direct lineage members of the family of the MLH1 gene, 7 cases were found to harbor the mutation and included in the LS high-risk control. Follow-up to October 2023 showed that the patient had endometrial and cervical polyps, one case had colorectal cancer, and two cases had intestinal polyps, all were treated with early intervention and therapy; two cases did not show any clinical symptoms. This study is the first to report a new mutation site for the potentially pathogenic MLH1 c.463dupC, providing a rationale for the pathogenicity of the mutation and standardized health management for familial carriers.

Small Oversized Stent Graft Is Associated With Increased Patency for the Treatment of Central Venous Disease in Hemodialysis Patients

PURPOSE

The purpose of this study was to identify the independent predictors of higher patency rates and investigate the selection of specifications of stent graft in the treatment of central venous disease.

MATERIALS AND METHODS

This retrospective study included 54 patients who underwent stent-grafts' placement for the treatment of central venous disease between March 2017 and September 2022 at a tertiary hospital. The demographic data for the patients and the clinical data of the treated lesions were collected and analyzed. The patency rates of the treated lesions with different oversizing range were calculated via the Kaplan-Meier and log-rank analyses. The multivariate Cox proportional hazard models were constructed to identify the independent predictor of the target site primary patency.

RESULTS

The median follow-up period was 21.5 months. The primary patency rates of the target sites were 90.7%, 72.2%, and 55.1% at 6, 12, and 24 months, respectively. The assisted primary patency rates of the lesions were 96.3%, 92.5%, and 80.3% at 6, 12, and 24 months, respectively. The log-rank analysis showed that the stent-grafts' placement with small oversizing had significantly higher primary patency rates than those with large oversizing (p=0.022). The multivariate analysis revealed that concomitant stenosis and large oversizing stent graft were the independent predictors of target site primary patency.

CONCLUSIONS

Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing.

CLINICAL IMPACT

Stent grafts showed reasonable primary patency for the treatment of central venous disease in hemodialysis patients. Few studies, however, have explored the efficiency of stent grafts to treat CVD by considering different factors such as sizing considerations, the rate of oversizing percentage, etc. A stent graft with small oversizing is associated with better target site primary patency rates than those with large oversizing. Excessive oversizing should be avoided to prevent infolding or stent collapse.

Recent advances in the color of aquatic products: Evaluation methods, discoloration mechanism, and protection technologies

Color plays a pivotal role in guiding and assessing the industrial production of aquatic products due to the swift sensory perception of information through vision. This review provides a comprehensive overview of the following four aspects: (a) mechanisms governing natural color formation in aquatic products, (b) factors and mechanisms contributing to the discoloration of aquatic products, (c) cutting-edge methods for color analysis and detection, and (d) current valuable techniques for preserving color quality. The natural color of aquatic products is derived from skin chromatophores, endogenous pigment proteins, and astaxanthin. Discoloration of aquatic products can occur due to lipid oxidation, as well as enzymatic and non-enzymatic browning. Furthermore, this review examines frontier color protective technologies, encompassing physical methods like ultra-high pressure, irradiation, and low-temperature plasma, as well as chemical methods involving natural preservatives. The findings of this study offer significant insights into the development of high-quality aquatic products.

In Silico-Predicted Dynamic Oxlipidomics MS/MS Library: High-Throughput Discovery and Characterization of Unknown Oxidized Lipids

Nontargeted lipidomics using liquid chromatography-tandem mass spectrometry can detect thousands of molecules in biological samples. However, the annotation of unknown oxidized lipids is limited to the structures present in libraries, restricting the analysis and interpretation of experimental data. Here, we describe Doxlipid, a computational tool for oxidized lipid annotation that predicts a dynamic MS/MS library for every experiment. Doxlipid integrates three key simulation algorithms to predict libraries and covers 32 subclasses of oxidized lipids from the three main classes. In the evaluation, Doxlipid achieves very high prediction and characterization performance and outperforms the current oxidized lipid annotation methods. Doxlipid, combined with a molecular network, further annotates unknown chemical analogs in the same reaction or pathway. We demonstrate the broad utility of Doxlipid by analyzing oxidized lipids in ferroptosis hepatocellular carcinoma, tissue samples, and other biological samples, substantially advancing the discovery of biological pathways at the trace oxidized lipid level.

Hydrolysis and Transport Characteristics of Phospholipid Complex of Alkyl Gallates: Potential Sustained Release of Alkyl Gallate and Gallic Acid

Phospholipid complexes of alkyl gallates (A-GAs) including ethyl gallate (EG), propyl gallate (PG), and butyl gallate (BG) were successfully prepared by the thin film dispersion method. HPLC-UV analysis in an everted rat gut sac model indicated that A-GAs can be liberated from phospholipid complexes, which were further hydrolyzed by intestinal lipase to generate free gallic acid (GA). Both A-GAs and GA are able to cross the membrane, and the hydrolysis rate of A-GAs and the transport rate of GA are positively correlated with the alkyl chain length. Especially, compared with the corresponding physical mixtures, the phospholipid complexes exhibit slower sustained-release of A-GAs and GA. Therefore, the formation of phospholipid complexes is an effective approach to prolong the residence time in vivo and additionally enhance the bioactivities of A-GAs and GA. More importantly, through regulating the carbon skeleton lengths, controlled-release of alkyl gallates and gallic acid from phospholipid complexes will be achieved.

Translational medical bioengineering research of traumatic brain injury among Chinese and American pedestrians caused by vehicle collision based on human body finite element modeling

Based on the average human body size in China and the THUMS AM50 finite element model of the human body, the Kriging interpolation algorithm was used to model the Chinese 50th percentile human body, and the biological fidelity of the model was verified. We built three different types of passenger vehicle models, namely, sedan, sports utility vehicle (SUV), and multi-purpose vehicle (MPV), and used mechanical response analysis and finite element simulation to compare and analyze the dynamic differences and head injury differences between the Chinese 50th percentile human body and the THUMS AM50 model during passenger vehicle collisions. The results showed that there are obvious differences between the Chinese mannequin and THUMS in terms of collision time, collision position, invasion speed, and angle. When a sedan collided with the mannequins, the skull damage to the Chinese human body model was more severe, and when a sedan or SUV collided, the brain damage to the Chinese human body was more severe. The abovementioned results suggest that the existing C-NCAP pedestrian protection testing regulations may not provide the best protection for Chinese human bodies, and that the regulations need to be improved by combining collision damage mechanisms and the physical characteristics of Chinese pedestrians. This thorough investigation is positioned to shed light on the fundamental biomechanics and injury mechanisms at play. Furthermore, the amalgamation of clinically rooted translational and engineering research in the realm of traumatic brain injury has the potential to establish a solid foundation for discerning preventive methodologies. Ultimately, this endeavor holds the potential to introduce effective strategies aimed at preventing and safeguarding against traumatic brain injuries.

Effects of Edible Organic Acid Soaking on Color, Protein Physicochemical, and Digestion Characteristics of Ready-to-Eat Shrimp upon Processing and Sterilization

Soft-packed ready-to-eat (RTE) shrimp has gradually become popular with consumers due to its portability and deliciousness. However, the browning caused by high-temperature sterilization is a non-negligible disadvantage affecting sensory quality. RTE shrimp is processed through "boiling + vacuum soft packing + high temperature and pressure sterilization". Ultraviolet-visible (UV) spectroscopy with CIELAB color measurement showed that phytic acid (PA) + lactic acid (LA), PA + citric acid (CA), and PA + LA + CA soaking before cooking alleviated browning, as well as UVabsorbance and the browning index (BI). Meanwhile, UV spectroscopy and fluorescence spectroscopy showed that organic acid soaking reduced the content of carbonyl, dityrosine, disulfide bonds, surface hydrophobicity, and protein solubility, but promoted the content of free sulfhydryl and protein aggregation. However, in vitro digestion simulations showed that organic acid soaking unexpectedly inhibited the degree of hydrolysis and protein digestibility. This study provides the basis for the application of organic acids as color protectors for RTE aquatic muscle product.

Unraveling the Formation Mechanism of Egg's Unique Flavor via Flavoromics and Lipidomics

Egg products after thermal treatment possess a unique flavor and are favored by consumers. In this study, the key aroma-active compounds of egg yolk products and their formation mechanism during thermal treatment were investigated. The volatile aroma compounds in egg yolks were monitored using an electronic nose, gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS), and the lipid molecular species were explored using ultra-high-performance liquid chromatography- mass spectrometry with a Q-Exactive HF-X Orbitrap (UPLC-Q-Exactive HF-X). A total of 68 volatile compounds were identified. Boiled eggs mainly derived their flavor from hexanal, 2-pentyl-furan, 2-butanone, 3-methyl-butanal and heptane. Meanwhile, fried eggs relied mainly on 14 compounds, the most important of which were 2-ethyl-3-methyl-pyrazine, 3-ethyl-2,5-dimethyl-pyrazine, 2-ethyl-3,5-dimethyl-pyrazine, nonanal and 2,3-diethyl-5-methyl-pyrazine, providing a baked and burnt sugar flavor. A total of 201 lipid molecules, belonging to 21 lipid subclasses, were identified in egg yolks, and 13 oxidized lipids were characterized using a molecular network. Phosphoethanolamines (PEs) containing polyunsaturated fatty acids were the primary flavor precursors contributing to the development of egg yolks' flavor, participating in lipid oxidation reactions and the Maillard reaction and regulating the production of aldehydes and pyrazine compounds. This study provides reference and guidance for the development of egg yolk flavor products.

Efficacy and Safety of Sharp Recanalization with the Stiff End of a Microguidewire for Treatment of Refractory Central Venous Occlusions in Hemodialysis Patients

BACKGROUND

Sharp recanalization is a viable procedure for some refractory central venous occlusions that cannot be recanalized with the conventional technique. The sharp recanalization procedures reported in previous studies are often rely on costly devices and with a certain proportion of complications. This study aimed to present an inexpensive and risk-controllable coaxial centrifugally sharp recanalization technique that was independent of any additional costly devices.

METHODS

This retrospective study enrolled 8 patients who had received sharp recanalization of central venous occlusions, between August 2017 and May 2021. The sharp recanalization technique was performed centrifugally with the stiff end of a microguidewire after the lesions failed to be passed through with the conventional technique. Clinical data of patients on their lesions, technical success rate, procedure-related complications, and patency rates were collected and analyzed to assess the efficacy and safety of the technique.

RESULTS

Technical success was achieved in all patients, with no complications were observed. All symptoms were ameliorated within 48h postsurgery. The median follow-up period was 22 months. All patients maintained patency or assisted patency at 12 month follow-up.

CONCLUSIONS

Sharp recanalization performed centrifugally with the stiff end of the microguidewire could be a cost-effective and safe alternative procedure for the treatment of refractory central venous occlusion that cannot be recanalized with conventional technique.

A critical review of a typical research system for food-derived metal-chelating peptides: Production, characterization, identification, digestion, and absorption

In the past decade, food-derived metal-chelating peptides (MCPs) have attracted significant attention from researchers working towards the prevention of metal (viz., iron, zinc, and calcium) deficiency phenomenon by primarily inhibiting the precipitation of metals caused by the gastrointestinal environment and exogenous substances (including phytic and oxalic acids). However, for the improvement of limits of current knowledge foundations and future investigation directions of MCP or their derivatives, several review categories should be improved and emphasized. The species' uniqueness and differences in MCP productions highly contribute to the different values of chelating ability with particular metal ions, whereas comprehensive reviews of chelation characterization determined by various kinds of technique support different horizons for explaining the chelation and offer options for the selection of characterization methods. The reviews of chelation mechanism clearly demonstrate the involvement of potential groups and atoms in chelating metal ions. The discussions of digestive stability and absorption in various kinds of absorption model in vitro and in vivo as well as the theory of involved cellular absorption channels and pathways are systematically reviewed and highlighted compared with previous reports as well. Meanwhile, the chelation mechanism on the molecular docking level, the binding mechanism in amino acid identification level, the utilizations of everted rat gut sac model for absorption, and the involvement of cellular absorption channels and pathway are strongly recommended as novelty in this review. This review makes a novel contribution to the literature by the comprehensive prospects for the research and development of food-derived mineral supplements.

Analysis of transjugular intrahepatic portosystemic shunt by hemodynamic simulation

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS), which artificially creates a portocaval shunt to reduce portal venous pressure, has gradually become the primary treatment for portal hypertension (PH). However, there is no prefect shunting scheme in TIPS to balance the occurrence of postoperative complications and effective haemostasis.

OBJECTIVE

To construct cirrhotic PH models and compare different shunting schemes in TIPS.

METHODS

Three cases of cirrhotic PH with different liver volumes were selected for enhanced computed tomography scanning. The models for different shunting schemes were created using Mimics software, and following FLUENT calculation, all the models were imported into the software computational fluid dynamic-post for processing. In each shunting scheme, the differences in portal vein pressure, hepatic blood perfusion and blood flow from the superior mesenteric vein in the shunt tract were compared. The coefficient G was adapted to evaluate the advantages and disadvantages.

RESULTS

(1) Concerning the precise location of the shunt tract, the wider the diameter of the shunt tract, the lower the pressure of the portal vein and the lesser the hepatic blood perfusion. Meanwhile, the pressure drop objective was not achieved with the 6 mm-diameter shunting scheme. (2) The 8 mm-diameter shunting scheme through the left portal vein (LPV) had the highest coefficient G.

CONCLUSION

The 8 mm-diameter shunting scheme through the LPV may demonstrate a superior effect and prognosis in TIPS procedures.

Dual regulations on texture and water mobility of shrimp surimi gel with sustained-release epigallocatechin-3-gallate in γ-cyclodextrin metal organic frameworks: Insights into functionality and mechanisms

Epigallocatechin-3-gallate (EGCG) could demonstrate crosslinking effects on myofibrillar proteins, yet its proneness to self-aggregation could bring excessive crosslinking and water loss within gels, hindering its application as an additive during thermal gelation process. Here, encapsulation with the γ-cyclodextrin metal organic framework (γ-CD-MOF) before the use of EGCG was found to play a dual role: alleviating over-crosslinking of proteins and elevating water retention within gels. Results showed that EGCG got a sustainable release throughout the thermal process due to the gradual fracture of O-K coordinate bounds and structural collapse of γ-CD-MOF. Mechanism insights revealed that the use of EGCG loaded γ-CD-MOF (EGCG@γ-CD-MOF) could regulate formation efficiency on disulfide bounds and promote protonation transition of the amino groups in proteins. Moreover, EGCG@γ-CD-MOF brought a higher retention of phenols within gels through preventing oxidative transformation of phenols towards quinones, which were verified to display a higher affinity towards myosin via molecular calculations.

Characterization of Oyster Protein Hydrolysate-Iron Complexes and their In Vivo Protective Effects against Iron Deficiency-Induced Symptoms in Mice

Iron is one of the trace mineral elements, and iron deficiency is a common phenomenon that negatively influences human health. Food-derived iron supplements were considered excellent candidates for improving this syndrome. In this work, oyster-protein hydrolysates (OPH) and ferrous chloride successfully formed the OPH-Fe complex (6 mg/mL, 40 °C, 30 min), where the main binding sites involved were the carboxyl and amino groups. The OPH-Fe complex showed no obvious changes in the secondary structure, while the iron changed the morphological appearance and also showed fluorescence quenching, an ultraviolet shift, and an increase in size distribution. The OPH-Fe complex showed better dynamic absorption of iron (64.11 μmol/L) than ferrous sulfate (46.90 μmol/L), and the medium dose had better protective effects against iron-deficiency anemia in vivo. Three representative peptides (DGKGKIPEE, FAGDDAPRA, and VLDSGDGVTH) that were absorbed intact were identified. This experiment provided a theoretical foundation for further study of the digestion and absorption of the OPH-Fe complex.

Food-grade encapsulated polyphenols: recent advances as novel additives in foodstuffs

A growing inclination among consumers toward the consumption of natural products has propelled the usage of natural compounds as novel additives. Polyphenols are among the most popular candidates of natural food additives with multiple functionalities and bioactivities but are limited by instability. In this regard, a series of food-grade encapsulated polyphenols has been tailored for incorporating into food formulations as novel additives, which could better satisfy the complicated industry processing. This review seeks to present the most recent discussions regarding their application status in diverse foodstuffs as novel additives, involving functionalities, action mechanisms, and relevant encapsulation technologies. The scientific findings confirm that such novel additives show positive effects on physicochemical, sensory, and nutritional properties as well as the shelf life of diverse food matrices. However, poor heat resistance is still the major defect that restricts their application in thermal processes. Future research should focus on the evaluation of the compatibility and applicability of encapsulated polyphenols in real food processes as well as track and deepen their molecular action mechanisms in the context of complex foodstuffs. Innovation of existing encapsulation technologies should also be concerned in the future to bridge the gap between lab and scale-up production.

Encapsulation Alleviates the Auto-browning of Epigallocatechin-3-gallate in Aqueous Solutions through Regulating Molecular Self-Aggregation Behavior

Catechins are widely recognized for superb antioxidant capability, but their application as food antioxidants is hindered by susceptibility to auto-browning under high-moisture conditions. Here, we proposed a strategy of ordered encapsulation with cyclodextrin-based metal-organic frameworks (CD-MOFs) to alleviate the auto-browning phenomenon of catechins while preserving their antioxidant capability and demonstrated the feasibility of this strategy via selecting epigallocatechin-3-gallate (EGCG) as a model. Even in aqueous solutions, EGCG@CD-MOFs still possessed delayed browning, in contrast with pristine EGCG, characterized by suppressed efficiencies on the generation of oxidative dimers (theasinensin A) and semiquinone radicals. Mechanism insights revealed that ordered encapsulation brought dual regulations on the self-aggregation behavior of EGCG: EGCG@CD-MOFs exhibited a gradual structural collapse from the framework toward irregular aggregates as O-K bonds broke progressively, which restricted molecular mobility of EGCG, and EGCG molecular conformations became constrained by the structure of EGCG@CD-MOFs as well as rich intermolecular forces, even after structural collapse.

Ethanol-mediated synthesis of γ-cyclodextrin-based metal-organic framework as edible microcarrier: performance and mechanism

Here, an ethanol-mediated method was introduced to fabricate γ-cyclodextrin-based metal-organic frameworks (γ-CD-MOFs) as microcarriers for epigallocatechin-3-gallate (EGCG). Through adjusting ethanol gas diffusion temperature and ethanol liquid feed speed, we achieved control of crystallization efficiency and crystals size without extra surfactants. Under the sequential regulatory by ethanol in two phases, the obtained γ-CD-MOFs with cubic shape exhibited excellent crystallinity, high surface area, and uniform size distribution. Through the interplay of hydrogen bonding, hydrophobic interactions and π stacking, EGCG molecules could be stored efficiently within cavities and tunnels of the γ-CD-MOFs with high load capability of 334 mg g^-1. More importantly, the incorporation of EGCG within frameworks wouldn't disintegrate the unique body-centered cubic structure of γ-CD-MOFs, in turn, would improve the thermostability and antioxidative activity of EGCG. Significantly, all food-grade materials ensured the γ-CD-MOFs high acceptance and applicability for food and biomedical applications.

The Effect of Heat Treatment on the Digestion and Absorption Properties of Protein in Sea Cucumber Body Wall

This study was designed, for the first time, to investigate the effect of oxidation on the digestion and absorption properties of protein in boiled sea cucumber body wall (BSCBW) via simulated digestion combined with everted-rat-gut-sac models. Boiling heat treatments led to protein oxidation in SCBW, manifested by increases in free radical intensity, thiobarbituric acid reactive substances, carbonyl groups, disulfide bonds, dityrosine bonds, advanced glycation end products, protein hydrophobicity and aggregation, and declines in both free sulfhydryl groups and secondary structure transition from α-helix to β-sheet. Boiling for 2 h caused anti-digestion collagen unfolding, provided the action site for protease and improved protein digestion and absorption levels. On the contrary, excessive oxidative modification of 4 h BSCBW resulted in decreased protein digestion and absorption levels. From the perspective of texture, digestion and absorption properties, boiling for 2 h can obtain sea cucumber products with better edible and digestible properties, which is considered to be a better processing condition.

Hydrolysis and transport characteristics of tyrosol-SCFA esters in rat intestine and blood: Two-step release of tyrosol and SCFAs to enhance the beneficial effects

The models of rat everted gut sac and hydrolysis by rat plasma were used to clarify the hydrolysis and transport characteristics of tyrosol-SCFA esters (TYr-SEs). HPLC-UV results indicated that TYr-SEs could be hydrolyzed by intestinal lipase, which showed sustained release of SCFAs and TYr. Meanwhile, TYr-SEs and the liberated SCFAs and TYr could cross the membrane and were transported into blood circulation. TYr-SEs were further hydrolyzed by carboxylesterase in plasma. Obviously, the hydrolysis of TYr-SEs in blood also showed sustained release of SCFAs and TYr. Especially, the rates of hydrolysis and transport correlated positively with the acyl chain lengths. Besides, the above rates of the TYr-SE with a straight chain were greater than those of its isomer with a branched chain. Therefore, the above-mentioned two-step release of SCFAs and TYr clearly demonstrated that TYr-SEs would be an effective approach to enhance the beneficial health effects of SCFAs and TYr.

Insight into the relationship between metabolite dynamic changes and microorganisms of sea urchin (S. intermedius) gonads during storage

Sea urchin gonads have high nutritional value and degenerate rapidly during storage. Previous assessment of the freshness of sea urchin gonads was based on experience without valid biochemical indicators. Thus, the current study is to find biochemical indicators representing the freshness of sea urchin gonads. Results showed that the dominant genera of sea urchin gonads were changed from Psychromonas, Ralstonia, and Roseimarinus to Aliivibrio, Psychrilyobacter, and Photobacterium. The differential metabolites of sea urchin gonads were mainly produced through amino acids metabolism. Among them, GC-TOF-MS based differential metabolites had the greatest enrichment in the valine, leucine and isoleucine biosynthesis pathway, while LC-MS based differential metabolites had the greatest enrichment in the alanine, aspartate and glutamate metabolism pathway. The growth of dominant genus (Aliivibrio) had a great influence on the production of differential metabolites. These results will provide valuable information for accurately judging the freshness and shelf life of sea urchin gonads.

In Vitro Gastrointestinal Digestion and Microbial Hydrolysis of Hydroxytyrosol-SCFA and Tyrosol-SCFA Acyl Esters: Controlled-Release of SCFAs and Polyphenols

Phenolipids such as hydroxytyrosol-SCFA acyl esters (HTy-SEs) and tyrosol-SCFA acyl esters (TYr-SEs) with various alkyl chains lengths (C1-C4) and different isomers (branched-chain and straight-chain) were successfully synthesized. All esters were hydrolyzed by pancreatic lipase to produce polyphenols (HTy and TYr) and SCFAs (iso-butyric acid, acetic acid, propionic acid, and n-butyric acid). Moreover, HTy-SEs (and TYr-SEs) could also be hydrolyzed to free HTy (and TYr) and SCFAs by gut microbiota and Lactobacillus from mice feces. Especially, the hydrolysis rates showed positive correlation with the carbon skeleton length, and the hydrolysis degree (DH) of ester with a branched-chain fatty acid was weaker than that of ester with a straight-chain fatty acid. Besides, the DH values of TYr -SEs were significantly higher than those of HTy-SEs. Therefore, through regulating the structures of polyphenols, carbon skeleton lengths, and isomers, controlled-release of polyphenols and SCFAs from phenolipids will be easily achieved.

The potential of hydroxytyrosol fatty acid esters to enhance oral bioavailabilities of hydroxytyrosol and fatty acids: Continuous and slow-release ability in small intestine and blood

HPLC-UV analysis in rat everted gut sac and in vitro simulated digestion models indicated that hydroxytyrosol fatty acid esters (HTy-Es) could be hydrolyzed by pancreatic lipase to slow-release of free fatty acids (FAs) and HTy. Meanwhile, the HTy-Es, the liberated FAs and the HTy could cross the membrane and were transported into blood circulation. HTy-Es were further hydrolyzed by carboxylesterase in in vitro rat plasma hydrolysis model, which also showed slow-release of FAs (C1-C4) and HTy. Especially, the rates of hydrolysis and transport initially increased and then decreased with the increasing alkyl chain length. Besides, the above rates of the HTy-Es with a straight chain were greater than those of its isomer with a branched chain. Therefore, the above-mentioned continuous and slow-release of FAs and HTy in small intestine and blood clearly demonstrated that HTy-Es would be an effective approach to enhance oral bioavailabilities of free fatty acids and hydroxytyrosol.

Effects of Non-Enzymatic Browning and Lipid Oxidation on Color of Ready-to-Eat Abalone during Accelerated Storage and Its Control

The deepening of color of ready-to-eat (RTE) abalone during storage leads to sensory quality degradation, which seriously affects the shelf life of products and consumers’ purchasing desire. The goal of this study is to look into the causes of non-enzymatic browning and lipid oxidation, as well as how to control them, and their effect on the color of RTE abalone during storage. The control, bloodletting and antioxidants groups (lactic acid, citric acid and 4-hexylresorcinol) of RTE abalone were stored for 0, 20 and 40 days at 40 °C, respectively, to explore the rule and mechanism of the color change in RTE abalone. This research shows that RTE abalone undergoes browning during storage. Meanwhile, the content of reducing sugar, phenols and unsaturated fatty acids decreases, while the formation of lipid hydroperoxides and aldehydes increases during storage. In addition, the color change in RTE abalone during storage is mainly related to the Maillard reaction, while the lipid oxidation mainly forms pyrrole and participates in the Strecker degradation process as part of the Maillard reaction. The quality of RTE abalone can be maintained by controlling browning effectively as well as lipid oxidation through bloodletting and the addition of antioxidants to ensure that RTE abalone has high storage stability. According to our research, bloodletting and the addition of antioxidants to RTE abalone have a good application prospect and popularizing value in the storage of RTE abalone.

Nanoprecipitates of γ-cyclodextrin/epigallocatechin-3-gallate inclusion complexes as efficient antioxidants for preservation of shrimp surimi products: synthesis, performance and mechanism

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is well known for excellent chain-breaking antioxidant capability. However, browning by oxidation and aggregation of EGCG is a non-negligible defect that hinders its applications as an antioxidant in various foodstuffs. Therefore, how to eliminate or mitigate browning efficiently, while retaining functionalities as food additive is a challenge in the food industry.

RESULTS

Our results demonstrated that EGCG could be anchored within the internal cavity of γ-cyclodextrin (γ-CD) to form an inclusion structure, where hydrophobic interaction, hydrogen bonding, and π-stacking were identified to be the primary drivers. The interplay between two molecules and the steric hindrance from γ-CD could restrict the motion and aggregation of EGCG efficiently, thus alleviating the browning effect. In addition, the conformational adaption of EGCG within the inclusions would result in general decreases in hydrogen-bond dissociation enthalpies for the pyrogallol-type structure on the b ring, thus enhancing the antioxidant capability. In practical application, the nanoscale γ-CD/EGCG inclusion complexes were validated preliminarily as efficient additives in the preservation of shrimp surimi, presenting significant effects on prolonging the shelf-life of products.

CONCLUSION

Here, nanoscale γ-CD/EGCG inclusion complexes as alternatives to EGCG were tailored as food antioxidants for the preservation of shrimp surimi products, exerting antioxidant effects while mitigating the browning effects of EGCG on products. Through self-assembly, EGCG would be anchored with the cavity of γ-CD, which could regulate the release modes and restrict the aggregation of EGCG. This facile strategy has great potential in food preservation. © 2023 Society of Chemical Industry.

Achieving dual functions of texture modification and water retention of shrimp surimi products with the combination of epigallocatechin-3-gallate and γ-cyclodextrin

Epigallocatechin-3-gallate (EGCG) exhibits excellent cross-linking effects of myofibrillar proteins, it is prone to self-aggregation, causing excessive cross-linking and moisture loss of gels, which limits its application as a food additive in surimi products. Here, through combination γ-cyclodextrin and EGCG into one inclusion complex, we achieved proper usage of EGCG in shrimp surimi products: elevating both water holding capability and texture properties (hardness, chewiness and resilience). Moreover, the mechanism behind excellent performance was elucidated: as texture modifiers, the complexes improved gel network integrity through intermolecular interactions and moderated disulfide bonds; and as water retainer agents, the complexes promoted transformation of nitrogen in proteins towards the form of protonated amino, facilitating the occurrence of hydration. Furthermore, the inclusion complexes brought a higher phenolic retention within products in contrast with direct addition of EGCG. This work may propose novel insights for the usage of polyphenols as additives in surimi-based products.

Mechanisms of polyphenols on quality control of aquatic products in storage: A review

Aquatic products are easily spoiled during storage due to oxidation, endogenous enzymes, and bacteria. At the same time, compared with synthetic antioxidants, based on the antibacterial and antioxidant mechanism of biological agents, the development of natural, nontoxic, low-temperature, better-effect green biological preservatives is more acceptable to consumers. The type and molecular structure of polyphenols affect their antioxidant and antibacterial effectiveness. This review will describe how they achieve their antioxidant and antibacterial effects. And the recent literature on the mechanism and application of polyphenols in the preservation of aquatic products was updated and summarized. The conclusion is that in aquatic products, polyphenols alleviate lipid oxidation, protein degradation and inhibit the growth and reproduction of microorganisms, so as to achieve the effect of storage quality control. And put forward suggestions on the application of the research results in aquatic products. We hope to provide theoretical support for better exploration of the application of polyphenols and aquatic product storage.

Unraveling the Thermal Oxidation Products and Peroxidation Mechanisms of Different Chemical Structures of Lipids: An Example of Molecules Containing Oleic Acid

Lipid structures affect lipid oxidation, causing differences in types and contents of volatiles and nonvolatiles in various foods. In this study, the oxidation differences of monoacylglycerol (MAG), triacylglycerol (TAG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) with oleoyl residues and oleic acid (FA) during thermal treatment were investigated. Volatiles and nonvolatiles were monitored by gas chromatography-mass spectrometry and ultrahigh-performance liquid chromatography-Q-Exactive HF-X Orbitrap Mass Spectrometer, respectively. The results showed that the structures of MAG and TAG could delay the chain initiation reaction. The polar heads of PC and PE remarkably influenced the oxidation rate and the formation of the oxidation products probably due to the hydrogen bonds formed with free radicals. Among the volatile oxidation products, aldehydes, acids, and furans with eight or nine carbon atoms accounted for the majority in FA, MAG, TAG, and PC samples, but PE samples mainly generated ketones with nine or 10 carbon atoms. The formation of nonvolatile products in TAG samples possessed significant stage-specific changes. Fatty acid esters of hydroxy fatty acids were only produced in the free fatty acid oxidation model. The activity of chemical bonds participating in the truncation reaction decreased to both sides from the double bond position.

Gastrointestinal Digestion and Microbial Hydrolysis of Alkyl Gallates: Potential Sustained Release of Gallic Acid

Phenolipids such as alkyl gallates (A-GAs) have been approved by the food industry as non-toxic antioxidant additives, which are also regarded as an emerging source of functional food ingredients. However, comprehensive understanding of their digestive absorption is needed. Thus, the models of live mice and anaerobic fermentation were used to clarify the distribution and microbial hydrolysis characteristics of A-GAs in the gastrointestinal tract. HPLC-UV results demonstrated that A-GAs could be hydrolyzed by intestinal lipases and gut microorganisms including Lactobacillus to produce free gallic acid (GA). Through regulating the chain length of the lipid part in A-GAs, the sustained and controllable release of the GA can be easily achieved. Furthermore, A-GAs were also able to reach the colon and the cecum, which would lead to potential gastrointestinal protective effects. Therefore, A-GAs may be applied as possible ingredient for functional foods.

Holothuria Leucospilota polysaccharides alleviate hyperlipidemia via alteration of lipid metabolism and inflammation-related gene expression

Hyperlipemia is becoming a chronic disease that threatens human health. At the same time, people pay more and more attention to hyperlipemia. Holothuria Leucospilota polysaccharide (HLP) has been reported to ameliorate hyperlipidemia in high-fat diet-induced rats. Therefore, this study aimed to explore further metabolomics' role in improving liver function and reveal its mechanism. After oral administration of HLP for 4 weeks, total cholesterol (TC) and triglycerides (TG) levels of the liver in 100 and 200 mg/kg HLP groups were both decreased significantly (p < .05). The results showed that serum AST and ALT activity decreased by professing to be convinced of HLP. HLP also exerted antioxidant activities and up-regulated the expression of ACC, CD36, TNF-α and NF-κB in the liver of diabetic rats. Six potential biomarkers were recognized by UPLC-Q-TOF/MS and OPLS-DA. HLP alleviated liver injury by regulating the contents of metabolic end products in the serum of hyperlipidemic rats, such as nadolol and glycodeoxycholic acid. The results indicated that HLP effectively relieved HFD-induced hyperlipidemia by regulating metabolic disorders. PRACTICAL APPLICATIONS: As a chronic disease, hyperlipidemia has attracted more and more attention. Studies have shown that HLP regulates dyslipidemia, oxidative damage and inflammation to relieve hyperlipidemia. It mainly improved the liver damage caused by hyperlipidemia by inhibiting the expression of hepatic lipogenesis, oxidative stress and inflammatory factors. At the same time, we also detected six metabolites, among which high GDCA content indicated serious liver damage. Therefore, in the future, it can be suggested that HLP may be used as a functional, active substance in health products to assist in relieving hyperlipidemia, and GDCA may be used as an essential metabolic marker for the degree of liver injury.

Response surface methodology-optimized extraction of flavonoids with antioxidant and antimicrobial activities from the exocarp of three genera of coconut and characterization by HPLC-IT-TOF-MS/MS

Response surface methodology optimization based on central composite design was applied to extract flavonoids from the exocarp of three coconut genera. The antioxidant and antimicrobial activities and structures of the flavonoids were determined. The results indicated that the optimal extraction conditions were ethanol concentration, 60%; temperature, 50 ℃; time, 90 min; liquid/material ratio, 40 mL/g; ultrasonic power, 150 W. Under these conditions, the yields of green, red and yellow coconut exocarp were 366.03 ± 7.57, 596.38 ± 10.32, and 403.78 ± 5.56 mg rutin/g powder, respectively. The flavonoids exhibited eminent DPPH and ABTS radical scavenging activities with IC₅₀ values of 0.01-0.02 mg/mL. At a concentration of 2 mg/mL, they exhibited antimicrobial activity against Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa. In total, 17 flavonoids and 5 phenolic acids were characterized by UPLC-IT-TOF-MS/MS; among them, catechin, kaempferol, and quercetin were abundant. Yellow coconut had a distinct flavonoid spectrogram from other genera and contained more methoxy flavonoids.

The effects of polyphenols on fresh quality and the mechanism of partial freezing of tilapia fillets

BACKGROUND

Fish is one of the most popular foods for consumers because of its abundant nutrition, tenderness and delicious taste. With increasing demand for tilapia fillets, practical preservation is widely used to maintain quality and safety during long-distance transportation and storage. Thus the effects of polyphenols (2 g L^-1 ) on color, flavor quality and mechanism of tilapia fillets were studied during 49 days of partial freezing (-4 °C).

RESULTS

Treatment with carnosic acid (CA), procyanidin (PA), quercetin (QE) and resveratrol (RSV) inhibited water migration, myoglobin oxidation and psychrophilic bacteria stability during partial freezing storage. Aeromonas and Acinetobacter were the dominant bacteria of tilapia fillets during -4 °C storage. The relative abundance of aromatic substances (T70/2) in the polyphenol groups (>20%) was richer than in the control (CON) group (17%). Partial least squares discriminant analysis results showed that the different odors of the control and polyphenol groups were completely separated. Moreover, 35 fatty acids were identified by gas chromatographic analysis. On 49 days, the ratios of unsaturated fatty acids in the PA group (58.64%), QE group (57.70%) and RSV group (57.25%) were higher than in the control group (57.19%), and the PA group was the highest.

CONCLUSION

Polyphenol treatment effectively maintained freshness and improved the quality of tilapia fillets during partial freezing. The polyphenol treatment comprehensively sustained the color and flavor quality of tilapia fillets found in the proposed mechanism. In particular, PA treatment was considered a potential method for preserving the freshness of fillets. © 2022 Society of Chemical Industry.

Acidolysis of phospholipids with medium-chain fatty acids over M-SBA-15 (M = Zn, Al) silicas as efficient solid catalysts

BACKGROUND

Efficient and sustainable production of structured phospholipids (SPLs) enriched in medium-chain fatty acids (MCFAs) in a heterogeneous manner is crucial for their potential applications in functional foods and drugs. Herein, for the first time, Zn- and Al-incorporated SBA-15 silicas were prepared by the coprecipitation method and further researched for catalytic synthesis of MCFA-enriched SPLs through acidolysis reaction of natural phospholipids with capric or caprylic acid.

RESULTS

The as-prepared Zn- and Al-incorporated SBA-15 samples exhibited superior catalytic activities under mild experimental conditions (50 °C, 6 h) to commercial homogeneous Lewis acids and benchmark enzymes. Correspondingly, the capric acid and caprylic acid incorporations were respectively achieved up to ~40.25 ± 0.40% (or 35.08 ± 0.09%) and 37.26 ± 0.38% (or 33.02 ± 0.13%) for Zn- (or Al-) incorporated SBA-15 catalyst. Moreover, various methods such as scanning electron microscopy with energy-dispersive X-ray spectrometry, ultraviolet-visible diffuse reflectance spectroscopy and pyridine-Fourier transform infrared spectroscopy were utilized to characterize the two catalysts in order to elucidate the possible structure-performance relationship. Accordingly, the above-mentioned satisfactory results are most probably due to the well-ordered mesostructures and large amounts of active Lewis acid sites existing in the investigated materials. Noticeably, the two catalysts featured good separation and excellent recyclability as well.

CONCLUSION

The Zn- and Al-incorporated SBA-15 catalysts studied in this work might shed light on novel, sustainable and economic alternatives for effective SPL production to diminish the applications of conventional homogeneous catalysts and biocatalysts in food industries. © 2022 Society of Chemical Industry.

Characterization of a synthetic zinc-chelating peptide from sea cucumber (Stichopus japonicus) and its gastrointestinal digestion and absorption in vitro

BACKGROUND

Zinc absorption in intestinal system could be strongly affected by the gastrointestinal digestion and absorption of zinc-chelating peptides serving as zinc carriers. In this study, a novel zinc-chelating sea cucumber synthetic peptide (SCSP) was synthesized to estimate its gastrointestinal digestion and promotive effect of zinc absorption in vitro.

RESULTS

Analysis of isothermal titration calorimetry suggested that the binding of SCSP and zinc (N ≈ 1) was exothermic, with relatively weak binding affinity (K = 1.0 × 10^-3  mol L^-1 ). The formation of SCSP-Zn complexes brought morphological changes to the peptides confirmed by scanning electron microscopy (SEM), which also indicated 6.88% of the existence of zinc element. In addition, the SCSP-Zn complexes remained stable under simulated human gastrointestinal digestion. In an in vitro study, the SCSP-Zn complex could successfully transport through the intestinal membrane in the model of everted rat gut sacs (nearly 7.5 μM cm^-2 ) as well as Caco-2 cells where the zinc transport reached 0.0014 mg mL^-1 carried by SCSP. Fluorescence staining experiments revealed free zinc accumulation inside the tissues and cells treated with the SCSP-Zn complex.

CONCLUSIONS

The chelation SCSP-Zn had the promotion ability of zinc absorption in vitro and ex vivo experiments, which suggested a theoretical basis for the design and production of effective zinc chelating peptides as zinc carriers to improve zinc bioavailability. © 2022 Society of Chemical Industry.

Metal Ion-Mediated Pro-oxidative Reactions of Different Lipid Molecules: Revealed by Nontargeted Lipidomic Approaches

Unsaturated fatty acids are easily affected by metal ions, leading to the changes of their flavor, nutrition, and safety through lipid oxidation. Nevertheless, there is a lack of comprehensive evaluation of the pro-oxidative ability of different metal ions, which have different effects on different lipids. Thus, in this work, crude lipids extracted from abalone were incubated with different metal ions, and the comprehensive lipid oxidation products were analyzed by nontargeted lipidomics approaches using an ultra-high-performance liquid chromatography-Q-Exactive HF-X Orbitrap Mass Spectrometer (UPLC-Q-Exactive HF-X). Results showed that the overall pro-oxidative ability from strong to weak was Fe³⁺, Fe²⁺, Cu²⁺, Zn²⁺, Mn²⁺, Mg²⁺, Na⁺, and K⁺. Among them, Fe³⁺ and Fe²⁺ could promote the accumulation of oxidation intermediates and branched fatty acid esters of hydroxy fatty acids. Na⁺, K⁺, Cu²⁺, and Mg²⁺ could accelerate the oxidation of N-acyl ethanolamines and ceramides. K⁺ and Na⁺ had more influences on the free fatty acids than Zn²⁺ and Mn²⁺. Slow oxidation of triglyceride may be attributed to its long distance from the oil-water interface and the restriction of the polar headgroups of phospholipids on free radicals.

Quality changes and deterioration mechanisms in three parts (belly, dorsal and tail muscle) of tilapia fillets during partial freezing storage

The quality changes in tilapia belly muscle (BM), dorsal muscle (DM) and tail muscle (TM) were studied and the hypothesis of browning of the fillets was revealed during partial freezing. Compared with DM and TM groups, BM samples had higher thiobarbituric acid reactive substances (TBARS) (0.41 mg malondialdehyde eq/kg at 49 d) and K values (61.81% at 42 d) (P < 0.05). The microstructure of the BM group deteriorated most obviously during storage. Therefore, the BM group was considered to be the fastest to oxidize and deteriorate. In addition, 54 different micromolecular metabolites were identified from tilapia fillets by UHPLC-Q-TOF-MS analysis, and there were significant differences in the micromolecular metabolites in the three parts of tilapia. Therefore, proteins and lipids were degraded by the action of enzymes and microorganisms to produce some amines and small molecular acids, leading to the deterioration of the quality of tilapia fillets.