Prebiotic saccharides polymerization improves the encapsulation efficiency, stability, bioaccessibility and gut microbiota modulation of urolithin A liposomes.

This work was to investigate the effect of four prebiotic saccharides gum arabic (GA), fructooligosaccharide (FOS), konjac glucomannan (KGM), and inulin (INU) incorporation on the encapsulation efficiency (EE), physicochemical stability, and in vitro digestion of urolithin A-loaded liposomes (UroA-LPs). The regulation of liposomes on gut microbiota was also investigated by in vitro colonic fermentation. Results indicated that liposomes coated with GA showed the best EE, bioaccessibility, storage and thermal stability, the bioaccessibility was 1.67 times of that of UroA-LPs. The UroA-LPs coated with FOS showed the best freeze-thaw stability and transformation. Meanwhile, saccharides addition remarkably improved the relative abundance of Bacteroidota, reduced the abundances of Proteobacteria and Actinobacteria. The UroA-LPs coated with FOS, INU, and GA exhibited the highest beneficial bacteria abundance of Parabacteroides, Monoglobus, and Phascolarctobacterium, respectively. FOS could also decrease the abundance of harmful bacteria Collinsella and Enterococcus, and increase the levels of acetic acid, butyric acid and iso-butyric acid. Consequently, prebiotic saccharides can improve the EE, physicochemical stability, gut microbiota regulation of UroA-LPs, and promote the bioaccessibility of UroA, but the efficiency varied based on saccharides types, which can lay a foundation for the application of UroA in foods industry and for the enhancement of its bio-activities.

Lipidomics profile and volatile compounds of squids (Illex argentinus, Ommastrephes Bartram and Dosidicus gigas) in the Argentine, North Pacific Ocean, Equator and Peru by UPLC-triple TOF-MS and HS-SPME-GC-O-MS.

Comprehensive lipid and volatile compound analyses were performed with squids collected from four varied geographical locations to discriminate the regional characteristics. A total of 1442 lipid molecules and 110 volatiles were detected in the squid muscle samples. There were significant differences in the lipid profiles between Argentine squid (Illex argentinus, AGT), North Pacific Ocean squid (Ommastrephes Bartram, NPO), Equatorial squid (Dosidicus gigas, EQ), and Peruvian squid (Dosidicus gigas, PR) muscle. Phosphatidylcholines (14.64%), triacylglycerols (12.42%), and ceramides (10.97%) were the main lipid components. The contents of polyunsaturated fatty acid in phospholipids and in glycerolipids were 30.35-52.05% and 18.11-25.15%, respectively. The volatiles in squids exhibited significant regional variation; 1-pentanol and 1-octanol, 2-ethyl-1-hexanol and terpinen-4-ol, 2,7-ethyl-1-hexanol, 3-methy-1-butanol and 2-propyl-1-pentanol were identified as characteristic flavor compounds in AGT, NPO, EQ, and PR, respectively. Sphingomyelin, phosphatidylserine, phosphatidylethanolamine, and ceramide were strongly correlated with volatiles in squid muscle. Our study is a reference for the lipid nutritional value and flavor compounds of squids.

Investigating the Mechanism of Microwave-Assisted Enzymolysis Synergized with Magnetic Bead Adsorption for Reducing Ovalbumin Allergenicity through Biomass Spectrometry Analysis.

This study found that, after microwave treatment at 560 W for 30 s, alkaline protease enzymolysis significantly reduced the allergenicity of ovalbumin (OVA). Furthermore, specific adsorption of allergenic anti-enzyme hydrolyzed peptides in the enzymatic products by immunoglobulin G (IgG) bound to magnetic bead further decreased the allergenicity of OVA. The results indicated that microwave treatment disrupts the structure of OVA, increasing the accessibility of OVA to the alkaline protease. A comparison between 17 IgG-binding epitopes identified through high-performance liquid chromatography-higher energy collisional dissociation-tandem mass spectrometry and previously reported immunoglobulin E (IgE)-binding epitopes revealed a complete overlap in binding epitopes at amino acids (AA)125-135, AA151-158, AA357-366, and AA373-381. Additionally, partial overlap was observed at positions AA41-59, AA243-252, and AA320-340. Consequently, these binding epitopes were likely pivotal in eliciting the allergic reaction to OVA, warranting specific attention in future studies. In conclusion, microwave-assisted enzymolysis synergized with magnetic bead adsorption provides an effective method to reduce the allergenicity of OVA.

Gut Microbiome-Serum Metabolism Revealed the Allergenicity of Ferulic Acid Combined with Glucose-Modified ß-Lactoglobulin.

A novel strategy combining ferulic acid and glucose was proposed to reduce ß-lactoglobulin (BLG) allergenicity and investigate whether the reduction in allergenicity was associated with gut microbiome and serum metabolism. As a result, the multistructure of BLG changed, and the modified BLG decreased significantly the contents of IgE, IgG, IgG1, and mMCP-1 in serum, improved the diversity and structural composition of gut microbiota, and increased the content of short-chain fatty acids (SCFAs) in allergic mice. Meanwhile, allergic mice induced by BLG affected arachidonic acid, tryptophan, and other metabolic pathways in serum, the modified BLG inhibited the production of metabolites in arachidonic acid metabolism pathway and significantly increased tryptophan metabolites, and this contribution helps in reducing BLG allergenicity. Overall, reduced allergenicity of BLG after ferulic acid was combined with glucose modification by regulating gut microbiota, the metabolic pathways of arachidonic acid and tryptophan. The results may offer new thoughts alleviating the allergy risk of allergenic proteins.

Rheology, physicochemical properties, and microstructure of fish gelatin emulsion gel modified by γ-polyglutamic acid.

In this work, the effect of the addition of γ-polyglutamic acid (γ-PGA) on the rheology, physicochemical properties, and microstructure of fish gelatin (FG) emulsion gel was investigated. Samples of the emulsion gel were evaluated for rheological behavior and stability prior to gelation. The mechanical properties and water-holding capacity (WHC) of the emulsion were determined after gelation. The microstructure of the emulsion gel was further examined using confocal laser scanning microscopy (CLSM). The results indicated a gradual increase in the apparent viscosity and gelation temperature of the emulsion at a higher concentration of γ-PGA. Additionally, frequency scan results revealed that on the addition of γ-PGA, FG emulsion exhibited a stronger structure. The emulsion containing 0.1% γ-PGA exhibited higher stability than that of the control samples. The WHC and gel strength of the emulsion gel increased on increasing the γ-PGA concentration. CLSM images showed that the addition of γ-PGA modified the structure of the emulsion gel, and the droplets containing 0.1% γ-PGA were evenly distributed. Moreover, γ-PGA could regulate the droplet size of the FG emulsion and its size distribution. These findings suggest that the viscoelasticity and structure of FG emulsion gels could be regulated by adjusting the γ-PGA concentration. The γ-PGA-modified FG emulsion gel also exhibited improved rheology and physicochemical properties. The results showed that γ-PGA-modified FG emulsion gel may find potential applications in food, medicine, cosmetics, and other industries.

Regulating effects of low salt dry-curing pre-treatment on microbiota, biochemical changes and flavour precursors of grass carp (Ctenopharyngodon idella) fillets during storage at 4 °C.

Low salt dry-curing (LSD), as a healthier pre-treatment for the preservation of fishery products, is a potential technique substitute for excessively salty curing. The regulatory effects of 2 % and 3 % LSD on the quality evolution through an intrinsic correlation between microbiota succession and flavour precursors of refrigerated grass carp fillets were investigated in this study. The results showed that the LSD pre-treatment was effective in promoting proteolysis, free amino acid and fatty acid metabolism with the microbiota succession and quality evolution. Compared with unpre-treated samples, the 3 % LSD pre-treatment effectively extended the shelf life by 10 days within the acceptable quality attributes. Not only did the LSD pre-treatment lead to catalytic microbiota succession and inhibitive spoilage substance production but it also improved the flavour precursors, which are taste-active amino acids and polyunsaturated fatty acids (PUFAs). Moreover, considerable correlations between quality attributes, taste-active amino acids, PUFAs and microbiota were obtained.

Effects of Maillard reaction of different monosaccharide-modified on some functional properties of fish gelatin.

In this work, the effects of Maillard reaction of different monosaccharide-modified fish gelatin were studied. The changes of gel properties, rheology and structure of fish gelatin before and after modification were compared and analyzed, and oil-in-woter emulsions were prepared. The results showed that the five-carbon monosaccharide had stronger modification ability than the six-carbon monosaccharide, which was mainly due to the different steric hindrance of the amino acids in the nuclear layer and the outer layer to the glycosylation reaction. With the progress of the Maillard reaction, the color of fish gelatin gradually became darker. The attachment of sugar chains inhibited the gelation process of fish gelatin, decreased the gelation rate, changed the secondary structure, increased the content of ß-turn or α-helix, increased the degree of fluorescence quenching, and enhanced the emulsifying properties and emulsion stability. This study provides useful information for the preparation of different types of monosaccharide-modified proteins and emulsions.

Interaction mechanisms of edible film ingredients and their effects on food quality.

Traditional food packaging has problems such as nondegradable and poor food safety. Edible films play an important role in food packaging, transportation and storage, having become a focus of research due to their low cost, renewable, degradable, safe and non-toxic characteristics. According to the different materials of edible films substrate, edible films are usually categorized into proteins, polysaccharides and composite edible films. Functional properties of edible films prepared from different substrate materials also vary, single substrate edible films are defective in some aspects. Functional ingredients such as proteins, polysaccharides, essential oils, natural products, nanomaterials, emulsifiers, and so on are commonly added to edible films to improve their functional properties, extend the shelf life of foods, improve the preservation of sensory properties of foods, and make them widely used in the field of food preservation. This paper introduced the classification, characteristics, and modification methods of common edible films, discussed the interactions among the substrate ingredients of composite edible films, the influence of functional ingredients on the properties of edible films, and the effects of modified edible films on the quality of food, aiming to provide new research ideas for the wide application and further study of edible films.

Corrigendum: From function to metabolome: metabolomic analysis reveals the effect of probiotic fermentation on the chemical compositions and biological activities of Perilla frutescens leaves.

[This corrects the article DOI: 10.3389/fnut.2022.933193.].

Insight into the Mechanism Underlying the Reduction of Digestibility and IgG/IgE Binding Ability in Ovalbumin during Different High-Temperature Conduction Modes-Induced Glycation.

Effects of different high-temperature conduction modes [high-temperature air conduction (HAC), high-temperature contact conduction (HCC), high-temperature steam conduction (HSC)]-induced glycation on the digestibility and IgG/IgE-binding ability of ovalbumin (OVA) were studied and the mechanisms were investigated. The conformation in OVA-HSC showed minimal structural changes based on circular dichroism, fluorescence, and ultraviolet spectroscopy. The degree of hydrolysis analysis indicated that glycated OVA was more resistant to digestive enzymes. Liquid chromatography-Orbitrap mass spectrometry identified 11, 14, and 15 glycation sites in OVA-HAC, OVA-HCC, and OVA-HSC, respectively. The IgG/IgE-binding ability of OVA was reduced during glycation and digestion, and the interactions among glycation, allergenicity, and digestibility were further investigated. Glycation sites masked the IgG/IgE epitopes resulting in a reduction in allergenicity. Digestion enzymes destroyed the IgG/IgE epitopes thus reducing allergenicity. Meanwhile, the glycation site in proximity to the digestion site of pepsin was observed to cause a reduction in digestibility.

Identification of novel angiotensin converting enzyme (ACE) inhibitory peptides from Pacific saury: In vivo antihypertensive effect and transport route.

Nature food-derived angiotensin converting enzyme inhibitory peptides (ACEIPs) can be potent and safe therapeutics for many medical illnesses, particularly hypertension. In this study, novel ACEIPs were screened and identified from Pacific saury by bio-activity guided approach through ultrafiltration membrane, Sephadex G-25 and RP-HPLC. The antihypertensive effect of ultrafiltration fraction was confirmed with spontaneous hypertensive rats' (SHRs) model. The peptides sequences of which gave the best activity was identified by Q-Orbitrap-MS/MS and selectively synthesized based on the binding energy of molecular docking. Five peptides VVLASLK, LTLK, LEPWR, ELPPK and LPTEK were synthesized, and the peptide LEPWR (IC50 = 99.5 µM) showed the best ACE inhibitory ability. Furthermore, LEPWR against ACE in a mixed competitive pattern and formed six hydrogen bonds with ACE. Additionally, the apparent permeability coefficient (Papp) of LEPWR was 3.56 ± 0.14 × 10-6 cm/s and paracellular transport across tight junctions was the main pathway across the Caco-2 monolayer. Therefore, the Pacific saury is a good material to prepare ACEIPs, but antihypertensive mechanism of peptide LEPWR on SHRs needs further investigation.

Peptidomics Screening and Molecular Docking with Umami Receptors T1R1/T1R3 of Novel Umami Peptides from Oyster (Crassostrea gigas) Hydrolysates.

In this study, novel umami peptides were prepared from oyster (Crassostrea gigas) hydrolysates, and their umami mechanisms were investigated. Umami fractions G2 and G3 were isolated by gel filtration chromatography (GFC) and sensory evaluation. The umami scores of the G2 and G3 fractions were 7.8 ± 0.12 and 7.5 ± 0.18, respectively. 36 potential umami peptides with molecular weights below 1500 Da, E and D accounting for >30% of the peptides and iUmami-SCM > 588 were screened by peptidomics. Peptide source analysis revealed that myosin, paramyosin, and sarcoplasmic were the major precursor proteins for these peptides. The electronic tongue results demonstrated that the synthetic peptides DPNDPDMKY and NARIEELEEE possessed an umami characteristic, whereas SIEDVEESRNK and ISIEDVEESRNK possessed a saltiness characteristic. Additionally, molecular docking results indicated that the umami peptide (DPNDPDMKY, NARIEELEEE, SIEDVEESRNK, and ISIEDVEESRNK) binds to H145, S276, H388, T305, Y218, D216, and Q389 residues in the T1R3 taste receptor via a conventional hydrogen bond and a carbon-hydrogen bond. This research provides a new strategy for the screening of umami peptides.

Simulated in vitro gastrointestinal digestion of ß-lactoglobulin treated by ultrasound: Detection of peptides profile and the antioxidant activity.

The influence of ultrasonic pretreatment on the release and antioxidant activity of potential antioxidant peptides after in-vitro simulated gastrointestinal digestion of ß-lactoglobulin (BLG) were measured by HPLC-MS/MS, chemical and cellular-based assays. The gastrointestinal digest was fractionated into four fractions by Sephadex G-25 gel filtration column, and fractions showed a considerable ABTS·+ scavenging ability. The fraction with the strongest antioxidant activity was produced by ultrasonicated BLG after gastrointestinal digestion, which relies on ultrasonic-promoted proteolysis to produce many small-molecule antioxidant peptides. The best active fraction has better cellular antioxidant activity and protection of H2O2-induced oxidative HepG2 cell model, which significantly increases the activities of antioxidant enzyme, and is concentration-dependent. HPLC-MS/MS analysis showed that there were more potential antioxidant peptides in the best active fraction. This research will provide a basis for the further application of ultrasonic in dairy products, which can promote the release of more potential antioxidant peptides-derived from gastrointestinal digestion.

Preparation of high content collagen peptides and study of their biological activities.

Collagen peptides play an important role in the increasing use of collagen peptides as dietary supplements in food and beverages and as bioactive ingredients in cosmetics, healthcare, and pharmaceuticals. Collagenase enzymatically cleaves gelatin to produce collagen polypeptides. However, the enzymatic activity of collagenase is very low (25900 U) and does not allow for adequate enzymatic digestion. Therefore, proteases are used to assist in enzymatic digestion. Porcine gelatin, bovine gelatin, and fish protein gum were enzymatically digested, and the content of collagen peptides in the enzymatically digested lyophilized powder was identified by high-performance liquid chromatography and mass spectrometry, and then the content of the desired collagen peptides was increased by isolation and purification, and the result of the determination was that the content of collagen peptides was the highest after enzymatic digestion and isolation and purification with the use of porcine gelatin as the raw material, and the content of the collagen peptides was about 45.47%. ß-nicotinamide mononucleotide (NMN) was mixed with the prepared samples to determine its antioxidant properties and ability to promote the growth of human dermal fibroblasts. The results showed that the antioxidant capacity was enhanced with the increase of collagen polypeptide content, and NMN could promote the scavenging of DPPH• and •OH free radicals by collagen polypeptides. The ability to promote the growth of human dermal fibroblasts was enhanced with the increase of collagen polypeptide content. This paper aimed to prepare a high content of collagen polypeptides from three raw materials, porcine gelatin, bovine gelatin, and fish protein gum, and further to determine the biological activities.

Liposomes encapsulation by pH driven improves the stability, bioaccessibility and bioavailability of urolithin A: A comparative study.

Urolithin A (UroA) is gut metabolites of ellagitannins possessing a vast range of biological activities, but its poor water solubility and low bioavailability hinder its potential applications. This study utilized the pH dependent dissolution characteristics of UroA and employed a simple pH-driven method to load UroA into liposomes. The characterization and stability of obtained liposomes under different conditions were evaluated, and their oral bioavailability was tested by pharmacokinetics, and compared with UroA liposomes prepared using traditional thin film dispersion (TFM-ULs). Results indicated that liposomes could effectively encapsulate UroA. The UroA liposomes prepared by the pH-driven method (PDM-ULs) showed lower particle size, polydispersity index, zeta potential, and higher encapsulation efficiency than TFM-ULs. Interestingly, better thermal stability, storage stability, in vitro digestion stability, and higher bioaccessibility were also found on PDM-ULs. Moreover, pharmacokinetic experiments in rats demonstrated that PDM-ULs could significantly improve the bioavailability of UroA, with an absorption efficiency 1.91 times that of TFM-ULs. Therefore, our findings suggest that liposomes prepared by pH-driven methods have great potential in improving the stability and bioavailability of UroA.

Effects of different high-temperature conduction modes on the ovalbumin-glucose model: AGEs production and regulation of glycated ovalbumin on gut microbiota.

Food high-temperature processing frequently induces the production of advanced glycation end products (AGEs) in the food industry. In this study, the effects of three high-temperature conduction modes on the AGEs production derived from ovalbumin (OVA)-glucose model and the regulation of glycated OVA on gut microbiota were investigated. The peak time of OVA shifted maximally from 13.72 to 13.57 due to the rise in molecular weight, confirming successful coupling between OVA and glucose. The inhibition of superheated steam (SS) on AGEs was observed, with the sample treated by SS showing the lowest content among glycated OVA groups. The analysis revealed an increase in AGEs during digestion and a decrease in fermentation, suggesting the release during digestion and the availability by intestinal flora. Furthermore, an expansion of Bifidobacterium and Lactobacillus, and the inhibition of Desulfovibrio and Escherichia-Shigella were observed, indicating the prebiotic activity of glycated OVA and its potential to improve intestinal health. These results provide valuable information for controlling high-temperature processing to inhibit AGEs formation and highlight the positive effects of glycated proteins on intestinal health.

Methionine restriction constrains lipoylation and activates mitochondria for nitrogenic synthesis of amino acids.

Methionine restriction (MR) provides metabolic benefits in many organisms. However, mechanisms underlying the MR-induced effect remain incompletely understood. Here, we show in the budding yeast S. cerevisiae that MR relays a signal of S-adenosylmethionine (SAM) deprivation to adapt bioenergetic mitochondria to nitrogenic anabolism. In particular, decreases in cellular SAM constrain lipoate metabolism and protein lipoylation required for the operation of the tricarboxylic acid (TCA) cycle in the mitochondria, leading to incomplete glucose oxidation with an exit of acetyl-CoA and α-ketoglutarate from the TCA cycle to the syntheses of amino acids, such as arginine and leucine. This mitochondrial response achieves a trade-off between energy metabolism and nitrogenic anabolism, which serves as an effector mechanism promoting cell survival under MR.

Ultrasonic treatment regulates the properties of gelatin emulsion to obtain high-quality gelatin film.

Gelatin emulsion was an important process for preparing gelatin films. A gelatin film with water resistance and ductility could be prepared using gelatin emulsion, whereas the prepared gelatin film has several defects (e.g., low tensile strength and poor thermal stability). This study aimed to modify gelatin emulsion through ultrasonic treatment, then gelatin film was prepared by the modified gelatin emulsion. The results showed that: under the condition of ultrasonic treatment for 12 min at 400 w, zeta potential and viscosity of gelatin emulsion were the largest; thickness, water vapor permeability (WVP) and water solubility (WS) of corresponding gelatin film were the lowest, and the tensile strength (TS), elongation at break (EAB), denaturation temperature (Tm) and enthalpy value (ΔH) of corresponding gelatin film were the highest. The above result suggested that ultrasonic treatment can be used to prepare a gelatin film with better quality by regulating the properties of gelatin emulsion, and a certain correlation was found between the properties of gelatin emulsion and the properties of gelatin film.

A comparative study on the allergenic potential of ß-lactoglobulin conjugated to glucose, caffeic acid and caffeoyl glucopyranose.

This work intends to perform a comparative study on the allergenic potential of ß-lactoglobulin (BLG)-glucose, BLG-caffeic acid and BLG-caffeoyl glucopyranose conjugates. The modifications changed the molecular weight and multi-structure of BLG and destroyed the allergenic epitope, which resulted in a decrease in the IgE binding level and the release ability of histamine and IL-6 in KU812 cells. Compared with BLG, the conjugates reduced the serum levels of IgG, IgE, ß-Hex and IL-4 in vivo, while increasing the level of interferon-γ, which caused an imbalance of Th1/Th2 immune response. Meanwhile, these conjugates not only increased the relative abundance of allergy-related gut flora, such as Lachnospiraceae, norank_o_Clostridia_UCG-014, Erysipelotrichaceae, Turicibacter and Lachnospiraceae_NK4A136_group, but also improved the level of short-chain fatty acids (SCFAs). Caffeoyl glucopyranose with a large molecular weight and long carbon chains exerted a great influence on the allergy-related gut flora and SCFAs. Therefore, the changes in the Th1/Th2 balance and SCFA level produced by the allergy-related gut flora were responsible for reducing the potential allergy of BLG.

Insight into the effect of traditional frying techniques on glycosylated hazardous products, quality attributes and flavor characteristics of grass carp fillets.

This study aimed to evaluate the evolution of quality attributes, oxidation index, glycosylated hazardous products, aroma characteristics of grass carp fillets and their relationship under air-frying, roast-frying and pan-frying. With frying progressed, the level of carbonyl protein and lipid oxidation products increased significantly (following air-frying > pan-frying > roast-frying), and the latter decreased subsequently after 6 min. Fillets possessed by frying increased significantly Nε-carboxymethyl-lysines (CML) and 5-hydroxymethylfurfural (5-HMF) levels, whose increment was pan-frying > air-frying > roast-frying. Compared to raw, eighty-seven volatiles were identified and the total concentrations of those increased gradually in air-frying, but then decreased up to 6 min in roast-frying and pan-frying. Furthermore, significant correlations between CML, TBARS and 5-HMF, quality attributes, oxidation index; volatiles (VIP and/or OAV > 1) and lipid oxidation index were obtained. Conclusively, fillets possessed by air-/roast-frying showed more lipid oxidation and alcohols/aldehydes, while pan-fried enriched CML and pyrazines.