Differential Digestive Stability of Food-Derived microRNAs: The Case of miR-30c-5p and miR-92a-3p in Polyfloral Honey.

Dietary microRNAs (miRs) represent a new area in food science. Although they have been found in many foods, including honey, more research is needed about their stability and fate during digestion. Hence, this study aimed to analyze the digestive stability of two selected miRs in honey. We extracted miR-92a-3p and miR-30c-5p from pasteurized and unpasteurized forms of polyfloral honey using two different methods and kits: a column-based manual method and a phenol-free semi-automated magnetic-bead-based method. The latter option was used for the subsequent analysis of samples according to the INFOGEST static in vitro digestion protocol. Also, the honey samples were examined for exosome-like particles using dynamic light scattering. Although the expression levels of both miRs were significantly lower following intestinal digestion, we found a difference in the resilience of the miRs to gastrointestinal conditions, with miR-30c-5p being relatively stable compared to miR-92a-3p following digestion, regardless of the honey's pasteurization treatment. Moreover, there was marked heterogeneity in the extracellular vesicle profile of the pasteurized sample. We identified the presence of two broadly conserved miRs in honey: miR-92a-3p and miR-30c-5p. Despite honey exhibiting high digestibility, miR-92a-3p was less resilient than miR-30c-5p, demonstrating considerable resistance under gastrointestinal conditions. Although further research is needed, the results obtained from this study may represent a starting point for utilizing honey as a source of exogenous miRNAs for preventive strategies and more "natural" treatments.

Effects of selenium enrichment on fermentation characteristics, selenium content and microbial community of alfalfa silage.

BACKGROUND: Selenium is essential for livestock and human health. The traditional way of adding selenium to livestock diets has limitations, and there is a growing trend to provide livestock with a safe and efficient source of selenium through selenium-enriched pasture. Therefore, this study was conducted to investigate the effects of selenium enrichment on fermentation characteristics, selenium content, selenium morphology, microbial community and in vitro digestion of silage alfalfa by using unenriched (CK) and selenium-enriched (Se) alfalfa as raw material for silage. RESULTS: In this study, selenium enrichment significantly increased crude protein, soluble carbohydrate, total selenium, and organic selenium contents of alfalfa silage fresh and post-silage samples, and it significantly decreased neutral detergent fiber and acid detergent fiber contents (p < 0.05). Selenium enrichment altered the form of selenium in plants, mainly in the form of SeMet and SeMeCys, which were significantly higher than that of CK (p < 0.05). Selenium enrichment could significantly increase the lactic acid content, reduce the pH value, change the diversity of bacterial community, promote the growth of beneficial bacteria such as Lactiplantibacillus and inhibit the growth of harmful bacteria such as Pantoea, so as to improve the fermentation quality of silage. The in vitro digestibility of dry matter (IVDMD), in vitro digestibility of acid detergent fibers (IVADFD) and in vitro digestibility of acid detergent fibers (IVNDFD) of silage after selenium enrichment were significantly higher than those of CK (p < 0.05). CONCLUSION: This study showed that the presence of selenium could regulate the structure of the alfalfa silage bacterial community and improve alfalfa silage fermentation quality. Selenium enrichment measures can change the morphology of selenium in alfalfa silage products, thus promoting the conversion of organic selenium.

Honey Varietals Differentially Impact Bifidobacterium animalis ssp. lactis Survivability in Yogurt through Simulated In Vitro Digestion.

BACKGROUND: Bifidobacterium animalis ssp. lactis DN-173 010/CNCM I-2494 (B. animalis) is a probiotic strain commonly added to yogurt. Yogurt and honey are a popular culinary pairing. Honey improves bifidobacteria survival in vitro. However, probiotic survival in yogurt with honey during in vitro digestion has not been investigated. OBJECTIVES: The study aimed to evaluate the effects of different honey varietals and concentrations on B. animalis survivability in yogurt through in vitro digestion. METHODS: Yogurt with honey or control-treated samples underwent in vitro simulated oral, gastric, and intestinal digestion. B. animalis cells were enumerated on de Man Rogosa and Sharpe (MRS) medium followed by an overlay with a modified selective MRS medium; all underwent anaerobic incubation. B. animalis were enumerated predigestion and after oral, gastric, and intestinal digestion. There were 2 study phases: Phase 1 tested 4 honey varietals at 20% wt/wt per 170 g yogurt, and Phase 2 tested 7 dosages of clover honey (20, 14, 10, 9, 8, 6, and 4% wt/wt) per 170 g yogurt. RESULTS: Similar B. animalis counts were observed between all treatments after oral and gastric digestion (<1 Log colony forming units (CFU)/g probiotic reduction). Higher B. animalis survivability was observed in yogurt with clover honey after exposure to simulated intestinal fluids (∼3.5 Log CFU/g reduction; P < 0.05) compared to all control treatments (∼5.5 Log CFU/g reduction; P < 0.05). Yogurt with 10-20% wt/wt clover honey increased B. animalis survivability after simulated in vitro digestion (≤ ∼4.7 Log CFU/g survival; P < 0.05). CONCLUSIONS: Yogurt with added honey improves probiotic survivability during in vitro digestion. The effective dose of clover honey in yogurt was 10-20% wt/wt per serving (1-2 tablespoons per 170 g yogurt) for increased probiotic survivability during in vitro digestion.

Characterization of recombinant phytase of Klebsiella sp. and the influence of novel 3-phytase on mineral solubility in broiler diets under an in vitro digestion assay.

Phytate (inositol hexaphosphate) is the major storage form of phosphorus (P) in nature, and phytases catalyze the hydrolysis of P from phytate and the formation of inositol phosphate isomers. In this study, a bacterium that produces phytase was isolated in a phytase screening medium. The bacterium was identified as Klebsiella sp. using phenotypic and molecular techniques. The PhyK phytase gene was successfully amplified from the genome, inserted into the pET-21a (+) vector, and expressed as a recombinant protein in E. Coli BL21. The efficiency of a laboratory phytase (Lab-Ph, PhyK phytase) was determined and compared with a commercial phytase (Com-Ph, Quantum Blue 40P phytase, AB Vista) under an in vitro digestion assay. The native signal peptide effectively facilitated the translocation of the protein to the periplasmic space of E. Coli BL21, resulting in the proper folding of the protein and the manifestation of desirable enzyme activity. The Lab-Ph displayed the temperature and pH optima at 50 °C and 5 respectively. In addition, the Lab-Ph was inactivated at 80 °C. Under an in vitro digestion assay condition, Lab-Ph improved the P solubility coefficient in broiler diets. In comparison, the Com-Ph significantly increased the P solubility coefficient even when compared with the Lab-Ph. In summary, this study has shown that Lab-Ph possesses the necessary biochemical properties to be used in various industrial applications. However, Lab-Ph is extremely sensitive to heat treatment. The Lab-Ph and Com-Ph under an in vitro digestion assay improved the solubility coefficient of P in the broiler diet.

Plant-based proteins: advances in their sources, digestive profiles in vitro and potential health benefits.

Plant-based proteins (PBPs), which are environmentally friendly and sustainable sources of nutrition, can address the emerging challenges facing the global food supply due to the rapidly increasing population. PBPs have received much attention in recent decades as a result of high nutritional values, good functional properties, and potential health effects. This review aims to summarize the nutritional, functional and digestive profiles of PBPs, the health effects of their hydrolysates, as well as processing methods to improve the digestibility of PBPs. The diversity of plant protein sources plays an important role in improving the PBPs quality. Several types of models such as in vitro (the static and semi-dynamic INFOGEST) and in silico models have been proposed and used in simulating the digestion of PBPs. Processing methods including germination, fermentation, thermal and non-thermal treatment can be applied to improve the digestibility of PBPs. PBPs and their hydrolysates show potential health effects including antioxidant, anti-inflammatory, anti-diabetic, anti-hypertensive and anti-cancer activities. Based on the literature, diverse PBPs are ideal protein sources, and exhibit favorable digestive properties and health benefits that could be further improved by different processing technologies. Future research should explore the molecular mechanisms underlying the bioactivity of PBPs and their hydrolysates.

Content and Bioaccessibility of Minerals and Proteins in Fish-Bone Containing Side-Streams from Seafood Industries.

With the aim to upcycle fish side-streams, enzymatic hydrolysis is often applied to produce protein hydrolysates with bioactive properties or just as a protein source for food and feed. However, the production of hydrolysates generates a side-stream. For underutilized fish and fish backbone this side-stream will contain fish bones and make it rich in minerals. The aim of this study was to assess the relative bioaccessibility (using the standardized in vitro model INFOGEST 2.0) of minerals in a dietary supplement compared to bone powder generated after enzymatic hydrolysis of three different fish side-streams: undersized whole hake, cod and salmon backbones consisting of insoluble protein and bones. Differences in the bioaccessibility of protein between the powders were also investigated. The enzyme hydrolysis was carried out using different enzymes and hydrolysis conditions for the different fish side-streams. The content and bioaccessibility of protein and the minerals phosphorus (P), calcium (Ca), potassium (K) and magnesium (Mg) were measured to evaluate the potential of the powder as an ingredient in, e.g., dietary supplements. The bone powders contained bioaccessible proteins and minerals. Thus, new side-streams generated from enzymatic hydrolysis can have possible applications in the food sector due to bioaccessible proteins and minerals.

Predigested Mixture of Arachidonic and Docosahexaenoic Acids for Better Bio-Accessibility.

A predigested product from arachidonic acid oil (ARA) and docosahexaenoic acid (DHA) oil in a 2:1 (w/w) ratio has been developed and evaluated in an in vitro digestion model. To produce this predigested lipid mixture, first, the two oils were enzymatically hydrolyzed up to 90% of free fatty acids (FFAs) were achieved. Then, these two fatty acid (FA) mixtures were mixed in a 2:1 ARA-to-DHA ratio (w/w) and enzymatically esterified with glycerol to produce a mixture of FFAs, mono-, di-, and triacylglycerides. Different glycerol ratios and temperatures were evaluated. The best results were attained at 10 °C and a glycerol-to-FA molar ratio of 3:1. The bio-accessibility of this predigested mixture was studied in an in vitro digestion model. A total of 90% of the digestion product was found in the micellar phase, which contained 30% monoacylglycerides, more than 50% FFAs, and a very small amount of triacylglycerols (3% w/w). All these data indicate an excellent bio-accessibility of this predigested mixture.

In vitro evaluation of the effect of yogurt acid whey fractions on iron bioavailability.

A side effect of the raised consumption of Greek yogurt is the generation of massive amounts of yogurt acid whey (YAW). The dairy industry has tried several methods for handling these quantities, which constitute an environmental problem. Although the protein content of YAW is relatively low, given the huge amounts of produced YAW, the final protein amount in the produced YAW should not be underestimated. Taking into consideration the increased interest for bioactive peptides and the increased demand for dietary proteins, combined with protein and peptides content of YAW, efforts should be made toward reintroducing the latter in the food supply chain. In this context and in view of the prevalent dietary iron deficiency problem, the objective of the present study was the investigation of YAW fractions' effect on Fe bioavailability. With this purpose, an in vitro digest approach, following the INFOGEST protocol, was coupled with the Caco2 cell model. To evaluate whether YAW digest fractions exert positive, negative or neutral effect on Fe bioavailability, they were compared with the ones derived from milk, a well-studied food in this context. Milk and YAW showed the same effectiveness on both Fe bioavailability and the expression of relative genes (DCYTB, DMT1, FPN1, and HEPH). Focusing further on YAW fractions, by comparison with their blank digest control counterparts, it resulted that YAW 3- to 10-kDa digests fraction had a superior effect over the 0- to 3-kDa fraction on Fe-uptake, which was accompanied by a similar effect on the expression of Fe metabolism-related genes (DCYTB, FPN1, and HEPH). Finally, although the 3- to 10-kDa fraction of bovine YAW digests resulted in a nonsignificant increased Fe uptake, compared with the ovine and caprine YAW, the expression of DCYTB and FPN1 genes underlined this difference by showing a similar pattern with statistically significant higher expression of bovine compared with ovine and bovine compared with both ovine and caprine, respectively. The present study deals with the novel concept that YAW may contain factors affecting Fe bioavailability. The results show that it does not exert any negative effect and support the extensive investigation for specific peptides with positive effect as well as that YAW proteins should be further assessed on the prospect that they can be used in human nutrition.

Assessment of in vitro digestibility and post-digestion peptide release of mare milk in relation to different management systems and lactation stages.

Mare milk has a unique protein composition that makes it a preferred option for adult and infant nutrition. Several functional properties have been attributed to this milk but with little evidence yet. In fact, knowledge on mare milk composition is still limited. In particular, studies addressing the performance of mare milk proteins during human gastrointestinal digestion are scarce, which limits the understanding of mare milk nutritional quality and functionality. For this reason, the present study describes the digestibility of mare milk proteins and the release of peptides as affected by management and lactation stage, factors known to affect milk composition. Mare milk samples from 3 different farms, and collected during 6 mo of lactation (n = 54), were subjected to a static in vitro gastrointestinal model to measure peptide release and protein digestibility. In the present study, a detailed description of protein and individual amino acid behavior during the digestion process was given. For the first time, digestion of the 2 equine ß-lactoglobulin isoforms (I and II) was described individually. In addition, it was found that lactation stage and management system can significantly affect protein digestibility and peptide release during gastrointestinal digestion of mare milk. Presumably, differences in the composition of mare milk influence the protein structure and enzyme accessibility, which might have an impact on digestion behavior. Despite no specific bioactive peptides were identified, several precursors of previously described bioactive peptides were found. These findings could support the idea of mare milk as a food with added value.

Invited review: Camel milk and gut health-Understanding digestibility and the effect on gut microbiota.

Camel milk (CM), known for its immune-regulatory, anti-inflammatory, antiapoptotic, and antidiabetic properties, is a natural healthy food. It is easily digestible due to the high levels of ß-casein and diverse secreted antibodies, exhibiting superior antibacterial and antiviral activities compared with bovine milk. ß-casein is less allergic and more digestible because it is more susceptible to digestive hydrolysis in the gut; therefore, higher levels of ß-casein make CM advantageous for human health. Furthermore, antibodies help the digestive system by destroying the antigens, which are then overwhelmed and digested by macrophages. The connection between the gut microbiota and human health has gained substantial research attention, as it offers potential benefits and supports disease treatment. The gut microbiota has a vital role in regulating the host's health because it helps in several biological functions, such as protection against pathogens, immune function regulation, energy harvesting from digested foods, and reinforcement of digestive tract biochemical barriers. These functions could be affected by the changes in the gut microbiota profile, and gut microbiota differences are associated with several diseases, such as inflammatory bowel disease, colon cancer, irritable bowel disorder, mental illness, allergy, and obesity. This review focuses on the digestibility of CM components, particularly protein and fat, and their influence on gut microbiota modulation. Notably, the hypoallergenic properties and small fat globules of CM contribute to its enhanced digestibility. Considering the rapid digestion of its proteins under conditions simulating infant gastrointestinal digestion, CM exhibits promise as a potential alternative for infant formula preparation due to the high ß-/αs-casein ratio and protective proteins, in addition to the absence of ß-lactoglobulin.

The A1/A2 ß-casein genotype of cows, but not their horn status, influences peptide generation during simulated digestion of milk.

The effect of the horn status of cows on their milk composition and quality is a controversial research topic. In this study, 128 milk samples from 64 horned and 64 disbudded Brown Swiss and Original Braunvieh cows were collected from alpine farms where both horned and disbudded cows were grazing on mountain pastures. The samples were analyzed for their detailed composition and protein digestion in a simulated in vitro digestion (INFOGEST). To exclude probable influences on digestion, the ß-casein genotype with its variants A1 and A2 was also included in the study. The effects of horn status and ß-casein genotype were investigated in linear mixed models, which included additional influencing random factors such as Original Braunvieh blood proportion, stage of lactation, and farm. Horn status did not have any effect on milk composition or digestion. In contrast, milk from A1A1 cows showed a different protein digestion than milk of A1A2 and A2A2 cows in the gastric phase, including smaller amounts of ß-casomorphin(BCM)21-associated peptides and larger amounts of BCM11-associated peptides. Abundances of BCM7 did not differ between ß-casein genotypes. At the end of the intestinal phase, the digested milk of A1A1 and A2A2 b-casein genotypes did not differ.

Modeling Dynamics of Human Gut Microbiota Derived from Gluten Metabolism: Obtention, Maintenance and Characterization of Complex Microbial Communities.

Western diets are rich in gluten-containing products, which are frequently poorly digested. The human large intestine harbors microorganisms able to metabolize undigested gluten fragments that have escaped digestion by human enzymatic activities. The aim of this work was obtaining and culturing complex human gut microbial communities derived from gluten metabolism to model the dynamics of healthy human large intestine microbiota associated with different gluten forms. For this purpose, stool samples from six healthy volunteers were inoculated in media containing predigested gluten or predigested gluten plus non-digested gluten. Passages were carried out every 24 h for 15 days in the same medium and community composition along time was studied via V3-V4 16S rDNA sequencing. Diverse microbial communities were successfully obtained. Moreover, communities were shown to be maintained in culture with stable composition for 14 days. Under non-digested gluten presence, communities were enriched in members of Bacillota, such as Lachnospiraceae, Clostridiaceae, Streptococcaceae, Peptoniphilaceae, Selenomonadaceae or Erysipelotrichaceae, and members of Actinomycetota, such as Bifidobacteriaceae and Eggerthellaceae. Contrarily, communities exposed to digested gluten were enriched in Pseudomonadota. Hence, this study shows a method for culture and stable maintenance of gut communities derived from gluten metabolism. This method enables the analysis of microbial metabolism of gluten in the gut from a community perspective.

Vitamin D3 Bioaccessibility from Supplements and Foods-Gastric pH Effect Using a Static In Vitro Gastrointestinal Model.

Vitamin D3 deficiency is a global phenomenon, which can be managed with supplementation and food fortification. However, vitamin D3 bioaccessibility may depend on factors such as matrix composition and interactions throughout the gastrointestinal (GI) tract. This research focused on the effect of different matrices on vitamin D3 content during digestion, as well as the effect of pH on its bioaccessibility. The INFOGEST protocol was employed to simulate digestion. Three different types of commercial supplements, two foods naturally rich in vitamin D3, and three fortified foods were investigated. High-Performance Liquid Chromatography was used to determine the initial vitamin D3 content in the supplements and foods, as well as after each digestion stage. The results indicate that the foods exhibited higher bioaccessibility indices compared to the supplements and a higher percentage retention at the end of the gastric phase. The pH study revealed a positive correlation between an increased gastric pH and the corresponding content of vitamin D3. Interestingly, exposing the matrix to a low pH during the gastric phase resulted in an increased intestinal content of D3. Vitamin D3 is more bioaccessible from foods than supplements, and its bioaccessibility is susceptible to changes in gastric pH. Fasting conditions (i.e., gastric pH = 1) enhance the vitamin's bioaccessibility.

Bioaccessibility of Rosmarinic Acid and Basil (Ocimum basilicum L.) Co-Compounds in a Simulated Digestion Model-The Influence of the Endogenous Plant Matrix, Dose of Administration and Physicochemical and Biochemical Digestion Environment.

The objective of this study is to determine the effect of endogenous plant matrix components, dose and digestion-related factors on the bioaccessibility of rosmarinic acid and basil co-compounds in in vitro digestion conditions. Different forms of administration, i.e., basil raw plant material, dry extract, and isolated rosmarinic acid at various doses, were applied for the digestion experiment. To evaluate the contribution of biochemical and physicochemical digestion factors, samples were subjected to a full digestion process or treated only with a digestion fluid electrolyte composition without using biochemical components (i.e., digestion enzymes and bile salts), and bioaccessibility was monitored at the gastric and intestinal steps of digestion. The results showed that the components of the endogenous raw plant matrix significantly limited the bioaccessibility of rosmarinic acid and basil co-compounds, especially at the gastric stage of digestion. Physicochemical digestion factors were mainly responsible for the bioaccessibility of basil phytochemicals. Higher doses allowed maintenance of bioaccessibility at a relatively similar level, whereas the most negative changes in bioaccessibility were induced by the lowest doses. In conclusion, the determination of the bioaccessibility of bioactive phytochemicals from basil and factors influencing bioaccessibility may help in better prediction of the pro-health potential of this plant.

Effects of different wall-breaking methods on the nutrient release of Ganoderma lucidum spore powder during in vitro digestion.

BACKGROUND: The hard double-walled structure of Ganoderma lucidum spore powder (GLSP) is difficult for the human body to digest, so it is very important to break the wall of GLSP. In this study, the wall of GLSP was broken by mechanical milling at room temperature (MM-R) and ultra-fine grinding at low temperature (UFG-L), respectively. RESULTS: Compared with MM-R, UFG-L could better retain the sporangium powder's morphological and structural integrity. During in vitro digestion, compared with unbroken GLSP, the released amounts of polysaccharides and triterpenes from broken GLSP were significantly increased, and they increased with the increase of specific surface area. The bioaccessibility of polysaccharide and triterpene from unbroken GLSP after the intestinal stage were 29.52% and 5.37%, respectively. The bioaccessibility of polysaccharides and triterpene from broken GLSP by MM-R after the intestinal phase were 39.73-72.45% and 16.44-24.97%, while those by UFG-L were 44.53-104.18% and 12.96-32.90%, respectively. CONCLUSION: The active ingredients of broken GLSP showed better digestion and absorption abilities than unbroken GLSP. Moreover, the specific surface area of GLSP by UFG-L was lower than that by MM-R, and the bioaccessibility of GLSP by UFG-L was higher than that by MM-R. © 2024 Society of Chemical Industry.

Enhancement of functional properties, digestive properties, and in vitro digestion product physiological activity of extruded corn gluten meal by enzymatic modification.

BACKGROUND: Enzymatic modification is an effective means of improving the functional properties, digestive properties, and in vitro digestion product physiological activity of proteins, thus significantly expanding protein uses in various food applications. RESULTS: In this study, the addition of chymotrypsin (CT) at pH 9.0 and 11.0 was found to significantly improve the functional properties (solubility, foaming properties, water holding capacity, oil holding capacity, etc.) and digestive properties of extruded corn gluten meal (ECGM). Similar changes were observed when treating ECGM with glutaminase, protein glutaminase, and papain. These changes were likely due to the increase in number of carboxyl groups and the multiple effects of change in protein net charge and conformation caused by enzymatic deamidation. Of note, ECGM deamidated by CT showed the highest degree of deamidation, solubility, and gastrointestinal digestibility at pH 11.0, up to 44.92%, 43.75%, and 82.22%, respectively. In addition, CT-ECGM digestion product exhibited strong antioxidant activity and potential to promote alcohol metabolism in both a static digestion model and dynamic digestion model, even comparable to commercial corn peptides (CCP), while being inexpensive and of low bitterness compared to CCP. Meanwhile, the physiological activity enhanced as the molecular weight of digestion product decreased with the digested component having strongest activity. CONCLUSION: This study may promote the application of ECGM as a food component in the food industry or even as a substitute for CCP. © 2023 Society of Chemical Industry.

The construction of Moringa oleifera seed protein emulsion: in vitro digestibility and delivery of ß-carotene.

BACKGROUND: ß-Carotene (BC) is difficult to apply effectively in the food industry due to its low solubility and bioavailability. This work aimed to fabricate Moringa oleifera seed protein (MOSP) stabilized emulsions as delivery vehicles for BC and investigate the effect of aqueous phase conditions including pH and ionic strength on this system. RESULTS: All MOSP samples were positively charged and the particle size of MOSP increased with the increase of pH. At pH 5.0 and 0.2 mol L-1 sodium chloride (NaCl), the MOSP emulsion demonstrated the highest stability coefficient and minimal creaming index, while exhibiting a lower release rate in vitro digestion. The rheological behavior of all MOSP emulsions within the frequency range of 0.1-10 Hz was dominated by viscoelasticity, forming an elastic network structure through dispersed droplets. Additionally, the MOSP emulsion loaded with BC prepared at pH 5.0 and 0.2 mol L-1 NaCl displayed enhanced ultraviolet light stability (52.31 ± 0.03% and 51.86 ± 0.05%) as well as thermal stability (72.39 ± 8.67% and 86.78 ± 10.69%). Furthermore, the BC in the emulsion at pH 7.0 exhibited favorable stability (65.14 ± 0.02%) and optimal bioaccessibility (40.30 ± 0.04%) in vitro digestion. CONCLUSION: The results provided reference data for utilizing MOSP as a novel emulsifier and broadening the application of BC in the food industry. © 2024 Society of Chemical Industry.

In vitro digestion and colonic fermentation characteristics of media-milled purple sweet potato particle-stabilized Pickering emulsions.

BACKGROUND: Pickering emulsions stabilized by multicomponent particles have attracted increasing attention. Research on characterizing the digestion and health benefit effects of these emulsions in the human gastrointestinal tract are quite limited. This work aims to reveal the digestive characteristics of media-milled purple sweet potato particle-stabilized Pickering emulsions (PSPP-Es) during in vitro digestion and colonic fermentation. RESULTS: The media-milling process improved the in vitro digestibility and fermentability of PSPP-Es by reaching afree fatty acids release rate of 43.11 ± 4.61% after gastrointestinal digestion and total phenolic content release of 101.00 ± 1.44 µg gallic acid equivalents/mL after fermentation. In addition, PSPP-Es exhibited good antioxidative activity (2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays), α-glucosidase inhibitory activity (half-maximal inhibitory concentration: 6.70%, v/v), and prebiotic effects, reaching a total short-chain fatty acids production of 9.90 ± 0.12 mol L-1, boosting the growth of Akkermansia, Bifidobacterium, and Blautia and inhibiting the growth of Escherichia-Shigella. CONCLUSIONS: These findings indicate that the media-milling process enhances the potential health benefits of purple sweet potato particle-stabilized Pickering emulsions, which is beneficial for their application as a bioactive component delivery system in food and pharmaceutical products. © 2024 Society of Chemical Industry.

Effect of mechanical properties on in vitro dynamic digestion of starch contained in hydrogels.

BACKGROUND: This study evaluates the effect of mechanical properties on the in vitro dynamic gastrointestinal digestion of hydrogels containing starch (HCSs) as a model for studying the nutrient digestibility of solid foods. It provides a useful theoretical basis for the processing of specific foods. RESULT: Four types of HCSs with two levels of fracture stress (17.4-20.9 kPa and 55.5-57.6 kPa) and two levels of fracture strain (25.4-28.5% and 53.7-57.4%) were prepared. For these HCSs, the degree of gastric disintegration of hydrogels reduced significantly when fracture strain exceeded 30% (P < 0.05). The gastric emptying of HCS particles was also affected by mechanical properties. For example, even at the same level of fracture stress (ca. 20 kPa), the dry solids retention ratio decreased markedly from 0.90 to 0.43 with a decrease in fracture strain from 53.7% to 25.4% (P < 0.05). For the starch hydrolysis of HCSs after gastric digestion, more than 70% of starch in the particles of all types of HCSs emptied did not undergo digestion. The starch hydrolysis of HCSs during small intestinal digestion was also influenced by their mechanical properties. Fracture strains of HCSs, rather than their fracture stress, affected starch digestibility in hydrogels. CONCLUSION: The gastric disintegration, the gastric emptying, and the starch hydrolysis of HCSs are suppressed when fracture strain exceeded 30%. Even with the amount of nutritional components contained in hydrogels being the same, the in vitro gastrointestinal digestion behavior of HCSs depends on their mechanical properties. This behavior has the potential to be used in the design of processed foods with controlled bioaccessibility. © 2023 Society of Chemical Industry.

Transport of glycinin, the major soybean allergen, across intestinal epithelial IPEC-J2 cell monolayers.

Soybean allergen entering the body is the initial step to trigger intestinal allergic response. However, it remains unclear how glycinin, the major soybean allergen, is transported through the intestinal mucosal barrier. The objective of this study was to elucidate the pathway and mechanism of glycinin hydrolysate transport through the intestinal epithelial barrier using IPEC-J2 cell model. Purified glycinin was digested by in vitro static digestion model. The pathway and mechanism of glycinin hydrolysates transport through intestinal epithelial cells were investigated by cellular transcytosis assay, cellular uptake assay, immunoelectron microscopy and endocytosis inhibition assay. The glycinin hydrolysates were transported across IPEC-J2 cell monolayers in a time/dose-dependent manner following the Michaelis equation. Immunoelectron microscopy showed a number of glycinin hydrolysates appeared in the cytoplasm, but no glycinin hydrolysates were observed in the intercellular space of IPEC-J2 cells. The inhibitors, colchicine, chlorpromazine and methyl-ß-cyclodextrin, significantly inhibited the cellular uptake of glycinin hydrolysates. The glycinin hydrolysates crossed IPEC-J2 cell monolayers through the transcellular pathway. Both clathrin- and caveolae-dependent endocytosis were involved in the epithelial uptake of the hydrolysates. These findings provided potential targets for the prevention and treatment of soybean allergy.