Application of resveratrol on oxidative stability of protein-based Antarctic krill oil high internal phase emulsion.

Antarctic krill oil (KO) is known for its poor oxidative stability, especially in emulsion systems. In this experiment, a complex of scallop water-soluble protein-resveratrol (SWPs-RES) was mixed with KO to create high internal phase emulsions (HIPEs) with varying RES ratios. The addition of RES led to noticeable conformational changes in SWPs, including fluorescence bursts, alterations in secondary structure, and modifications in binding motifs. The SWPs-RES complex (1:0.2) demonstrated the most effective free radical scavenging activities (HO: 38.61%, DPPH: 72.49%, ABTS: 85.66%), while the SWPs-RES complex (1:0.025) exhibited the highest emulsifying capacity. Furthermore, HIPEs containing the SWPs-RES complex (1:0.2) displayed improved rheological properties, physical stability, and enhanced oxidative stability against lipid oxidation during storage and simulated in vitro digestion. This study lays a scientific foundation for the utilization of scallop protein and Antarctic krill oil in the food industry.

The change rule of lipid oxidation and hydrolysis driven via water in Antarctic krill oil: Based on association colloid formation.

The residual water and amphiphilic compounds such as phospholipids in bulk oil can form reverse micelles, which affect oxidative stability. In this study, the Antarctic krill oil (AKO) samples with different water contents were subjected to accelerated storage. During storage, AKO exhibited oxidative changes, manifested as increased POV, TBARS values, and volatile compound levels but decreased PUFA percentages. Meanwhile, AKO underwent hydrolysis, evidenced by decreased PC, PE, and TG contents but increased FFA contents. Moreover, the degree of lipid oxidation and hydrolysis is dose-dependent with water added. Cryogenic scanning electron microscopy imaging and micelle size distribution measurement proved the presence of reverse micelle, and their size and interfacial area improved with increased water contents. Correlation analysis suggested that lipid oxidation and hydrolysis positively correlated with the size and interfacial area of reverse micelle. Therefore, it is speculated that the oil-water interface may be the site of lipid oxidation and hydrolysis.

Influence of lipid oxidation on the digestive efficiency of Antarctic krill oil: insights from a simulated gastrointestinal digestion model.

Lipid oxidation profoundly impacts its digestibility, a topic that has been predominantly investigated in triglyceride (TAG)-based dietary lipids. However, there is a dearth of similar research on lipids with diverse classes, such as Antarctic krill oil (AKO), which encompasses a spectrum of lipids including glycerides and phospholipids. This study aimed to elucidate the influence of lipid oxidation on the digestibility of AKO through a simulated gastrointestinal digestion (SGID) model. Post-SGID, AKO exhibited oxidative changes, evidenced by an escalation in peroxide value, conjugated diene value, thiobarbituric acid reactive substances and Schiff base formation. Concurrently, the digestibility of oxidized AKO was found to be inferior to that of fresh AKO, as indicated by a diminished hydrolysis degree of TAGs and phosphatidylcholine (PC), along with a reduced release of free fatty acids. Furthermore, co-digestion with tea polyphenol palmitate was observed to mitigate the oxidation of AKO and the digestion of PC during the SGID, while exerting no significant impact on TAG digestion. Notably, the emulsification capacity of oxidized AKO in a simulated intestinal fluid (without pancreatin and phospholipase A2) was also found to be inferior to that of its fresh counterpart. These findings suggest that lipid oxidation may adversely affect the emulsification capacity of AKO under simulated intestinal conditions, thereby leading to a decrement in digestibility.

Effect of ultra-high pressure heat-assisted technology combined with L-cysteine on the color of ready-to-eat shrimp during storage.

This study used ultra-high pressure processing (HPP) heat-assisted technology combined with L-cysteine (L-cys) to process ready-to-eat (RTE) shrimp. Subsequently, the effects of physical field and chemical modifications on the color of RTE shrimp were studied. The results showed that the RTE shrimp treated with HPP-Heat-L-cys showed better performance in terms of brightness value (65.25) and astaxanthin (AST) content (0.71 µg/g) during storage, maintaining the original color of RTE shrimp effectively. In addition, it was observed that the application of HPP-Heat-L-cys significantly delayed phenol oxidation, lipid oxidation, and Maillard reaction compared with traditional HPP or heat treatments. Specifically, the total phenolic content of RTE shrimp treated with HPP-Heat-L-cys was higher than that of other samples, but the TBARS and browning index were lower. Furthermore, HPP-Heat-L-cys could delay the production of dark products (such as 2-methylanthraquinone, p-benzoquinone, lipofuscin and melanin), ultimately safeguarding the color stability of RTE shrimp during storage.

Mechanism of discoloration of Antarctic krill oil upon storage: A study based on model systems.

The reddish-orange color of Antarctic krill oil fades during storage, and the mechanism remains unclear. Model systems containing different combinations of astaxanthin (ASTA), phosphatidylethanolamine (PE), and tocopherol were subjected to accelerated storage. Among all groups containing ASTA, only the ones with added PE showed significant fading. Meanwhile, the specific UV-visible absorption (A470 and A495) showed a similar trend. Peroxide value and thiobarbituric acid reactive substances increased during storage, while ASTA and PE contents decreased. Correlation analysis suggested that oxidized PE promoted fading by accelerating the transformation of ASTA. PE content exceeded the critical micelle concentration (1µg/g) indicating the formation of reverse micelles. Molecular docking analysis indicated that PE also interacted with ASTA in an anchor-like manner. Therefore, it is speculated that amphiphilic ASTA is more readily distributed at the oil-water interface of reverse micelles and captured by oxidized PE, which facilitates oxidation transfer, leading to ASTA oxidation and color fading.

Mechanism of color change in Antarctic krill oil during storage.

Antarctic krill oil (AKO) is reddish-orange in color but undergoes changes during storage. To investigate the color deterioration and potential mechanisms involved, the changes in color, endogenous components (astaxanthin, fatty acids, and phospholipids), and reaction products (aldehydes, α-dicarbonyl compounds, and pyrroles) of AKO upon storage were determined. Although the visual color of AKO tended to darken upon storage, the colorimetric analysis and ultraviolet-visible spectrum analysis both indicated a fading in red and yellow due to the oxidative degradation of astaxanthin. During storage of AKO, lipid oxidation led to the formation of carbonyl compounds such as aldehydes and α-dicarbonyls. In addition, phosphatidylethanolamines (PEs) exhibited a faster loss rate than phosphatidylcholines. Moreover, hydrophobic pyrroles, the Maillard-like reaction products associated with primary amine groups in PEs accumulated. Therefore, it is suggested that the Maillard-like reaction between PEs and carbonyl compounds formed by lipid oxidation contributed to color darkening of AKO during storage.

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.

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.

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.

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.

Development and characterization of self-emulsifying high internal phase emulsions using endogenous phospholipids from Antarctic krill oil.

High internal phase emulsions (HIPEs) have emerged as a promising structured oil system in food industry. This study developed self-emulsifying HIPEs (SHIPEs) using Antarctic krill oil (KO) with endogenous phospholipids as surfactant and algae oil as a diluent. The influence of phospholipids self-assembly on SHIPEs formation was investigated by evaluating the microstructures, particle size, rheological properties, and water distribution. Results demonstrated that the concentration and self-assembly behavior of phospholipids dominated the SHIPEs formation. Optimized SHIPEs with desirable gel properties contained 10 wt% krill oil in the oil phase at an 80 wt% oil phase level. Furthermore, these SHIPEs exhibited excellent performance in 3D printing applications. Hydrated phospholipids formed lamellar network at the oil-water interface, enhancing gel strength by crosslinking oil droplets. These findings shed light on the self-assembly of phospholipids during HIPEs formation and highlight the potential phospholipids-rich marine lipids in SHIPEs for functional food products development.

Arthritis of the hip caused by arteriovenous malformations: A case report.

BACKGROUND Arthritis of the hip caused by arteriovenous malformations (AVMs) has been rarely reported. Therefore, total hip replacement (THR) in patients with AVM-induced arthritis of the hip is challenging. CASE SUMMARY We report a 44-year-old woman with aggravated right hip pain during the past decade. The patient presented with severe pain and a functional disorder of the right hip. X-ray examination revealed severely narrowed right hip joint space and abnormal trabecular bone loss in the femoral neck and trochanter area. Doppler ultrasound, magnetic resonance imaging and computed tomography angiography revealed AVMs surrounding the right hip, along with erosion. To ensure the safety of THR, we performed vascular embolization and temporary balloon occlusion of the iliac artery three times during the operation. However, serious hemorrhage occurred, which was rescued by the multimodality blood conservation strategy. THR was successfully performed, and the patient was discharged 8 d later for rehabilitation. Postoperative pathological examination showed osteonecrosis of the femoral head with malformed thick-walled vessels and focal granulomatous inflammation of the surrounding soft tissues. The Harris Hip Scale score increased from 31 to 82 at 3 mo of follow-up. The patient was followed up for 1 year, and all her clinical symptoms were significantly alleviated. CONCLUSION Arthritis of the hip caused by AVMs is rare in clinical practice. The activity and function of the involved hip joint can be effectively treated with THR after comprehensive imaging and multidisciplinary consultation.

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.

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.

Effects of Addition of Tea Polyphenol Palmitate and Process Parameters on the Preparation of High-Purity EPA Ethyl Ester.

High-purity eicosapentaenoic acid (EPA) ethyl ester (EPA-EE) can be produced from an integrated technique consisting of saponification, ethyl esterification, urea complexation, molecular distillation and column separation. In order to improve the purity and inhibit oxidation, tea polyphenol palmitate (TPP) was added before the procedure of ethyl esterification. Furthermore, through the optimization of process parameters, 2:1 (mass ratio of urea to fish oil, g/g), 6 h (crystallization time) and 4:1 (mass ratio of ethyl alcohol to urea, g/g) were found to be the optimum conditions in the procedure of urea complexation. Distillate (fraction collection), 115 °C (distillation temperature) and one stage (the number of stages) were found to be the optimum conditions for the procedure of molecular distillation. With the addition of TPP and the above optimum conditions, high-purity (96.95%) EPA-EE was finally obtained after column separation.

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.

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.

Chitosan-wampee seed essential oil composite film combined with cold plasma for refrigerated storage with modified atmosphere packaging: A promising technology for quality preservation of golden pompano fillets.

The effect of chitosan-wampee seed essential oil (WSEO) composite film coating before cold plasma (CP) treatment on the quality preservation of golden pompano fillets during refrigerated storage was investigated and compared with that of chitosan and CP alone. The results indicated that the chitosan-WSEO composite film coating before CP treatment and modified atmosphere packaging (MAP), referred to as CPCW-M, exhibited the lowest total bacterial count, total volatile base nitrogen, and peroxide and thiobarbituric acid values of 4.03 log culture-forming units (CFU)/g, 13.45 mg/100 g, 24.65 meq/kg, and 1428.4 µg MDAeq/kg, respectively. Simultaneously, it contributed to the most profound inhibition of the lipid hydrolase, lipoxygenase, thus effectively preventing the oxidative deterioration of unsaturated fatty acids. Moreover, minimal color changes, drip loss, and texture deterioration of the fillets were observed. Therefore, the edible chitosan-WSEO composite film, together with CP and MAP, was effective in preserving golden pompano fillets and extending shelf life throughout the refrigerated storage period.

Effects of Tea Polyphenol and Its Combination with Other Antioxidants Added during the Extraction Process on Oxidative Stability of Antarctic Krill (Euphausia superba) Oil.

Antarctic krill (Euphausia superba) oil contains high levels of marine omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In industrial production, krill oil is usually extracted from krill meals by using ethanol as a solvent. Water in the krill meal can be easily extracted by using ethanol as an extraction solvent. During the extraction process, the EPA and DHA are more easily oxidized and degraded when water exists in the ethanol extract of krill oil. Based on the analysis of peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), fatty acid composition, and lipid class composition, the present study indicated that the composite antioxidants (TP-TPP) consist of tea polyphenol (TP) and tea polyphenol palmitate (TPP) had an excellent antioxidant effect. By contrast, adding TP-TPP into ethanol solvent during the extraction process is more effective than adding TP-TPP into krill oil after the extraction process.

Preparation and Hepatoprotective Activities of Peptides Derived from Mussels (Mytilus edulis) and Clams (Ruditapes philippinarum).

Low molecular weight (<5 kDa) peptides from mussels (Mytilus edulis) (MPs) and the peptides from clams (Ruditapes philippinarum) (CPs) were prepared through enzymatic hydrolysis by proteases (dispase, pepsin, trypsin, alcalase and papain). Both the MPs and the CPs showed excellent in vitro scavenging ability of free radicals including OH, DPPH and ABTS in the concentration range of 0.625−10.000 mg/mL. By contrast, the MPs hydrolyzed by alcalase (MPs-A) and the CPs hydrolyzed by dispase (CPs-D) had the highest antioxidant activities. Furthermore, MPs-A and CPs-D exhibited protective capabilities against oxidative damage induced by H2O2 in HepG2 cells in the concentration range of 25−800 µg/mL. Meanwhile, compared with the corresponding indicators of the negative control (alcohol-fed) mice, lower contents of hepatic MDA and serums ALT and AST, as well as higher activities of hepatic SOD and GSH-PX were observed in experiment mice treated with MPs-A and CPs-D. The present results clearly indicated that Mytilus edulis and Ruditapes philippinarum are good sources of hepatoprotective peptides.