Intestinal Digestion Research Articles

Nutritional, Textural, and Sensory Attributes of Protein Bars Formulated with Mycoproteins.

Research accumulated over the past decades has shown that mycoprotein could serve as a healthy and safe alternative protein source, offering a viable substitute for animal- and plant-derived proteins. This study evaluated the impact of substituting whey protein with fungal-derived mycoprotein at different levels (10%, 20%, and 30%) on the quality of high-protein nutrition bars (HPNBs). It focused on nutritional content, textural changes over storage, and sensory properties. Initially, all bars displayed similar hardness, but storage time significantly affected textural properties. In the early storage period (0-5 days), hardness increased at a modest rate of 0.206 N/day to 0.403 N/day. This rate dramatically escalated from 1.13 N/day to 1.36 N/day after 5 days, indicating a substantial textural deterioration over time. Bars with lower mycoprotein levels (10%) exhibited slower hardening rates compared with those with higher substitution levels (20% and 30%), pointing to a correlation between mycoprotein content and increased bar hardness during storage. Protein digestibility was assessed through in vitro gastric and intestinal phases. Bars with no or low-to-medium levels of mycoprotein substitution (PB00, PB10, and PB20) showed significantly higher digestibility (40.3~43.8%) compared with those with the highest mycoprotein content (PB30, 32.9%). However, digestibility rates for all mycoprotein-enriched bars were lower than those observed for whey-protein-only bars (PB00, 84.5%), especially by the end of the intestinal digestion phase. The introduction of mycoprotein enriched the bars' dietary fiber content and improved their odor, attributing a fresh mushroom-like smell. These findings suggest that modest levels of mycoprotein can enhance nutritional value and maintain sensory quality, although higher substitution levels adversely affect texture and protein digestibility. This study underscores the potential of mycoprotein as a functional ingredient in HPNBs, balancing nutritional enhancement with sensory acceptability, while also highlighting the challenges of textural deterioration and reduced protein digestibility at higher substitution levels.

Intestinal digestion in poultry compared to other animal species with a diverse diet.

Intestinal digestion in poultry compared to other animal species with a diverse diet.

Features of digestion in the middle intestine of the honey bee

The midgut of the honey bee is considered the only midgut. Processes related to digestion take place in this department. At the same time, the middle intestine takes part in the processes that indicate the immune status. The purpose of the research was to study the effect of protein feed on the morphometric parameters of the epithelium of the midgut of honeybees and the peretrophic membrane. Two groups of families participated in the study. The first group received bee pollen collected from winter rape with a protein content of 25 % as protein feed. The second group consumed dandelion meal with a protein content of 15 %. After reaching the required age, the insects were taken from the nest, and the midgut was dissected. The conducted studies indicate that the length of the enterocytes of the midgut of a honey bee at the age of 10 days ranges from 18.89 to 34.11 μm. Morphometric differences of midgut enterocytes in the experimental groups did not reveal any significant difference. It has been proven that the thickness of the pertrophic membrane in hive bees is greater than that of flying bees by 22.7 % (P < 0.001). This value depends on the area where it is placed. In particular, in the caudal part, the thickness of the pertrophic membrane is more significant on average by 25.0 % compared to the cranial part (P < 0.01). The decrease in the thickness of the midgut of flying bees is related to the nature of nutrition. Older bees consume less pollen and eat more carbohydrate feed. Along with this, it has been proven that the thickness of the pertrophic membrane depends on the composition of the diet. In hive bees that consumed protein-enriched feed, the thickness of the pertrophic membrane in the caudal part of the midgut is 22.1 % greater (P < 0.001).

Effect of dietary l-glutamine supplementation on the intestinal physiology and growth during Solea senegalensis larval development

The maturation of the intestinal digestive and absorptive functions might limit the amount of absorbed nutrients to fulfil the high requirements of the fast-growing marine fish larva. Glutamine (Gln) has been described to improve intestinal epithelium functions, due to its involvement in energy metabolism and protein synthesis. The purpose of this study was to evaluate dietary 0.2% Gln supplementation on aspects of intestinal physiology, protein metabolism and growth-related genes expression in Senegalese sole larvae. Experiment was carried out between 12 and 33 days post hatching (DPH) and fish were divided into two experimental groups, one fed Artemia spp. (CTRL) and the other fed Artemia spp. supplemented with Gln (GLN). GLN diet had two times more Gln than the CTRL diet. Samples were collected at 15, 19, 26 and 33 DPH for biometry, histology, and digestive enzymes activity, and at 33 DPH for gene expression, protein metabolism and AA content determination. Growth was significantly higher for Senegalese sole fed GLN diet, supported by differences on protein metabolism and growth-related gene expression. Slight differences were observed between treatments regarding the intestinal physiology. Overall, GLN diet seems to be directed to enhance protein metabolism leading to higher larval growth.

The intestinal digesta microbiota of tropical marine fish is largely uncultured and distinct from surrounding water microbiota

Studying the gut microbes of marine fishes is an important part of conservation as many fish species are increasingly threatened by extinction. The gut microbiota of only a small fraction of the more than 32,000 known fish species has been investigated. In this study we analysed the intestinal digesta microbiota composition of more than 50 different wild fish species from tropical waters. Our results show that the fish harbour intestinal digesta microbiota that are distinct from that of the surrounding water and that location, domestication status, and host intrinsic factors are strongly associated with the microbiota composition. Furthermore, we show that the vast majority (~97%) of the fish-associated microorganisms do not have any cultured representative. Considering the impact of the microbiota on host health and physiology, these findings underpin the call to also preserve the microbiota of host species, especially those that may be exposed to habitat destruction.

Comparison of forages’ digestion levels for different in vitro digestion techniques in horses

Forages are widely used in horse diets. Different in vitro techniques are being tried to determine the fermentation levels of forages in the horse digestive tract. This study aimed to evaluate the digestion levels of four dry forages commonly used in horse nutrition: alfalfa herbage, meadow hay, wheat straw, and Italian ryegrass. In vitro total digestion (TDT), in vitro Sunvold-large intestine digestion (SDT) and in vitro Menke-large intestine digestion (MDT) techniques were compared. The study determined in vitro true dry matter digestion (T-DMD), in vitro true organic matter digestion (T-OMD) and in vitro true neutral detergent fibre digestion (T-NDFD). Additionally, concentrations of straight short-chain fatty acids (SCFAs; acetic acid - AA, propionic acid , butyric acid, and valeric acid ) and branched short-chain fatty acids (BSCFA) were assessed. The highest in vitro T-DMD, T-OMD and T-NDFD values were determined by the in vitro TDT for the four forages (p<0.05). In vitro T-DMD and T-OMD values of alfalfa herbage were higher than those of Italian ryegrass, meadow hay and wheat straw in the in vitro TDT (p<0.001). In addition, in vitro T-DMD and T-OMD values of alfalfa herbage in the in vitro SDT were higher than those of meadow hay and wheat straw (p<0.001). In the in vitro TDT, the molarity of AA, total SCFA and BSCFA in the digestion fluid of alfalfa herbage was higher than those of other forages (p<0.05). The in vitro total enzymatic+fermentative digestion technique for horse forages revealed higher values than the in vitro fermentative digestion techniques. In general, the higher the non-structural carbohydrate and crude protein contents in the forage, the higher the results of the in vitro TDT compared to the other techniques.

Unveiling the significance of gastric digestion in gastrointestinal fate of octenylsuccinylated starch-stabilized emulsions

The importance of gastric digestion in starch-based emulsion is often overshadowed compared to intestinal digestion, despite acknowledging the activity of salivary α-amylase in the stomach. This study aimed to address this gap by investigating the digestion of starch-based emulsions through orogastrointestinal digestion experiments. Our observations revealed the crucial role of salivary α-amylase, which hydrolyzed ∼8 %, ∼56 %, and ∼ 28 % of starch in emulsions stabilized by octenylsuccinylated maize starch (OMS-E), gelatinized OMS (GOMS-E), and retrograded OMS (ROMS-E), respectively, during the gastric phase. Consequently, ∼23 % of the oil in GOMS-E underwent lipolysis during this phase, whereas ∼13 and ∼ 6 % of the oil was lipolyzed in OMS-E and ROMS-E, respectively. These phenomena significantly influenced their small intestinal digestion and the bioaccessibility of encapsulated curcumin. Notably, GOMS-E exhibited ∼28 % lower curcumin bioaccessibility than that of curcumin encapsulated in OMS-E or ROMS-E. This difference was attributed to premature gastric digestion and subsequent encapsulant release in the case of GOMS-E. This understanding can be utilized to manipulate the delivery and digestion of starch-based emulsions. Importantly, our findings highlight the necessity of considering gastric amylolysis and lipolysis when investigating the gastrointestinal fate of starch-based emulsions.

Probiotic Yogurt Supplemented with Lactococcus lactis R7 and Red Guava Extract: Bioaccessibility of Phenolic Compounds and Influence in Antioxidant Activity and Action of Alpha-amylase and Alpha-glucosidase Enzymes.

The industry has increasingly explored the development of foods with functional properties, where supplementation with probiotics and bioactive compounds has gained prominence. In this context, the study aimed to evaluate the influence of in vitro biological digestion on the content of phenolic compounds, antioxidant activity, and inhibition of α-amylase and α-glucosidase activities of probiotic yogurt supplemented with the lactic acid bacteria Lactococcus lactis R7 and red guava extract (Psidium cattleianum). A yogurt containing L. lactis R7 (0.1%) and red guava extract (4%) was characterized for the content of phenolic compounds, antioxidant activity, and potential for inhibition of digestive enzymes after a simulated in vitro digestion process. After digestion, the caffeic and hydroxybenzoic acids remained, and sinapic acid only in the last digestive phase. Antioxidant activity decreased during digestion by 28.93, 53.60, and 27.97% for DPPH, nitric oxide and hydroxyl radicals, respectively, and the inhibition of the α-amylase enzyme decreased only 4.01% after the digestion process. α-glucosidase was more efficient in intestinal digestion, demonstrating an increase of almost 50% in probiotic yogurt with red guava extract before digestion. Possibly, the phenolics change their conformation during digestion, generating new compounds, reducing antioxidant activity, and increasing the inhibitory activity of α-glucosidase digestive enzymes. It was concluded that the probiotic yogurt formulation supplemented with red guava extract could interfere with the concentration of phenolic compounds and the formation of new compounds, suggesting a positive and effective inhibition of the digestive enzymes, even after the digestive process.

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.

Allium sativum L. var. Voghiera Reduces Aflatoxin B1 Bioaccessibility and Cytotoxicity In Vitro

The present work focuses on the evaluation of AFB1′s bioaccessibility and cytotoxicity in vitro using bread (naturally contaminated) enriched or not enriched with fresh Voghiera garlic (2%). Two different experiments were carried out: experiment 1 (E1), with low-AFB1-concentration breads (1.6–1.7 mg/kg); and experiment 2 (E2), with high-AFB1-concentration breads (96.4–102.7 mg/kg). Eight breads were prepared, four for E1 (experiment 1) and another four for E2 (experiment 2), with each experiment having a control group (C), a garlic-enriched group (2%) (G), an AFB1 group (A), and an AFB1 + garlic group (A + G). Simulated digestion was performed on each type of bread, and gastric and intestinal digests were obtained. AFB1 content in flours, baked bread, and gastric and intestinal digests was measured by High-Performance Liquid Chromatography coupled to Fluorescence Detection. The results demonstrate dose-dependent AFB1 bioaccessibility and that the presence of garlic contributed to its reduction in both doses (7–8%). Moreover, garlic’s presence in AFB1-contaminated bread increased cell viability (9–18%) in differentiated Caco-2 cells and mitigated the arrest of S and G2/M phases provoked by AFB1 on Jurkat T cells and reduced apoptosis/necrosis, cellular reactive oxygen species (ROS), and mitochondrial ROS by 16%, 71%, and 24% respectively. The inclusion of garlic as a functional ingredient helped relieve the presence and effects of AFB1.

Effect of in vitro Digestion on the Bioaccessibility of Polyphenols and Potential Prebiotic Properties of Potato Peel.

Potato peel is a byproduct of the potato processing industry and a potential source of functional ingredients such as dietary fiber, polyphenols, and prebiotics. However, the bioaccessibility of polyphenols and antioxidants during in vitro digestion and prebiotic potential after in vitro digestion of potato peel flour has not been reported. The study was designed to assess the bioaccessibility of polyphenols and the prebiotic potential of potato peel flour. In this study, the changes in polyphenol content and antioxidant capacity during different phases of in vitro digestion, including salivary, gastric and intestinal phases were studied. Additionally, an investigation was conducted to evaluate the prebiotic properties of potato peel flour by in vitro fermentation with Lactobacillus acidophilus. The findings revealed a significant increase in the recovery index for total phenolic content during both gastric (106.90%) and intestinal (102.71%) digestive phases. Furthermore, polyphenols in potato peel flour exhibited high residual intestinal digestibility index values (>90%). The antioxidant capacity increased by >50% during various phases of in vitro digestion. Regarding prebiotic properties, potato peel flour significantly increased L. acidophilus counts and promoted the production of short-chain fatty acids, specifically propionate and butyrate. This study suggests that potato peel flour has the potential to serve as a functional ingredient or nutraceutical that can enhance health and may help in reducing environmental problems.

Effect of Steam Pressure Toasting Duration on Snowbird Faba Bean Seeds and the Impact on the Intestinal and Metabolic Characteristics in Dairy Cows

The response of feedstuffs to thermal processing depends on the type of feed and the thermal processing methods being applied. Steam pressure toasting (SPT) has been used to modify the nutrient degradability and enhance the nutritional quality of pulses, including faba bean seeds (FBS). Strategic feeding approaches are essential for balancing diets and maintaining adequate nutrition, especially in high-performing ruminants. This research aimed to determine the effects of SPT duration in FBS on the intestinal and metabolic characteristics of dairy cows. Faba Bean seeds (three harvesting years) were processed at 121 °C for 0, 30, 60, 90, and 120 min. Rumen degradation and intestinal digestion were determined using the in situ and modified in vitro three-step techniques. The true protein supplied to the small intestine was also determined using the NRC and DVE systems. Our results showed a reduced total digested DM (TDDM) with longer SPT duration (quadratic, p = 0.02). The intestinally digested crude protein (IADP) increased from 62 to 220 g/kg DM with 0 to 120 min of SPT, respectively (p &lt; 0.01), whereas the total tract digestible starch (TDSt) gradually decreased from 321 to 182 g/kg DM based on SPT time (p &lt; 0.01). On the other hand, the truly digested protein in the small intestine (DVE) and the total metabolizable protein (MP) increased from 138 to 282 g/kg DM and 129 to 282 g/kg DM, respectively, with 0 to 120 min of SPT (quadratic, p &lt; 0.01). The Feed Milk Value (FMV), based on both the DVE/OEB and NRC dairy nutrition systems, also increased with SPT (Quadratic, p &lt; 0.01). The processing of FBS with SPT at 121 °C effectively reduced the highly degradable protein fraction in the rumen, shifting to a higher rumen undegraded protein (RUP) which was able to reach the small intestine. In the current study, the total MP, DVE, and FMV in dairy cows showed an overall increase with SPT in FBS.

Influence of pasteurization and spray drying on the fat digestion behavior of human milk fat analog emulsion: a simulated in vitro infant digestion study.

Human milk fat analog emulsion (HMFAE) is an emulsion that mimics the composition and structure of human milk (HM) fat globules. The application of HMFAE in infant formula requires a series of milk powder processing steps, such as pasteurization and spray drying. However, the effect of milk powder processing on fat digestion of HMFAE is still unclear. In this study, the influence of pasteurization and spray drying on the lipolysis behavior of HMFAE was studied and compared with HM using a simulated infant in vitro digestion model. Pasteurization and spray drying increased the flocculation and aggregation of lipid droplets in HMFAE during digestion. Spray drying destroyed the lipid droplet structure of HMFAE, and partial milk fat globule membrane-covered lipid droplets turned into protein-covered lipid droplets, which aggravated lipid-protein aggregation during gastric digestion and hindered fat digestion in the small intestine. The final lipolysis degree was in the order HM (64.55%) > HMFAE (63.41%) > pasteurized HMFAE (61.75%) > spray-dried HMFAE (60.57%). After complete gastrointestinal digestion, there were no significant differences in free fatty acid and sn-2 monoacylglycerol profile among the HMFAE, pasteurized HMFAE, and spray-dried HMFAE. Milk powder processing can reduce lipolysis by altering the lipid droplet structure of HMFAE and the degree of lipid droplet aggregation during digestion. © 2024 Society of Chemical Industry.

Encapsulation of tuna oil by liquid and solid self‐emulsifying delivery system: in vitro digestion and oxidative stability assessment

SummaryTuna oil, one of the main sources of omega‐3 polyunsaturated fatty acids (omega‐3 or n‐3 PUFAs), is known to have limited bioavailability due to its hydrophobicity. Moreover, the main n‐3 PUFAs found in tuna oil, that is docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are prone to oxidation. To overcome these drawbacks, tuna oil encapsulation via liquid (LSEDS) and solid self‐emulsifying delivery system (SSEDS) was developed. Different LSEDS formulations were prepared and evaluated in terms of tuna oil droplet size and dispersibility. Accordingly, the formulation with small droplets size and narrow size distribution was selected and further developed into SSEDS by spray drying process. SSEDS was thereafter characterised concerning production yield, moisture content, size, size distribution and morphology. Furthermore, the in vitro simulated gastrointestinal model of LSEDS and SSEDS was carried out. The results showed that after intestinal digestion stage, 87% and 72% of DHA were released from LSEDS and SSEDS, respectively. Therefore, these formulations of LSEDS and SSEDS were proven their ability to enhance the bioaccessibility of DHA. Moreover, the oxidative stability of LSEDS and SSEDS formulation was investigated and compared to pure tuna oil using non‐isothermal differential scanning calorimetry (DSC) analysis under oxygen. The results showed that both LSEDS and SSEDS formulations exhibited a high oxidative resistance with a higher energy needed to induce tuna oil oxidation than pure tuna oil. The chemical and thermal stability given by LSEDS and SSEDS may be efficiently applied in food area to enhance the techno‐functional properties of hydrophobic compounds.

Chitosan surface-modified bovine serum albumin-oleic acid self-assembled complexes: Improving the thermal stability, controlled release and bioaccessibility of fucoxanthin

Fucoxanthin (FUCO) is a marine xanthophyll carotenoid with widespread potential physiological functions. However, poor water solubility and chemical instability limit FUCO's processing adaptability and bioavailability. In this study, chitosan surface-modified bovine serum albumin (BSA)-oleic acid (OA) self-assembled complexes were fabricated to improve the thermal stability as well as the controlled release and bioaccessibility of FUCO during gastrointestinal digestion. The results showed that glucose-grafted chitosan (GGC) could surface modify BSA-OA complexes by non-covalent affinity adhesion, resulting in a stable hydrophilic dispersion system with a polydispersity index <0.25 and a Zeta potential > −20 mV. Fourier transform infrared spectroscopy and transmission electron microscope observations revealed that GGC covered the surface of BSA-OA particles through hydrogen bonding, hydrophobic and electrostatic interactions. The GGC-BSA-OA delivery system captured FUCO with >88.00% encapsulation efficiency. Additionally, embedding FUCO in the GGC-modified BSA-OA complex improved its thermal stability. In vitro, gastrointestinal digestion simulations showed that the GGC-modified protein shell had a controlled-release effect on FUCO, which prevented acidic pH from destroying FUCO due to premature release during gastric digestion and released it during intestinal digestion. As expected, GGC-BSA-OA, an encapsulated carrier, dramatically improved the FUCO's digestive stability (retention rate >74.00%), bioaccessibility (>54.42%), and micellization rate (>70.00%) in simulated gastrointestinal digestion. These findings suggested that GGC-BSA-OA as a delivery vehicle could effectively improve FUCO's thermal processing stability and absorbability.

Host-associated Bacillus velezensis T20 improved disease resistance and intestinal health of juvenile turbot (Scophthalmus maximus)

The development of host-derived probiotics offers an alternative nutritional strategy for aquaculture. Turbot (Scophthalmus maximus L.) is an important cultured fish in the world. However, research on its host-associated probiotics is limited. The present study evaluates the probiotic potential of Bacillus velezensis T20 (T20) isolated from the intestine of turbot. In the experiment, turbots were fed with two diets: the control diet (CON) and CON supplemented with 1 × 108 CFU/g T20 for 8 weeks. Results showed that the addition of T20 did not affect the growth performance of turbot, but significantly decreased the mortality of turbot challenged by Edwardsiella tarda. Moreover, T20 could survive in the intestine of turbot, it might contribute to the improved intestinal antioxidant capacity, physical barrier and digestive enzymes activities of turbot. In terms of intestinal microbiota, T20 modulated intestinal microbiota communities. Specifically, T20 increased the relative abundances of Bacillus and B. velezensis in both intestinal mucosa and digesta, and decreased potential pathogen such as Mycoplasma, Staphylococcus and Weissella in intestinal digesta. In conclusion, the present study showed that dietary B. velezensis T20 could enhance the disease resistance, improve the communities of intestinal microbiota and promote the intestinal health of turbot.

Matrix characteristics modulate black rice phenolic compounds bioaccessibility and antioxidant activity during simulated gastrointestinal digestion

Black rice (Oryza sativaL.) is a valuable source of bioactive phenolic compounds. This study aimed to explore the impact of the rice matrix on the recovery and bioaccessibility of total phenolic content (TPC), total anthocyanin content (TAC), phenolic composition, and total antioxidant activity (TAA) quantified as 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, 2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, and ferric reducing activity power (FRAP) during simulated gastrointestinal digestion, in addition to physicochemical characterization of the samples. Freshly cooked black rice (CBR) and black rice phenolic extract (BRE) were subjected to three-phase simulated gastrointestinal digestion. The results showed that the CBR showed a lower recovery index for TPC, TAC, and TAA than that of the BRE during oral and gastric digestion. However, intestinal digestion of CBR increased the TPC and TAC recovery indices compared with the BRE matrix. Digestion of the CBR matrix resulted in a marked improvement (p < 0.05) in the bioaccessibility of monomeric anthocyanins and FRAP activity while maintaining comparable levels (p > 0.05) of TPC, ABTS, and gallic acid to the BRE matrix. Cyanidin-3-glucoside decomposition was evident during the intestinal digestion of both samples, followed by a notable surge in gallic acid and protocatechuic acid. Isolated starch (BRS) demonstrated superior starch digestibility during oral and intestinal digestion compared with CBR. The samples displayed distinct matrix characteristics, which were confirmed by the DSC, FTIR, and XRD patterns. These findings highlight the significance of the digestion matrix in determining the bioavailability and antioxidant capacity of rice-derived phenolic compounds.

Characterization of ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from feedstocks and coproducts from Canola bio-oil processing: Impact by source origin.

The objective of this study was to characterize ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from canola feedstock (canola seeds) and coproducts (meal and pellets) from bio-oil processing which were impacted by source origin. The feedstocks and coproducts (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). In situ rumen degradation kinetics were determined using four fistulated Holstein cows with incubation times at 0, 2, 4, 8, 12, 24 and 48 h. Intestinal digestions were determined using the three-step in vitro method with preincubation at 12 h. The DVE/OEB and National Research Council systems were applied to evaluate the truly absorbable nutrient supply to dairy cows and feed milk values (FMVs). The results showed that in situ undegradable fractions (U) (p = 0.025) were higher in CA meals, and potentially degradable fraction of D was higher (p = 0.016) in CH meals. CH meals had higher total digestible dry matter (TDDM, p = 0.018) and intestinal digestibility of protein (dIDP, p = 0.016). Canola meals from CA had lower MREE (microbial protein synthesized in the rumen based on available rumen degradable protein; p = 0.011) and DVME (rumen synthesized microbial protein digested in the small intestine; p = 0.011) and had higher ECP (endogenous protein in the small intestine, p = 0.001) and absorbed endogenous crude protein (truly absorbed ECP in the small intestine) than CH (p = 0.001). The FMV evaluated based on the metabolic protein and net energy showed no differences between CA and CH in both coproducts and feedstocks.

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

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. 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. 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.

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

BackgroundBifidobacterium 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. ObjectivesThe study aimed to evaluate the effects of different honey varietals and concentrations on B. animalis survivability in yogurt through in vitro digestion. MethodsYogurt 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. ResultsSimilar 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). ConclusionsYogurt 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.