Simulated Digestion Research Articles

Fatty Acid Release and Gastrointestinal Oxidation Status: Different Methods of Processing Flaxseed.

Flaxseed has been recognized as a superfood worldwide due to its abundance of diverse functional phytochemicals and nutrients. Various studies have shown that flaxseed consumption is beneficial to human health, though methods of processing flaxseed may significantly affect the absorption and metabolism of its bioactive components. Hence, flaxseed was subjected to various processing methods including microwaving treatment, microwave-coupled dry milling, microwave-coupled wet milling, and high-pressure homogenization. In vitro digestion experiments were conducted to assess the impact of these processing techniques on the potential gastrointestinal fate of flaxseed oil. Even though more lipids were released by the flaxseed at the beginning of digestion after it was microwaved and dry-milled, the full digestion of flaxseed oil was still restricted in the intestine. In contrast, oil droplets were more evenly distributed in wet-milled flaxseed milk, and there was a greater release of fatty acids during simulated digestion (7.33 ± 0.21 μmol/mL). Interestingly, wet-milled flaxseed milk showed higher oxidative stability compared with flaxseed powder during digestion despite the larger specific surface area of its oil droplets. This study might provide insight into the choice of flaxseed processing technology for better nutrient delivery efficiency.

Biodirected Screening and Preparation of Larimichthys crocea Angiotensin-I-Converting Enzyme-Inhibitory Peptides by a Combined In Vitro and In Silico Approach.

Food-derived angiotensin-I-converting enzyme (ACE)-inhibitory peptides have gained attention for their potent and safe treatment of hypertensive disorders. However, there are some limitations of conventional methods for preparing ACE-inhibitory peptides. In this study, in silico hydrolysis, the quantitative structure-activity relationship (QSAR) model, LC-MS/MS, inhibition kinetics, and molecular docking were used to investigate the stability, hydrolyzability, in vitro activity, and inhibition mechanism of bioactive peptides during the actual hydrolysis process. Six novel ACE-inhibitory peptides were screened from the Larimichthys crocea protein (LCP) and had low IC50 values (from 0.63 ± 0.09 µM to 10.26 ± 0.21 µM), which were close to the results of the QSAR model. After in vitro gastrointestinal simulated digestion activity of IPYADFK, FYEPFM and NWPWMK were found to remain almost unchanged, whereas LYDHLGK, INEMLDTK, and IHFGTTGK were affected by gastrointestinal digestion. Meanwhile, the inhibition kinetics and molecular docking results were consistent in that ACE-inhibitory peptides of different inhibition forms could effectively bind to the active or non-central active centers of ACE through hydrogen bonding. Our proposed method has better reproducibility, accuracy, and higher directivity than previous methods. This study can provide new approaches for the deep processing, identification, and preparation of Larimichthys crocea.

Compound probiotics microcapsules improve milk yield and milk quality of dairy cows by regulating intestinal flora

AbstractTo address the issues of probiotic activity loss during storage and feeding, as well as the limited efficacy of single probiotics, a solution was devised by embedding a mixture of Bacillus coagulans SN‐8 (SN‐8) and Saccharomyces boulardii SN‐6 (SN‐6) in a gel. The initial step involved screening the probiotic microcapsules' preparation method and wall material. Using sodium alginate and β‐cyclodextrin as composite wall material and chitosan as the outer coating material allowed for an embedding rate of 82.11% in composite probiotic microcapsules prepared by the air atomization method. Next, in vitro, simulated digestion experiments were conducted to determine the number of viable bacteria and the release rate of the microcapsules. The results showed that compared to the free strain, the mixed probiotic microcapsules retained a survival rate of 67.5% after 3 h of simulated gastric juice exposure and 70.56% after 42 days of storage at 4°C. This demonstrated higher survival rates and storage stability. The prepared probiotic microcapsules were then administered to dairy cows. 16S rDNA gene sequencing showed that consumption of the microcapsules reduced the number of harmful bacteria, such as Paeniclostridium, in the intestinal tract of dairy cows while accelerating the growth of beneficial bacteria, such as Bifidobacterium. In particular, this resulted in a significant improvement in the lactation performance of the cows, with a 4.5% increase in milk fat content, a 92.5% increase in milk protein content, and a 3.5% increase in milk urea nitrogen content (6.75 mL/dL). In conclusion, probiotic microcapsules can effectively regulate intestinal flora, improving milk production, and quality in dairy cows.

Egg Yolk Selenopeptides: Preparation, Characterization, and Immunomodulatory Activity.

In this study, egg yolk selenium peptides (Se-EYP) were prepared using double-enzyme hydrolysis combined with a shearing pretreatment. The properties of the selenopeptides formed were then characterized, including their yield, composition, molecular weight distribution, antioxidant activity, in vitro digestion, and immunomodulatory activity. The peptide yield obtained after enzymatic hydrolysis using a combination of alkaline protease and neutral protease was 74.5%, of which 82.6% had a molecular weight <1000 Da. The selenium content of the lyophilized solid product was 4.01 μg/g. Chromatography-mass spectrometry analysis showed that 88.6% of selenium in Se-EYP was in the organic form, of which SeMet accounted for 60.3%, SeCys2 for 21.8%, and MeSeCys for 17.9%. After being exposed to in vitro simulated digestion, Se-EYP still had 65.1% of oligopeptides present, and the in vitro antioxidant activity was enhanced. Moreover, Se-EYP exhibited superior immune detection indices, including immune organ index, level of immune factors in the serum, histopathological changes in the spleen, and selenium content in the liver. Our results suggest that Se-EYP may be used as selenium-enriched ingredients in functional food products.

Alginate beads loaded with rambutan extract: characterization and stability during in vitro gastrointestinal digestion.

Fallen young rambutan fruit is an underrated agricultural waste which may contain several bioactive compounds. In this study, fallen young rambutan fruit was assessed regarding its phenolic contents and antioxidant activities. In order to expand its utilization, rambutan extract-loaded hydrogel beads were developed by a basic spherification technique using sodium alginate. The effect of ratios of polymer and extract and different calcium sources were evaluated. The recovery of bioactive compounds from the hydrogel beads was determined using in vitro gastrointestinal digestion models. Use of 50% (v/v) ethanol yielded rambutan extract with good chemical properties. The production of hydrogel beads using a ratio of 1:3 with calcium lactate provided the highest production yield of 122.94%. The hydrogel beads developed using the ratio of 1:3 with a combination of calcium lactate and calcium chloride showed high recovery of phenolic compounds and antioxidant activity after simulated intestinal digestion, which were greater compared to unencapsulated extract. The findings demonstrate that the ratio of wall material to rambutan extract and the calcium source influence the physical properties, chemical properties and in vitro gastrointestinal digestion stability of alginate beads. The obtained hydrogel beads may have potential for application in the food or pharmaceutical industries. © 2024 Society of Chemical Industry.

The Effect of Different Grape Varieties and Adding Different Ratios of Mustard Seeds on the Phenolic Compounds, Antioxidant Capacity, and Bioaccessibility Values of Hardaliye under In Vitro Digestion

Hardaliye, grape-based fermented beverage, rich in antioxidant phenolic compounds. Bioaccessibility and antioxidant capacity of bioactive compounds in hardaliye, produced using varying amounts of mustard seeds (1%, 1.5%, and 2%) with Merlot and Papazkarası grape varieties, were evaluated under in vitro gastrointestinal digestion conditions. After digestion, Merlot and Papazkarası samples with 2% addition of mustard seed showed significantly higher total phenolic compounds (TPC) (358.48±14.73 and 89.01±2.42 mg GAE/L, respectively) compared to other samples (P&lt;0.05). 2% mustard seed added Merlot samples resulted in the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and cupric reducing antioxidant capacity (CUPRAC) values (19.06±3.91 and 9.96±1.83 mmol TEAC/L, respectively) which differed significantly from other samples (P&lt;0.05). The Merlot sample with 2% addition of mustard seed showed significantly higher TPC, total flavonoid compounds (TFC), DPPH, and CUPRAC bioaccessibility values compared to other Merlot samples (P&lt;0.05). For Papazkarası samples with 2% mustard seed addition, significant differences were observed only in terms of TPC and TFC bioaccessibility values (15.87±2.30% and 15.27±1.29%, respectively) compared to samples with 1% and 1.5% mustard seed addition (P&lt;0.05). The study demonstrated that the bioaccessibility of bioactive compounds in hardaliye can vary depending on the grape variety and to some extent, the use of mustard seed. This suggests that the food matrix and interaction with other food matrices in the environment can affect the stability and bioavailability of bioactive compounds during simulated digestion.

Pickering emulsion stabilized by sugarcane leaf polyphenols-zein covalent nanoparticles for curcumin delivery: In-vitro and inhibition of oxidative hemolytic activity evaluation

Pickering emulsion have been widely used to encapsulate bioactives with the aim of preventing degradation, improving bioavailability and achieving the effect of slow release. Curcumin (Cur), as a bioactive compound, was famous as its excellent beneficial human health functions. However, the low solubility and susceptibility to environmental influences limit the application of Cur. In our previous study, the covalent nanoparticles (sugarcane leaf polyphenols-zein, SGLpZ) with excellent antioxidant capacity were successfully fabricated. In addition, the pickering emulsion stabilized using SGLpZ with significance storage stability and antioxidant properties, which inspired us for Cur delivery application. Therefore, in this study, SZP (pickering emulsion stabilized by SGLpZ) were prepared and were firstly used to delivery Cur evaluation. Results exhibited that the mechanism of excellent stabilization of SZP may be due to the wide range of O/W phase interfaces with SGLpZ, which could be further used as a delivery system for Cur. An in-vitro simulated digestion suggested that SZP provided better protection to Cur under three different conditions (different Na+ concentration, temperatures and UV exposure times), compared to ZZP (pickering emulsion stabilized by zein nanoparticles alone). SZP was able to achieve a slow release of Cur as well as the high bioaccessibility of Cur during the in-vitro simulated digestion. Finally, Cur, Cur-ZZP and Cur-SZP inhibited respectively by 33.20±1.00%, 53.26±0.94% and 71.59±0.14% (p＜0.05) at the Cur concentration of 20 μg/mL in the in-vitro inhibition of AAPH-induced erythrocyte hemolysis assay. The study indicated that the pickering emulsion stabilized by SGLpZ was a reliable Cur delivery system and provided a novel idea of food material application for bioacitive substances delivery.

Nutritional and Physiological Properties of Thymbra spicata: In Vitro Study Using Fecal Fermentation and Intestinal Integrity Models.

(Poly)phenolic-rich Mediterranean plants such as Thymbra spicata have been associated with several health-promoting effects. The nutritional value, as well as physiological interaction of T. spicata with the gastrointestinal tract, has not been investigated before. The nutritional composition of T. spicata leaves was here characterized by standard analytical methods. T. spicata leaves were subjected to ethanolic extraction, simulated gastrointestinal digestion, and anaerobic microbial gut fermentation. Phenols/flavonoid contents and radical scavenging activity were assessed by colorimetric methods. The volatile organic compounds (VOCs) were detected by gas chromatography coupled with mass spectrometry. The effect on intestinal integrity was evaluated using a Caco-2 monolayers mounted in a Ussing chamber. T. spicata contains a high amount of fiber (12.3%) and unsaturated fatty acids (76% of total fat). A positive change in VOCs including short-chain fatty acids was observed without significant change in viable microbe. T. spicata and carvacrol (main phenolic compound) enhanced ionic currents in a concentration-dependent manner without compromising the Caco-2 monolayer's integrity. These effects were partially lost upon simulated digestion and completely abolished after colonic fermentation in line with polyphenols and carvacrol content. Conclusion: T. spicata represents a promising nutrient for the modulation of gut microbiota and the gut barrier. Further studies must better define its mechanisms of action.

Impact of Whey Protein Corona Formation around TiO2 Nanoparticles on Their Physiochemical Properties and Gastrointestinal Fate.

Previously, we found that whey proteins form biomolecular coronas around titanium dioxide (TiO2) nanoparticles. Here, the gastrointestinal fate of whey protein-coated TiO2 nanoparticles and their interactions with gut microbiota were investigated. The antioxidant activity of protein-coated nanoparticles was enhanced after simulated digestion. The structure of the whey proteins was changed after they adsorbed to the surfaces of the TiO2 nanoparticles, which reduced their hydrolysis under simulated gastrointestinal conditions. The presence of protein coronas also regulated the impact of the TiO2 nanoparticles on colonic fermentation, including promoting the production of short-chain fatty acids. Bare TiO2 nanoparticles significantly increased the proportion of harmful bacteria and decreased the proportion of beneficial bacteria, but the presence of protein coronas alleviated this effect. In particular, the proportion of beneficial bacteria, such as Bacteroides and Bifidobacterium, was enhanced for the coated nanoparticles. Our results suggest that the formation of a whey protein corona around TiO2 nanoparticles may have beneficial effects on their behavior within the colon. This study provides valuable new insights into the potential impact of protein coronas on the gastrointestinal fate of inorganic nanoparticles.

The influence of the food matrix on the content of cholesterol and oxysterols during simulated process of digestion

AbstractThe purpose of the study was to evaluate the influence of the simulated digestion process on the content of the standard cholesterol and this sterol found in fats. Additionally, the content of cholesterol oxides formed after the thermal processing of fats and standard of cholesterol was investigated in samples after performing in vitro digestion procedure. The next step was to evaluate changes in the concentration of cholesterol and cholesterol oxidation products in all analyzed samples. On that basis, the bioaccessibility of cholesterol and cholesterol oxidation products in analyzed samples was established. Cholesterol bioaccessibility ranged from 1.05% to 28.38% in thermally processed samples, while cholesterol standard samples accounted for 7.16% and 5.00%. The bioaccessibility of cholesterol oxides found in analyzed fats and fats with 0.2% addition of cholesterol standard ranged from 5.44% to 19.20%, and only in butter heated at 180°C per 1 h, it reached 47.61%. Studies show that cholesterol present in the food matrix is better protected from degradation, and oxidation during thermal treatment than the standard of cholesterol (processed without food matrix). The results of this study confirm that the bioavailability of cholesterol and its oxides are influenced by the food matrix.Practical applications: The results of our experiment can be used for further scientific analyzes related to the process of estimating the bioavailability of cholesterol and cholesterol oxidation products, which can be found in food products.

PH-Responsive Carrier-Free Polyphenol Nanoparticles Assembled by Oxidative Polymerization with Enhanced Stability and Antioxidant Activity for Improved Bioaccessibility.

Encapsulation of plant polyphenols with micro-/nano-carriers for enhanced bioavailability has been well documented, but the preparation of these carriers and subsequent loading of polyphenols is a multiple process, which is generally complicated with potentially unexpected negative effects on the bioactivity of the polyphenols. Here, we reported a convenient method to assemble carrier-free polyphenol nanoparticles (NPs) based on oxidative coupling polymerization. The effectiveness was assessed with five different polyphenols including pyrocatechol (PY), catechin (CA), epigallocatechin gallate (EGCG), tannic acid (TA), and proanthocyanidin (PC). The structural characteristics of these assembled nanoparticles (PY NPs, CA NPs, EG NPs, TA NPs, and PC NPs) were systematically analyzed with dynamic light scattering (DLS), transmission electron microscopy (TEM), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). All NPs were colloidally stable with varying NaCl concentrations from 0 to 300 mM, were acid-resistant and alkali-intolerant, and were suitable for oral administration. An array of antioxidant assays further confirmed the superior antioxidant capabilities of NPs over Trolox and polyphenol monomers, indicating that the oxidative polymerization of polyphenols did not compromise the polyphenol activity of NPs. The in vitro simulated digestion studies validated that these responsive NPs were actually gastrointestinal pH-responsive and applicable to the gastrointestinal physiological environment. The bioaccessibility assessments by using a static in vitro digestion model revealed that better results were achieved with NPs than polyphenol monomers, with TA NPs showing about 1.5-fold higher bioaccessibility than other polyphenol nanoparticles. The present study with five polyphenols demonstrated that the oxidative polymerization of polyphenols provides an effective platform to assemble various carrier-free NPs with enhanced antioxidant activity, favorable stability, and improved bioaccessibility, which could be used promisingly as a functional food ingredient in food matrices or as oral drug delivery candidates for helping to manage human health or treating various gastrointestinal disorders in both the pharmaceutical and nutritional fields.

Investigating the Probiotic Potential of Vegan Puree Mixture: Viability during Simulated Digestion and Bioactive Compound Bioaccessibility.

This study aimed to develop a fermented puree mixture containing plant-based ingredients and potential probiotic strains Lacticaseibacillus rhamnosusK3 and Lactobacillus johnsonii K4. The survival of potential probiotic strains, changes in sugar and organic acid concentrations, bioaccessibility of polyphenols, and antioxidant capacity after simulated digestion were examined with sensory quality. The mixture of apple puree, chia seeds, and oat bran or oat flakes was fermented. The sensory quality of the puree mixture was assessed by the quantitative descriptive profile (QDP) method. In vitro digestion was simulated using a static gastrointestinal model. Antioxidant capacity and total polyphenol content were analyzed before and after the digestion phases. All samples changed sensory profiles after fermentation. The overall quality was above six out of ten for every product. Fermentation also changed the organic acid composition, with significant increases in lactic, succinic, and acetic acids. After the digestion process, the survival rate remained above 5.8 log10 CFU/g. As a result of fermentation with potential probiotics, the bioaccessibility of the total phenolics and antioxidant activity increased. These results showed that the addition of potential probiotic strains increases nutritional value and could help with healthy nourishment habits. This knowledge can guide the development of consumer-satisfying products in the food industry, expanding the probiotic food market with innovative alternatives.

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.

Quantitative Analysis of Bioaccessible Phenolic Compounds in Aegean Bee Bread Using LC-HRMS Coupled with a Human Digestive System Model.

Bee bread, a valuable bee product that has recently attracted significant public interest as a nutritional supplement. The aim of this study was to evaluate the presence of phenolic compounds in bee bread samples from the Aegean Region and assess their bioaccessibility using a simulated human digestion model. Various extraction techniques, such as maceration, ultrasound-assisted extraction, and supercritical fluid extraction were employed to obtain extracts of bee bread. The antioxidant capabilities of these extracts were carried out using assays like DPPH⋅, ABTS⋅+ , CUPRAC, and β-carotene linoleic acid bleaching, and their effectiveness was quantified through IC50 values. The bioaccessibility of phenolic compounds was analysed by using LC-HRMS in a simulated human digestive system using ethanol extracts obtained from bee bread samples of each season by ultrasound-assisted extraction, which has the highest antioxidant activity. In the Aegean bee bread, a total of 25 phenolic compounds which were major phenolics including quercetin, ascorbic acid, isorhamnetin, kaempferol, and hyperoside were identified and quantified. Also, ascorbic acid was the one of the most bioaccessible compounds with the bioaccessibility index 35.38 % for 2021, 16.79 % for 2022. These findings underscore the substantial transformation of the phenolic profile of bee bread as it traverses the human digestive system.

Effects of different isolation methods on the structure and functional properties of starch from tiger nut (Cyperus esculentus L.) meal

Tiger nut (Cyperus esculentus L.) tuber meal as the major by-product of tiger nut oil production is a promising starch source. Starches obtained from tiger nut meal using different isolation methods were compared: distilled water (DWS), citric acid (CAS), enzyme (ESS), 0.5 g/L NaOH (LNS-0.5), 2 g/L NaOH (MNS-2), and 5 g/L NaOH (HNS-5). The highest yield (36.2% of tiger nut meal) was observed in HNS-5. Moreover, HNS-5 demonstrated the smallest particle size (7.69 μm), the highest amylose ratio (13.7%), and strongest freeze-thaw stability. ESS showed the highest relative crystallinity (20.0%), pasting temperature (79.1 °C), and its gel demonstrated higher hardness and adhesiveness compared to others. The average chain length of amylopectin (degrees of polymerization: 20.0−20.6), and the proportion of the amorphous phase (7.67%–8.66%) in starches were slightly affected by different isolation methods. Nevertheless, the crystalline pattern (C-type) of all starches was not changed, and all starch gels exhibited a similar single rate constant (0.037 min−1) during the simulated digestion process. Therefore, different isolation methods could be used to achieve different processing objectives, such as high yield or obtaining starch with enhanced properties.

Glycation of tilapia protein hydrolysate decreases cellular antioxidant activity upon in vitro gastrointestinal digestion

Changes in structural characteristics and antioxidant activity of tilapia hydrolysate glycated with glucose, fructose, or xylose at 90 °C for 12 h, and following in vitro gastrointestinal (GI) digestion were investigated. Fourier-transformed infrared (FTIR) band between 1,800 and 1,400 cm−1 confirmed the structural modifications of hydrolysate under glycations. Glycation drastically increased ATBS·+ and ONOO- scavenging activities (p < 0.05) as well as ferric-reducing antioxidant power (FRAP). Xylose was the most effective sugar for glycation, yielding the highest chemical antioxidant activities (p < 0.05). However, glycated hydrolysates exhibited lower cellular antioxidant activity (CAA) on HepG2 cell when compared to hydrolysates. The extensive glycation of hydrolysates resulted in lower GI digestibility as confirmed by the FTIR spectra of CO, CN, NH, CC, CO, and CH stretching vibrations. Glycation of tilapia hydrolysates only improved chemical antioxidant activities, but alleviated CAA, especially upon simulated GI digestion.

Improved Bacterial Survival and Antioxidant Activity After In Vitro Digestion of Fermented Dairy Beverages by Lacticaseibacillus casei LC-01 and Lactiplantibacillus plantarum BG-112 Containing Yacon.

The fermentation of milk containing 0%, 3%, 6%, and 9% (w/v) yacon root flour (YRF) by Lacticaseibacillus casei LC-1 and Lactiplantibacillus plantarum BG-112 was evaluated for bacterial survival and antioxidant activity (AA) before and after simulated gastrointestinal digestion. After 28days of refrigerated storage, samples of the beverages were analyzed for cell viability, AA (using ferric ion reducing antioxidant power (FRAP) and (ABTS), and molecular mass profile of proteins (using electrophoresis). The presence of 9% YRF increased bacterial survival during 28days of storage and passage through the gastrointestinal tract for both L. casei and L. plantarum, which showed a greater capacity to reduce ferric ions compared to 0% YRF, and the ability to capture free radicals increased from below 5mM to over 15mM TE after digestion. Milk proteins are hydrolyzed during digestion, and the generation of bioactive peptides with AA may explain the increase in AA levels. Since peptides are generated from milk proteins, YRF did not influence AA after digestion. These results showed that fermentation of milk by L. casei and L. plantarum with YRF increased the chances of these bacteria reaching the colon in adequate quantities. After simulated digestion, the beverages showed improved AA due to milk protein hydrolysis.

The Role of Gastric Lipase and Pepsin in Lipid Digestion of a Powder Infant Formula Using a Simulated Neonatal Gastric System

This study has sought to determine the impact of interfacial dynamics on the in vitro lipid digestion of a commercial infant formula; in particular, the specific role of interfacial proteolysis on the subsequent rates of reaction of droplet lipolysis. A powder infant formula was used as the as a protein-stabilised emulsion substrate during simulated infant gastric digestion at different pH level 3.5, 4.5 and 5.5. The digestate was treated with a fungal lipase and porcine pepsin (used to analogue human gastric lipase and pepsin) respectively and in a combined action. The study found that for fungal lipase treated digestate, the rate and extent of lipolysis were observed to be maxim at pH 5.5, in accordance with the optimal pH activity of the lipase. Findings also indicated that the proteinaceous interface did not appear to act as a barrier to lipolysis, since treatment with lipase and pepsin did not result in any significant increase in extent of lipolysis. However, it was observed that surface proteolysis did lead to alteration of the structural fate of the enzyme during digestion when compared to when the emulsion was digested solely by lipase. Findings suggest that lipolysis under these conditions may be independent of the structural dynamics of the emulsion during digestion, as observed within the context of this study design.

Understanding the Impact of Sheep Digestion on Seed Germination in the Cold Desert Annual Diptychocarpus strictus with Emphasis on Fruit and Seed Heteromorphism.

This study aimed to investigate the morphological characteristics of fruits and seeds from Diptychocarpus strictus, a plant species inhabiting the cold desert pastoral area of China. Furthermore, this study sought to evaluate the germination potential of these seeds following digestion by sheep. This study employed the sheep rumen fistula method to simulate rumen digestion at various time intervals. Subsequently, an in vitro simulation method was utilized to simulate true gastric and intestinal digestion after rumen digestion. Paper germination tests were then conducted to assess the impact of the digestive process on the heteromorphic seed morphology and germination. During rumen digestion, the seeds were protected by wide wings. The results revealed a highly significant negative correlation (p < 0.01) between seed wing length and digestion time. Post-rumen digestion, variations in the germination rate among seeds from fruits at different locations were observed. Indicators, such as germination rate, exhibited a highly significant negative correlation with rumen digestion time (p < 0.01). In vitro simulated digestion tests demonstrated that Diptychocarpus strictus seeds retained their ability to germinate even after complete digestion within the livestock's digestive tract. The polymorphic nature of Diptychocarpus strictus seeds, coupled with their capacity to survive and germinate through the digestive tract, facilitates the spread of these seeds. This finding has implications for mitigating desert grassland degradation and promoting sustainable ecological development.

Effect of soluble dietary fiber on soy protein isolate emulsion gel properties, stability and delivery of vitamin D3

Emulsion gels with denser network microstructure and stronger mechanical properties have attracted increasing attentions for delivering lipophilic compounds. In this study, the effect of three distinct soluble dietary fiber (inulin (IN), resistant dextrin (RD) and stachyose (ST)) on the rheological, mechanical and microstructural properties of soy protein isolate (SPI) emulsion gel were firstly investigated. Compared with RD and IN, ST significantly accelerated water holding capacity and thermal stability, which exhibited more compact microstructure and more uniform emulsified oil droplets. Subsequently, the stability and bioavailability of vitamin D3 (VD3) in different delivery systems (medium chain triglycerides (MCT) embedding, SPI-ST emulsion embedding, SPI emulsion gel embedding and SPI-ST emulsion gel embedding) were continue evaluated. In vitro simulated digestion experiment demonstrated that the bioaccessibility of encapsulated VD3 in SPI-ST emulsion gel (69.95 %) was much higher than that of free embedding (48.99 %). In vivo pharmacokinetic experiment revealed that the bioavailability of VD3 was significantly enhanced in SPI-ST gel (p < 0.05), with the AUC0-24h value of 25-OH VD3 (the main circulating form of VD3) were 1.34-fold, 1.23-fold higher than that of free embedding, MCT embedding, respectively. These findings provide a possible approach for the development of high protein/fiber functional foods containing enhanced hydrophobic bioactives.