Adsorption,in vitro digestion and human gut microbiota regulation characteristics of three Poria cocos polysaccharides

Poria cocos(PC)is a famous traditional Chinese medicine(TCM)and a widely used healthcare ingredient,which has antiobesity,enhancing immunity and improving sleep effects.Traditionally,only water-soluble poria polysaccharide(WSP)is extracted and applied for clinical application,while insoluble polysaccharide(alkali-soluble poria polysaccharide,ASP)is discarded as herb residue.However,the whole PC has also been historically utilized as functional herbal food.Considering the beneficial role of dietary fiber and the traditional use of PC,ASP may also contribute substantially to the therapy function of PC.Compared to WSP,little attention has been paid to ASP and ASP modified product carboxymethyl poria polysaccharide(CMP)which has been used as an antitumor adjuvant drug.In this study,the oil,cholesterol,metal ions and polyphenols adsorption ability,in vitro simulated digestive and the gut microbiota fermentation characteristics of WSP,ASP and CMP were studied to evaluate the functional values of three P.cocos polysaccharides(PCPs).The results showed that all three PCPs had good adsorption capacity on cholesterol,polyphenols and metal ions(Cd^(2+)/Zn^(2+)/Mg^(2+)),among which ASP showed the highest capacity than WSP and CMP.The adsorption capacity of all three PCPs on heavy metal ions(Cd^(2+)/Zn^(2+))was stronger than that of non-heavy metal ions(Mg^(2+));The in vitro digestibility of all three PCPs was very low,but WSP was slightly higher than ASP and CMP;Moreover,the indigestible residue of all three PCPs could improve the richness and diversity of gut microbiota,among which ASP had the greatest influence.In general,ASP and CMP could significantly promote the proliferation of some probiotics and inhibit the growth of some harmful bacteria.The gut microbiota diversity of CMP was reduced,but the richness of probiotics,especially Parabacteroides distasonis was significantly enhanced compared with the ASP group,and the growth of harmful bacteria Klebsiella pneumoniae was inhibited after CMP treatment.The short-chain fatty acids(SCFAs)analysis results showed that all three PCPs could significantly promote the production of acetic acid,propionic acid and the total acid content compared with blank control group,and SCFAs producing activity was positively correlated with the proliferative capacity of probiotics.Taken together,the good adsorption characteristics and gut microbiota regulatory activity of ASP may lay foundation for its lipid-lowering and immune-improving function.Additionally,the probiotic effect of CMP and ASP indicated that except for only use the water extract of PC in clinic,CMP and ASP also can be used in healthcare to take full advantage of this valuable medicine.

Simultaneous determination of typical toxic aldehydes formed during food frying and digestion using isotope dilution UHPLC-QqQ-MS/MS

An isotope dilution ultra-performance liquid chromatography-triple quadrupole mass spectrometry method was developed to simultaneously detect two typical kinds ofα,β-unsaturated aldehydes,namely 4-hydroxy-2-hexenal(4-HHE)and 4-hydroxy-2-nonenal(4-HNE),in foods.The proposed method exhibited a linear range of 10-1000 ng/mL with a limit of detection of 0.1-2.0 ng/g and a limit of quantification of 0.3-5.0 ng/g.The recovery rates of these typical toxic aldehydes(i.e.,4-HHE,4-HNE)and their d3-labeled analogues were 91.54%-105.12%with a low matrix effect.Furthermore,this proposed method was successfully applied to a real frying system and a simulated digestion system,wherein the contents of 4-HHE and 4-HNE were determined for both.Overall,the obtained results provide strong support for further research into the production of 4-HHE and 4-HNE resulting from foods during oil digestion and frying.

Impact of particle size of pulverized citrus peel tissue on changes in antioxidant properties of digested fluids during simulated in vitro digestion

To examine the effect of mechanical processing for plant-based materials on antioxidant properties during digestion,relationships between the size of pulverized plant tissue and changes in antioxidant activities during simulated in vitro digestion were investigated.The citrus peel tissue was pulverized and classified into four powder fractions followed their particle size distributions as 125−180m,180−355m,355−500m and 500−710m.These fractions were regarded as a plant tissue model with various degrees of cell damages.Powder samples were collected during the digestion and measured their particle sizes and colors.Besides,total phenolic content and antioxidant activities of digested fluid were also evaluated.The results showed that the powder color of smaller particles were significantly changed than the bigger ones.The bio-properties of digested fluid for the bigger particle sizes comparatively retained more than smaller ones at the simulated gastric stage.It also showed mostly stable during simulated gastric or small intestinal digestion stage.This suggested that the release of bioactive compounds from plant tissues during digestion could be related to their structural attributes such as degrees of cell damages which could be affected by processing methods and conditions.

Changes in Antioxidant Activity of Alcalase-Hydrolyzed Soybean Hydrolysate under Simulated Gastrointestinal Digestion and Transepithelial Transport

Peptides from Alcalase-hydrolyzed soybean protein hydrolysate(SPH)may hold the potential as natural antioxidants.In addition,the effect of human gastrointestinal(GI)tract on peptide bioavailability needs to be explored.In this study,the impact of simulated GI digestion and transepithelial transport on various antioxidant properties of SPH were investigated.SPH displayed DPPH radical scavenging(IC50=4.22 mg/m L),ABTS·+radical scavenging(IC50=2.93 mg/m L),reducing power and metal ion-chelating activities(IC50=0.67 mg/m L).Furthermore,SPH significantly(P<0.05)inhibited the generation of intracellular reactive oxygen species(ROS)in Caco-2 cells.After simulated GI digestion,the antioxidant properties of SPH were enhanced,except for a decrease in ABTS·+radical scavenging activity.After transepithelial transport,the permeates maintained partial antioxidant activity and the LC-MS/MS data further identified the absorbed soybean peptides.These results suggest that SPH contains the antioxidant peptides that are potentially bioavailable and can be regarded as a promising source of functional food ingredients.

Herba Epimedii′s biotransformation in vitro simulated gastrointestinal digestion and faecal fermentation systems

OBJECTIVE Epimedium is rich in a variety of beneficial active ingredients,and has been widely used in the ethnopharmacological practices,however,its biotransformation in gastrointestinal digestions remain unclear.This study aimed to investigate the dynamic changes of components and biological activity of Epimedium in the in vitro simulated digestion and subsequent human faecal fermentation.METHODS The models of in vitro simulated saliva,gastric and intestinal digestion,as well as colonic fermentation were constructed to simulate the digestion process of Epimedium.The dynamic changes of components of Epimedium during the simulated digestions in vitro and subsequent human faecal fermentation were investigated by UPLC-MS,HPLC-DAD combined with principal component analysis(PCA)and multi-ingredient quantitative analysis.RESULTS A variety of metabolites with high contents were produced after 0.5 h of intestinal digestion and colonic fermentation 0.5 h.Application of PCA to HPLC data showed the obvious separation of colonic fermentation 0.5 h stage samples from other colonic fermentation stages samples(24,48 and 72 h).Additionally,non-digestion and saliva digestion stage samples clustered together,and there was obvious separation between intestinal digestion samples and gastric digestion samples.The contents of epimedium C,icariin and baohuside I all increased significantly after intestinal digestion[58.70±7.08,47.15±5.68 and(12.78±0.55)mg·g^(-1)]compared with gastric digestion[29.00±5.65,17.40±4.55 and(2.77±0.19)mg·g^(-1)].There were significant differences between sample after 0.5 h of colonic fermentation[64.22±9.32,51.26±6.33 and(16.68±3.19)mg·g^(-1)]and other time points(24,48 and 72 h)in components and the contents of active ingredient,and the content of these components all decreased with the fermentation time.The ability of scavenging ABTS free radicals[IC50=(0.29±0.02)g·L^(-1)]increased significantly compared with gastric digestion[(1.57±0.02)g·L^(-1)],and after 0.5 h of colonic fermentation,the ability also increased significantly.CONCLUSION Gastrointestinal digestion had a significant impact on the contents of active components in Epimedium,and the metabolism of these components mainly occurred in the colon.The intestinal digestion and colonic fermentation significantly improved the anti-ABTS activity of epimedium.

Purifi cation, characterization and hypoglycemic activity of glycoproteins obtained from pea (Pisum sativum L.)

This study aimed to isolate and characterize the structures of glycoproteins from peas and determine their hypoglycemic activity.The crude pea glycoproteins(PGP)were extracted by hot water and purified by diethylaminoethyl(DEAE)-Sepharose chromatography and Sephadex G-100 size-exclusion chromatography in sequence.Then three main fractions were obtained,namely PGP1,PGP2 and PGP3,with molecular weights of 897615,846740 and 1194692 Da,respectively.The physical and chemical properties of the three fractions were evaluated and compared by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),scanning electron microscope(SEM),high performance liquid chromatography(HPLC)and other analytical techniques.The fraction PGP2 with the highest hypoglycemic activity,was screened using the Caco-2 monolayer cell model.It can inhibit the uptake of glucose in the small intestine,as well as the activities of maltase and sucrase.After simulated gastrointestinal digestion,PGP2 signifi cantly enhanced the inhibitory effect of α-glucosidase,and slightly reduced the inhibitory ability ofα-amylase.In summary,PGP2 possessed strong hypoglycemic activity after digestion.These results indicated that PGP2 has the potential to be developed into a functional food or natural medicine for the treatment of type 2 diabetes mellitus.

Negative effect of dissolved organic compounds on settling behavior of synthetic monominerals in red mud

Hydration grossular and hematite monominerals were synthesized. The effects of dissolved organic compounds(including sodium formate, sodium acetate, sodium oxalate, sodium salicylate or disodium phthalate) on the settling performance of hydration grossular or hematite slurries were studied. The settling of the slurries was also investigated with the addition of sodium polyacrylate(PAAS) or hydroxamated polyacrylamide flocculant(HCPAM). The adsorption mechanism of organic compounds on monominerals surfaces was studied by FT-IR and XPS, respectively. A deterioration in settling is observed in order of disodium phthalate>sodium salicylate>sodium oxalate>sodium formate(or sodium acetate). Moreover, PAAS can efficiently eliminate the negative effects of organic compounds on the settling performance of the hydration grossular slurry. HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the hematite slurry, but it only partially improves the settling performance of hematite slurry containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that organic compounds are physically adsorbed on hydration grossular surface, and chemisorptions of organic compounds occur on hematite surface with a bidentate chelating complex.

In vitro Evaluating the Influence of Grape Seed Polyphenol Extract on the Digestibility of Macronutrients

Interaction between dietary polyphenol and proteins including digestive enzymes may result in reduced digestibility of food macronutrients, thus lowering absorption of nutrients that contributing to high energy accumulation in human body. The objective of this study was to investigate the effect of grape seed polyphenol extract （GSPE） on the digestibility of starch, food lipid and food protein by digestive enzymes such as u-amylase, lipase, pepsin and trypsin. The digestion of each substrate was conducted at the optimal pH and temperature of specific enzyme. Bread containing different amount of grape pomace was used as a real food model and its digestion was conducted under simulated digestion condition. Concentrations of reducing sugar, fatty acid and amino acids in enzyme digested mixtures were determined as indicators of starch, lipid and protein digestions, respectively. Results indicate that GSPE significantly inhibited the digestion of starch, cooking oil and casein, but did not inhibit digestion of whey protein and egg white protein. Instead, the digestion of egg white and whey protein by trypsin was moderately enhanced in the presence of GSPE. However, under simulated human digestion condition, the grape pomace in the bread significantly reduced the digestibility of bread starch and protein.

The dual-function of bioactive peptides derived from oyster (Crassostrea gigas) proteins hydrolysates

Oysters(Crassostrea gigas)have a wide range of functionality due to their nutritional and bioactive components. However, the bioactive peptides of oyster proteins are rarely reported, particularly their antidiabetes effects and antioxidants. Oyster proteins were extracted from fresh oysters using phosphatebuffered saline and simulated gastrointestinal digestion was performed. The degree of hydrolysis(DH), structural characterization, molecular weight(Mw)distribution, free amino acid, anti-diabetic activity, and antioxidant activity were studied during in vitro simulated gastrointestinal digestion. The results showed that the α-glucosidase inhibitory activity, α-amylase inhibitory activity, DPPH radical scavenging activity, and ABTS radical scavenging activity of the oyster protein gastrointestinal digest were increased(P < 0.05)from 0 to 33.96%, from 9.17% to 44.22%, from 9.01 μg trolox/mg protein to 18.48 μg trolox/mg protein, and from 21.44 μg trolox/mg protein to 56.21 μg trolox/mg protein, respectively. Additionally, the DH, β-turn structure, fluorescence intensity, free amino acid, and short peptide content(Mw < 1 000 Da)increased in the simulated gastrointestinal digestion. These results indicate that the digestive hydrolysates obtained from oyster proteins could be used as natural anti-diabetic and antioxidant agents.

Bioaccessibility of phenolic compounds from Brazilian grape juices using a digestion model with intestinal barrier passage

Grape juices are rich in bioactive compounds;however,for these compounds to exert their functionality,they must be bioaccessible.Thus,the present study evaluated a simulated digestion process on the main bioactive compounds of monovarietal grape juices of five Brazilian hybrid cultivars(V.vinifera x V.labrusca).Characterization of the chemical profiles in liquid chromatography(HPLC-DAD-RID),behaviour of phenolics in the stages of digestion and bioaccessibility through the INFOGEST protocol plus intestinal barrier passage were carried out.Of the 24 polyphenols identified in the grape juice samples,11 were bioaccessible,with emphasis on the class of flavanols.Procyanidin B2(101-426%),(+)-catechin(169-370%)and gallic acid(61-230%)stood out in all juices,showing that these compounds are key to the functionality of these drinks.Particularities were observed to differ between juices,demonstrating that factors such as the cultivar should be explored more extensively in studies on functional foods.The study also suggests that quality components such as sugars and organic acids influence the bioaccessibility of beverages.

An automatically progressed computer-controlled simulated digestion system to predict digestible and metabolizable energy of unconventional plant protein meals for growing pigs

The objective of this experimentwas to develop a new computer-controlled simulated digestion system to predict the digestible energy(DE)and metabolizable energy(ME)of unconventional plant protein meals for growing pigs.Nine meals tested included 1 source of rapeseed meal,4 sources of cottonseed meal,2 sources of sunflower meal,and 2 sources of peanut meal.Twenty growing pigs(Duroc[LandraceLarge White])with an initial body weight(BW)of 41.7±2.6 kg were allotted to a replicated 103 incomplete Latin square design to determine the DE and ME of 1 basal diet and 9 experimental diets formulated with 9 unconventional plant protein meals.The DE andMEvalues of unconventional plant protein meals were calculated by the difference method.The in vitro digestible energy(IVDE)of 1 basal diet,9 experimental diets,and 9 unconventional plant protein meals were determined with 5 replicates of each sample in a complete randomized arrangement.The IVDE/DE or IVDE/ME ranged from 0.96 to 0.98 or 1.00 to 1.01,and the correlation coefficient between IVDE and DE or MEwas 0.97 or 0.98 in 10 experimental diets.Accordingly,the IVDE/DE or IVDE/ME ranged from 0.86 to 1.05 or 0.96 to 1.20,and the correlation coefficient between IVDE and DE orME was 0.92 or 0.91 in 9 unconventional plant protein meals.The coefficient of variation(CV)of IVDE was less than that of DE and ME in the experimental diets(0.43%,0.80%,and 0.97%for CV of IVDE,DE and ME,respectively)and unconventional plant protein meals(0.92%,4.84%,and 6.33%for CV of IVDE,DE and ME,respectively).The regression equations to predict DE from IVDE in 10 experimental diets and 9 unconventional plant protein meals were DE=0.8851IVDE t539(R^(2)=0.9411,residual standard deviation[RSD]=23 kcal/kg DM,P<0.01)and DE=0.9880IVDE t 166(R^(2)=0.8428,RSD=182 kcal/kg DM,P<0.01),respectively.Therewas no statistical difference in the slopes(P=0.82)or intercepts(P=1.00)of these 2 equations.Thus,10 diets and 9 unconventional plant protein meals were pooled to establish the regression equation of DE on IVDE as:DE=0.9813IVDE t187(R^(2)=0.9120,RSD=118 kcal/kg DM,P<0.01).The regression equations to predictME from IVDE in 10 experimental diets and 9 unconventional plant protein meals were ME=0.9559IVDE t146(R^(2)=0.9697,RSD=18 kcal/kg DM,P<0.01)and ME=0.9388IVDEt3(R^(2)=0.8282,RSD=182 kcal/kg DM,P<0.01),respectively.Therewas no statistical difference in slopes(P=0.97)but significant difference between the intercepts(P=0.02)of these 2 equations.Our results indicate IVDE has similar response to the DE but different response to the ME in 10 experimental diets and 9 unconventional plant protein meals.Therefore,IVDE is moresuitable to predict DE than ME of diets and unconventional plant protein meals for growing pigs.

Microencapsulation of immunoglobulin Y: optimization with response surface morphology and controlled release during simulated gastrointestinal digestion

Immunoglobulin Y(Ig Y)is an effective orally administered antibody used to protect against various intestinal pathogens,but which cannot tolerate the acidic gastric environment.In this study,Ig Y was microencapsulated by alginate(ALG)and coated with chitooligosaccharide(COS).A response surface methodology was used to optimize the formulation,and a simulated gastrointestinal(GI)digestion(SGID)system to evaluate the controlled release of microencapsulated Ig Y.The microcapsule formulation was optimized as an ALG concentration of 1.56%(15.6 g/L),COS level of 0.61%(6.1 g/L),and Ig Y/ALG ratio of 62.44%(mass ratio).The microcapsules prepared following this formulation had an encapsulation efficiency of 65.19%,a loading capacity of 33.75%,and an average particle size of 588.75μm.Under this optimum formulation,the coating of COS provided a less porous and more continuous microstructure by filling the cracks on the surface,and thus the GI release rate of encapsulated Ig Y was significantly reduced.The release of encapsulated Ig Y during simulated gastric and intestinal digestion well fitted the zero-order and first-order kinetics functions,respectively.The microcapsule also allowed the Ig Y to retain 84.37%immune-activity after 4 h simulated GI digestion,significantly higher than that for unprotected Ig Y(5.33%).This approach could provide an efficient way to preserve Ig Y and improve its performance in the GI tract.

Impact of simulated in vitro gastrointestinal digestion on bioactive compounds,bioactivity and cytotoxicity of melon (Cucumis melo L. inodorus) peel juice powder

The objectives of this research work were to evaluate the effect of in vitro gastrointestinal digestion (GIT) on melon peel juice (MPJ) powder from fruit processing industry by-products,considering (i) the recovery and accessibility indexes,(ii) the changes on antioxidant activity,and (iii) the prebiotic effect.Throughout exposition to GIT conditions a decrease on the total phenolic content (TPC = 65.31%) and antioxidant activity by ABTS = 39.77% and DPPH = 45.91% were observed.However,these both parameters exhibited stable accessibility,accounting with 81.89%,76.55%,and 54.07% for TPC,ABTS and DPPH,respectively.After gastrointestinal digestion,the non-absorbed fraction exhibited a positive impact on the growth of Bifidobacterium and Lactobacillus strains,possibly associated with the high content of simple sugar (glucose and fructose).This fraction also showed to be safe on Caco-2 intestinal cells.These findings suggest that MPJ might be used as a potential food functional ingredient.

Influence of fatty acids in edible oils on lutein micellization and permeation in a simulated digestion model

Lutein is a nutraceutical compound that promotes human eye health and prevents neurodegenerative diseases.The oral bioavailability of lutein is affected by both extrinsic and intrinsic factors in the host.Although hydrophobicity of the compound is further challenging,its lipophilicity can be utilized to micellize and thereby improve its oral bioavailability.Currently,available data on the effects of dietary fats on lutein micellization and permeation is limited and needs further exploration.In this study,the influence of 17 carrier type edible oils on lutein micellization and permeation,was investigated in a simulated digestion model.The overall effectiveness of these oils to permeate micellized lutein was attributed to its Fatty Acid(FA)profile.While 94%of the edible oils exhibited a positive influence on the permeation of micellized lutein,the micellization and permeation efficiency of these oils were significantly(p≤0.05)modulated by the saturation of FA in the order Saturated(SFA)>Mono-Unsaturated(MUFA)>Poly-Unsaturated(PUFA).The highest apparent permeability coefficient was exhibited by lutein micellized in ghee(3.01×10^(-6) cm/s)and butter(2.93×10^(-6) cm/s),which was 1.28 and 1.24 folds higher than lutein alone(2.35×10^(-6) cm/s)respectively.Exceptionally MUFA rich olive oil and PUFA rich flaxseed oil improved lutein permeation by 1.19(2.80×10^(-6) cm/s)and 1.14 folds(2.69×10^(-6) cm/s)respectively.This study is the first to report the influence of saturated fatty acids on micellization and permeation of lutein.Furthermore,the outcomes of this study offer the field of lutein delivery systems a fresh perspective.

Synthesis of ECG ((-)-epicatechin gallate) acylated derivatives as new inhibitors of α-amylase and their mechanism on delaying starch digestion

(-)-Epicatechin gallate(ECG),as a naturalα-amylase inhibitor,has received extensive attention.However,poor liposolubility of ECG limits its application.In this study,lipophilic derivatives of ECG(1A-ECG,2A-ECG,1B-ECG,and 2B-ECG)were synthesized by Lipozyme TLIM(Thennomyces lanuginosus)and their mechanism on delaying starch digestion was investigated.The results showed that the conversion of ECG exceeded 70%under optimal conditions.Interestingly,compared with ECG,the inhibitory activities of ECG derivatives onα-amylase decreased,while the inhibitory activity of 1A-ECG onα-amylase increased.Though the main force between ECG and 1A-ECG withα-amylase was induced by hydrogen bond,hydrophobic interaction was the main force between other derivatives withα-amylase.However,the addition of four ECG derivatives can effectively reduce the proportion of rapidly digestible starch,and delay the digestion of starch.This study may expand the applications of ECG and provide a theoretical basis for 1A-ECG to delay the digestion of starch.

Effect of lactic acid fermentation and in vitro digestion on the bioactive compounds in Chinese wolfberry(Lycium barbarum)pulp

Two commercial probiotics,Lactobacillus helveticus 76(Lh)and Bifidobacterium lactis 80(Bla),were employed to investigate the effect of lactic acid fermentation and in vitro digestion on bioactive compounds in Chinese wolfberry pulp.The changes of antioxidant capacity of pulp were also studied.Our results demonstrated that Chinese wolfberry pulp was a suitable carrier for both probiotics.Lactic acid fermentation increased total phenolic,total flavonoids and betaine,and improved bioaccessibility of flavonoids and carotenoids in vitro digestion.Fermentation had no remarkable influence on the content and basic structure of polysaccharides,but reduced their particle size.In addition,fermentation improved the antioxidant activities of Chinese wolfberry pulp before and after in vitro digestion mainly due to the metabolism of polyphenols.This study thus would provide valuable information about the development of Chinese wolfberry as a functional drink fermented with probiotics.

In-vitro gastrointestinal digestion of functional cookies enriched with chestnut shells extract:Effects on phenolic composition,bioaccessibility,bioactivity,andα-amylase inhibition

Chestnut(Castanea sativa)shells(CS)are an appealing source of antioxidants.In previous studies,the research team validated a nutraceutical extract from CS,recovered by an eco-friendly technology,by in-vitro and in-vivo assays,and developed functional cookies enriched with this extract.This study attempts,for the first time,to investigate the impact of the in-vitro gastrointestinal digestion in the phenolic composition,bioaccessibility,antioxidant/antiradical properties,andα-amylase inhibition of CS extract-enriched cookies.The outcomes revealed higher polyphenols concentrations retained after intestinal digestion,endorsing its better antioxidant,antiradical,and hypoglycemic properties.The phenolics recovery enhanced in the following order:oral<gastric<intestinal phases,achieving 93.50%of maximum bioaccessibility and unveiling a protective effect of the cookie matrix and slow phenolics release during digestion.Regardless the identical composition in phenolic acids,changes in their concentrations were attested between digested and undigested cookies.Multivariate analysis predicted the outstanding contribution of polyphenols to the bioactivity of cookies.This study high-lighted the valorization of CS as nutraceutical ingredient for functional cookies,proving its efficacy after in-vitro digestion.

Peptides-carrageenan-xanthan gum:Printing mechanism and anti-oxidation under in vitro digestion

Surimi is a protein-rich food.The peptides hydrolyzed by surimi have many functional activities and showed strong antioxidant activity in ABTS free radical scavenging experiments,hydroxyl radical scavenging experiments and iron ion reduction experiments.The scavenging rates of ABTS ions,hydroxyl radicals and iron ions were 62.83%,74.81%and 0.035 mg/mL,respectively.3D printing ink was formulated by compounding carrageenan,xanthan gum and surimi peptides.The surimi polypeptide“ink”contains 3%carrageenan,4%xanthan gum and 4 mg/mL surimi polypeptide.This“ink”not only has good printability,but also has stable antioxidant properties.The effect of the peptides on the printed structures can also be observed under an inverted fluorescence microscope.In the in vitro digestion experiment,the surimi polypeptide 3D printing ink added with carrageenan and xanthan gum can release most of the peptides.After in vitro digestion experiments,the antioxidant activity of surimi polypeptides increased.The above experiments have proved that surimi polypeptide is a high-quality raw material for preparing 3D printing ink.

Estimation of bioaccessibility and potential human health risk of mercury in Chinese patent medicines

Mercury（Hg）, mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines（CPMs） was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry（ICP-MS）. The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar（2.5%–30.9%）, the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower（0.037%）. By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives（FAO/WHO） safety guideline, the average daily intake dose（ADD） of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs.

Transglutaminase-catalyzed modification of fish skin gelatin enhanced the protection of microcapsules to Limosilactobacillus reuteri

In the present study,the tilapia skin gelatin was modified with Transglutaminase(TGase)to obtain wall materials with good film-forming performance.The effects of different fish skin gelatin cross-linking degree on the physical and chemical properties of the wall material solution were compared.When the fish skin gelatin cross-linking degree was 15.45%,the wall material solution had the highest emulsification,emulsification stability,foaming ability and foam stability,which were 4.25 m2/g,63.27 min,140.00%and 32.14%,respectively.Therefore,the wall material with 15.45%fish skin gelatin cross-linking degree was used for spray drying to prepare Limosilactobacillus reuteri microcapsules.The particle size of the microcapsules was 40.5μm,the moisture content was 3.93%,the microcapsules had good storage stability at 4°C,and the expected shelf life was 28 days.The survival rate of L.reuteri in simulated gastrointestinal fluid increased by 43.94%,It was indicated that microcapsules with fish skin gelatin modified by TGase had the strong gastric acid resistance and could release more live bacteria in the gastrointestinal tract.The results can provide guidance for the large-scale production of L.reuteri-loaded microcapsules and the application of probiotics in food.