In-situ growth of metal-organic frameworks on cellulose nanofiber aerogels for rapid adsorption of heterocyclic aromatic amines.

Heterocyclic aromatic amines (HAAs) are the main carcinogens produced during thermal processing of protein-rich foods. In this paper, a composite aerogel (TOCNFCa) with a stabilized dual-network structure was prepared via a template for the in-situ synthesis of UiO-66 on cellulose for the adsorption of HAAs in food. The dual-network structure of TOCNFCa provides the composite aerogel with excellent wet strength, maintaining excellent compressive properties. With the in-situ grown UiO-66 content up to 71.89 wt%, the hierarchical porosity endowed TOCNFCa@UiO-66 with the ability to rapidly adsorb HAAs molecules with high capacity (1.44-5.82 µmol/g). Based on excellent thermal stability, adsorption capacity and anti-interference, TOCNFCa@UiO-66 achieved satisfactory recoveries of HAAs in the boiled marinade, which is faster and more economical than the conventional SPE method. Moreover, TOCNFCa@UiO-66 could maintain 84.55 % of the initial adsorption capacity after 5 times of reuse.

Defective UiO-66/cellulose nanocomposite aerogel for the adsorption of heterocyclic aromatic amines.

Heterocyclic aromatic amines (HAAs), arising as chemical derivatives during the high-temperature culinary treatment of proteinaceous comestibles, exhibit notable carcinogenic potential. In this paper, a composite aerogel (AGD-UiO-66) with high-capacity and fast adsorption of HAAs was made with anchoring defective UiO-66 (D-UiO-66) mediated by lauric acid on the backbone of cellulose nanofibers (CNF). AGD-UiO-66 with hierarchical porosity reduced the mass transfer efficiency for the adsorption of HAAs and achieved high adsorption amount (0.84-1.05 µmol/g) and fast adsorption (15 min). The isothermal adsorption model demonstrated that AGD-UiO-66 belonged to a multilayer adsorption mechanism for HAAs. Furthermore, AGD-UiO-66 was successfully used to adsorb 12 HAAs in different food (roasted beef, roasted pork, roasted salmon and marinade) with high recoveries of 94.65%-104.43%. The intrinsic potential of AGD-UiO-66 demonstrated that it could be widely applicable to the adsorption of HAAs in foods.

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.

Improving the in vitro and in vivo bioavailability of pterostilbene using Yesso scallop gonad protein isolates-epigallocatechin gallate (EGCG) conjugate-based emulsions: effects of carrier oil.

This study investigated the influence of carrier oils on the in vitro and in vivo bioavailability of PTE encapsulated in scallop gonad protein isolates (SGPIs)-epigallocatechin gallate (EGCG) conjugate stabilized emulsions. The SGPIs-EGCG stabilized emulsions were subjected to an in vitro simulated digestion, and the resulting corn oil and MCT micelles were used to evaluate the PTE transportation using the Caco-2 cell model. Both emulsions remarkably improved the bioaccessibility of PTE in the micelle phase. Nevertheless, corn oil emulsions increased trans-enterocyte transportation of PTE more efficiently than MCT emulsions. Furthermore, the maximum plasma concentrations of PTE and its metabolites in mice fed with PTE emulsions were prominently higher than those in mice fed with PTE solution, while the in vivo metabolic patterns of PTE in different oil-stabilized emulsions were different. Therefore, SGPIs-EGCG stabilized emulsions could enhance the bioavailability of PTE through controlled release, in which corn oil is more suitable than MCT.

Effects of antioxidants of bamboo leaves on protein digestion and transport of cooked abalone muscles.

The effects of oxidation on protein digestion and transport in cooked abalone muscles were investigated using a combination of simulated digestion and everted-rat-gut-sac models for the first time. Boiling heat treatments caused protein oxidation in the abalone muscles, reflected by increases in the carbonyl group and disulfide bond contents, protein hydrophobicity and aggregation degree, as well as decreases in the free sulfhydryl group and amino acid contents. Protein oxidation significantly inhibited the degree of hydrolysis, digestion rate, and digestibility of the abalone muscles in the simulated digestion model. The results from the everted-rat-gut-sac model showed that amino acid and peptide transport levels from the digestion products of the cooked abalone muscles were lower than those of the uncooked samples. In contrast, the addition of antioxidants of bamboo leaves mitigated heat-treatment-induced protein oxidation, aggregation and increased hydrophobicity, and consequently improved abalone muscle protein digestibility and transport levels.

Free amino acid, 5'-Nucleotide, and lipid distribution in different tissues of blue mussel (Mytilis edulis L.) determined by mass spectrometry based metabolomics.

Blue mussel (Mytilus edulis L.) is a popular, nutritional, and tasty mollusk. To better understand the composition of nutrients and improve further processing of the mussels, metabolomic approaches were used to analyze the free amino acids, 5'-nucleotides, and lipid compositions of different tissues. Our results showed that the viscera and gonad were rich in glutamine and glycine. Adenosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and inosine 5'-monophosphate were abundant in the mantle, foot, and adductor muscle. Three main types of lipids, phospholipids (PLs), glycerides, and fatty acids (FAs), were semi-quantified. PLs were mainly distributed in the gonad of male mussels and viscera, gonad, and mantles of female mussels. FAs were relatively high in the viscera of males and in the gonad and viscera of females. The viscera of females were rich in phosphatidylcholine, such as 16:0/22:6 and 16:0/20:5. Triglycerides were the key lipids for distinguishing different tissues, especially 16:0/18:1/18:3 and 16:0/18:4/20:5.

Combined effects of ultrasound and antioxidants on the quality maintenance of bay scallop (Argopecten irradians) adductor muscles during cold storage.

The combined effects of ultrasound and the antioxidants of bamboo leaves (AOB) on the quality maintenance of the adductor muscle of scallops (AMSs) during cold storage was investigated. Ultrasound power at 350 W coupled with AOB solution (2% w/v) (UAOB-350) was applied to treat the AMSs according to Taylor diagram analysis. The microstructure, oxidative changes (lipid and protein oxidation), total numbers of colonies, total volatile basic nitrogen, and texture of the AMSs during 6 days of cold storage were analysed. The results indicated that UAOB-350 treatment could effectively retard protein and lipid oxidation and bacterial growth and maintain better microstructure and texture characteristics than AOB solution treatment alone, prolonging the shelf life of the AMSs by 2 days during storage at 4 °C. These results indicate that the UAOB-350 combination method has promising potential to maintain the quality and extend the shelf life of AMSs during cold storage.

Marine Bioactive Compounds as Nutraceutical and Functional Food Ingredients for Potential Oral Health.

Oral diseases have received considerable attention worldwide as one of the major global public health problems. The development of oral diseases is influenced by socioeconomic, physiological, traumatic, biological, dietary and hygienic practices factors. Currently, the main prevention strategy for oral diseases is to inhibit the growth of biofilm-producing plaque bacteria. Tooth brushing is the most common method of cleaning plaque, aided by mouthwash and sugar-free chewing gum in the daily routine. As the global nutraceutical market grows, marine bioactive compounds are becoming increasingly popular among consumers for their antibacterial, anti-inflammatory and antitumor properties. However, to date, few systematic summaries and studies on the application of marine bioactive compounds in oral health exist. This review provides a comprehensive overview of different marine-sourced bioactive compounds and their health benefits in dental caries, gingivitis, periodontitis, halitosis, oral cancer, and their potential use as functional food ingredients for oral health. In addition, limitations and challenges of the application of these active ingredients are discussed and some observations on current work and future trends are presented in the conclusion section.

Structural characteristics and improved in vitro hepatoprotective activities of Maillard reaction products of decapeptide IVTNWDDMEK and ribose.

Here, a novel decapeptide IVTNWDDMEK with Maillard reactivity derived from scallop Chlamys farreri mantle was identified. The structural characteristics and in vitro hepatoprotective effects of IVTNWDDMEK conjugated with ribose were further investigated. The changes in decapeptide structures were determined by ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR), and atomic force microscopy (AFM), and the modification sites induced by Maillard reaction of IVTNWDDMEK and ribose were monitored by high performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS). Maillard reaction products (MRPs) of IVTNWDDMEK-ribose demonstrate hepatoprotective benefits through the suppression of DNA damage and apoptosis induced by oxidative stress in human HepG2 cells in addition to enhancing the antioxidant activities. Moreover, after treatment with decapeptide-ribose MRPs, the activities of cellular antioxidative enzymes, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione reductase (GSH-Rx) were remarkably increased, while the content of malondialdehyde (MDA) was decreased compared with H2 O2 - treated group, thereby enhancing the intracellular antioxidant defenses. These findings demonstrate the potential utilization of decapeptide IVTNWDDMEK-ribose MRPs as food antioxidants to suppress oxidative damage. PRACTICAL APPLICATION: In recent years, several food-derived bioactive peptides and their derivatives are regarded as good dietary antioxidants for reducing oxidative stress and improving liver function. Here, a novel Maillard reactive decapeptide IVTNWDDMEK, identified from scallop mantle hydrolysates by peptidomics in the previous study was synthesized. Then, the correlation between intercellular antioxidant activities and chemical structure changes of IVTNWDDMEK-ribose Maillard reaction conjugates was further studied. The preferable hepatoprotective activities of decapeptide IVTNWDDMEK-ribose MRPs indicated that these MRPs could be potentially utilized as food antioxidants or additives in the production of nutritional foods.

A phosphorescence resonance energy transfer-based "off-on" long afterglow aptasensor for cadmium detection in food samples.

Cadmium contamination is a severe food safety risk for human health. Herein, a long afterglow "off-on" phosphorescent aptasensor was developed based on phosphorescence resonance energy transfer (PRET) for the detection of Cd2+ in complex samples which minimizes the interference of background fluorescence. In this scheme, initially the phosphorescence of Cd2+-binding aptamer conjugated long afterglow nanoparticles (Zn2GeO4:Mn) was quenched by black hole quencher 1 (BHQ1) modified complementary DNA. Upon encountering of Cd2+, the aptamer interacted with Cd2+ and the complementary DNA with BHQ1 was released, leading to phosphorescence recovery. The content of Cd2+ could be quantified by the intensity of phosphorescence recovery with 100 µs gate time (which eliminated the sample autofluorescence) with a linear relationship between 0.5 and 50 µg L-1 and a limit of detection (LOD) of 0.35 µg L-1. This method was successfully demonstrated for Cd2+ detection in drinking water and yesso scallop samples. The "off-on" phosphorescent aptasensor based on PRET of long afterglow nanomaterials could be an effective tool for Cd2+ detection in food samples.

Differences in oxidative susceptibilities between glycerophosphocholine and glycerophosphoethanolamine in dried scallop (Argopecten irradians) adductor muscle during storage: an oxidation kinetic assessment.

BACKGROUND: Phospholipids, the main lipid component in marine shellfish, mainly comprise glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE). GPC and GPE in marine shellfish, especially scallop, carry n-3 long-chain polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), although different types of glycerophospholipids (GP) have different health benefits on human health. Moreover, different GP subclasses such as GPC and GPE have different oxidative susceptibilities in complex food systems. The present study compared the oxidative susceptibilities of GPC and GPE in dried scallop during storage by high-performance liquid chromatography-tandem mass spectrometry and kinetic models, and also investigated the effects of natural phenolic antioxidant on their susceptibilities. RESULTS: The results showed that GPC and GPE molecular species (carrying EPA or DHA) contents in samples continuously reduced during storage at two different temperatures. The first-order kinetic model better reflected the changes of GPC and GPE molecular species (carrying EPA or DHA) in samples than the zero-order kinetic model during storage. According to the oxidation rate (k) obtained from first-order kinetic models, GPE possessed a greater oxidation rate than GPC during storage. Moreover, the results showed that antioxidants of bamboo leaves (AOB, polar polyphenolic antioxidants) significantly decreased the oxidation rates of GPC and GPE molecular species (carrying EPA or DHA) in samples during storage, and GPC could be more effectively protected by AOB compared to GPE. CONCLUSION: The present study provides a practical method for accurately evaluating the oxidative susceptibility of different phospholipid classes in complex food systems. © 2020 Society of Chemical Industry.

Construction of Ginsenoside Nanoparticles with pH/Reduction Dual Response for Enhancement of Their Cytotoxicity Toward HepG2 Cells.

The aim of this study is to construct a pH- and reduction-responsive nanodrug delivery system to effectively deliver a ginsenoside (Rh2) and enhance its cytotoxicity against human hepatocarcinoma cells (HepG2). Here, pullulan polysaccharide was grafted by urocanic acid and α-lipoic acid (α-LA) to obtain a copolymer, α-LA-conjugated N-urocanyl pullulan (LA-URPA), which was expected to have pH and redox dual response. Then, the copolymer LA-URPA was used to encapsulate ginsenoside Rh2 to form Rh2 nanoparticles (Rh2 NPs). The results showed that Rh2 NPs exhibited an average size of 119.87 nm with a uniform spherical morphology. Of note, Rh2 NPs showed a high encapsulation efficiency of 86.00%. Moreover, Rh2 NPs possessed excellent pH/reduction dual-responsive drug release under acidic conditions (pH 5.5) and glutathione (GSH) stimulation with a low drug leakage of 14.8% within 96 h. Furthermore, Rh2 NPs with pH/reduction dual response had higher cytotoxicity than Rh2 after incubation with HepG2 cells for 72 h, indicating that Rh2 NPs had a longer circulation time. After the treatment with Rh2 NPs, the excessive increase of reactive oxygen species and the decrease of superoxide dismutase, glutathione (GSH), and mitochondrial membrane potential suggested that the mitochondrial pathway mediated by oxidative stress played a role in this Rh2 NP-induced apoptosis. In conclusion, this study provides a new strategy for improving the application of ginsenoside Rh2 in the food and pharmaceutical fields.

The effects of carbon dots produced by the Maillard reaction on the HepG2 cell substance and energy metabolism.

Endogenous nanoparticles produced during food processing have received considerable attention due to their unique physicochemical properties and potential safety risks. However, the bio-impact of endogenous nanoparticles on cell metabolism has not been fully studied. In this work, the effects of carbon dots (CDs) derived from the Maillard reaction of glucose and lysine on the cellular substance and energy metabolism were assessed using HepG2 cells as a model. When the HepG2 cells were incubated with 10.0 mg mL-1 of CDs, the mitochondrial membrane potential decreased significantly and the mitochondrial function was affected. The extracellular acidification rate and oxygen consumption rate were decreased in comparison to normal cells without CDs. The CDs blocked the glycolysis pathway by reducing the activities of key enzymes including phosphofructokinase and pyruvate kinase. The energy supply pathway of HepG2 cells changed from glycolysis to TCA cycle, but the increase of the TCA cycle flux could not meet the requirements for restoring cell proliferation. The increase of the compensatory flux in the TCA cycle may be the result of up-regulation of the metabolism of glucogenic amino acids and ketogenic amino acids, while lipid metabolism did not seem to be affected in this process.

Action of endogenous proteases on texture deterioration of the bay scallop (Argopecten irradians) adductor muscle during cold storage and its mechanism.

Texture deterioration occurs in adductor muscle of scallop (Argopecten irradians) (AMS) after 5 d of cold storage. Principal component analysis indicated the texture deterioration resulted in significant decrease of hardness, springiness, adhesiveness and chewiness, but significantly increased cohesiveness. Endogenous proteases degraded structural proteins, among which cysteine proteases were mainly responsible for myofibrillar proteins (MPs) degradation, while serine proteases degraded both MPs and connective tissue proteins. Pearson coefficient analysis showed that texture indicators significantly correlated with structural protein indicators in AMS. To be more specific, the hardness, springiness, adhesiveness and chewiness negatively correlated with myofibrillar fragmentation index, soluble hydroxyproline (Hyp) and soluble glycosaminoglycans, but positively correlated with solubility of MPs and water holding capacity. Meanwhile, the cohesiveness positively correlated with soluble Hyp. The Taylor diagram and Hierarchical cluster analysis confirmed that the inhibitors of cysteine and serine proteases could effectively retard textural deterioration of AMS during 5 d of cold storage.

Effects of natural phenolics on shelf life and lipid stability of freeze-dried scallop adductor muscle.

Effects of natural phenolics on the shelf life of dried scallop adductor muscle predicted by accelerated shelf life testing (ALST) combined with Arrhenius model were investigated. This allows the food industries to reliably and rapidly determine the shelf life of dried shellfish species treated with antioxidants. The shelf life of dried scallop adductor muscle treated with antioxidants of bamboo leaves (AOB) and tea polyphenols (TP) was more than 1.70-fold that of dried control scallop adductor muscle. Thus, the highly nutritional value of dried scallop adductor muscle, based on its lipid constituents, is maintained during storage. OXITEST method further confirmed the improvement of lipid stability of antioxidant treated dried scallop adductor muscle by protecting polyunsaturated fatty acids, especially eicosapentaenoic and docosahexaenoic acids, against autoxidation. Moreover, the natural phenolics employed effectively limited lipid oxidation by breaking the autoxidative chain reaction and/or inhibiting free radical formation in dried scallop adductor muscle during storage.

High-Throughput, Rapid Quantification of Phthalic Acid Esters and Alkylphenols in Fish Using a Coated Direct Inlet Probe Coupled with Atmospheric Pressure Chemical Ionization.

Intake of endocrine-disrupting chemicals (EDCs) by humans could disturb the metabolism of hormones, induce cancer, and damage the liver and other organs. Phthalate acid esters (PAEs) and alkylphenols (APs) are important EDCs and environmental contaminants. With the increasing use of plastics and nonionic surfactants worldwide, PAEs and APs have entered environmental water and accumulated in edible fish, which are finally consumed by humans. In this study, a coated direct inlet probe (CDIP) based on an atmospheric solid analysis probe, which can rapidly and simultaneously extract both PAEs and APs in fish, was developed. Twelve PAEs and APs were quantified by using a stable-isotope-labeled internal standard. Standard curves of the PAEs and APs having correlation coefficients of R2 ≥ 0.9837 were obtained. The limit of detection of the PAEs and APs was distributed from 0.01 to 40 ng g-1. The relative recovery of the method was 78-120% between low, medium, and high spiked levels. Combined with principal component analysis, PAE- and AP-contaminated Carassius auratus from different habitats could be identified. Multiple sample analysis mode allowed the extraction of up to 12 samples at once, and the total analysis time (including sample pretreatment, extraction, and analysis time) was less than 10 min per sample, which indicates that CDIP is useful for rapid quantitative analysis.

Flavor formation in different production steps during the processing of cold-smoked Spanish mackerel.

This study aimed to determine the changes in the flavor profile during different operating units when making cold-smoked Spanish mackerel. Sensory evaluation and instrumental analysis of tenderness were applied to optimize the processing parameters. For the overall odor perception, distinct odor among fresh and processed samples could be distinguished using electronic nose (e-Nose). Purge-and-trap (P&T) extraction combined with gas chromatography-mass spectrometry (GC-MS) was used to identify volatile compounds. Alcohols were the major volatiles in Spanish mackerel over the whole processing, while 2-butanol was found in the highest concentration. Curing was an effective way to remove fishy odor. Drying decreased the concentration of volatiles, especially sulfur compounds. Odor formation in cold-smoked mackerel could be divided into four steps (curing, drying, cold smoking and heating) as a result of partial least squares discriminant analysis (PLS-DA).

Adverse effects of fluorescent carbon dots from canned yellow croaker on cellular respiration and glycolysis.

The effect of endogenous carbon nanoparticles from food sources is one of the hot topics in the current food research field. The relationship between the foodborne nanoparticle properties and the cytotoxic mechanism has been insufficiently studied. In this work, carbon dots (CDs) with strong fluorescence were found and purified from canned yellow croaker, and their cytotoxicity was investigated for the first time. The canned yellow croaker CDs are nearly spherical with a particle size distribution in the range of 1.8-5.8 nm. The fluorescence quantum yield of the isolated CDs is 9.7% and the maximum excitation wavelength is 340 nm, with a significant redshift phenomenon in fluorescence spectra. The surface elemental analysis showed that the composition of the canned yellow croaker CDs was C (76.42%), N (6.49%), and O (16.7%), and various functional groups are on the surface. The CDs have good stability in sodium chloride solution and the fluorescence intensity was stable within the pH value of 4 to 10. A strong fluorescence quenching effect was found upon the addition of Cu2+ and Fe3+ to the CD aqueous solution. The CDs can easily enter the interior of the live cells. Moreover, a concentration-dependent behavior of HepG2 cell viability was found when the cells were incubated with the canned yellow croaker CDs. Glycolysis and mitochondrial function analysis of HepG2 cells revealed that both the extracellular acidification rate and oxygen consumption rate significantly decreased in contrast to the normal level prior to the addition of CDs. In addition, the CDs significantly inhibited the glycolytic pathway by reducing the activity of key enzymes hexokinase and pyruvate kinase in the glycolytic pathway.

Mechanism of antioxidant action of natural phenolics on scallop (Argopecten irradians) adductor muscle during drying process.

Lipid hydrolysis and oxidation occurred in Argopecten irradians adductor muscle during hot air drying. Using an in vivo imaging system, we found that antioxidants of bamboo leaves (AOB) could diffuse into the adductor muscle upon marinating. Both tea polyphenols (TP) and AOB efficiently retarded lipid oxidation but had a slight effect on lipid hydrolysis during drying process. The in situ antioxidant mechanisms of AOB as well as TP were revealed, including quenching of free radicals detected by electron spin resonance, chelating metal ions determined by confocal laser scanning microscopy and inhibiting lipoxygenase. Less than 8% of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in AOB and TP marinated adductor muscle were decreased compared to more than 28% decrease in control adductor muscle during the drying process. Overall, these natural antioxidants, TP and AOB, efficiently maintained high nutritive value of adductor muscle, especially, their lipid quality.

Bioaccessibility and cellular uptake of ß-carotene in emulsion-based delivery systems using scallop (Patinopecten yessoensis) gonad protein isolates: effects of carrier oil.

Emulsion-based delivery systems were structured by using scallop gonad protein isolates (SGPIs) as novel food-grade emulsifiers. The effects of carrier oil, including the long chain triglycerides (LCT) and medium chain triglycerides (MCT), on the bioaccessibility and cellular uptake of ß-carotene (BC) were investigated. Both LCT and MCT delivery systems remained stable at pH 7-8 but aggregated at lower pH values (3-6) according to the results of light scattering and microscopy measurements. LCT droplets fabricated within SGPIs were digested and released more slowly than MCT droplets during the simulated gastrointestinal tract digestion. The LCT emulsion showed higher BC bioaccessibility (65.5%) than the MCT emulsion (23.1%) as a result of the greater solubilization of BC in mixed micelles fabricated from long-chain fatty acids. Moreover, the LCT emulsion produced higher cellular uptake of BC as compared with the MCT emulsion in intestinal epithelial cells. These results demonstrated that SGPIs could be used as novel food-grade emulsifiers to protect lipophilic bioactive compounds in emulsion-based delivery systems, in which LCT is more suitable to encapsulate and deliver BC than MCT.