Simulated Gastrointestinal Digestion Research Articles

Detection of intact bovine milk proteins after simulated gastrointestinal infant digestion using UHPLC-HRMS.

This study demonstrates the development and application of an ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) method for the rapid and sensitive identification of intact bovine milk proteins following simulated gastrointestinal infant digestion. The new method enables the differentiation between partially hydrolysed/modified and fully intact proteins. In the raw milk, intact α-lactalbumin was visible on SDS-PAGE until the end of the gastrointestinal digestion, while it was not detected with UHPLC-HRMS. Analysis of both raw and heated milk samples revealed that the method is applicable to various milk types. Interestingly, heated milk showed additional signals in the mass spectrum, indicating non-enzymatic post-translational modifications. The relative abundance of these proteoforms could be followed along digestion. These findings highlight the versatility and sensitivity of UHPLC-HRMS in elucidating protein structures and modifications, providing valuable insights into how simulated digestion affects milk protein composition.

Assessing foodborne health risks from dietary exposure to antibiotic resistance genes and opportunistic pathogens in three types of vegetables: An in vitro simulation of gastrointestinal digestion

Foodborne health risks posed by antibiotic resistant genes (ARGs) and pathogenic bacteria have garnered increasing global attention. However, the patterns of their propagation and reduction, as well as the resulting health risks in the human gastrointestinal tract, remain unknown. We employed leafy vegetables (water spinach), solanaceous vegetables (pepper), and root vegetables (radish) to investigate the propagation and reduction patterns of ARGs and pathogenic bacteria within an in vitro simulated digestion system. This system mimicked the soil-vegetable-stomach-small intestine (SVSTI) transmission chain. We found that kan, oqxA, and multidrug resistance genes were enriched by 1.10-fold, 11.2-fold, and 2.21-fold, respectively, along the transmission chain. The succession of bacterial communities and horizontal gene transfer mediated by intl1 were identified as the primary drivers of ARG accumulation. Notably, certain pathogenic bacteria (Bacillus cereus, Klebsiella pneumoniae) accumulated in the intestinal environment. According to our proposed health risk assessment system, Bacillus species, as potential ARG hosts, and multidrug ARGs are at a higher risk of exposure to intestinal environment through the transmission chain. Our findings highlight the significant health risks associated with the intake of ARGs and pathogenic bacteria carried by vegetables, emphasizing an urgent need to implement effective biological control measures in vegetable production and consumption.

Simulated gastrointestinal digestion of milk caseins containing A1 β-casein does not lead to increased production of inflammatory proteins in intestinal epithelial cells in vitro when compared to milk caseins containing A2 β-casein.

Simulated gastrointestinal digestion of milk caseins containing A1 β-casein does not lead to increased production of inflammatory proteins in intestinal epithelial cells in vitro when compared to milk caseins containing A2 β-casein.

Improving the prebiotic activity and oxidative stability of carboxymethyl curdlan - quercetin conjugates stabilized Pickering emulsions for the colonic targeting delivery of curcumin.

The carboxymethyl curdlan-quercetin conjugate (CMCD-QUE) was synthesized to stabilize curcumin (CUR) -loaded Pickering emulsions. The physicochemical properties, antioxidant activity, and prebiotic activity of CMCD-QUE were investigated. The effects of different concentrations of CMCD-QUE on CUR-loaded emulsions were also explored. CMCD-QUE exhibited excellent antioxidant activity throughout in vitro simulated gastrointestinal digestion. The particle size and electrostatic repulsion of CMCD-QUE gradually increased with rising pH, indicating that CMCD-QUE was pH-responsive. CMCD-QUE exhibited prebiotic activity and specifically promoted the enrichment of Akkermansia. The droplet size of the CMCD-QUE stabilized emulsions became smaller and more uniform as the carrier concentration increased. A concentration of 5% CMCD-QUE could be stably adsorbed at the oil-water interface of the emulsion, which exhibited a maximum encapsulated efficiency (95.85%) of CUR. CMCD-QUE showed excellent antioxidant capacity, pH responsiveness, and prebiotic activity, making it a promising multifunctional emulsifier for colon-targeted delivery of functional ingredients.

In vitro gastrointestinal digestion simulation screening of novel ACEI peptides from broccoli: mechanism in high glucose-induced VSMCs dysfunction

Many natural angiotensin-converting enzyme inhibitory (ACEI) peptides have been widely studied. However, their stability in vivo is poor in most cases. In this study, peptides were initially digested from broccoli in vitro, and absorption was simulated by Caco2 cells transport and then analyzed by Peptideomics and molecular docking. Subsequently, the mechanisms were verified using a high glucose-induced vascular smooth muscle cells (VSMCs) dysfunction model. Results showed that ACEI activity of broccoli crude peptide increased by 70.73 ± 1.42% after digestion. The enzymatic hydrolysates of crude broccoli peptides before and after digestion were detected by HPLC. The digested crude peptides were highly stable (with a stability level > 90%) in the intestine and possessed a strong absorptive potential. Five peptides with high stability and strong permeability were first identified, including HLEVR, LTEVR, LEHGF, HLVNK, and LLDGR, which exhibited high activity with IC50 values of 3.19 ± 0.23 mM, 17.07 ± 1.37 mM, 0.64 ± 0.02 mM, 0.06 ± 0.01 mM, and 2.81 ± 0.12 mM, respectively. When the VSMCs model was exposed to Ang II, the expressions of PCNA, MMP2, and Bcl2 were increased, while the expression of BAX was inhibited. When the VSMCs was exposed to high glucose (HG), the Ang II concentration significantly increased. This indicates that HG elevated Ang II levels. Finally, five peptides significantly attenuated Ang II-induced VSMCs proliferation and migration by down-regulating AT1R expression and inhibiting ERK and p38 MAPK phosphorylation. Notably, in exploring VSMCs dysfunction on a high glucose-induced model, ACEI peptides resulted in down-regulation of ACE and up-regulation of ACE2 expression. Therefore, it can be further referenced for the functional food against hypertension and cardiovascular diseases.

Enhancing Probiotic Viability in Yogurt: The Role of Apple Fibers in Supporting Lacticaseibacillus casei ATCC 393 During Storage and Gastrointestinal Transit

Probiotics are widely recognized for their health benefits, but their viability during food processing and digestion poses significant challenges. The present study evaluated the impact of incorporating apple fibers into yogurt on the viability of the probiotic strain Lacticaseibacillus casei ATCC 393 during production, storage, and simulated gastrointestinal digestion. Apple fibers, a by-product of apple processing, were used as a prebiotic ingredient due to their functional and technological benefits. The incorporation of apple fibers increased probiotic viability during 28 days of refrigerated storage, improving it from 90.4% in the control yogurt to 93.9%. Under simulated gastrointestinal conditions, yogurt alone acted as a protective matrix, preserving probiotic viability, during gastric (71.0% at pH 2 after 3 h) and intestinal digestion (73.3% at 0.3% bile salts after 6 h). The inclusion of apple fibers further enhanced this protection, reducing probiotic viability loss in both gastric (81.9% at pH 2 after 3 h) and intestinal (79.0% at 0.3% bile salts after 6 h) environments. Similar results were obtained using the INFOGEST 2.0 static protocol. After the completion of the protocol (oral, gastric and intestinal phase) a viability of 71.1% (6.61 logCFU/g) was observed in the yogurt with apple fibers compared to 64.5% (6.10 logCFU/g) in the control yogurt. This enhanced protection could be attributed to the potential prebiotic properties of apple fibers, including their pectin and cellulose content, which may shield probiotics from acidic and enzymatic degradation. These findings highlight the potential of apple fiber-enriched yogurt as a functional food that supports probiotic viability during storage and throughout gastrointestinal transit. These insights may open the way for developing new food products with enhanced health benefits, aligning with growing consumer demand for functional foods.

Exploitation of the Nutraceutical Potential of the Infesting Seaweed Chaetomorpha linum as a Yellow Mealworms' Feed: Focus on Nutrients and Antioxidant Activity.

According to the Sustainable Blue Economy Communication, the Farm to Fork Strategy, and the European Green Deal, novel business models supporting the use of resources from oceans and seas are of primary importance. Interestingly, several infesting seaweeds are consumed as foods in Asia and are fundamental ingredients in several traditional dishes. Herein, according to the circular economy approach, we investigate the use of Chaetomorpha linum (CL) as a Tenebrio molitor larvae feed in different percentages: 20%, 50%, and 100%, respectively. We analyzed the effects of CL on the survival and biometric parameters of larvae. The survival rate remained comparable to the control, while the mean weight was inversely proportional to the CL%. The nutrient composition was substantially different from the control, showing increased protein and reduced fat content. Analysis of the secondary metabolites revealed a better fatty acid composition, rich in PUFA, with lipid nutritional indexes comparable to seaweeds and crabs. The simulated gastrointestinal digestion highlights the increased content of essential amino acids, and a two times higher antioxidant activity with respect to the control. Taken together, our results confirm that CL can be used as a TML supplement, with beneficial effects in protein content and fat quality.

Interbreed variation of dairy cow milk in terms of specific proteome and lipidome for establishing criteria of milk selection.

Ruminant milk is a very complex table food and naturally encrypted with different components possessing various health-promoting characteristics. In the present study, we focused on breed-wise compositional difference in milk including various components and release of fatty acids and peptides during digestion. First, milk samples were analysed using lactoscan LW milk analyser, MALDI-TOF and gas chromatography. In addition, in vitro simulated gastrointestinal digestion of milk was performed to determine the fatty acid and peptide concentration. Percentage fat was significantly less in Karan Fries (KF) and Holstein Friesian (HF) milk compared to Sahiwal (SW), Tharparkar (TP), Gir (GIR) and Karan Swiss (KS). The mean conductivity displayed the healthy status in SW, TP, GIR, KF and HF milk. The protein was significantly higher in KF milk compared to SW, TP, GIR and HF milk. KS milk possessed the highest number of peptides followed by HF, SW, TP, GIR and KF milk. The fatty acid compositional difference was primarily observed in saturated fatty acids including the C4:0, C21:0 and also w6 linoleic acid. On the basis of peptide number of MALDI-TOF, milk from SW and KS was selected for digestion in in vitro to check the availability of fatty acids and peptides in the intestine. There was more release of fatty acids in SW milk and more peptide from KS milk in intestinal conditions. Therefore, the difference in composition exists based on protein and fat components in indigenous and crossbred cows' milk. The breed-wise difference in composition of milk is important to study as it not only reflected the nutritional value and various biological activities, but also emphasis on specific proteomic and lipidomic of milk that eventually can be used as criteria for selection of milk.

Molecular Docking Studies and In Vitro Activity of Pancreatic Lipase Inhibitors from Yak Milk Cheese.

Pancreatic lipase serves as a primary trigger for hyperlipidemia and is also a crucial target in the inhibition of hypercholesterolemia. By synthesizing anti-hypercholesterolemic drugs such as atorvastatin, which are used to treat hypercholesterolemia, there were some side effects associated with the long-term use of statins. Based on this idea, in the present study, we identified peptides that inhibited PL by virtual screening and in vitro activity assays. In addition, to delve into the underlying mechanisms, we undertook a dual investigative approach involving both molecular docking analyses and molecular dynamics simulations. The results showed that peptides RK7, KQ7, and TL9, all with molecular weights of <1000 Da and a high proportion of hydrophobic amino acids, inhibited PL well. Molecular docking and molecular dynamics showed that peptides RK7, KQ7, and TL9 bound to important amino acid residues of PL, such as Pro and Leu, through hydrogen bonding, hydrophobic interactions, salt bridges, and π-π stacking to occupy the substrate-binding site, which inhibited PL and identified them as potential PL inhibitors. In vitro tests showed that the IC50 of RK7 and KQ7 on PL were 0.690 mg/mL and 0.593 mg/mL, respectively, and the inhibitory effects of RK7 and KQ7 on PL were significantly enhanced after simulated gastrointestinal digestion. Our results suggested that peptides RK7 and KQ7 from yak milk cheese can be identified as a novel class of potential PL inhibitors.

Exploring the Bioaccessibility of Roasted Japanese Green Tea: Impact of Simulated Gastrointestinal Digestion.

In this study, the effects were explored of digestive enzymes and pH on the bioaccessibility of polyphenols, flavonoids, and antioxidant activities in Hojicha (roasted green tea, RT) infusions during simulated in vitro digestion. Roasting modifies its polyphenolic profile and reduces bitterness, making it a popular variation of green tea. In this study, RT was used for assessing how the roasting-induced changes influenced the tea's bioaccessibility and stability under digestive conditions. A two-step gastrointestinal digestion model was applied to mimic real digestion. Total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity (DPPH, ABTS, FRAP, and MIC) were measured at different digestion stages. Gastric conditions led to a 2.07-fold reduction in TPC and a 4.27-fold reduction in TFC. Digestive enzymes enhanced bioactive compound stability, with TPC and TFC bioaccessibility reaching 56% and 25% in the simulated digestion with digestive enzymes (MD) group, compared to 52% and 20% in the without digestive enzymes (WOE) group. Antioxidant activities were also better preserved, with antioxidant activity retention at 31% in the MD samples versus 19% in the WOE. These findings emphasize the key role of digestive enzymes in maintaining the antioxidant potential of roasted green tea during digestion, providing insight into future research on roasting methods and tea functionality for product development.

Ex Vivo, In Vitro and In Vivo Bone Health Properties of Grana Padano Cheese.

Grana Padano (GP) is an Italian hard cooked cheese characterized by a long ripening process and high protein and Ca contents. After in vitro static simulated gastrointestinal digestion, GP digest contained caseinophosphopeptides that were 6 to 24 amino acids in length, including tri-phosphorylated species incorporating the pSer-pSer-pSer-Glu-Glu cluster. Using rat ileum tissue, the digest was used to assess Ca absorption ex vivo, which showed significantly better results for the GP digest in comparison to the CaCO3 aqueous solution. An in vitro intestinal model based on Caco-2/HT-29 cell co-culture was able to mimic Ca absorption from GP digest, with Ca-rich water as a control. The metabolite-containing medium was then used to treat osteoblast-like SaOS-2 cells. As a consequence, metabolized GP digest significantly increased the number of osteoblasts, whereas the metabolized water did not exert this effect. Finally, the mice were fed diets containing GP or CaCO3 and pea isolate and the in vivo outcomes were assessed through fluorescent probe and computed tomography. Mice fed a diet containing GP showed a higher increase in bone remodeling and volume in comparison to those fed a control diet containing CaCO3 and pea isolate. Overall, the ex vivo, in vitro and in vivo experiments highlighted the effectiveness of GP in improving Ca absorption, osteoblast proliferation and bone remodeling and volume.

Protein hydrolysates derived from superworm (Zophobas morio): Composition, bioactivity, and techno-functional properties.

This study aimed to produce protein hydrolysates from superworm (Zophobas morio) flour using the enzymes alcalase (HA), protamex (HP), or flavourzyme (HF), and to characterize their nutritional composition, techno-functional properties, bioactive capacity, and bioaccessibility index. The enzymatic process increased the total amino acid and crude protein contents of the hydrolysates by approximately 36% and 46%, respectively, generating better foaming capacity, oil retention, and emulsification capacity, when compared to raw flour. Although 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical capture was similar between the hydrolysates, HA (1479,66μM FeSO4/g) and HP (1514,66μM FeSO4/g) showed greater antimicrobial and iron reducing power (FRAP) activity, while HF has a higher scavenging efficiency for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (27.53%). The best antimicrobial activity was observed for HA against Vibrio corallilyticus (400mg/mL), and HP showed a better antioxidant response scavenging for DPPH radical. The antioxidant capacity against ABTS radical after in vitro simulation of gastrointestinal digestion (GID) was as follows: HA (79.07±1.53%), HP (74.65±5.85%), and HF (57.95±8.31%). Therefore, insect flour is a promising ingredient for the production of protein hydrolysates and their application in animal and human feeds.

Construction of Pickering Double Emulsions Based on Xanthan Gum/Lysozyme Nanoparticles: Structure, Stability, and Co-Encapsulation of Epigallocatechin Gallate and β-Carotene.

The low stability of water-in-oil-in-water (W1/O/W2) double emulsions greatly limits their applications. Therefore, in this study, W1/O/W2 Pickering double emulsions (PDEs) were prepared by a two-step emulsification method using polyglycerol polyricinoleate (PGPR) and xanthan gum/lysozyme nanoparticles (XG/Ly NPs) as lipophilic and hydrophilic emulsifiers, respectively. The regulation mechanism of the performance of PDEs by XG/Ly NPs was investigated, and the ability of the system to co-encapsulate epigallocatechin gallate (EGCG) and β-carotene was evaluated. The results showed that increasing the XG/Ly NPs concentration can enhance the stability of PDEs. At 60% W2 phase percentage and 2.0% XG/Ly NPs, the PDEs showed a smaller droplet size (23.47 ± 2.28 μm) and no phase separation after 21 days of storage. Additionally, the PDEs co-encapsulated system showed higher encapsulation efficiency (EGCG: 89.21%; β-carotene: 99.14%) and maintained high retention of active substances after 8 h of UV illumination (EGCG: 75.51%; β-carotene: 77.24%). As demonstrated by in vitro simulated gastrointestinal digestion assays, the bioaccessibility of EGCG and β-carotene simultaneously encapsulated was improved by 66.0% and 36.2%, respectively, compared with that of individually encapsulated EGCG and β-carotene. Overall, this study provides a new reference for the construction of highly stable PDEs and is promising as a co-encapsulation carrier for environmentally sensitive components.

Milk osteopontin has high iron-binding capacity and facilitates iron absorption in intestinal cells.

Insufficient absorption of iron and the consequent development of iron deficiency have serious health consequences. Hence, identification and development of iron delivery systems that can increase the bioavailability and uptake of dietary iron are important. Osteopontin (OPN) is an acidic and highly phosphorylated integrin-binding protein found in milk where it exists as a full-length protein and as N-terminally derived fragments. Milk OPN can be taken up by enterocytes and transported across the intestinal barrier into the circulation. Milk OPN has previously been shown to bind calcium and magnesium. This study investigates milk OPN as a carrier of iron and its potential to increase iron absorption in intestinal cells. Full-length OPN and N-terminal fragments of OPN were shown to bind ∼30 and ∼10 mol of iron, respectively, and the phosphorylated residues were crucial for iron binding. Osteopontin retained iron bound after simulated gastrointestinal digestion. Immunodetection of digested OPN and OPN-Fe complexes showed that the OPN-Fe complexes were more resistant to pepsin digestion than OPN without bound iron. The cellular uptake of iron was investigated by measuring intracellular ferritin formation and mRNA expression of divalent metal transporter 1 in Caco-2 cells. Osteopontin increased the uptake of iron even in the presence of phytic acid, a dietary inhibitor of iron absorption. These data indicate that OPN can function as an iron carrier for use in alternative strategies for delivering iron in a bioavailable form for intestinal uptake.

Identification and characterization of two novel dipeptidyl peptidase-IV inhibitory peptides from the simulated gastrointestinal digestion of Tartary buckwheat proteins

Identification and characterization of two novel dipeptidyl peptidase-IV inhibitory peptides from the simulated gastrointestinal digestion of Tartary buckwheat proteins

Enhancing Digestibility and Intestinal Peptide Release of Pleurotus eryngii Protein: An Enzymatic Approach.

Pleurotus eryngii is a tasty and low-calorie mushroom containing abundant high-quality protein. This study aims to improve the digestibility of P. eryngii protein (PEP) and hence to facilitate its development as a healthy alternative protein. The extracted PEP was pretreated with 1000-5000 U of papain, neutral protease and alkaline protease. The Chyme collected from in vitro simulated gastrointestinal digestion was analyzed by fluorescence microscopy and protein particle analyzer, and the endpoint profiles of peptides and amino acids were determined by UHPLC-MS/MS and NanoLC-MS/MS. The particle size curve and fluorescence microscopy images jointly supported that protease hydrolysis improved decomposition and dispersion of PEP during digestion, particularly in the gastric phase. The impact on Zeta potential was minimal. Proteases effectively increased the abundance of amino acids after digestion, particularly L-isomer Lys and Arg Maximum release was achieved when pretreated with 5000 U of alkaline protease, reaching 7.54 times that of control. Pretreatments by proteases also notably increased digestive yields of 16,736-19,870 peptides, with the maximum reaching 1.70 times that of the control, which mainly consisted of small peptides composed of 7-15 amino acids with molecular weight below 800 Da. The findings indicated that protease hydrolysis, especially pretreatment with 5000 U of alkaline protease, effectively enhanced the digestibility of PEP, which shed light on providing enzymatic approaches for improving bioavailability and developing healthy fungal proteins.

Spray-Dried Wheat Gluten Protein Hydrolysate Microcapsules: Physicochemical Properties, Retention of Antioxidant Capability, and Release Behavior Under Simulated Gastrointestinal Digestion Conditions.

Wheat gluten is a by-product of the wheat starch industry, rich in bioactive peptides. Spray drying is an effective method for improving the stability of bioactive compounds. So, the aim of this study was to produce gluten hydrolysate by different proteases (alcalase, pancreatin, and trypsin) at different times (40-200 min). The hydrolysate with the strongest antioxidant potential (produced by pancreatin after 200 min of hydrolysis) was encapsulated by spray drying. The effect of wall material's type (maltodextrin, potato starch, and their combination at different ratios) on the encapsulation efficiency, physicochemical properties (moisture content, solubility, water activity, tapped and bulk density, and hygroscopicity), release behavior under simulated gastrointestinal digestion conditions, and morphology of microcapsules were evaluated. The microcapsules produced by maltodextrin and potato starch at a 30:70 ratio possessed the highest water activity (0.36), encapsulation efficiency (85.79%), and moisture content (8.2%). An increase in maltodextrin concentration increased the solubility, bulk, and tapped density. SEM images showed that microparticles were spherical with wrinkled surfaces. The microcapsules showed higher stability than free gluten hydrolysate. The combination of maltodextrin and potato starch at a 30:70 ratio could control the release of gluten hydrolysate under simulated gastrointestinal conditions. As a result, the use of maltodextrin and potato starch carriers at a 30:70 ratio in spray drying could effectively protect the bioactive properties of gluten hydrolysate and control its release.

Effect of the Type of Herbal Preparations (Powdered Plant Material vs. Dry Ethanolic Extracts) on the Bioaccessibility of Bearberry (Arctostaphylos uva-ursi (L.) Spreng.) Phytochemicals in Simulated Digestion Conditions.

The main aim of this study was to determine the potential bioaccessibility of bearberry phytochemicals influenced by the type of herbal preparations. Herbal preparations-powdered plant materials and dry extracts obtained using various ethanol concentrations (0%, 20%, 40%, 60%, 80%, and 100%) were subjected to simulated gastric or gastrointestinal digestion for the evaluation of the bioaccessibility of the phytochemicals. The phytochemical characterization of the plant material, dry extracts, and potentially bioaccessible fractions was performed using high-performance liquid chromatography (HPLC) and spectrophotometric assays. The content of the main compounds, i.e., arbutin, hydroquinone, hyperoside, pentagalloylglucose, and picein, as well as the total phenolic content and in vitro antioxidant activity through the ABTS•+-scavenging activity and Fe3+-reducing power were determined. The bioaccessibility of arbutin, i.e., the main compound in bearberry, was high, in most cases exceeding 95%, and was generally unaffected by the experimental factors; however, the changes in the content of the other compounds, the total phenolic content, and the antioxidant activity were more prominent and influenced by the type of the herbal preparation and the stage of digestion. Given the compromise between the abundance of the bearberry phytochemicals, the antioxidant activity, and the resulting potential bioaccessibility of these phytochemicals, the dry extracts prepared with 40% ethanol seem to be the most promising for phytopharmaceutical purposes and functional food applications.

Electrospray whey protein-polysaccharide microcapsules co-encapsulating Lactiplantibacillus plantarum and EGCG: Enhanced probiotic viability and antioxidant activity.

Probiotics are often subjected to adverse factors during processing, storage and digestion. To enhance the viability and function of probiotics, whey protein concentrate (WPC)-based microcapsules were systematically fabricated to co-encapsulate probiotic Lactiplantibacillus plantarum KLDS 1.0328 (LP KLDS 1.0328) and epigallocatechin gallate (EGCG) by electrospray. Scanning electron microscopy showed that spherical and smooth particles were developed. Attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray diffraction suggested that probiotics and EGCG were successfully encapsulated in WPC-based microcapsules. Thermogravimetric analysis revealed that the addition of EGCG and probiotics improved the thermal stability of WPC-based microcapsules. Furthermore, the incorporation of polysaccharides and polyphenol significantly enhanced the antioxidant activity of the microcapsules (P<0.05). The viability of probiotics encapsulated in WPC/polysaccharides microcapsules was elevated compared with that of encapsulated in WPC microcapsules under simulated gastrointestinal digestion, thermal treatments and NaCl stresses. Notably, WPC/β-CD/EGCG/LP KLDS 1.0328 exhibited better protection against these environmental stresses. Moreover, the incorporation of polysaccharides could maintain viability over 7.50 lg CFU/g after 28 d of storage. Furthermore, WPC/β-CD/LP KLD 1.0328/EGCG microcapsules exhibited the highest scores by the results of principal component analysis. This study provides valuable insights for protecting probiotics with appropriate polysaccharide-protein composites and developing functional foods with probiotics.

Physicochemical Properties, Antioxidant Capacity and Bioavailability of Whey Protein Concentrate-Based Coenzyme Q10 Nanoparticles

Coenzyme Q10 (CoQ10) is a powerful antioxidant. However, the poor water solubility and low bioavailability still remain challenges for its application. An embedded delivery system of CoQ10 based on whey protein concentrate (WPC) and polymerized whey protein concentrate (PWPC) was prepared, and the physicochemical properties, antioxidant capacity and bioavailability were characterized in this study. Both groups of nanoparticles showed a particle size distribution from 241 to 331 nm in the protein-to-CoQ10 mass ratio range of 100:1 to 20:1. In addition, the minimum polydispersity index value was observed at the mass ratio of 20:1. Differential scanning calorimetry and Fourier transform infrared spectra analysis revealed that the CoQ10 was successfully dispersed in the WPC and PWPC particles through hydrophobic interaction in both groups in addition to the hydrogen bond present in the WPC group. All nanoparticles exhibited irregular spherical or aggregate structure in the transmission electron microscopy diagram. The PWPC-based nanoparticles showed a slightly higher antioxidant capacity than that of the WPC, and both values were significantly higher than that of its corresponding physical mixture and free CoQ10 (p &lt; 0.05). The results of the simulated gastrointestinal digestion experiments denoted that these two nanoparticles could protect CoQ10 from gastric digestion and then deliver it to the intestine. Compared with its free state, the bioavailability of CoQ10 embedded in WPC and PWPC increased by nearly 7.58 times and 7.48 times, respectively. The data indicated that WPC and PWPC could be effective delivery carriers to enhance the bioavailability of active substances like CoQ10.