Distinguishable short-term effects of tea and water drinking on human saliva redox.

Food consumption can alter the biochemistry and redox status of human saliva, and the serving temperature of food may also play a role. The study aimed to explore the immediate (3 min) and delayed (30 min) effects of hot tea (57 ± 0.5 °C) ingestion and cold tea (8 ± 0.5 °C) ingestion on the salivary flow rate and salivary redox-relevant attributes. The saliva was collected from 20 healthy adults before, 3-min after and 30-min after the tea ingestion. The hot or cold deionised water at the same temperatures were used as control. The salivary flow rate and redox markers in hot tea (HBT), cold tea (CBT), hot water (HW) and cold water (CW) group were analysed and compared. The results demonstrated that neither the black tea nor the water altered the salivary flow rate; the black tea immediately increased the salivary thiol (SH) and malondialdehyde (MDA) content while reduced salivary uric acid (UA) significantly. The tea ingestion showed a tendency to elevate the ferric reducing antioxidant power (FRAP) in saliva, although not significantly. The water ingestion decreased the MDA content immediately and increased the UA level significantly. Cold water was found to induce a greater delayed increase in total salivary total protein (TPC) than the hot water. In conclusion, the black tea ingestion affects the redox attributes of human saliva acutely and significantly, while the temperature of drink makes the secondary contribution.

Dynamic changes of key metabolites in Longjing green tea during processing revealed by widely targeted metabolomic profiling and sensory experiments.

In this study, widely targeted metabolomics and chemometrics were utilized to comprehensively analyse the formation of taste compounds in Longjing green tea. A total of 580 non-volatile metabolites were identified by using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, and alterations in three metabolic pathways were investigated. Notably, the fixation process reduced phosphatidic acid levels, resulting in the formation of lyso-phosphatidylcholine and lyso-phosphatidylethanolamine, as well as the release of esterified polyunsaturated fatty acids. Baiye No.1 had high levels of L-glutamic acid and l-glutamine, while Longjing 43 showed elevated levels of flavones. Correlation analysis and sensory verification indicated that the specific concentration of L-leucine could decrease the umami of the tea. These findings advance our understanding of Longjing green tea quality improvement and cultivar development.

Fabrication and characterization of curcumin-loaded nanoparticles using licorice protein isolate from Radix Glycyrrhizae.

Licorice was widely used in food and herbal medicine. In its extract industry, a substantial amount of licorice protein was produced and discarded as waste. Herein, we extracted Licorice Protein Isolate (LPI) and explored its potential as a curcumin nanocarrier. Using a pH-driven method, we fabricated LPI-curcumin nanoparticles with diameters ranging from 129.30 ± 3.21 nm to 75.03 ± 1.19 nm, depending on the LPI/curcumin molar ratio. The formation of LPI-curcumin nanoparticles was primarily driven by hydrophobic interactions, with curcumin entrapped in LPI being in an amorphous form. These nanoparticles significantly enhanced curcumin properties in terms of solubility, photochemical stability, and stability under varying pH, storage, and physiological conditions. Moreover, the loaded curcumin exhibited a 2.58-fold increase in cellular antioxidant activity on RAW 264.7 cells and a 1.86-fold increase in antitumor activity against HepG2 cells compared to its free form. These findings suggested that LPI could potentially serve as a promising novel delivery material.

Incidental nanoparticles in black tea alleviate DSS-induced ulcerative colitis in BALB/c mice.

As the dominant herbal drink consumed worldwide, black tea exhibits various health promoting benefits including amelioration of inflammatory bowel diseases. Despite extensive studies on the tea's components, little is known about the bioactivities of nanoparticles (NPs) which were incidentally assembled in the tea infusion and represent the major components. This study investigated the alleviative effects of black tea infusion, the isolated black tea NPs, and a mixture of caffeine, epigallocatechin-3-gallate, gallic acid and epicatechin gallate on dextran sodium sulfate (DSS)-induced ulcerative colitis. The results showed that both the black tea infusion and the NPs significantly alleviated colitis, suppressed the mRNA levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1ß, and suppressed the DSS-induced loss of cell-cell junction proteins (e.g., E-cadherin, ZO-1, and claudin-1) and increase of p-STAT3. The mixture of four tea components, which is the analogue of bioactive payloads carried by the NPs, was much less effective than the tea infusion and NPs. It shows that the NPs elevate the efficiency of polyphenols and caffeine in black tea in restoring the intercellular connection in the intestine, inhibiting mucosal inflammation, and alleviating ulcerative colitis. This work may inspire the development of tea-based therapeutics for treating inflammatory bowel diseases and have wide influences on value-added processing, quality evaluation, functionalization, and innovation of tea and other plant-based beverages.

Fish oil nano-emulsion kills macrophage: Ferroptosis triggered by catalase-catalysed superoxide eruption.

Fish oil is increasingly utilised in the form of nano-emulsion as a nutrient and function fortifier. The nano-emulsions exceptionally high content of polyunsaturated fatty acids and electron donors at the oil/water interface provide an ideal site of the redox reaction. Here we report that a vigorous superoxide production in the fish oil nano-emulsion was catalysed by mammalian catalase in acellular and cellular systems. The resulting superoxide increased cytosolic reactive oxygen species (ROS) and membrane lipid peroxidation of murine macrophage, which eventually causes fatal oxidative damages. Cell death, was significantly inhibited by a catalase-specific inhibitor 3-Amino-1,2,4-triazole (3-AT), was via ferroptosis and not apoptosis. The ferroptosis was independent of free iron or glutathione peroxidase suppression. Our findings discovered a hidden health risk of the widely acclaimed fish oil emulsion, suggesting a novel cellular damage mechanism caused by dietary unsaturated fats on the alimentary tract mucosa.

A nationwide Chinese consumer study of public interest on agriculture.

A nationwide study was undertaken in China to understand why public interest has shifted away from agriculture and to discuss approaches that may help restore interest and support for agriculture. The study collected 2586 questionnaires from 242 cities in 31 provinces in mainland China. The results suggest that agriculture is still of public interest, but interest has shifted from traditional farming to the consumer perspective in food safety, nutrition and health, food security and agricultural history. Two groups in this study, the younger generation and those with college degrees, show less interest in production agriculture. The accelerating shift in population from rural China to urban areas explains why these two groups are less connected with agricultural issues. The authors contend that it is critically important to keep the urban population knowledgeable of the importance of agriculture and suggest ways to improve communication and support from this educated, city-dweller point of view in order to ensure a stable and secure future. The approach of science appreciation (ways to effectively communicate science to general publics) is proposed to effectively gain renewed interest and engagement with the public in the science of agriculture in order to optimize the needs and benefits from agriculture to society.

Effects of peroxidase and superoxide dismutase on physicochemical stability of fish oil-in-water emulsion.

How to maintain the physicochemical stability of oil emulsion has been one of the major challenges in food industry. Previously we reported the demulsification effects of catalase in the fish oil emulsion. In comparison, the influences of other two metal ion-containing oxidoreductases, horseradish peroxidase (HRP) and copper/zinc superoxide dismutase (SOD), on the emulsion's stability were investigated. Submicron fish oil-in-water emulsion stabilized by polysorbate 80 was prepared by high-speed homogenization. Its physical stability was evaluated by visual and microscopic observation, turbidity and light scattering measurements, while chemical stability by the hydroperoxide content and lipid peroxidation. HRP demulsified the emulsion in a concentration-responsive manner after 3-7 days' incubation, resulting in a decreased turbidity and significant delamination. The enlargement of oil-polysorbate droplets and protein precipitates were confirmed by size distribution and TEM observation. HRP initially elevated the emulsion's hydroperoxide then decreased it while raising TBARS levels during 7-Day incubation. In contrary, SOD stabilized the emulsion physically and chemically. The demulsification was correspondingly attributed to the oxidation catalyzing activity of the peroxidase and the electrostatic and hydrophobic interaction between lipids and proteins. This study adds new insight to the influences of the two oxidoreductases on the stability, lipids and peroxides of food emulsions, proposes an exciting subject of elucidating the underlying mechanism.

Nanoparticles Isolated From Porcine Bone Soup Ameliorated Dextran Sulfate Sodium-Induced Colitis and Regulated Gut Microbiota in Mice.

Daily foods contain a great number of self-assembled nanoparticles (NPs) which were incidentally produced during food processing. These food incidental NPs can directly access the human gastrointestinal tract in high frequency and large quantities. Limited reports were focused on whether and how these food incidental NPs affected the gastrointestinal tissues and gut microbiota. In the present study, bone soup and its NPs both significantly ameliorated colitis symptoms in dextran sulfate sodium (DSS)-induced mice and inhibited the release of pro-inflammatory cytokines. They also restored intestinal microbiota dysbiosis by improving the diversity and richness of intestinal microbiota and regulating community composition, such as a remarkable increase in Muribaculaceae, Alistipes, and Alloprevotella, and a decrease in Helicobacter. Moreover, the correlation analysis showed that pro-inflammatory cytokines were negatively correlated with Muribaculaceae, Alloprevotella, and Alistipes, but positively correlated with Helicobacter. These findings suggest that the food incidental NPs can influence human health through regulating the inflammation of the gastrointestinal tissues and the gut microbiota.

Food nanoparticles from rice vinegar: isolation, characterization, and antioxidant activities.

Abundant nanostructures have been constantly found in various foods, like vinegar, tea, coffee, and milk. However, these structures largely remain unexplored and even been eliminated for stability reasons in food industry. Here we report the isolation, characterization, and antioxidant activities of food nanoparticles (NPs) carrying polyphenols from Chinese rice vinegar. Using a gel-chromatography-based isolation protocol, the vinegar was separated into three major fractions. They were identified as spherical NPs (P1), lollipop-like NPs (P2) and spherical microparticles (P3) with average hydrodynamic diameter of 210, 245,1643 nm, separately. The former two fractions accounted for the major parts of dry matter in the vinegar. The P1-NPs fraction was composed of proteins, carbohydrates, and a high number of polyphenols (15 wt%), demonstrated potent antioxidant activity as determined by ABTS and ORAC assays. Moreover, they effectively quenched peroxyl free radicals in peritoneal macrophages and promoted cellular growth. The P2 fraction contained majority of organic acids, esters and mineral elements of the vinegar. It demonstrated the NPs are bioactive units of the rice vinegar, inspiring the development of novel functional nanomaterials with nutraceutical and pharmaceutical applications.

Effect of hydroxychloroquine sulfate on the gelation behavior, water mobility and structure of gelatin.

Hydroxychloroquine sulfate (HCQ) is a well-established antimalarial drug that has received considerable attention during the COVID-19 associated pneumonia epidemic. Gelatin is a multifunctional biomacromolecule with pharmaceutical applications and can be used to deliver HCQ. The effect of HCQ on the gelation behaviors, water mobility, and structure of gelatin was investigated to understand the interaction between the drug and its delivery carrier. The gel strength, hardness, gelling (Tg) and melting (Tm) temperatures, gelation rate (kgel), and water mobility of gelatin decreased with increasing amounts of HCQ. The addition of HCQ led to hydrogen bonding that interfered with triple helix formation in gelatin. Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD) analysis further confirmed that the interaction between HCQ and gelatin is primarily through hydrogen bonding. Atomic force microscopy (AFM) revealed that higher content of HCQ resulted in more and larger aggregates in gelatin. These results provide not only an important understanding of gelatin for drug delivery design but also a basis for the studying interactions between a drug and its delivery carrier.

Effects of valerate on intestinal barrier function in cultured Caco-2 epithelial cell monolayers.

BACKGROUND: Short-chain fatty acids (SCFAs) are a group of microbial metabolites of undigested dietary fiber, protein and unabsorbed amino acids in the colon, well-known for their gut health promoting benefits. A relatively high intestinal level of valerate was found in the healthy human subjects. However, the intestinal protection effects and the underlying mechanism of valerate are waiting to be verified and elucidated. METHODS AND RESULTS: In the present study, valerate, a SCFAs mainly converted from proteins or amino acids, was demonstrated to promote intestinal barrier function at its physiological concentrations of 0-4 mM in the Caco-2 cell monolayer model of intestinal barrier using transepithelial electrical resistance (TEER) assay and paracellular permeability assay. Valerate achieved the maximum increase in the TEER at 2 mM and reduced the paracellular permeability. Its intestinal barrier function promoting activity is similar to that of butyrate, with a broader range of effective concentrations than the later. Through western blot analysis, this activity is linked to the valerate-induced AMPK activation and tight junctions (TJs) assembly, but not to the reinforced expression of TJs related proteins. CONCLUSIONS: It provides direct experimental evidence supporting valerate's function in intestinal health, implying the once under-valued function of valerate and its amino acid precursors. The valerate's role in regulating intestine homeostasis and its possible synergetic effects with other SCFAs warranted to be further investigated.

Inhibition of acrylamide toxicity in vivo by arginine-glucose maillard reaction products.

Acrylamide has a variety of toxicities, including carcinogenicity, and can be present in food via the Maillard reaction in processing of certain foods. Previous studies have demonstrated that co-existing Maillard reaction products (MRPs) ameliorated acrylamide-induced abnormal physiological status in mice. This study is focused on the effects on hematological parameters, erythrocyte osmotic fragility, oxidative stress in plasma and liver, and contents of 8-hydroxy-2-deoxyguanosine (8-OHdG) in mice exposed to acrylamide and to acrylamide and MRPs derived from arginine and glucose. Acrylamide alone caused significant increases in liver indexes, erythrocyte osmotic fragility, malonaldehyde level in liver and 8-OHdG level in testis, and significant decreases in weight gain, hematological parameters, levels of glutathione, glutathione peroxidase and total superoxide dismutase in plasma. Whether MRPs and acrylamide were physically mixed or when the solution is prepared from heating the mixture of arginine, glucose and acrylamide, the presence of MRPs effectively reduced the adverse changes caused by acrylamide. These results suggest that the toxicity of acrylamide to mice can be ameliorated by MRPs, the common compositions simultaneously generated with acrylamide in food matrix.

Isolation and Characterization of Bioactive Proteoglycan-Lipid Nanoparticles from Freshwater Clam (Corbicula fluminea Muller) Soup.

Nanoparticles can be prepared by several sophisticated processes but until now, it cannot be prepared by simple home cooking. Here, we report that two incidental food nanoparticles (iFNPs) consisting of proteoglycans and phytosterols were isolated from soup made from freshwater clam (Corbicula fluminea Muller), a renowned folk remedy for liver problems in China and other parts of East Asia. These two bioactive iFNPs were obtained and characterized by anionic exchange chromatography coupled with multi-angle laser light scattering measurement. Their hydrodynamic diameters and ζ-potentials were 50 ± 0.2 nm and -28.0 mV and 67 ± 0.4 nm and -9.96 mV, respectively. FT-IR revealed that the proteoglycans in the particles contained α-type heteropolysaccharides. Both iFNPs were resistant to pH changes and separation by mechanical force but responsive to temperature changes. They effectively inhibited cholesterol uptake in vitro, which resonates with the traditional belief that freshwater clam soup provides hepatoprotective benefits. This study suggests that these two proteoglycan-lipid iFNPs are the active moieties and offers a supramolecular structure-based approach to study the function of such complex matrices derived from food.

Polysaccharide Nanoparticles from Isatis indigotica Fort. Root Decoction: Diversity, Cytotoxicity, and Antiviral Activity.

It has been revealed that numerous nanoparticles are formed during the boiling preparation of traditional Chinese medical decoctions and culinary soups. They may possess physiological effects different from those of constituent components and are worth paying attention to but are barely noticed and investigated as of yet. In this study, six groups of nanoparticles, whose size ranged from 57 to 300 nm, were successfully isolated from the decoction of Isatis indigotica Fort. root, according to their particle size by the means of size-exclusive chromatography. All of the obtained nanoparticles have a high content of polysaccharides, which distinguishes them from the disclosed BLG protein nanoparticles. They also have high similarities in other compositions, surface charge, and stimuli responses. However, four out of these six nanoparticles (F2, F3, F4, and F5) exhibited significant antiviral activity against influenza virus H1N1, and their antiviral activities and cytotoxicity towards MDCK cells varied with their sizes. It suggested that the antiviral efficacy of BLG decoction could also be from its nanoparticles besides its well-known antiviral phytochemicals. It also implied that the biological effects of these polysaccharide nanoparticles, including cytotoxicity and antiviral activity, may be correlative with the physicochemical properties, especially the particle size.

Catalase to demulsify oil-in-water fish oil-polysorbate emulsion and affect lipid oxidation.

The physicochemical and oxidative stability of oil emulsion has been one of the major challenges in food industry. Factors influencing the emulsion stability have seemingly been exhaustedly elucidated, such as temperature, pH, salts, proteins, polysaccharides and digestive enzymes. Here we report the previously unrecognized influence of catalase on emulsion stability. Submicron oil-in-water fish oil emulsion was prepared by high speed homogenization in the presence of polysorbate 80. Influence of catalase on the emulsion's stability was investigated in comparison with its deactivated version and bovine serum albumin (BSA) by visual examination, turbidity and DLS measurement and TEM observation. Catalase demulsified the emulsion instantly in a concentration-responsive manner at concentrations higher than 0.8 µmol/L, resulting a decreased turbidity, oil flocculation and precipitation of the enzyme itself. Neither BSA nor the thermally inactivated CAT caused demulsification at the same speed, indicating that CAT's demulsification effect was attributed to its enzymatic activity rather than its general protein properties. The enlargement of oil-polysorbate droplets and precipitation of CAT were confirmed by both TEM and DLS. Furthermore, CAT's demulsification effect was found irrelevant of the lipid oxidation. This insight into catalase's influences on emulsion not only sheds lights on food processing and shelf-life, nutritional value and potential biological effects, but also presents an exciting challenge to elucidate the mechanism behind.

Purification and characterization of the major protein isolated from Semen Armeniacae Amarum and the properties of its thermally induced nanoparticles.

From the aqueous extract of Semen Armeniacae Amarum, a major protein isolate was purified and characterized as a novel member of the 11S globulin family, which is composed of three polypeptides linked by disulfide bond. Furthermore, the feasibility of using the isolated protein for fabricating nanocarriers was investigated. The results indicate that thermal treatment of the globulin induced the rearrangement of the disulfide bond to form homodimers of acid polypeptides during the formation of nanoparticles. The harvested nanoparticles produced by heat-induced assembly are spherical in shape, with an average size of 92 nm and exhibited low cytotoxicity to L-02 and MDCK cell lines. These nanoparticles are capable to encapsulate paclitaxel, estimated the maximum encapsulation efficiency of paclitaxel loaded to the nanoparticles was 92.6% and the maximum release of paclitaxel was 57.4%. This research suggests that the screening of traditional herbal extracts could provide a novel source of protein nanocarriers.

Influences of calcium and magnesium ions on cellular antioxidant activity (CAA) determination.

The cellular antioxidant activity (CAA) assay is wildly used for quantifying antioxidant activities of foods and dietary supplements in vitro. Among various incubation and handling buffers used in different laboratories, the inconsistence in concentrations of ions, particularly calcium and magnesium, has somehow been neglected. We hired the Hank's balanced salt solution with or without calcium and magnesium to perform CAA assay in Caco-2 cells and HepG2 cells, evaluating the impacts of these cations. The absence of calcium and magnesium reduced intracellular ROS level and underestimated the CAA of quercetin, Trolox and catechin. The abnormally high extracellular calcium and magnesium can also produce inaccurate results. Hank's buffer is recommended to ensure the accuracy and reproducibility. It elucidates precautions must be taken on these cations' concentrations of the buffers while conducting CAA determinations on different types of cells and when comparing foods and beverages with various calcium/magnesium contents.

Rapid separation and quantification of self-assembled nanoparticles from a liquid food system by capillary zone electrophoresis.

Food processing generates a large amount of self-assembled colloidal nanoparticles (NPs), which have defined structures and directly interact with macrophages. Their promising potential as a new source of functional NPs and a key to elucidate food-body interactions prompt the importance of the method development. This study attempts to apply capillary zone electrophoresis (CZE) in studying self-assembled nanoparticles in a real liquid food system of freshwater clam (Corbicula fluminea) soup, a popular delicacy in East Asia with proven hepatoprotective effects. The soup sample was satisfactorily separated into one nanoparticle fraction and multiple molecular fractions within five minutes by the single and rapid CZE analysis, which was of high repeatability (peak area RSD < 4%, migration time RSD < 1%) and accurate quantification with a linear area-number relationship in the range of (7.5-110) × 1011 particles/mL (R2 > 0.99). Therefore, CZE analysis can be an efficient tool for the investigation of self-assembled nanoparticles in real liquid food systems.

Identification of protein-polysaccharide nanoparticles carrying hepatoprotective bioactives in freshwater clam (Corbicula fluminea Muller) soup.

Bioactives can impact food function either by their dosage or by their forms of dispersion, though the latter remains mostly neglected. Here we report the incidental nanoparticles (iNPs) carrying hepatoprotective bioactives identified in freshwater clam (Corbicula fluminea Muller) soup, which is a folk remedy for liver conditions in East Asia. The soup was fractionated into two iNPs containing fractions with high yield (95.8%) in 35 min by gel chromatography. With hydrodynamic diameter (Dh) range from 40 nm to 149 nm, iNPs were mainly constituted by carbohydrates and proteins. Notably, the majority of bioactives, e.g. taurine (63.2%), ornithine (68.1%) and phytosterols (60.0%), was determined to be carried by the iNPs. It suggested a possible mechanism of elevated delivery and absorption of bioactives, explaining why the clam soup can work at the bioactive concentrations way lower than the individual compound. These iNPs have great potential to be developed into a functional food with most potent nutraceutical effects.

An Evidence for a Novel Antiviral Mechanism: Modulating Effects of Arg-Glc Maillard Reaction Products on the Phase Transition of Multilamellar Vesicles.

Maillard reaction products (MRPs) of protein, amino acids, and reducing sugars from many foods and aqueous extracts of herbs are found to have various bioactivities, including antiviral effects. A hypothesis was proposed that their antiviral activity is due to the interaction with the cellular membrane. Aiming to estimate the possible actions of MRPs on phospholipid bilayers, the Arg-Glc MRPs were prepared by boiling the pre-mixed solution of arginine and glucose for 60 min at 100°C and then examined at a series of concentrations for their effects on the phase transition of MeDOPE multilamellar vesicles (MLVs), for the first time, by using differential scanning calorimetry (DSC) and temperature-resolved small-angle X-ray scattering (SAXS). Arg-Glc MRPs inhibited the lamellar gel-liquid crystal (L ß-L α), lamellar liquid crystal-cubic (L α-Q II), and lamellar liquid crystal-inverted hexagonal (L α-H II) phase transitions at low concentration (molar ratio of lipid vs. MRPs was 100:1 or 100:2), but promoted all three transitions at medium concentration (100:5). At high concentration (10:1), the MRPs exhibited inhibitory effect again. The fusion peptide from simian immunodeficiency virus (SIV) induces membrane fusion by promoting the formation of a non-lamellar phase, e.g., cubic (Q II) phase, and inhibiting the transition to H II. Arg-Glc MRPs, at low concentration, stabilized the lamellar structure of SIV peptide containing lipid bilayers, but facilitated the formation of non-lamellar phases at medium concentration (100:5). The concentration-dependent activity of MRPs upon lipid phase transition indiciates a potential role in modulating some membrane-related biological events, e.g., viral membrane fusion.