Lower Digestibility Research Articles

Genotype and grain pretreatment effects on digestibility of sorghum proteins in the Ethiopian fermented bread

AbstractBackground and ObjectivesSorghum is the principal food source for smallholder farmers in Sub‐Saharan Africa. Animal proteins are beyond economic reach, and only few food legumes are well‐adapted in major sorghum‐growing regions. Hence, sorghum serves as the primary source of protein and calories. However, the low digestibility of its proteins renders the communities vulnerable to protein malnutrition. Several factors, including genotypes and processing methods, have been shown to affect the digestibility of proteins in sorghum food products. The objective of this study was to investigate the impact of grain pretreatment on the protein digestibility of Ethiopian fermented flatbread.FindingsThe effect of four grain pretreatment processes: decortication, sprouting, parching, and untreated control was compared using four diverse sorghum genotypes milled to medium (2 mm) and fine (0.5 mm) particle sizes. The in‐vitro protein digestibility (IVPD) was significantly lower in the parched samples compared to the unprocessed control, while sprouting significantly increased IVPD. Decortication appears to have no impact on IVPD. Finer particle size tended to enhance IVPD in all genotypes and for all pretreatement methods. The treatments had no significant effect on protein content except the sprouting consistently but marginally increased total protein.ConclusionsSprouting sorghum grains can significantly improve the protein digestibility of fermented breads. Given that it involves little cost, the process can be readily adopted by the local community, provided that they are educated about the impact of protein deficiency on the health and productivity of the community.Significance and NoveltyLow‐cost grain pretreatment procedures such as sprouting can have a significant impact on the availability of nutrients, especially protein, the most limiting nutrient in smallholder communities. Combining the procedure with genetically enhanced varieties and improved cropping systems that integrate food legumes can significantly enhnace protein nutrition for smallholder farmers.

Research Note: Proteases effect on soybean meal: enzyme product and area of production differences on standardized ileal amino acids digestibility of broiler chickens

This study evaluated the effects of two protease products added to feeds having two soybean meal (SBM) sources (South and North of Brazil). A total of five hundred and sixty, 21 d male broiler chickens were allocated into 7 dietary treatments: a nitrogen-free diet (NFD) and other six diets prepared with a 40% replacement of the NFD with each SBM source. Two commercial protease products (RONOZYME® ProAct and ProAct 360TM) were added at 15,000 PROT and 30,000 NFP per kg feed, respectively. After 5-day diet adaptation, all birds were euthanized for ileal digesta collection. Results show that the North SBM sample was inherently higher (P < 0.05) in apparent ileal digestibility (AID) of dry matter (DM), nitrogen (N), and the standardized ileal amino acid digestibility (SIAAD) compared to South SBM sample. The DM digestibility and SIAAD of North SBM sample were not different from the un-treated control and protease treatments (P > 0.05, except Val and Ile, which had higher digestibility with ProAct 360). The DM digestibility and SIAAD from South SBM sample were increased (P < 0.05, except Met, Asp and Cys) with both supplemental proteases. Correlation analysis showed that AA digestibility of the two SBM samples were negatively associated with the effect of protease products. These data demonstrated that the SIAAD of SBM was influenced by SBM source with the South SBM sample being lower than that from the North while the protease effects were more evident in the SBM sample from South; responses of ProAct 360 were superior to ProAct. Exogenous proteases can enhance nutritional value of SBM, particularly for those with inherently low amino acid digestibility.

Fiber composition, in vitro true digestibility, and fiber degradation of hempseed meal compared to mainstream feedstuffs using equine feces as microbial inoculum within the DaisyII Incubator.

Recent changes in legislation have put hempseed meal (Cannabis sativa L.; HSM) under consideration as a potential livestock feedstuff. Digestibility of HSM has been researched in other species, however, there are little data in horses. The study objective was to determine the in vitro true digestibility (IVTD) of HSM compared to common equine feedstuffs. An in vitro split-split plot design used four geldings (8.5 ± 3.9yr; 558.4 ± 31.0kg; 6.0 ± 0.4 BCS) to investigate the IVTD of HSM compared to alfalfa hay (ALF), Coastal Bermudagrass hay (CBH), soybean meal (SBM), rice bran pellets (RBP), and a commercial concentrate (Bluebonnet Equilene Pellets; EQU). Fresh feces were collected after a 21-d acclimation period and used as incubation inoculum. Dried ground feed samples were incubated in ANKOM filter bags within 2 DaisyII incubators for 48h. Split samples were analyzed for pre-fermentation neutral detergent fiber (NDF). Incubated filter bags were dried and analyzed for NDF to determine IVTD and fiber degradation. Hempseed meal NDF was greater than ALF (P<0.001), RBP (P<0.001), and SBM (P<0.001) but less than CBH (P<0.001) and tended to be greater than EQU (P=0.077). The IVTD of HSM was greater than CBH (P<0.001) but less than all other feedstuffs (P<0.001). The results indicate that HSM has an NDF and IVTD between ALF and CBH. Due to its lower digestibility and NDF content compared to concentrates, HSM has potential to be used as a fiber source in equine rations.

Study on the effects of endogenous polyphenols on the structure, physicochemical properties and in vitro digestive characteristics of Euryales Semen starch based on multi-spectroscopies, enzyme kinetics, molecular docking and molecular dynamics simulation

Euryales Semen (ES) is a highly nutritious food with low digestibility, which is closely associated with its endogenous phenolic compounds. In this study, five phenolic compounds (naringenin, isoquercitrin, gallic acid, epicatechin and quercetin) with high concentrations in ES were selected to prepare starch-polyphenol complexes. Subsequently, the effects of endogenous polyphenols on the structure, physicochemical properties and digestion characteristics of ES starch were studied using multiple techniques. The addition of phenolic compounds markedly reduced the in vitro digestibility, swelling power, gelatinization enthalpy, while increased the solubility of ES starch. Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that phenolic compounds interacted with the starch through non-covalent bonds. Five phenolic compounds inhibited α-amylase activity through a mixed competitive inhibition mechanism, with the inhibition potency ranked as follows: quercetin > epicatechin > gallic acid > isoquercitrin > naringenin. The spectroscopic analysis and molecular dynamics simulations confirmed that five phenolic compounds interacted with the amino acid residues of α-amylase through hydrogen bonding and hydrophobic interactions, caused α-amylase static fluorescence quenching, and altered its conformation and microenvironment. This study provides a better understanding of the interaction mechanisms between ES starch and polyphenols, and supports the development of ES as a food that lowers sugar levels.

Efficient Biosynthesis of Theanderose, a Potent Prebiotic, Using Amylosucrase from Deinococcus deserti.

The study aimed to develop an efficient bioprocess for the discovery and synthesis of theanderose by using amylosucrase from Deinococcus deserti (DdAS). An unknown trisaccharide produced by DdAS was detected by high-performance anion-exchange chromatography-pulsed amperometric detection and high-performance liquid chromatography-evaporative light scattering detection, purified using medium-pressure liquid chromatography, and identified as theanderose (α-d-glucopyranosyl-(1→6)-α-d-glucopyranosyl-(1→2)-β-d-fructofuranoside) through nuclear magnetic resonance and mass spectrometry. DdAS synthesized theanderose with a 25.4% yield (174.1 g/L) using 2.0 M sucrose at 40 °C for 96 h. In an in vitro digestion model, theanderose showed a 6.5% hydrolysis rate over 16 h. Prebiotic efficacy tests confirmed that theanderose significantly enhanced the proliferation of selected Bifidobacterium strains in the culturing medium with theanderose as the main carbon source. Subsequently, fecal fermentation was performed by adding theanderose to the feces of 20 individuals of varying ages to assess its effect on the gut microbiota. Theanderose increased the relative abundance of Bifidobacteriaceae and Prevotellaceae while decreasing the population ratio of Lachnospiraceae and Ruminococcaceae. Conclusively, theanderose displayed excellent prebiotic potential when judged by low digestibility and selective growth of beneficial microbes over harmful microbes.

Gastrointestinal fate of proteins from commercial plant-based meat analogs: Silent passage through the stomach, oxidative stress in intestine, and gut dysbiosis in Wistar rats.

Plant-based meat analogs (PBMAs) are common ultra-processed foods (UPFs) included in the vegan/vegetarian diets as presumed healthy alternatives to meat and meat products. However, such health claims need to be supported by scientific evidence. To gain further insight into this topic, two commercial UPFs typically sold as meat analogs, namely, seitan (S) and tofu (T), were included in a cereal-based chow and provided to Wistar rats for 10weeks. A group of animals had, simultaneously, an isocaloric and isoprotein experimental diet formulated with cooked beef (B). In all cases, experimental chows (∼4kcal/g feed) had their basal protein concentration increased from 14% to 30% using proteins from S, T, or B. Upon slaughter, in vivo protein digestibility was assessed, and the entire gastrointestinal tract (digests and tissues) was analyzed for markers of oxidative stress and untargeted metabolomics. Metagenomics was also applied to assess the variation of microbiota composition as affected by dietary protein. Diets based on PBMAs showed lower protein digestibility than those containing meat and promoted an intense luminal glycoxidative stress and an inflammatory intestinal response. The fermentation of undigested oxidized proteins from T in the colon of Wistar rats likely led to formation of mutagenic metabolites such as p-cresol. The presence of these compounds in the animal models raises concerns about the potential effects of full replacement of meat by certain PBMAs in the diet. Therefore, future research might target on translational human studies to shed light on these findings.

Novel Porous Starch Granules Fabricated Using Controlled Lipase-Amylase Treatments: Application as Delivery Systems and Resistant Starches.

Porous starch granules (PSGs) are promising biomaterials for the encapsulation, protection, and delivery of bioactive ingredients. In this study, a lipase treatment was first used to generate pores in native starch granules, and then α-amylase was used to enlarge these pores. Electron and fluorescence microscopy analysis showed that the lipase treatment exposed the starch molecules located below the lipid-rich regions on the starch granule surfaces, which increased the swelling of the granules in aqueous solutions. Moreover, lipase treatment caused the surrounding areas to become more loosely packed, which facilitated subsequent starch hydrolysis and the formation of large internal cavities. Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analyses provided further insights, these methods showed that the short-range order, long-range order, and thermal stability of the PSGs was enhanced by the sequential lipase-amylase modification. PSGs were highly resistant to amylase digestion and had strong adsorption capacity to hydrophobic and hydrophilic substances. This study shows that a combined lipase-amylase treatment can be used to fabricate PSGs, which may have health benefits due to their low digestibility and ability to encapsulate bioactive agents. These PSGs may therefore be suitable for application in the functional food, supplement, personal care, and pharmaceutical industries.

Lactiplantibacillus plantarum encapsulated by chitosan-alginate and soy protein isolate-reducing sugars conjugate for enhanced viability

To investigate the protective effects of various wall materials on probiotics, two types of Lactiplantibacillus plantarum 90 (Lp90) microcapsules were prepared using sodium alginate and chitosan (Lp-AC), soy protein isolate (SPI) and reducing sugars conjugate (Lp -MRP) as wall materials, respectively. The physical properties, cell viability under different conditions and the application of the microcapsules were investigated. Results showed that the selected wall materials were safe to Lp90 and their simulated digestion products exhibited antioxidant activities and prebiotic properties. The encapsulation efficiencies of Lp-AC and Lp-MRP were above 80 %. Both microcapsules significantly enhanced cell survival rates under various conditions including low pH, bile salts, thermal processing, mechanical force, storage, and gastrointestinal digestion, with Lp-MRP demonstrating superior protective effects. When incorporated into milk and orange juice and stored at 4 °C for 28 d, the colony counts of beverages containing Lp90 microcapsules exceeded 6 Log CFU/mL, with minimal changes in total soluble solids. Lp-MRP exhibited higher cell viability and smaller viscosity changes at 25 °C for 28 d. Therefore, the single-layer encapsulation using SPI and reducing sugars conjugate showed promise over traditional chitosan-alginate double-layer encapsulation concerning probiotic protection, targeted delivery, and application.

Lentil protein and trehalose conjugates: Structural interactions and mechanisms for improving multi-level structure and functional characteristics.

This study aimed to improve lentil proteins' (LPs) functionality and nutritional value, specifically addressing their lower water solubility and digestibility. A unique combination of LP-disaccharide interactions was employed. Spectroscopic technologies, which include fluorescence spectra, ultraviolet spectra, and Fourier-transform infrared, investigated the structure of LPs at various concentrations of trehalose. The results indicate that the LP structures and conformation were considerably modified (p<0.05) following trehalose conjugation. The surface charge and hydrophobicity of the trehalose-conjugated LPs (T-LPs) were significantly altered (p<0.05), from -22.7 to -31.4 and 753 and 543 a.u., respectively. Furthermore, the digestibility and solubility of T-LPs increased from 75% to 81.8% and 60% to 66%, respectively. In conclusion, this study showed that combining LPs and trehalose conjugation could improve the quality of conjugates LPs, which could expand their use in manufacturing as the acceptance of plant-based diets increases. PRACTICAL APPLICATION: Currently, lentil proteins (LPs) are used in plant-based protein powders and supplements. Though less popular than soy or pea proteins, LPs are valued for their high protein content and good amino acid profile. LPs are utilized in meat alternatives and high-protein snack products. The application of these products is mainly due to their nutritional benefits rather than functional properties due to their poor water solubility. Increasing the water solubility of LPs could significantly expand their application in various food industries, making LPs a more competitive and functional plant-based protein source. Trehalose-conjugated LPs with better water solubility allow LPs to be used in other food products, such as plant-based protein beverages. Better solubility would enhance the clarity and smoothness of these products, making them more appealing to consumers.

Anti-Obesity Effects of a Collagen with Low Digestibility and High Swelling Capacity: A Human Randomized Control Trial

Background/Objectives: Collagen is a protein formed by very long amino acid chains. When conveniently treated, it can incorporate water into the net, thus increasing its volume and mass. The present work aimed to evaluate the potential anti-obesity effects of bovine collagen that has been technologically treated to increase its water retention capacity in an acid pH medium, with the objective of inducing satiation. Methods: Collagen’s digestibility was tested with a pepsin digestion test. Its swelling capacity was tested in an acid pH medium simulating gastric conditions. Postprandial levels of ghrelin in response to collagen supplementation were tested in rats. In a randomized control trial, 64 subjects with overweight/obesity were allocated in two groups: supplemented daily with two protein bars enriched with collagen (20 g per day) for 12 weeks, or control group. Anthropometric and biochemical measurements were assessed in all the participants. Results: This collagen showed a low digestibility (&lt;60%) and high swelling capacity (&gt;1900%) in vitro. In humans with overweight and obesity, this collagen significantly reduced body weight, body mass index (BMI), systolic blood pressure (SBP), and fatty liver index (FLI) and increased fat-free mass when compared with the control group. A significant reduction in the sarcopenic index; total, troncular, and visceral fat (measured by DEXA); and serum leptin levels were observed in the collagen group at the end of the intervention, with no differences with respect to controls. Collagen reduced the sensation of hunger and increased fullness and satisfaction. In male Wistar rats, collagen decreased postprandial blood ghrelin levels. Conclusions: Collagen supplementation (20 g per day for 12 weeks) reduced body weight, BMI, waist circumference, fat mass, FLI, and SBP in humans with overweight and obesity, which might be related to the increased sensation of fullness and satisfaction reported by the volunteers after the intake.

Production of Sugars and Ethanol from Acid–Alkaline-Pretreated Agave sisalana Residue

Drylands in Brazil have been exploring sisal (Agave sisalana) as an essential source of income. However, the solid residues generated because of this activity still need suitable destinations; therefore, research has been carried out to transform them into added-value products. Therefore, the present study evaluated the potential of sisal or agave solid residue as a precursor feedstock for second-generation ethanol production. Acid and acid–alkaline pretreatments were carried out on sisal residues to enrich the biomass with cellulose and maximize enzymatic digestibility. Second-generation ethanol production was carried out using Semi-simultaneous saccharification and fermentation (SSSF). Regardless of catalyst dosage and incubation time, oxalic acid pretreatments generated samples with a similar chemical composition to those pretreated with sulfuric acid. However, samples pretreated with oxalic acid showed lower enzymatic digestibility. Samples pretreated with oxalic acid and sodium hydroxide obtained 14.28 g/L of glucose and cellulose conversion of 79.1% (at 5% solids), while 21.49 g/L glucose and 91.2% of cellulose conversion were obtained in the hydrolysis of pretreated samples with sulfuric acid and sodium hydroxide combined pretreatments. The pretreatment sequence efficiently reduced cellulase dosage from 20 to 10 FPU/g without compromising sugar release. SSSF achieved maximum production of 40 g/L ethanol and 43% ethanol conversion using 30% solids and gradually adding biomass and cellulases.

The Satiating Effect of Extruded Plant Protein Compared with Native Plant and Meat Protein in a Ragú “Bolognaise” Meal: A Randomized Cross-Over Study

Protein increases satiety by, among other things, increasing the content of certain amino acids in the blood. Plant proteins generally have a lower digestibility than meat proteins. The digestibility increases after extrusion; thereby, extrusion potentially also increases the satiating effect. We investigated subjective appetite and ad libitum energy intake (adlib_EI) following ragú “bolognaise” meals with three different protein sources. We hypothesized that the satiating effect of texturized vegetable proteins (TVP) was comparable to that of animal protein (Meat) and that TVPs would have a stronger satiating effect than non-texturized legume proteins (Green). Test meals were theoretically designed to be similar in weight, energy (kJ), macronutrients and fiber. The in vitro protein digestibility (IVPD) and the amino acid composition were analyzed. A randomized, single-blinded, three-way, cross-over study including 25 healthy men was carried out. There were no significant differences between the three meals in terms of subjective appetite. The adlib_EI was significantly lower after the TVP meal (758 kJ) than after the Meat meal (957 kJ), with the Green meal in between (903 kJ). The IVPD was significantly higher in the Meat meal (30.72%) than in the Green meal (20.17%), with the TVP meal in between (21.05%). In conclusion, the TVP meal had a higher long-term satiating effect than a similar meal with meat.

Study on the Mechanism of Effect of Protein on Starch Digestibility in Fermented Barley.

Previous studies have shown that fermented barley has a lower digestion rate. However, it remains unclear whether the antidigestibility of starch in fermented barley is affected by other nonstarch components. In this paper, the removal of protein, lipid, and β-glucan improved the hydrolysis rate of starch and the protein showed the greatest effect. Subsequently, the inhibitory mechanism of protein on starch digestion was elucidated from the perspective of starch physicochemical properties and structural changes. The removal of protein increased the swelling power of starch from 10.09 to 11.14%. The short-range molecular ordered structure and the helical structure content decreased. The removal of protein reduced the coating and particle size of the starch particles, making the Maltese cross more dispersed. In summary, protein in fermented barley enhanced the ordered structure of starch by forming a physical barrier around starch and prevented the expansion of starch, which inhibited the hydrolysis of starch.

A Meta-Analysis on Quantitative Calcium, Phosphorus and Magnesium Metabolism in Horses and Ponies.

The aims of the present meta-analysis were (i) to re-evaluate the factorially calculated Ca, P and Mg requirements to replace endogenous faecal losses, taking new data into account, (ii) to identify potential differences between horses and ponies regarding requirements, apparent digestibility, serum levels and renal excretion of Ca, P and Mg and (iii) to investigate the influence of mineral sources, i.e., "inorganic" sources from added mineral salts and "organic" sources from feed plants. For P, the water solubility of "inorganic" sources was taken into consideration. Data on the aforementioned parameters from 42 studies were plotted against intake, similar to the Lucas test for true digestibility and faecal endogenous losses. Within specific intake ranges, data were compared using t-tests and an ANOVA, followed by Holm-Sidak post hoc tests. Ponies had lower endogenous faecal Mg losses than horses. Consequently, apparent Mg digestibility was higher in ponies. Factorial calculations of Mg requirements to replace faecal losses showed that ponies needed approximately half of the current recommended amount, while horses required 1.9 times the amount currently recommended by Kienzle and Burger. The overall mean matched previous recommendations. For Ca, there was no discernible difference between ponies and horses. True Ca digestibility calculated by the Lucas test was higher and endogenous losses were lower when "organic" Ca was fed as opposed to when "inorganic" sources were used. The resulting factorial calculations of the requirements to replace faecal losses were close to current recommendations for "organic" Ca. For "inorganic" sources, however, the new calculations were below the recommended level. For P, there were no discernible differences between horses and ponies. There were also no clear effects of "inorganic" or "organic" P sources. The water solubility of "inorganic" sources was the key factor determining P metabolism. Water-soluble P sources exhibited higher true and apparent digestibility. The intake of these P sources led to hyperphosphatemia and hyperphosphaturia, even at low intakes. In other species, this has been shown to pose a health risk. Therefore, it is recommended to avoid the use of highly water-soluble "inorganic" P sources in horses and ponies. Given the lower digestibility of insoluble P sources, the factorially calculated P requirements for such sources are higher than the current recommendations.

First record of Tonatia bidens bats foraging on moss

Cases of bryophyte consumption by vertebrates are often presumed incidental. In this paper we reported, for the first time, the behavior of foraging in moss by bats, Tonatia bidens (Phyllostomidae), in the Cagarras Archipelago Natural Monument, Rio de Janeiro, Brazil. Due to bryophytes low nutritional value and digestibility, we suggest that obtaining water or forage for invertebrates may be the main objectives, and that this behavior can result in moss dispersion.

Socially Acceptable Feed Formulations May Impact the Voluntary Feed Intake and Growth, but Not Robustness of Nile Tilapia (Oreochromis niloticus)

Society is becoming more demanding with aquaculture’s environmental footprint and animal wellbeing. In order to potentially mitigate these concerns, feed formulations could be based on eco-efficient (circular economy-driven) or organic ingredients. This study aimed to investigate the growth performance, feed utilization, and health status of juvenile Nile tilapia (Oreochromis niloticus) when fed with such feeds. The growth trial lasted for 8 weeks, and fish had an initial weight of 31.0 ± 0.5 g (mean ± SD). Fish were fed until visual satiation, in quadruplicate, with one of three isonitrogenous and isoenergetic experimental feeds: a commercial-like feed without fishmeal (PD), a diet based on ingredients compatible with organic certification (ORG), or a feed formulated using circular economy-driven subproducts and emergent ingredients (ECO). Fish fed ECO showed a tendency for decreased feed intake, while ORG fish significantly reduced their intake compared to those fed PD. Consequently, fish fed ECO (62.7 ± 5.4 g) exhibited almost half the growth than those fed PD (107.8 ± 6.1 g), while ORG fish almost did not increase their weight (32.7 ± 1.3 g). ECO and ORG diets had a lower digestibility for protein, lipid, and energy when compared to PD. Feed utilization of fish fed ECO or ORG was also lower than those fed PD. From the health-related genes analyzed, only glutathione reductase (gsr) showed statistically significant differences, being more expressed in fish-fed ECO than those fed PD. Thus, even when such novel formulations induced extreme effects on voluntary feed intake, their impact was noted only in fish growth, but not in robustness.

PSLBI-9 The growth performance and total tract starch digestibility of finishing Nelore bulls fed flint corn-based diets are improved by the corn processing method and urea source

Abstract The aim of this study was to evaluate the flint corn processing method (CPM) and urea source for finishing Nellore bulls fed corn-based diets. In this study, 80 Nellore bulls [initial body weight (BW) = 388 ± 45.7 kg] were allocated into 28 pens (7 pens/treatment; 6 pens with 3 bulls + 1 pen with 2 bulls). A completely randomized design with a 2 × 2 factorial arrangement of treatments was used to test two CPMs: dry ground corn (DGC) and reconstituted and ensiled corn (REC), and two US: feed-grade urea (FGU) and post-ruminal release urea (PRU). Dietary inclusion (% DM) of flint corn (vitreousness = 86.0%) was 61.3% (DGC or REC), and urea source addition was 0.5% as non-protein nitrogen (NPN; as FGU or PRU). The PRU source (Trouw Nutrition, Netherlands) contained 82% urea on a DM basis. In an in vitro assay, 27% of this urea was released into the rumen. Experimental period lasted 100 d (with 14 d of adaptation). Fecal samples from each bull were collected in two periods of three consecutive days (d 44 to 46 and 94 to 96) at different time (0600, 1200, and 1800 h). Samples were composited by pen and analyzed for fecal starch (FS) and indigestible NDF as markers for fecal excretion. At the end of the experiment, bulls were slaughtered and the jejunum and pancreas were sampled from one bull per pen. Interaction effects were not found (P ≥ 0.31) for any feedlot growth performance variables (Table 1). Final BW, average daily gain, and feed efficiency (gain to feed; G:F) were greater for bulls fed REC and PRU than for those fed DGC and FGU (P &amp;lt; 0.02), respectively. As a result, observed dietary net energy (NE) for maintenance and BW gain were about 7.0% and 9.0% greater for bulls fed REC diets, and 4.3% and 5.6% greater for bulls fed PRU diets, respectively. Bulls fed DGC had 2.2 times greater FS compared with bulls fed REC, resulting in lower fecal pH and total tract starch digestibility (TSD) for bulls fed DGC compared with those fed REC (P &amp;lt; 0.01). Interestingly, a similar trend was observed in bulls fed PRU compared with those fed diets with FGU (P &amp;lt; 0.06). Jejunal gene expression of SLC5A1 was not affected by treatments (P &amp;gt; 0.14). Nevertheless, bulls fed diets with PRU presented greater jejunal α-amylase activity (P = 0.02). Pancreatic α-amylase activity was less when bulls were fed DGC + PRU diet. In conclusion, REC markedly improved TSD and growth performance compared with DGC. Additionally, independent of CPM, PRU inclusion as NPN source increased G:F and dietary NE concentration due to the positive effects on jejunal amylase activity and TSD.

Evaluation of Serum Proteome Sample Preparation Methods to Support Clinical Proteomics Applications.

Serum contains several proteins that are associated with disease-related processes. Mass spectrometry (MS)-based proteomics approaches greatly facilitate serum protein biomarker development. However, the serum proteome complexity presents a technical challenge for the accurate, sensitive, and reproducible quantification of proteins by MS. Thus, efficient sample preparation methods are of critical importance for serum proteome analyses. In this study, we evaluated the technical performance of two serum proteome sample preparation methods using sera from patients with high-grade serous ovarian cancer and patients with benign nongynecological conditions with a goal of providing insight into their compatibility with clinical proteomics workflows. One method entailed the use of immobilized trypsin (SMART Digest Trypsin) with RapiGest SF, an acid-labile surfactant designed to enhance the in-solution enzymatic digestion of proteins. The other method incorporated a commercially available sample preparation kit, iST-BCT, which contains standardized reagents. Significantly higher protein sequence coverage, albeit with lower digestion efficiency, was obtained with the immobilized trypsin + RapiGest SF workflow, whereas the iST-BCT workflow was quicker and had marginally better reproducibility. Protein relative abundance analysis revealed that the serum proteomes clustered primarily by the sample processing workflow and secondarily by disease state. We conducted a time course study to determine whether differences in the relative abundance of diagnostic high-grade serous ovarian cancer serum protein biomarker candidates were biased according to the duration of enzymatic digestion. Our results highlight the importance of optimizing enzymatic digestion kinetics according to the peptide targets of interest while considering the sensitivity of the downstream analytical method utilized in clinical proteomics workflows designed to measure biomarkers.

Evaluation of the nutritional quality of yeast protein in comparison to animal and plant proteins using growing rats and INFOGEST model

Yeast, identified as a microorganism, boasts a considerable protein content, positioning yeast protein as a highly promising alternative in the quest for sustainable protein sources. The primary aim of this study is to evaluate the protein quality of yeast protein and compare it with animal proteins (whey concentrate/isolate proteins) and plant proteins (soy, wheat, pea proteins). Notably, yeast protein exhibits the highest ratio of indispensable/dispensable amino acids (IAAs/DAAs, 0.91). However, in both in vivo and in vitro digestion experiments, yeast protein demonstrated lower true protein digestibility (TPD) and true ileal digestibility (TID) compared to other proteins. Despite this, the yeast protein's amino acid score (AAS, 1.37 for >3 years), protein digestibility-corrected amino acid score (PDCAAS, 100 % for >3 years), and digestibility-corrected amino acid score (DIAAS, 82.42 % for >3 years) of yeast protein surpassed those of plant proteins, yet remained lower than animal proteins primarily due to its lower digestibility.

Nutrient digestibility and availability of mealworms (Tenebrio molitor), poultry by-product meal, and poultry viscera in female mink (Neogale vison) diets: insights on the nitrogen-to-protein conversion factor

This study measured the digestibility of crude protein, crude fat, and dry matter in three protein sources: poultry by-product meal (PBPM), poultry viscera, and crushed mealworms using diatomaceous earth as an indicator. A control diet was made, and test diets were mixed in a 70:30 control diet:test ingredient ratio. Forty-four female mink housed in individual cages were fed experimental diets for 5 days, and fecal samples were collected and analyzed for nutrient residues compared to the diet composition to determine digestible nutrient levels. Mealworms had a greater dry matter digestibility ( P &lt; 0.01; 96.26%) than poultry viscera (77.29%) and PBPM (86.76%). PBPM had a lower fat digestibility ( P &lt; 0.01; 84.64%) than mealworms (94.78%) and poultry viscera (98.15%). There was no significant difference among treatments for protein digestibility. Using a standard nitrogen-to-protein conversion factor of 6.25, the crude protein content of the mealworms was 51.74%, although with an apparent digestibility coefficient of 0.77, this ingredient had an available crude protein composition of 39.70 ± 2.95. A nitrogen-to-protein conversion factor of 4.80 would be more accurate than 6.25 when using mealworms as a feed ingredient for monogastric animals.